Copyright © 1997, 1998, 1999, 2000 by the PHP Documentation Group
Copyright
This manual is ⌐ Copyright 1997, 1998, 1999, 2000 by the PHP Documentation Group. The members of this group are listed on the front page of this manual.
This manual can be redistributed under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
PHP, which stands for "PHP: Hypertext Preprocessor", is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly.
This manual is written in XML using the DocBook XML DTD, using DSSSL (Document Style and Semantics Specification Language) for formatting. The tools used for formatting HTML, TeX and RTF versions are Jade, written by James Clark and The Modular DocBook Stylesheets written by Norman Walsh. PHP's documentation framework is maintained by Stig Sµther Bakken.
Daily HTML snapshots of the manual, including translations, can be found at http://snaps.php.net/manual/.
PHP (officially "PHP: Hypertext Preprocessor") is a server-side HTML-embedded scripting language.
Simple answer, but what does that mean? An example:
Notice how this is different from a CGI script written in other languages like Perl or C -- instead of writing a program with lots of commands to output HTML, you write an HTML script with a some embedded code to do something (in this case, output some text). The PHP code is enclosed in special start and end tags that allow you to jump into and out of PHP mode.
What distinguishes PHP from something like client-side Javascript is that the code is executed on the server. If you were to have a script similar to the above on your server, the client would receive the results of running that script, with no way of determining what the underlying code may be. You can even configure your web server to process all your HTML files with PHP, and then there's really no way that users can tell what you have up your sleeve.
At the most basic level, PHP can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies.
Perhaps the strongest and most significant feature in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple. The following databases are currently supported:
Adabas D Ingres Oracle (OCI7 and OCI8) dBase InterBase Ovrimos Empress FrontBase PostgreSQL FilePro (read-only) mSQL Solid Hyperwave Direct MS-SQL Sybase IBM DB2 MySQL Velocis Informix ODBC Unix dbm
PHP also has support for talking to other services using protocols such as IMAP, SNMP, NNTP, POP3, HTTP and countless others. You can also open raw network sockets and interact using other protocols.
PHP was conceived sometime in the fall of 1994 by Rasmus Lerdorf. Early non-released versions were used on his home page to keep track of who was looking at his online resume. The first version used by others was available sometime in early 1995 and was known as the Personal Home Page Tools. It consisted of a very simplistic parser engine that only understood a few special macros and a number of utilities that were in common use on home pages back then. A guestbook, a counter and some other stuff. The parser was rewritten in mid-1995 and named PHP/FI Version 2. The FI came from another package Rasmus had written which interpreted html form data. He combined the Personal Home Page tools scripts with the Form Interpreter and added mSQL support and PHP/FI was born. PHP/FI grew at an amazing pace and people started contributing code to it.
It is difficult to give any hard statistics, but it is estimated that by late 1996 PHP/FI was in use on at least 15,000 web sites around the world. By mid-1997 this number had grown to over 50,000. Mid-1997 also saw a change in the development of PHP. It changed from being Rasmus' own pet project that a handful of people had contributed to, to being a much more organized team effort. The parser was rewritten from scratch by Zeev Suraski and Andi Gutmans and this new parser formed the basis for PHP Version 3. A lot of the utility code from PHP/FI was ported over to PHP 3 and a lot of it was completely rewritten.
Today (10/2000) PHP 3 or PHP 4 now ships with a number of commercial products such as C2's StrongHold web server and RedHat Linux. A conservative estimate based on an extrapolation from numbers provided by NetCraft (see also Netcraft Web Server Survey) would be that PHP is in use on over 3,300,000 sites around the world. To put that in perspective, that is more sites than run Netscape's flagship Enterprise server on the Internet, and close to the total number of IIS servers on the Internet (3.8 million).
The latest version (PHP 4) uses the powerful Zend scripting engine to deliver higher performance, and also supports running under webservers other than Apache as a native server module.
The source code, and binary distributions for some platforms (including Windows), can be found at http://www.php.net/.
This section will guide you through the configuration and installation of PHP.
Prerequisite knowledge and software:
Basic UNIX skills (being able to operate "make" and a C compiler)
An ANSI C compiler
A web server
There are several ways to compile and configure PHP for the Unix platform. The entire configuration process is controlled by the use of commandline options to the configure script. This page outlines the usage of the most common options, but there are many others to play with. Check out the Complete list of configure options for an exhaustive rundown.
As an Apache module
As an fhttpd module
For use with AOLServer, NSAPI, phttpd, Pi3Web, Roxen, thttpd, or Zeus.
As a CGI executable
PHP can be compiled in a number of different ways as an Apache module. First we show the quick instructions. Following this is a list of various examples with explanations, to provide an overview of how to accomplish certain things.
You can select arguments to add to the configure on line 8 below from the Complete list of configure options.
This will create a libphp4.so shared library that is loaded into Apache using a LoadModule line in Apache's httpd.conf file. The PostgreSQL support is embedded into this libphp4.so library.
This will again create a libphp4.so shared library for Apache, but it will also create a pgsql.so shared library that is loaded into PHP either by using the extension directive in php.ini file or by loading it explicitly in a script using the dl() function.
This will create a libmodphp4.a library, a mod_php4.c and some accompanying files and copy this into the src/modules/php4 directory in the Apache source tree. Then you compile Apache using --activate-module=src/modules/php4/libphp4.a and the Apache build system will create libphp4.a and link it statically into the httpd binary. The PostgreSQL support is included directly into this httpd binary, so the final result here is a single httpd binary that includes all of Apache and all of PHP.
Same as before, except instead of including PostgreSQL support directly into the final httpd you will get a pgsql.so shared library that you can load into PHP from either the php.ini file or directly using dl().
When choosing to build PHP in different ways, you should consider the advantages and drawbacks of each method. Building as a shared object will mean that you can compile apache separately, and don't have to recompile everything as you add to, or change, PHP. Building PHP into apache (static method) means that PHP will load and run faster. For more information, see the Apache webpage on DSO support.
To build PHP as an fhttpd module, answer "yes" to "Build as an fhttpd module?" (the --with-fhttpd=DIR option to configure) and specify the fhttpd source base directory. The default directory is /usr/local/src/fhttpd. If you are running fhttpd, building PHP as a module will give better performance, more control and remote execution capability.
PHP can be built to support a large number of web servers. Please see Server-related options for a full list of server-related configure options.
The default is to build PHP as a CGI program. This creates a commandline interpreter, which can be used for CGI processing, or for non-web-related PHP scripting. If you are running a web server PHP has module support for, you should generally go for that solution for performance reasons. However, the CGI version enables Apache users to run different PHP-enabled pages under different user-ids. Please make sure you read through the Security chapter if you are going to run PHP as a CGI.
PHP has native support for a number of databases (as well as ODBC). To enable support for the various databases, options are given to the configure script at compile time. Read the list of all database-related options for more information.
For a list of all possible options to configure, please see the Complete list of configure options.
When PHP is configured, you are ready to build the CGI executable or the PHP library. The command make should take care of this. If it fails and you can't figure out why, see the Problems section.
If you have built PHP as a CGI program, you may test your build by typing make test. It is always a good idea to test your build. This way you may catch a problem with PHP on your platform early instead of having to struggle with it later.
If you have built PHP 3 as a CGI program, you may benchmark your build by typing make bench. Note that if safe mode is on by default, the benchmark may not be able to finish if it takes longer then the 30 seconds allowed. This is because the set_time_limit() can not be used in safe mode. Use the max_execution_time configuration setting to control this time for your own scripts. make bench ignores the configuration file.
Note: make bench is only available for PHP 3.
Note: These are only used at compile time. If you want to alter PHP's runtime configuration, please go to Configuration.
The following is a complete list of options supported by the PHP 3 and PHP 4 configure scripts, used when compiling in Unix-like environments. Some are available in PHP 3, some in PHP 4, and some in both, as noted. There are many options the names of which have changed between PHP 3 and PHP 4, but which accomplish the same things. These entries are cross-referenced to each other, so if you have a problem getting your PHP 3-era configuration options to work, check here to see whether the names have changed.
PHP 3, PHP 4: Include Adabas D support. DIR is the Adabas base install directory, defaults to /usr/local.
PHP 3: Option not available in PHP 3
PHP 4: Build DBA as a shared module
PHP 3: Option not available; use --with-dbase instead.
PHP 4: Enable the bundled dbase library. No external libraries are required.
PHP 3: Include the bundled dbase library. No external libraries are required.
PHP 4: Option not available; use --enable-dbase instead.
PHP 3, PHP 4: Include Berkeley DB2 support
PHP 3: Option not available in PHP 3
PHP 4: Include Berkeley DB3 support
PHP 3, PHP 4: Include DBM support
PHP 3: Option not available in PHP 3
PHP 4: Include DBMaker support. DIR is the DBMaker base install directory, defaults to where the latest version of DBMaker is installed (such as /home/dbmaker/3.6).
PHP 3, PHP 4: Include Empress support. DIR is the Empress base install directory, defaults to $EMPRESSPATH
PHP 3: Option not available; use --with-filepro instead.
PHP 4: Enable the bundled read-only filePro support. No external libraries are required.
PHP 3: Include the bundled read-only filePro support. No external libraries are required.
PHP 4: Option not available; use --enable-filepro instead.
PHP 3, PHP 4: Include GDBM support
PHP 3, PHP 4: Include Hyperwave support
PHP 3, PHP 4: Include IBM DB2 support. DIR is the DB2 base install directory, defaults to /home/db2inst1/sqllib.
PHP 3, PHP 4: Include Informix support. DIR is the Informix base install directory, defaults to nothing.
PHP 3: Option not available in PHP 3
PHP 4: Include Ingres II support. DIR is the Ingres base directory (default /II/ingres)
PHP 3, PHP 4: Include InterBase support. DIR is the InterBase base install directory, which defaults to /usr/interbase.
PHP 3: Include LDAP support. DIR is the LDAP base install directory. Defaults to /usr and /usr/local
PHP 4: Include LDAP support. DIR is the LDAP base install directory.
This provides LDAP (Lightweight Directory Access Protocol support). The parameter is the LDAP base install directory, defaults to /usr/local/ldap.
More information about LDAP can be found in RFC1777 and RFC1778.
PHP 3, PHP 4: Enables mSQL support. The parameter to this option is the mSQL install directory and defaults to /usr/local/Hughes. This is the default directory of the mSQL 2.0 distribution. configure automatically detects which mSQL version you are running and PHP supports both 1.0 and 2.0, but if you compile PHP with mSQL 1.0, you can only access mSQL 1.0 databases, and vice-versa.
See also mSQL Configuration Directives in the configuration file.
PHP 3: Include MySQL support. DIR is the MySQL base install directory, defaults to searching through a number of common places for the MySQL files.
PHP 4: Include MySQL support. DIR is the MySQL base directory. If unspecified, the bundled MySQL library will be used. This option is turned on by default.
See also MySQL Configuration Directives in the configuration file.
PHP 3, PHP 4: Include NDBM support
PHP 3: Option not available in PHP 3
PHP 4: Include Oracle-oci8 support. Default DIR is ORACLE_HOME.
PHP 3: Include Oracle database support. DIR is Oracle's home directory, defaults to $ORACLE_HOME.
PHP 4: Include Oracle-oci7 support. Default DIR is ORACLE_HOME.
Includes Oracle support. Has been tested and should be working at least with Oracle versions 7.0 through 7.3. The parameter is the ORACLE_HOME directory. You do not have to specify this parameter if your Oracle environment has been set up.
PHP 3: Include PostgresSQL support. DIR is the PostgresSQL base install directory, which defaults to /usr/local/pgsql.
PHP 4: Include PostgreSQL support. DIR is the PostgreSQL base install directory, which defaults to /usr/local/pgsql. Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
See also Postgres Configuration Directives in the configuration file.
PHP 3, PHP 4: Include Solid support. DIR is the Solid base install directory, defaults to /usr/local/solid
PHP 3, PHP 4: Include Sybase-CT support. DIR is the Sybase home directory, defaults to /home/sybase.
See also Sybase-CT Configuration Directives in the configuration file.
PHP 3, PHP 4: Include Sybase-DB support. DIR is the Sybase home directory, which defaults to /home/sybase.
See also Sybase Configuration Directives in the configuration file.
PHP 3, PHP 4: Include OpenLink ODBC support. DIR is the OpenLink base install directory, defaults to /usr/local/openlink.
PHP 3, PHP 4: Include iODBC support. DIR is the iODBC base install directory, defaults to /usr/local.
This feature was first developed for iODBC Driver Manager, a freely redistributable ODBC driver manager which runs under many flavors of UNIX.
PHP 3, PHP 4: Includes support for an arbitrary custom ODBC library. The parameter is the base directory and defaults to /usr/local.
This option implies that you have defined CUSTOM_ODBC_LIBS when you run the configure script. You also must have a valid odbc.h header somewhere in your include path. If you don't have one, create it and include your specific header from there. Your header may also require some extra definitions, particularly when it is multiplatform. Define them in CFLAGS.
For example, you can use Sybase SQL Anywhere on QNX as following: CFLAGS=-DODBC_QNX LDFLAGS=-lunix CUSTOM_ODBC_LIBS="-ldblib -lodbc" ./configure --with-custom-odbc=/usr/lib/sqlany50
PHP 3: Disable unified ODBC support. Only applicable if iODBC, Adabas, Solid, Velocis or a custom ODBC interface is enabled.
PHP 4: Option not available in PHP 4
The Unified ODBC module, which is a common interface to all the databases with ODBC-based interfaces, such as Solid, IBM DB2 and Adabas D. It also works for normal ODBC libraries. Has been tested with iODBC, Solid, Adabas D, IBM DB2 and Sybase SQL Anywhere. Requires that one (and only one) of these modules or the Velocis module is enabled, or a custom ODBC library specified. This option is only applicable if one of the following options is used: --with-iodbc, --with-solid, --with-ibm-db2, --with-adabas, --with-velocis, or --with-custom-odbc.
See also Unified ODBC Configuration Directives in the configuration file.
PHP 3: Option not available in PHP 3
PHP 4: Include unixODBC support. DIR is the unixODBC base install directory, defaults to /usr/local.
PHP 3, PHP 4: Include Velocis support. DIR is the Velocis base install directory, defaults to /usr/local/velocis.
PHP 3: Option not available in PHP 3
PHP 4: Compile CCVS support into PHP4. Please specify your CCVS base install directory as DIR.
PHP 3: Include Cybercash MCK support. DIR is the cybercash mck build directory, which defaults to /usr/src/mck-3.2.0.3-linux. For help, look in extra/cyberlib.
PHP 4: Option not available; use --with-cybercash instead.
PHP 3: Option not available; use --with-mck instead.
PHP 4: Include CyberCash support. DIR is the CyberCash MCK install directory.
PHP 3: Option not available in PHP 3
PHP 4: Include Verisign Payflow Pro support
PHP 3: Option not available in PHP 3
PHP 4: Include support for FreeType2 (experimental).
PHP 3: Include GD support (DIR is GD's install dir).
PHP 4: Include GD support (DIR is GD's install dir). Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
PHP 3, PHP 4: Disable GD support.
PHP 3: Include ImageMagick support. DIR is the install directory, and if left out, PHP will try to find it on its own. [experimental]
PHP 4: Option not available in PHP 4
PHP 3: jpeg dir for pdflib 2.0
PHP 4: jpeg dir for pdflib 3.x
PHP 3: Option not available in PHP 3
PHP 4: png dir for pdflib 3.x
PHP 3: Enable t1lib support.
PHP 4: Option not available; use --with-t1lib instead.
PHP 3: Option not available; use --enable-t1lib instead.
PHP 4: Include T1lib support.
PHP 3: tiff dir for pdflib 2.0
PHP 4: tiff dir for pdflib 3.x
PHP 3, PHP 4: Include FreeType support
PHP 3: Option not available in PHP 3
PHP 4: xpm dir for gd-1.8+
These are being classified over time, where appropriate.
PHP 3: Compile without BC arbitrary precision math functions. These functions allow you to operate with numbers outside of the ranges allowed by regular integers and floats; see BCMath Arbitrary Precision Mathematics Functions for more information.
PHP 4: Option not available; bcmath is not compiled in by default. Use --enable-bcmath to compile it in.
PHP 3: Compile without displaying source support
PHP 4: Option not available in PHP 4
PHP 3: Option not available in PHP 3
PHP 4: avoid locking (might break parallel builds)
PHP 3: Option not available in PHP 3
PHP 4: Do not install PEAR
PHP 3: Option not available in PHP 3
PHP 4: Disable PIC for shared objects
PHP 3: Option not available in PHP 3; use --without-posix instead.
PHP 4: Disable POSIX-like functions
PHP 3: Option not available in PHP 3
PHP 4: Disable passing additional runtime library search paths
PHP 3: Option not available in PHP 3
PHP 4: Disable session support
PHP 3: Option not available in PHP 3; bcmath is compiled in by default. Use --disable-bcmath to disable it.
PHP 4: Compile with bc style precision math functions. Read README-BCMATH for instructions on how to get this module installed. These functions allow you to operate with numbers outside of the ranges allowed by regular integers and floats; see BCMath Arbitrary Precision Mathematics Functions for more information.
PHP 3: Option not available in PHP 3
PHP 4: Enable C9x-inline semantics
PHP 3: Option not available in PHP 3
PHP 4: Enable support for calendar conversion
PHP 3, PHP 4: Compile with debugging symbols.
PHP 3: Compile with remote debugging functions
PHP 4: Option not available in PHP 4
PHP 3, PHP 4: If this is enabled, the PHP CGI binary can safely be placed outside of the web tree and people will not be able to circumvent .htaccess security.
PHP 3, PHP 4: Enable dmalloc
PHP 3: Option not available in PHP 3
PHP 4: Enable exif support
PHP 3: Option not available in PHP 3
PHP 4: This will most likely break your build
PHP 3: Option not available in PHP 3
PHP 4: optimize for fast installation [default=yes]
PHP 3, PHP 4: Enable the security check for internal server redirects. You should use this if you are running the CGI version with Apache.
PHP 3: Option not available in PHP 3
PHP 4: If you have much memory and are using gcc, you might try this.
PHP 3: Option not available in PHP 3
PHP 4: Enable explicitly linking against libgcc
PHP 3, PHP 4: enable make rules and dependencies not useful (and sometimes confusing) to the casual installer
PHP 3, PHP 4: Compile with memory limit support. [default=no]
PHP 3, PHP 4: Enable safe mode by default.
PHP 3: Option not available in PHP 3
PHP 4: Enable CORBA support via Satellite (Requires ORBit)
PHP 3: Option not available in PHP 3
PHP 4: build shared libraries [default=yes]
PHP 3, PHP 4: Enable PHP's own SIGCHLD handler.
PHP 3: Option not available in PHP 3
PHP 4: build static libraries [default=yes]
PHP 3, PHP 4: Enable System V semaphore support.
PHP 3, PHP 4: Enable the System V shared memory support
PHP 3: Option not available in PHP 3
PHP 4: Enable transparent session id propagation
PHP 3, PHP 4: Include CDB support
PHP 3: Sets the path in which to look for php3.ini. Defaults to /usr/local/lib
PHP 4: Sets the path in which to look for php.ini. Defaults to /usr/local/lib
PHP 3: Include ClibPDF support. DIR is the ClibPDF install directory, defaults to /usr/local.
PHP 4: Include cpdflib support (requires cpdflib >= 2). DIR is the cpdfllib install directory, defaults to /usr.
PHP 3: Option not available in PHP 3
PHP 4: Include Easysoft OOB support. DIR is the OOB base install directory, defaults to /usr/local/easysoft/oob/client.
PHP 3, PHP 4: Only allow executables in DIR when in safe mode defaults to /usr/local/php/bin
PHP 3, PHP 4: Include fdftk support. DIR is the fdftk install directory, defaults to /usr/local.
PHP 3: Option not available in PHP 3
PHP 4: assume the C compiler uses GNU ld [default=no]
PHP 3: Option not available in PHP 3
PHP 4: Include ICAP support.
PHP 3, PHP 4: Include IMAP support. DIR is the IMAP include and c-client.a directory.
PHP 3: Include IMSP support (DIR is IMSP's include dir and libimsp.a dir).
PHP 4: Option not available in PHP 4
PHP 3: Option not available in PHP 3
PHP 4: Include Java support. DIR is the base install directory for the JDK. This extension can only be built as a shared dl.
PHP 3: Option not available in PHP 3
PHP 4: Include Kerberos support in IMAP.
PHP 3, PHP 4: Include MCAL support.
PHP 3, PHP 4: Include mcrypt support. DIR is the mcrypt install directory.
PHP 3, PHP 4: Include mhash support. DIR is the mhash install directory.
PHP 3: Option not available in PHP 3
PHP 4: Include mm support for session storage
PHP 3, PHP 4: Enable transfer tables for mod_charset (Rus Apache).
PHP 3: Include pdflib support (tested with 0.6 and 2.0). DIR is the pdflib install directory, which defaults to /usr/local.
PHP 4: Include pdflib 3.x support. DIR is the pdflib install directory, which defaults to /usr/local.
PHP 3: Option not available in PHP 3
PHP 4: Include readline support. DIR is the readline install directory.
PHP 3: Option not available in PHP 3
PHP 4: regex library type: system, apache, php
PHP 3: Option not available in PHP 3
PHP 4: Include servlet support. DIR is the base install directory for the JSDK. This SAPI requires that the Java extension be built as a shared dl.
PHP 3: Option not available in PHP 3
PHP 4: Include swf support
PHP 3: Do not use the bundled regex library
PHP 4: (deprecated) Use system regex library
PHP 3: Option not available in PHP 3
PHP 4: Use GNU Pth.
PHP 3: Option not available in PHP 3
PHP 4: Use POSIX threads (default)
PHP 3: use the X Window System
PHP 4: Option not available in PHP 4
PHP 3: zlib dir for pdflib 2.0 or include zlib support
PHP 4: zlib dir for pdflib 3.x or include zlib support
PHP 3, PHP 4: Include zlib support (requires zlib >= 1.0.9). DIR is the zlib install directory, defaults to /usr.
PHP 3: Don't include Perl Compatible Regular Expressions support
PHP 4: Do not include Perl Compatible Regular Expressions support. Use --with-pcre-regex=DIR to specify DIR where PCRE's include and library files are located, if not using bundled library.
PHP 3: Don't include POSIX functions
PHP 4: Option not available in PHP 4; use --disable-posix instead.
PHP 3: Option not available in PHP 3
PHP 4: Include CURL support
PHP 3: Option not available; use --with-ftp instead.
PHP 4: Enable FTP support
PHP 3: Include FTP support.
PHP 4: Option not available; use --enable-ftp instead
PHP 3, PHP 4: Disable the URL-aware fopen wrapper that allows accessing files via http or ftp.
| Warning |
This switch is only available for PHP versions up to 4.0.3, newer versions provide an INI parameter called allow_url_fopen instead of forcing you to decide upon this feature at compile time. |
PHP 3, PHP 4: Include DAV support through Apache's mod_dav, DIR is mod_dav's installation directory (Apache module version only!)
PHP 3, PHP 4: Include OpenSSL support in SNMP.
PHP 3, PHP 4: Include SNMP support. DIR is the SNMP base install directory, defaults to searching through a number of common locations for the snmp install. Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
PHP 3, PHP 4: Enable UCD SNMP hack
PHP 3: Option not available in PHP 3
PHP 4: Enable sockets support
PHP 3: Option not available in PHP 3
PHP 4: Include YAZ support (ANSI/NISO Z39.50). DIR is the YAZ bin install directory
PHP 3: Option not available; use --with-yp instead.
PHP 4: Include YP support
PHP 3: Include YP support
PHP 4: Option not available; use --enable-yp instead.
PHP 3, PHP 4: Enable magic quotes by default.
PHP 3, PHP 4: Disable the short-form <? start tag by default.
PHP 3: Enable GET/POST/Cookie track variables by default.
PHP 4: Option not available in PHP 4; as of PHP 4.0.2, track_vars is always on.
PHP 3: Option not available in PHP 3
PHP 4: Specify path to the source distribution of AOLserver
PHP 3: Option not available in PHP 3
PHP 4: Specify path to the installed AOLserver
PHP 3, PHP 4: Build Apache module. DIR is the top-level Apache build directory, defaults to /usr/local/etc/httpd.
PHP 3, PHP 4: Build shared Apache module. FILE is the optional pathname to the Apache apxs tool; defaults to apxs.
PHP 3: Take advantage of versioning and scoping Provided by Solaris 2.x and Linux
PHP 4: Export only required symbols. See INSTALL for more information
PHP 3, PHP 4: Build fhttpd module. DIR is the fhttpd sources directory, defaults to /usr/local/src/fhttpd.
PHP 3: Option not available in PHP 3
PHP 4: Specify path to the installed Netscape
PHP 3: Option not available in PHP 3
PHP 4:
PHP 3: Option not available in PHP 3
PHP 4: Build PHP as a module for use with Pi3Web.
PHP 3: Option not available in PHP 3
PHP 4: Build PHP as a Pike module. DIR is the base Roxen directory, normally /usr/local/roxen/server.
PHP 3: Option not available in PHP 3
PHP 4: Build the Roxen module using Zend Thread Safety.
PHP 3: Option not available in PHP 3
PHP 4:
PHP 3: Option not available in PHP 3
PHP 4: Build PHP as an ISAPI module for use with Zeus.
PHP 3, PHP 4: Include ASPELL support.
PHP 3, PHP 4: Include GNU gettext support. DIR is the gettext install directory, defaults to /usr/local
PHP 3: Option not available in PHP 3
PHP 4: Include PSPELL support.
PHP 3: Include GNU recode support.
PHP 4: Include recode support. DIR is the recode install directory.
PHP 3: Option not available in PHP 3
PHP 4: Include DOM support (requires libxml >= 2.0). DIR is the libxml install directory, defaults to /usr
PHP 3: Option not available in PHP 3
PHP 4: Enable Descriptive errors
PHP 3: Option not available in PHP 3
PHP 4: Include Sablotron support
PHP 3: Option not available in PHP 3
PHP 4: Enable WDDX support
PHP 3: Option not available in PHP 3; XML functionality is not built in by default. Use --with-xml to turn it on.
PHP 4: Disable XML support using bundled expat lib
PHP 3: Include XML support
PHP 4: Option not available; XML support is built in by default. Use --disable-xml to turn it off.
This install guide will help you install and configure PHP on your Windows 9x/NT webservers. This guide was compiled by Bob Silva. The latest revision can be found at http://www.umesd.k12.or.us/php/win32install.html.
This guide provides installation support for:
Personal Web Server (Newest version recommended)
Internet Information Server 3 or 4
Apache 1.3.x
Omni HTTPd 2.0b1
The following steps should be performed on all installations before the server specific instructions.
Extract the distribution file to a directory of your choice. "C:\PHP\" is a good start.
Copy the file, 'php.ini-dist' to your '%WINDOWS%' directory and rename it to 'php.ini'. Your '%WINDOWS%' directory is typically:
| c:\windows for Windows 95/98 |
| c:\winnt or c:\winnt40 for NT servers |
Edit your 'php.ini' file:
You will need to change the 'extension_dir' setting to point to your php-install-dir, or where you have placed your 'php_*.dll' files. ex: c:\php
If you are using Omni Httpd, do not follow the next step. Set the 'doc_root' to point to your webservers document_root. ex: c:\apache\htdocs or c:\webroot
Choose which modules you would like to load when PHP starts. You can uncomment the: 'extension=php_*.dll' lines to load these modules. Some modules require you to have additional libraries installed on your system for the module to work correctly. The PHP FAQ has more information on where to get supporting libraries. You can also load a module dynamically in your script using: dl("php_*.dll");
On PWS and IIS, you can set the browscap.ini to point to: 'c:\windows\system\inetsrv\browscap.ini' on Windows 95/98 and 'c:\winnt\system32\inetsrv\browscap.ini' on NT Server. Additional information on using the browscap functionality in PHP can be found at this mirror, select the "source" button to see it in action.
The DLLs for PHP extensions are prefixed with 'php_'. This prevents confusion between PHP extensions and their supporting libraries.
The recommended method for configuring these servers is to use the INF file included with the distribution (php_iis_reg.inf). You may want to edit this file and make sure the extensions and PHP install directories match your configuration. Or you can follow the steps below to do it manually.
WARNING: These steps involve working directly with the windows registry. One error here can leave your system in an unstable state. We highly recommend that you back up your registry first. The PHP Development team will not be held responsible if you damage your registry.
Run Regedit.
Navigate to: HKEY_LOCAL_MACHINE /System /CurrentControlSet /Services /W3Svc /Parameters /ScriptMap.
On the edit menu select: New->String Value.
Type in the extension you wish to use for your php scripts. ex: .php
Double click on the new string value and enter the path to php.exe in the value data field. ex: c:\php\php.exe %s %s. The '%s %s' is VERY important, PHP will not work properly without it.
Repeat these steps for each extension you wish to associate with PHP scripts.
Now navigate to: HKEY_CLASSES_ROOT
On the edit menu select: New->Key.
Name the key to the extension you setup in the previous section. ex: .php
Highlight the new key and in the right side pane, double click the "default value" and enter phpfile.
Repeat the last step for each extension you set up in the previous section.
Now create another New->Key under HKEY_CLASSES_ROOT and name it phpfile.
Highlight the new key phpfile and in the right side pane, double click the "default value" and enter PHP Script.
Right click on the phpfile key and select New->Key, name it Shell.
Right click on the Shell key and select New->Key, name it open.
Right click on the open key and select New->Key, name it command.
Highlight the new key command and in the right side pane, double click the "default value" and enter the path to php.exe. ex: c:\php\php.exe -q %1. (don't forget the %1).
Exit Regedit.
If using PWS on Windows, reboot to reload the registry.
PWS and IIS 3 users now have a fully operational system. IIS 3 users can use a nifty tool from Steven Genusa to configure their script maps.
To install PHP on an NT Server running IIS 4, follow these instructions:
In Internet Service Manager (MMC), select the Web site or the starting point directory of an application.
Open the directory's property sheets (by right clicking and selecting properties), and then click the Home Directory, Virtual Directory, or Directory tab.
Click the Configuration button, and then click the App Mappings tab.
Click Add, and in the Executable box, type: c:\path-to-php-dir\php.exe %s %s. You MUST have the %s %s on the end, PHP will not function properly if you fail to do this.
In the Extension box, type the file name extension you want associated with PHP scripts. (You must repeat step 5 and 6 for each extension you want accociated with PHP scripts. (.php and .phtml are common.)
Set up the appropriate security. (This is done in Internet Service Manager), and if your NT Server uses NTFS file system, add execute rights for I_USR_ to the directory that contains php.exe.
You must edit your srm.conf or httpd.conf to configure Apache to work with the PHP CGI binary.
Although there can be a few variations of configuring PHP under Apache, this one is simple enough to be used by the newcomer. Please consult the Apache Docs for further configuration directives.
ScriptAlias /php/ "c:/path-to-php-dir/"
AddType application/x-httpd-php .php
AddType application/x-httpd-php .phtml
Action application/x-httpd-php "/php/php.exe"
To use the source code highlighting feature, simply create a PHP script file and stick this code in: <?php show_source ("original_php_script.php"); ?>. Substitute original_php_script.php with the name of the file you wish to show the source of. (this is only one way of doing it). Note: On Win-Apache all back slashes in a path statement such as: "c:\directory\file.ext", must be converted to forward slashes.
This has got to be the easiest config there is:
Step 1: Install Omni server
Step 2: Right click on the blue OmniHTTPd icon in the system tray and select Properties
Step 3: Click on Web Server Global Settings
Step 4: On the 'External' tab, enter: virtual = .php | actual = c:\path-to-php-dir\php.exe
Step 5: On the Mime tab, enter: virtual = wwwserver/stdcgi | actual = .php
Step 6: Click OK
Repeat steps 2 - 6 for each extension you want to associate with PHP.
The Windows PHP installer available from the downloads page at http://www.php.net/ installs the CGI version of PHP and, for IIS, PWS, and Xitami, configures the web server as well.
Install your choosen http server on your system and make sure it all works.
Run the installer exe file and follow the instructions provided by the installation wizard. Two types of installation are supported - standard, which provides sensible defaults for all the settings it can, and advanced, which asks questions as it goes along.
The installation wizard gathers enough information to set up the php.ini file and configure the web server to use PHP. For IIS and also PWS on NT Workstation, a list of all the nodes on the server with script map settings is displayed, and you can choose those nodes to which you wish to add the PHP script mappings.
Once the installation has completed the installer will inform you if you need to restart your system, restart the server, or just start using PHP.
Table 2-1. PHP Modules
| php_calendar.dll | Calendar conversion functions |
| php_crypt.dll | Crypt functions |
| php_dbase.dll | DBase functions |
| php_dbm.dll | GDBM emulation via Berkely DB2 library |
| php_filepro.dll | READ ONLY access to filepro databases |
| php_gd.dll | GD Library functions for gif manipulation |
| php_hyperwave.dll | HyperWave functions |
| php_imap4r2.dll | IMAP 4 functions |
| php_ldap.dll | LDAP functions |
| php_msql1.dll | mSQL 1 client |
| php_msql2.dll | mSQL 2 client |
| php_mssql.dll | MSSQL client (requires MSSQL DB-Libraries |
| php3_mysql.dll (Built into PHP 4) | MySQL functions |
| php_nsmail.dll | Netscape mail functions |
| php_oci73.dll | Oracle functions |
| php_snmp.dll | SNMP get and walk functions (NT only!) |
| php_zlib.dll | ZLib functions |
Some problems are more common than others. The most common ones are listed in the PHP FAQ, found at http://www.php.net/FAQ.php
If you think you have found a bug in PHP, please report it. The PHP developers probably don't know about it, and unless you report it, chances are it won't be fixed. You can report bugs using the bug-tracking system at http://www.php.net/bugs.php.
If you are still stuck, someone on the PHP mailing list may be able to help you. You should check out the archive first, in case someone already answered someone else who had the same problem as you. The archives are available from the support page on http://www.php.net/. To subscribe to the PHP mailing list, send an empty mail to php-general-subscribe@lists.php.net. The mailing list address is php-general@lists.php.net.
If you want to get help on the mailing list, please try to be precise and give the necessary details about your environment (which operating system, what PHP version, what web server, if you are running PHP as CGI or a server module, etc.), and preferably enough code to make others able to reproduce and test your problem.
The configuration file (called php3.ini in PHP 3.0, and simply php.ini as of PHP 4.0) is read when PHP starts up. For the server module versions of PHP, this happens only once when the web server is started. For the CGI version, it happens on every invocation.
When using PHP as an Apache module, you can also change the configuration settings using directives in Apache configuration files and .htaccess files.
With PHP 3.0, there are Apache directives that correspond to each configuration setting in the php3.ini name, except the name is prefixed by "php3_".
With PHP 4.0, there are just a few Apache directives that allow you to change the PHP configuration settings.
This sets the value of the specified variable.
This is used to set a Boolean configuration option.
This sets the value of the specified variable. "Admin" configuration settings can only be set from within the main Apache configuration files, and not from .htaccess files.
This is used to set a Boolean configuration option.
You can view the settings of the configuration values in the output of phpinfo(). You can also access the values of individial configuration settings using get_cfg_var().
This option enables the URL-aware fopen wrappers that enable accessing URL object like files. Default wrappers are provided for the access of remote files using the ftp or http protocol, some extensions like zlib may register additional wrappers.
Note: This option was introduced immediately after the release of version 4.0.3. For versions up to and including 4.0.3 you can only disable this feature at compile time by using the configuration switch --disable-url-fopen-wrapper.
Enables the use of ASP-like <% %> tags in addition to the usual <?php ?> tags. This includes the variable-value printing shorthand of <%= $value %>. For more information, see Escaping from HTML.
Note: Support for ASP-style tags was added in 3.0.4.
Specifies the name of a file that is automatically parsed after the main file. The file is included as if it was called with the include() function, so include_path is used.
The special value none disables auto-appending.
Note: If the script is terminated with exit(), auto-append will not occur.
Specifies the name of a file that is automatically parsed before the main file. The file is included as if it was called with the include() function, so include_path is used.
The special value none disables auto-prepending.
This determines whether errors should be printed to the screen as part of the HTML output or not.
PHP's "root directory" on the server. Only used if non-empty. If PHP is configured with safe mode, no files outside this directory are served.
This directive is really only useful in the Apache module version of PHP. It is used by sites that would like to turn PHP parsing on and off on a per-directory or per-virtual server basis. By putting engine off in the appropriate places in the httpd.conf file, PHP can be enabled or disabled.
Name of file where script errors should be logged. If the special value syslog is used, the errors are sent to the system logger instead. On UNIX, this means syslog(3) and on Windows NT it means the event log. The system logger is not supported on Windows 95.
Set the error reporting level. The parameter is an integer representing a bit field. Add the values of the error reporting levels you want.
The default value for this directive is 7 (normal errors, normal warnings and parser errors are shown).Limit the files that can be opened by PHP to the specified directory-tree.
When a script tries to open a file with, for example, fopen or gzopen, the location of the file is checked. When the file is outside the specified directory-tree, PHP will refuse to open it. All symbolic links are resolved, so it's not possible to avoid this restriction with a symlink.
The special value . indicates that the directory in which the script is stored will be used as base-directory.
Under Windows, separate the directories with a semicolon. On all other systems, separate the directories with a colon. As an Apache module, open_basedir paths from parent directories are now automatically inherited.
Note: Support for multiple directories was added in 3.0.7.
The default is to allow all files to be opened.
Set the order of GET/POST/COOKIE variable parsing. The default setting of this directive is "GPC". Setting this to "GP", for example, will cause PHP to completely ignore cookies and to overwrite any GET method variables with POST-method variables of the same name.
On by default. If changed to Off scripts will be terminated as soon as they try to output something after a client has aborted their connection. ignore_user_abort().
Specifies a list of directories where the require(), include() and fopen_with_path() functions look for files. The format is like the system's PATH environment variable: a list of directories separated with a colon in UNIX or semicolon in Windows.
Tells whether script error messages should be logged to the server's error log. This option is thus server-specific.
Sets the magic_quotes state for GPC (Get/Post/Cookie) operations. When magic_quotes are on, all ' (single-quote), " (double quote), \ (backslash) and NUL's are escaped with a backslash automatically. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.
If magic_quotes_runtime is enabled, most functions that return data from any sort of external source including databases and text files will have quotes escaped with a backslash. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.
If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash if magic_quotes_gpc or magic_quotes_runtime is enabled.
This sets the maximum time in seconds a script is allowed to take before it is terminated by the parser. This helps prevent poorly written scripts from tying up the server. The default setting is 30.
This sets the maximum amount of memory in bytes that a script is allowed to allocate. This helps prevent poorly written scripts for eating up all available memory on a server.
Tells whether or not to register the EGPCS (Environment, GET, POST, Cookie, Server) variables as global variables. You may want to turn this off if you don't want to clutter your scripts' global scope with user data. This makes the most sense when coupled with track_vars - in which case you can access all of the EGPCS variables through the $HTTP_ENV_VARS, $HTTP_GET_VARS, $HTTP_POST_VARS, $HTTP_COOKIE_VARS, and $HTTP_SERVER_VARS arrays in the global scope.
Tells whether the short form (<? ?>of PHP's open tag should be allowed. If you want to use PHP in combination with XML, you have to disable this option. If disabled, you must use the long form of the open tag (<?php ?>).
If enabled, the last error message will always be present in the global variable $php_errormsg.
If enabled, then Environment, GET, POST, Cookie, and Server variables can be found in the global associative arrays $HTTP_ENV_VARS, $HTTP_GET_VARS, $HTTP_POST_VARS, $HTTP_COOKIE_VARS, and $HTTP_SERVER_VARS.
Note that as of PHP 4.0.3, track_vars is always turned on.
The temporary directory used for storing files when doing file upload. Must be writable by whatever user PHP is running as.
The base name of the directory used on a user's home directory for PHP files, for example public_html.
If enabled, this option makes PHP output a warning when the plus (+) operator is used on strings. This is to make it easier to find scripts that need to be rewritten to using the string concatenator instead (.).
DNS name or IP address of the SMTP server PHP under Windows should use for mail sent with the mail() function.
Which "From:" mail address should be used in mail sent from PHP under Windows.
Where the sendmail program can be found, usually /usr/sbin/sendmail or /usr/lib/sendmail configure does an honest attempt of locating this one for you and set a default, but if it fails, you can set it here.
Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail.
Whether to enable PHP's safe mode. Read the Security chapter for more more information.
If PHP is used in safe mode, system() and the other functions executing system programs refuse to start programs that are not in this directory.
DNS name or IP address of host used by the debugger.
Port number used by the debugger.
Whether the debugger is enabled.
This directive is really only useful in the Apache module version of PHP. You can turn dynamic loading of PHP extensions with dl() on and off per virtual server or per directory.
The main reason for turning dynamic loading off is security. With dynamic loading, it's possible to ignore all the safe_mode and open_basedir restrictions.
The default is to allow dynamic loading, except when using safe-mode. In safe-mode, it's always imposible to use dl().
In what directory PHP should look for dynamically loadable extensions.
Which dynamically loadable extensions to load when PHP starts up.
Whether to allow persistent MySQL connections.
The default server host to use when connecting to the database server if no other host is specified.
The default user name to use when connecting to the database server if no other name is specified.
The default password to use when connecting to the database server if no other password is specified.
The maximum number of persistent MySQL connections per process.
The maximum number of MySQL connections per process, including persistent connections.
Whether to allow persistent mSQL connections.
The maximum number of persistent mSQL connections per process.
The maximum number of mSQL connections per process, including persistent connections.
Whether to allow persistent Postgres connections.
The maximum number of persistent Postgres connections per process.
The maximum number of Postgres connections per process, including persistent connections.
Name of BS2000 PLAM library containing the loadable SESAM driver modules. Required for using SESAM functions. The BS2000 PLAM library must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.
Name of SESAM application configuration file. Required for using SESAM functions. The BS2000 file must be readable by the apache server's user id.
The application configuration file will usually contain a configuration like (see SESAM reference manual):
Name of SESAM message catalog file. In most cases, this directive is not neccessary. Only if the SESAM message file is not installed in the system's BS2000 message file table, it can be set with this directive.
The message catalog must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.
Whether to allow persistent Sybase connections.
The maximum number of persistent Sybase connections per process.
The maximum number of Sybase connections per process, including persistent connections.
Whether to allow persistent Sybase-CT connections. The default is on.
The maximum number of persistent Sybase-CT connections per process. The default is -1 meaning unlimited.
The maximum number of Sybase-CT connections per process, including persistent connections. The default is -1 meaning unlimited.
Server messages with severity greater than or equal to sybct.min_server_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_server_severity(). The default is 10 which reports errors of information severity or greater.
Client library messages with severity greater than or equal to sybct.min_client_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_client_severity(). The default is 10 which effectively disables reporting.
The maximum time in seconds to wait for a connection attempt to succeed before returning failure. Note that if max_execution_time has been exceeded when a connection attempt times out, your script will be terminated before it can take action on failure. The default is one minute.
The maximum time in seconds to wait for a select_db or query operation to succeed before returning failure. Note that if max_execution_time has been exceeded when am operation times out, your script will be terminated before it can take action on failure. The default is no limit.
The name of the host you claim to be connecting from, for display by sp_who. The default is none.
Whether to allow persistent Informix connections.
The maximum number of persistent Informix connections per process.
The maximum number of Informix connections per process, including persistent connections.
The default host to connect to when no host is specified in ifx_connect() or ifx_pconnect().
The default user id to use when none is specified in ifx_connect() or ifx_pconnect().
The default password to use when none is specified in ifx_connect() or ifx_pconnect().
Set to true if you want to return blob columns in a file, false if you want them in memory. You can override the setting at runtime with ifx_blobinfile_mode().
Set to true if you want to return TEXT columns as normal strings in select statements, false if you want to use blob id parameters. You can override the setting at runtime with ifx_textasvarchar().
Set to true if you want to return BYTE columns as normal strings in select queries, false if you want to use blob id parameters. You can override the setting at runtime with ifx_textasvarchar().
Set to true if you want to trim trailing spaces from CHAR columns when fetching them.
Set to true if you want to return NULL columns as the literal string "NULL", false if you want them returned as the empty string "". You can override this setting at runtime with ifx_nullformat().
Number of decimal digits for all bcmath functions.
Name of browser capabilities file. See also get_browser().
ODBC data source to use if none is specified in odbc_connect() or odbc_pconnect().
User name to use if none is specified in odbc_connect() or odbc_pconnect().
Password to use if none is specified in odbc_connect() or odbc_pconnect().
Whether to allow persistent ODBC connections.
The maximum number of persistent ODBC connections per process.
The maximum number of ODBC connections per process, including persistent connections.
PHP is a powerful language and the interpreter, whether included in a web server as a module or executed as a separate CGI binary, is able to access files, execute commands and open network connections on the server. These properties make anything run on a web server insecure by default. PHP is designed specifically to be a more secure language for writing CGI programs than Perl or C, and with correct selection of compile-time and runtime configuration options, and proper coding practices, it can give you exactly the combination of freedom and security you need.
As there are many different ways of utilizing PHP, there are many configuration options controlling its behaviour. A large selection of options guarantees you can use PHP for a lot of purposes, but it also means there are combinations of these options and server configurations that result in an insecure setup.
The configuration flexibility of PHP is equally rivalled by the code flexibility. PHP can be used to build complete server applications, with all the power of a shell user, or it can be used for simple server-side includes with little risk in a tightly controlled environment. How you build that environment, and how secure it is, is largely up to the PHP developer.
This chapter starts by explaining the different configuration option combinations and the situations they can be safely used. It then describes different considerations in coding for different levels of security, and ends with some general security advice.
Using PHP as a CGI binary is an option for setups that for some reason do not wish to integrate PHP as a module into server software (like Apache), or will use PHP with different kinds of CGI wrappers to create safe chroot and setuid environments for scripts. This setup usually involves installing executable PHP binary to the web server cgi-bin directory. CERT advisory CA-96.11 recommends against placing any interpreters into cgi-bin. Even if the PHP binary can be used as a standalone interpreter, PHP is designed to prevent the attacks this setup makes possible:
Accessing system files: http://my.host/cgi-bin/php?/etc/passwd
The query information in a url after the question mark (?) is passed as command line arguments to the interpreter by the CGI interface. Usually interpreters open and execute the file specified as the first argument on the command line.
When invoked as a CGI binary, PHP refuses to interpret the command line arguments.
Accessing any web document on server: http://my.host/cgi-bin/php/secret/doc.html
The path information part of the url after the PHP binary name, /secret/doc.html is conventionally used to specify the name of the file to be opened and interpreted by the CGI program. Usually some web server configuration directives (Apache: Action) are used to redirect requests to documents like http://my.host/secret/script.php3 to the PHP interpreter. With this setup, the web server first checks the access permissions to the directory /secret, and after that creates the redirected request http://my.host/cgi-bin/php/secret/script.php3. Unfortunately, if the request is originally given in this form, no access checks are made by web server for file /secret/script.php3, but only for the /cgi-bin/php file. This way any user able to access /cgi-bin/php is able to access any protected document on the web server.
In PHP, compile-time configuration option --enable-force-cgi-redirect and runtime configuration directives doc_root and user_dir can be used to prevent this attack, if the server document tree has any directories with access restrictions. See below for full the explanation of the different combinations.
If your server does not have any content that is not restricted by password or ip based access control, there is no need for these configuration options. If your web server does not allow you to do redirects, or the server does not have a way to communicate to the PHP binary that the request is a safely redirected request, you can specify the option --enable-force-cgi-redirect to the configure script. You still have to make sure your PHP scripts do not rely on one or another way of calling the script, neither by directly http://my.host/cgi-bin/php/dir/script.php3 nor by redirection http://my.host/dir/script.php3.
Redirection can be configured in Apache by using AddHandler and Action directives (see below).
This compile-time option prevents anyone from calling PHP directly with a url like http://my.host/cgi-bin/php/secretdir/script.php3. Instead, PHP will only parse in this mode if it has gone through a web server redirect rule.
Usually the redirection in the Apache configuration is done with the following directives:
Action php3-script /cgi-bin/php
AddHandler php3-script .php3
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This option has only been tested with the Apache web server, and relies on Apache to set the non-standard CGI environment variable REDIRECT_STATUS on redirected requests. If your web server does not support any way of telling if the request is direct or redirected, you cannot use this option and you must use one of the other ways of running the CGI version documented here.
To include active content, like scripts and executables, in the web server document directories is sometimes consider an insecure practice. If, because of some configuration mistake, the scripts are not executed but displayed as regular HTML documents, this may result in leakage of intellectual property or security information like passwords. Therefore many sysadmins will prefer setting up another directory structure for scripts that are accessible only through the PHP CGI, and therefore always interpreted and not displayed as such.
Also if the method for making sure the requests are not redirected, as described in the previous section, is not available, it is necessary to set up a script doc_root that is different from web document root.
You can set the PHP script document root by the configuration directive doc_root in the configuration file, or you can set the environment variable PHP_DOCUMENT_ROOT. If it is set, the CGI version of PHP will always construct the file name to open with this doc_root and the path information in the request, so you can be sure no script is executed outside this directory (except for user_dir below).
Another option usable here is user_dir. When user_dir is unset, only thing controlling the opened file name is doc_root. Opening an url like http://my.host/~user/doc.php3 does not result in opening a file under users home directory, but a file called ~user/doc.php3 under doc_root (yes, a directory name starting with a tilde [~]).
If user_dir is set to for example public_php, a request like http://my.host/~user/doc.php3 will open a file called doc.php3 under the directory named public_php under the home directory of the user. If the home of the user is /home/user, the file executed is /home/user/public_php/doc.php3.
user_dir expansion happens regardless of the doc_root setting, so you can control the document root and user directory access separately.
A very secure option is to put the PHP parser binary somewhere outside of the web tree of files. In /usr/local/bin, for example. The only real downside to this option is that you will now have to put a line similar to:
as the first line of any file containing PHP tags. You will also need to make the file executable. That is, treat it exactly as you would treat any other CGI script written in Perl or sh or any other common scripting language which uses the #! shell-escape mechanism for launching itself.To get PHP to handle PATH_INFO and PATH_TRANSLATED information correctly with this setup, the php parser should be compiled with the --enable-discard-path configure option.
When PHP is used as an Apache module it inherits Apache's user permissions (typically those of the "nobody" user). This has several impacts on security and authorization. For example, if you are using PHP to access a database, unless that database has built-in access control, you will have to make the database accessable to the "nobody" user. This means a malicious script could access and modify the databse, even without a username and password. It's entirely possible that a web spider could stumble across a database adminisitror's web page, and drop all of your databases. You can protect against this with Apache authorization, or you can design your own access model using LDAP, .htaccess files, etc. and include that code as part of your PHP scripts.
Often, once security is established to the point where the PHP user (in this case, the apache user) has very little risk, it is discovered that PHP now has been prevented from writing virus files to user directories. Or perhaps it has been prevented from accessing or changing a non-public database. It has equally been secured from writing files that it should, or entering database transactions.
A frequent security mistake made at this point is to allow apache root permissions.
Escalating the Apache user's permissions to root is extremely dangerous and may compromise the entire system, so sudo'ing, chroot'ing ,or otherwise running as root should not be considered by those who are not security professionals.
PHP is subject to the security built into most server systems with respect to permissions on a file and directory basis. This allows you to control which files in the filesystem may be read. Care should be taken with any files which are world readable to ensure that they are safe for reading by all users who have access to that filesystem.
Since PHP was designed to allow user level access to the filesystem, it's entirely possible to write a PHP script that will allow you to read system files such as /etc/password, modify your ethernet connections, send massive printer jobs out, etc. This has some obvious implications, in that you need to ensure that the files that you read from and write to are the appropriate ones.
Consider the following script, where a user indicates that they'd like to delete a file in their home directory. This assumes a situation where a PHP web interface is regularly used for file management, so the Apache user is allowed to delete files in the user home directories.
Example 4-2. ... A filesystem attack
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Only allow limited permissions to t>
Check all variables which are submitted.
Example 4-3. More secure file name checking
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A standard attack tactic involves profiling a system by feeding it improper data, and checking for the kinds, and contexts, of the errors which are returned. This allows the system cracker to probe for information about the server, to determine possible weaknesses.
The PHP errors which are normally returned can be quite helpful to a developer who is trying to debug a script, indicating such things as the function or file that failed, the PHP file it failed in, and the line number which the failure occured in. This is all information that can be exploited.
For example, the very style of error indicates a system is running PHP. If the attacker was looking at an .html page, and wanted to probe for the back-end (to look for known weaknesses in the system), by feeding it the wrong data they may be able to determine that a system was built with PHP.
A function error can indicate whether a system may be running a specific database engine, or give clues as to how a web page or programmed or designed. This allows for deeper investigation into open database ports, or to look for specific bugs or weaknesses in a web page. By feeding different pieces of bad data, for example, an attacker can determine the order of authentication in a script, (from the line number errors) as well as probe for exploits that may be exploited in different locations in the script.
A filesystem or general PHP error can indicate what permissions the webserver has, as well as the structure and organization of files on the web server.
There are three major solutions to this issue. The first is to scrutinize all functions, and attempt to compensate for the bulk of the errors. The second is to disable error reporting entirely on the running code. The third is to use PHP's custom error handling functions to create your own error handler. Depending on your security policy, you may find all three to be applicable to your situation.
The greatest weakness in many PHP programs is not inherent in the language itself, but merely an issue of code not being written with security in mind. For this reason, you should always take the time to consider the implications of a given piece of code, to ascertain the possible damage if an unexpected variable is submitted to it.
Example 4-5. Dangerous Variable Usage
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Will this script only affect the intended files?
Can unusual or undesirable data be acted upon?
Can this script be used in unintended ways?
Can this be used in conjunction with other scripts in a negative manner?
Will any transactions be adequately logged?
You may also want to consider turning off register_globals, magic_quotes, or other convenience settings which may confuse you as to the validity, source, or value of a given variable. Working with PHP in error_reporting(E_ALL) mode can also help warn you about variables being used before they are checked or initialized (so you can prevent unusual data from being operated upon).
A completely secure system is a virtual impossibility, so an approach often used in the security profession is one of balancing risk and usability. If every variable submitted by a user required two forms of biometric validation (such as a retinal scan and a fingerprint), you would have an extremely high level of accountability. It would also take half an hour to fill out a fairly complex form, which would tend to encourage users to find ways of bypassing the security.
The best security is often inobtrusive enough to suit the requirements without the user being prevented from accomplishing their work, or over-burdening the code author with excessive complexity. Indeed, some security attacks are merely exploits of this kind of overly built security, which tends to erode over time.
A phrase worth remembering: A system is only as good as the weakest link in a chain. If all transactions are heavily logged based on time, location, transaction type, etc. but the user is only verified based on a single cookie, the validity of tying the users to the transaction log is severely weakened.
When testing, keep in mind that you will not be able to test all possibilities for even the simplest of pages. The input you may expect will be completely unrelated to the input given by a disgruntled employee, a cracker with months of time on their hands, or a housecat walking across the keyboard. This is why it's best to look at the code from a logical perspective, to discern where unexpected data can be introduced, and then follow how it is modified, reduced, or amplified.
The Internet is filled with people trying to make a name for themselves by breaking your code, crashing your site, posting inappropriate content, and otherwise making your day interesting. It doesn't matter if you have a small or large site, you are a target by simply being online, by having a server that can be connected to. Many cracking programs do not discern by size, they simply trawl massive IP blocks looking for victims. Try not to become one.
There are four ways of escaping from HTML and entering "PHP code mode":
Example 5-1. Ways of escaping from HTML
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The first way is only available if short tags have been enabled. This can be done by enabling the short_open_tag configuration setting in the PHP config file, or by compiling PHP with the --enable-short-tags option to configure.
The second way is the generally preferred method, as it allows for the next generation of XHTML to be easily implemented with PHP.
The fourth way is only available if ASP-style tags have been enabled using the asp_tags configuration setting.
Note: Support for ASP-style tags was added in 3.0.4.
The closing tag for the block will include the immediately trailing newline if one is present.
Instructions are separated the same as in C or perl - terminate each statement with a semicolon.
The closing tag (?>) also implies the end of the statement, so the following are equivalent:
PHP supports 'C', 'C++' and Unix shell-style comments. For example:
<?php
echo "This is a test"; // This is a one-line c++ style comment
/* This is a multi line comment
yet another line of comment */
echo "This is yet another test";
echo "One Final Test"; # This is shell-style style comment
?>
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The "one-line" comment styles actually only comment to the end of the line or the current block of PHP code, whichever comes first.
<h1>This is an <?php # echo "simple";?> example.</h1> <p>The header above will say 'This is an example'. |
You should be careful not to nest 'C' style comments, which can happen when commenting out large blocks.
PHP supports the following types:
The type of a variable is usually not set by the programmer; rather, it is decided at runtime by PHP depending on the context in which that variable is used.
If you would like to force a variable to be converted to a certain type, you may either cast the variable or use the settype() function on it.
Note that a variable may behave in different manners in certain situations, depending on what type it is at the time. For more information, see the section on Type Juggling.
Integers can be specified using any of the following syntaxes:
The size of an integer is platform-dependent, although a maximum value of about 2 billion is the usual value (that's 32 bits signed).Floating point numbers ("doubles") can be specified using any of the following syntaxes:
The size of a floating point number is platform-dependent, although a maximum of ~1.8e308 with a precision of roughly 14 decimal digits is a common value (that's 64 bit IEEE format).| Warning |
It is quite usual that simple decimal fractions like 0.1 or 0.7 cannot be converted into their internal binary counterparts without a little loss of precision. This can lead to confusing results: for example, floor((0.1+0.7)*10) will usually return 7 instead of the expected 8 as the result of the internal representation really being something like 7.9999999999.... This is related to the fact that it is impossible to exactly express some fractions in decimal notation with a finite number of digits. For instance, 1/3 in decimal form becomes 0.3333333. . .. So never trust floating number results to the last digit and never compare floating point numbers for equality. If you really need higher precision, you should use the arbitrary precision math functions instead. |
Strings can be specified using one of two sets of delimiters.
If the string is enclosed in double-quotes ("), variables within the string will be expanded (subject to some parsing limitations). As in C and Perl, the backslash ("\") character can be used in specifying special characters:
Table 6-1. Escaped characters
| sequence | meaning |
|---|---|
| \n | linefeed (LF or 0x0A in ASCII) |
| \r | carriage return (CR or 0x0D in ASCII) |
| \t | horizontal tab (HT or 0x09 in ASCII) |
| \\ | backslash |
| \$ | dollar sign |
| \" | double-quote |
| \[0-7]{1,3} | the sequence of characters matching the regular expression is a character in octal notation |
| \x[0-9A-Fa-f]{1,2} | the sequence of characters matching the regular expression is a character in hexadecimal notation |
You can escape any other character, but a warning will be issued at the highest warning level.
The second way to delimit a string uses the single-quote ("'") character. When a string is enclosed in single quotes, the only escapes that will be understood are "\\" and "\'". This is for convenience, so that you can have single-quotes and backslashes in a single-quoted string. Variables will not be expanded inside a single-quoted string.
Another way to delimit strings is by using here doc syntax ("<<<"). One should provide an identifier after <<<, then the string, and then the same identifier to close the quotation. The closing identifier must begin in the first column of the line. The label used must follow the same naming rules as any other label in PHP: it must contain only alphanumeric characters and underscores, and must start with a non-digit character or underscore.
Here doc text behaves just like a double-quoted string, without the double-quotes. This means that you do not need to escape quotes in your here docs, but you can still use the escape codes listed above. Variables are expanded, but the same care must be taken when expressing complex variables inside a here doc as with strings.
Example 6-1. Here doc string quoting example
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Note: Here doc support was added in PHP 4.
Strings may be concatenated using the '.' (dot) operator. Note that the '+' (addition) operator will not work for this. Please see String operators for more information.
Characters within strings may be accessed by treating the string as a numerically-indexed array of characters, using C-like syntax. See below for examples.
Example 6-2. Some string examples
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When a string is evaluated as a numeric value, the resulting value and type are determined as follows.
The string will evaluate as a double if it contains any of the characters '.', 'e', or 'E'. Otherwise, it will evaluate as an integer.
The value is given by the initial portion of the string. If the string starts with valid numeric data, this will be the value used. Otherwise, the value will be 0 (zero). Valid numeric data is an optional sign, followed by one or more digits (optionally containing a decimal point), followed by an optional exponent. The exponent is an 'e' or 'E' followed by one or more digits.
When the first expression is a string, the type of the variable will depend on the second expression.
$foo = 1 + "10.5"; // $foo is double (11.5)
$foo = 1 + "-1.3e3"; // $foo is double (-1299)
$foo = 1 + "bob-1.3e3"; // $foo is integer (1)
$foo = 1 + "bob3"; // $foo is integer (1)
$foo = 1 + "10 Small Pigs"; // $foo is integer (11)
$foo = 1 + "10 Little Piggies"; // $foo is integer (11)
$foo = "10.0 pigs " + 1; // $foo is integer (11)
$foo = "10.0 pigs " + 1.0; // $foo is double (11)
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For more information on this conversion, see the Unix manual page for strtod(3).
If you would like to test any of the examples in this section, you can cut and paste the examples and insert the following line to see for yourself what's going on:
Arrays actually act like both hash tables (associative arrays) and indexed arrays (vectors).
PHP supports both scalar and associative arrays. In fact, there is no difference between the two. You can create an array using the list() or array() functions, or you can explicitly set each array element value.
You can also create an array by simply adding values to the array. When you assign a value to an array variable using empty brackets, the value will be added onto the end of the array.
Arrays may be sorted using the asort(), arsort(), ksort(), rsort(), sort(), uasort(), usort(), and uksort() functions depending on the type of sort you want.
You can count the number of items in an array using the count() function.
You can traverse an array using next() and prev() functions. Another common way to traverse an array is to use the each() function.
Multi-dimensional arrays are actually pretty simple. For each dimension of the array, you add another [key] value to the end:
$a[1] = $f; # one dimensional examples
$a["foo"] = $f;
$a[1][0] = $f; # two dimensional
$a["foo"][2] = $f; # (you can mix numeric and associative indices)
$a[3]["bar"] = $f; # (you can mix numeric and associative indices)
$a["foo"][4]["bar"][0] = $f; # four dimensional!
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In PHP 3 it is not possible to reference multidimensional arrays directly within strings. For instance, the following will not have the desired result:
In PHP 3, the above will output This won't work: Array[bar]. The string concatenation operator, however, can be used to overcome this:In PHP 4, however, the whole problem may be circumvented by enclosing the array reference (inside the string) in curly braces:
You can "fill up" multi-dimensional arrays in many ways, but the trickiest one to understand is how to use the array() command for associative arrays. These two snippets of code fill up the one-dimensional array in the same way:
# Example 1:
$a["color"] = "red";
$a["taste"] = "sweet";
$a["shape"] = "round";
$a["name"] = "apple";
$a[3] = 4;
# Example 2:
$a = array(
"color" => "red",
"taste" => "sweet",
"shape" => "round",
"name" => "apple",
3 => 4
);
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The array() function can be nested for multi-dimensional arrays:
<?php
$a = array(
"apple" => array(
"color" => "red",
"taste" => "sweet",
"shape" => "round"
),
"orange" => array(
"color" => "orange",
"taste" => "tart",
"shape" => "round"
),
"banana" => array(
"color" => "yellow",
"taste" => "paste-y",
"shape" => "banana-shaped"
)
);
echo $a["apple"]["taste"]; # will output "sweet"
?>
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To initialize an object, you use the new statement to instantiate the object to a variable.
For a full discussion, please read the section Classes and Objects.
PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which that variable is used. That is to say, if you assign a string value to variable var, var becomes a string. If you then assign an integer value to var, it becomes an integer.
An example of PHP's automatic type conversion is the addition operator '+'. If any of the operands is a double, then all operands are evaluated as doubles, and the result will be a double. Otherwise, the operands will be interpreted as integers, and the result will also be an integer. Note that this does NOT change the types of the operands themselves; the only change is in how the operands are evaluated.
$foo = "0"; // $foo is string (ASCII 48)
$foo++; // $foo is the string "1" (ASCII 49)
$foo += 1; // $foo is now an integer (2)
$foo = $foo + 1.3; // $foo is now a double (3.3)
$foo = 5 + "10 Little Piggies"; // $foo is integer (15)
$foo = 5 + "10 Small Pigs"; // $foo is integer (15)
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If the last two examples above seem odd, see String conversion.
If you wish to force a variable to be evaluated as a certain type, see the section on Type casting. If you wish to change the type of a variable, see settype().
If you would like to test any of the examples in this section, you can cut and paste the examples and insert the following line to see for yourself what's going on:
Note: The behaviour of an automatic conversion to array is currently undefined.
While the above example may seem like it should clearly result in $a becoming an array, the first element of which is 'f', consider this:
Since PHP supports indexing into strings via offsets using the same syntax as array indexing, the example above leads to a problem: should $a become an array with its first element being "f", or should "f" become the first character of the string $a?
For this reason, as of PHP 3.0.12 and PHP 4.0b3-RC4, the result of this automatic conversion is considered to be undefined. Fixes are, however, being discussed.
Type casting in PHP works much as it does in C: the name of the desired type is written in parentheses before the variable which is to be cast.
The casts allowed are:
(int), (integer) - cast to integer
(real), (double), (float) - cast to double
(string) - cast to string
(array) - cast to array
(object) - cast to object
Note that tabs and spaces are allowed inside the parentheses, so the following are functionally equivalent:
It may not be obvious exactly what will happen when casting between certain types. For instance, the following should be noted.
When casting from a scalar or a string variable to an array, the variable will become the first element of the array:
When casting from a scalar or a string variable to an object, the variable will become an attribute of the object; the attribute name will be 'scalar':
Variables in PHP are represented by a dollar sign followed by the name of the variable. The variable name is case-sensitive.
Variable names follow the same rules as other labels in PHP. A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'
Note: For our purposes here, a letter is a-z, A-Z, and the ASCII characters from 127 through 255 (0x7f-0xff).
$var = "Bob";
$Var = "Joe";
echo "$var, $Var"; // outputs "Bob, Joe"
$4site = 'not yet'; // invalid; starts with a number
$_4site = 'not yet'; // valid; starts with an underscore
$tΣyte = 'mansikka'; // valid; 'Σ' is ASCII 228.
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In PHP 3, variables are always assigned by value. That is to say, when you assign an expression to a variable, the entire value of the original expression is copied into the destination variable. This means, for instance, that after assigning one variable's value to another, changing one of those variables will have no effect on the other. For more information on this kind of assignment, see Expressions.
PHP 4 offers another way to assign values to variables: assign by reference. This means that the new variable simply references (in other words, "becomes an alias for" or "points to") the original variable. Changes to the new variable affect the original, and vice versa. This also means that no copying is performed; thus, the assignment happens more quickly. However, any speedup will likely be noticed only in tight loops or when assigning large arrays or objects.
To assign by reference, simply prepend an ampersand (&) to the beginning of the variable which is being assigned (the source variable). For instance, the following code snippet outputs 'My name is Bob' twice:
<?php
$foo = 'Bob'; // Assign the value 'Bob' to $foo
$bar = &$foo; // Reference $foo via $bar.
$bar = "My name is $bar"; // Alter $bar...
echo $foo; // $foo is altered too.
echo $bar;
?>
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One important thing to note is that only named variables may be assigned by reference.
PHP provides a large number of predefined variables to any script which it runs. Many of these variables, however, cannot be fully documented as they are dependent upon which server is running, the version and setup of the server, and other factors. Some of these variables will not be available when PHP is run on the command-line.
Despite these factors, here is a list of predefined variables available under a stock installation of PHP 3 running as a module under a stock installation of Apache 1.3.6.
For a list of all predefined variables (and lots of other useful information), please see (and use) phpinfo().
Note: This list is neither exhaustive nor intended to be. It is simply a guideline as to what sorts of predefined variables you can expect to have access to in your script.
These variables are created by the Apache webserver. If you are running another webserver, there is no guarantee that it will provide the same variables; it may omit some, or provide others not listed here. That said, a large number of these variables are accounted for in the CGI 1.1 specification, so you should be able to expect those.
Note that few, if any, of these will be available (or indeed have any meaning) if running PHP on the command line.
What revision of the CGI specification the server is using; i.e. 'CGI/1.1'.
The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host.
Server identification string, given in the headers when responding to requests.
Name and revision of the information protocol via which the page was requested; i.e. 'HTTP/1.0';
Which request method was used to access the page; i.e. 'GET', 'HEAD', 'POST', 'PUT'.
The query string, if any, via which the page was accessed.
The document root directory under which the current script is executing, as defined in the server's configuration file.
Contents of the Accept: header from the current request, if there is one.
Contents of the Accept-Charset: header from the current request, if there is one. Example: 'iso-8859-1,*,utf-8'.
Contents of the Accept-Encoding: header from the current request, if there is one. Example: 'gzip'.
Contents of the Accept-Language: header from the current request, if there is one. Example: 'en'.
Contents of the Connection: header from the current request, if there is one. Example: 'Keep-Alive'.
Contents of the Host: header from the current request, if there is one.
The address of the page (if any) which referred the browser to the current page. This is set by the user's browser; not all browsers will set this.
Contents of the User_Agent: header from the current request, if there is one. This is a string denoting the browser software being used to view the current page; i.e. Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586). Among other things, you can use this value with get_browser() to tailor your page's functionality to the capabilities of the user's browser.
The IP address from which the user is viewing the current page.
The port being used on the user's machine to communicate with the web server.
The absolute pathname of the currently executing script.
The value given to the SERVER_ADMIN (for Apache) directive in the web server configuration file. If the script is running on a virtual host, this will be the value defined for that virtual host.
The port on the server machine being used by the web server for communication. For default setups, this will be '80'; using SSL, for instance, will change this to whatever your defined secure HTTP port is.
String containing the server version and virtual host name which are added to server-generated pages, if enabled.
Filesystem- (not document root-) based path to the current script, after the server has done any virtual-to-real mapping.
Contains the current script's path. This is useful for pages which need to point to themselves.
The URI which was given in order to access this page; for instance, '/index.html'.
These variables are imported into PHP's global namespace from the environment under which the PHP parser is running. Many are provided by the shell under which PHP is running and different systems are likely running different kinds of shells, a definitive list is impossible. Please see your shell's documentation for a list of defined environment variables.
Other environment variables include the CGI variables, placed there regardless of whether PHP is running as a server module or CGI processor.
These variables are created by PHP itself. The $HTTP_*_VARS variables are available only if the track_vars configuration is turned on.
Note: As of PHP 4.0.3, track_vars is always turned on, regardless of the configuration file setting.
If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $HTTP_*_VARS arrays. This feature should be used with care, and turned off if possible; while the $HTTP_*_VARS variables are safe, the bare global equivalents can be overwritten by user input, with possibly malicious intent. If you cannot turn off register_globals, you must take whatever steps are necessary to ensure that the data you are using is safe.
Array of arguments passed to the script. When the script is run on the command line, this gives C-style access to the command line parameters. When called via the GET method, this will contain the query string.
Contains the number of command line parameters passed to the script (if run on the command line).
The filename of the currently executing script, relative to the document root. If PHP is running as a command-line processor, this variable is not available.
An associative array of variables passed to the current script via HTTP cookies.
An associative array of variables passed to the current script via the HTTP GET method.
An associative array of variables passed to the current script via the HTTP POST method.
An associative array of variables containing information about files uploaded via the HTTP POST method. See POST method uploads for information on the contents of $HTTP_POST_FILES.
$HTTP_POST_FILES is available only in PHP 4.0.0 and later.
An associative array of variables passed to the current script via the parent environment.
An associative array of variables passed to the current script from the HTTP server. These variables are analogous to the Apache variables described above.
The scope of a variable is the context within which it is defined. For the most part all PHP variables only have a single scope. This single scope spans included and required files as well. For example:
Here the $a variable will be available within the included b.inc script. However, within user-defined functions a local function scope is introduced. Any variable used inside a function is by default limited to the local function scope. For example:
$a = 1; /* global scope */
Function Test () {
echo $a; /* reference to local scope variable */
}
Test ();
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This script will not produce any output because the echo statement refers to a local version of the $a variable, and it has not been assigned a value within this scope. You may notice that this is a little bit different from the C language in that global variables in C are automatically available to functions unless specifically overridden by a local definition. This can cause some problems in that people may inadvertently change a global variable. In PHP global variables must be declared global inside a function if they are going to be used in that function. An example:
The above script will output "3". By declaring $a and $b global within the function, all references to either variable will refer to the global version. There is no limit to the number of global variables that can be manipulated by a function.
A second way to access variables from the global scope is to use the special PHP-defined $GLOBALS array. The previous example can be rewritten as:
The $GLOBALS array is an associative array with the name of the global variable being the key and the contents of that variable being the value of the array element.
Another important feature of variable scoping is the static variable. A static variable exists only in a local function scope, but it does not lose its value when program execution leaves this scope. Consider the following example:
This function is quite useless since every time it is called it sets $a to 0 and prints "0". The $a++ which increments the variable serves no purpose since as soon as the function exits the $a variable disappears. To make a useful counting function which will not lose track of the current count, the $a variable is declared static:
Now, every time the Test() function is called it will print the value of $a and increment it.
Static variables also provide one way to deal with recursive functions. A recursive function is one which calls itself. Care must be taken when writing a recursive function because it is possible to make it recurse indefinitely. You must make sure you have an adequate way of terminating the recursion. The following simple function recursively counts to 10, using the static variable $count to know when to stop:
Sometimes it is convenient to be able to have variable variable names. That is, a variable name which can be set and used dynamically. A normal variable is set with a statement such as:
A variable variable takes the value of a variable and treats that as the name of a variable. In the above example, hello, can be used as the name of a variable by using two dollar signs. i.e.
At this point two variables have been defined and stored in the PHP symbol tree: $a with contents "hello" and $hello with contents "world". Therefore, this statement:
produces the exact same output as:
i.e. they both produce: hello world.
In order to use variable variables with arrays, you have to resolve an ambiguity problem. That is, if you write $$a[1] then the parser needs to know if you meant to use $a[1] as a variable, or if you wanted $$a as the variable and then the [1] index from that variable. The syntax for resolving this ambiguity is: ${$a[1]} for the first case and ${$a}[1] for the second.
When a form is submitted to a PHP script, any variables from that form will be automatically made available to the script by PHP. If the track_vars configuration option is turned on, then these variables will be located in the associative arrays $HTTP_POST_VARS, $HTTP_GET_VARS, and/or $HTTP_POST_FILES, according to the source of the variable in question.
For more information on these variables, please read Predefined variables.
When the above form is submitted, the value from the text input will be available in $HTTP_POST_VARS['username']. If the register_globals configuration directive is turned on, then the variable will also be available as $username in the global scope.
PHP also understands arrays in the context of form variables. You may, for example, group related variables together, or use this feature to retrieve values from a multiple select input:
Example 7-2. More complex form variables
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In PHP 3, the array form variable usage is limited to single-dimensional arrays. In PHP 4, no such restriction applies.
When submitting a form, it is possible to use an image instead of the standard submit button with a tag like:
When the user clicks somewhere on the image, the accompanying form will be transmitted to the server with two additional variables, sub_x and sub_y. These contain the coordinates of the user click within the image. The experienced may note that the actual variable names sent by the browser contains a period rather than an underscore, but PHP converts the period to an underscore automatically.
PHP transparently supports HTTP cookies as defined by Netscape's Spec. Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set cookies using the SetCookie() function. Cookies are part of the HTTP header, so the SetCookie function must be called before any output is sent to the browser. This is the same restriction as for the Header() function. Any cookies sent to you from the client will automatically be turned into a PHP variable just like GET and POST method data.
If you wish to assign multiple values to a single cookie, just add [] to the cookie name. For example:
Note that a cookie will replace a previous cookie by the same name in your browser unless the path or domain is different. So, for a shopping cart application you may want to keep a counter and pass this along. i.e.
PHP automatically makes environment variables available as normal PHP variables.
Since information coming in via GET, POST and Cookie mechanisms also automatically create PHP variables, it is sometimes best to explicitly read a variable from the environment in order to make sure that you are getting the right version. The getenv() function can be used for this. You can also set an environment variable with the putenv() function.
Typically, PHP does not alter the names of variables when they are passed into a script. However, it should be noted that the dot (period, full stop) is not a valid character in a PHP variable name. For the reason, look at it:
$varname.ext; /* invalid variable name */
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For this reason, it is important to note that PHP will automatically replace any dots in incoming variable names with underscores.
Because PHP determines the types of variables and converts them (generally) as needed, it is not always obvious what type a given variable is at any one time. PHP includes several functions which find out what type a variable is. They are gettype(), is_long(), is_double(), is_string(), is_array(), and is_object().
PHP defines several constants and provides a mechanism for defining more at run-time. Constants are much like variables, save for the two facts that constants must be defined using the define() function, and that they cannot later be redefined to another value.
The predefined constants (always available) are:
The name of the script file presently being parsed. If used within a file which has been included or required, then the name of the included file is given, and not the name of the parent file.
The number of the line within the current script file which is being parsed. If used within a file which has been included or required, then the position within the included file is given.
The string representation of the version of the PHP parser presently in use; e.g. '3.0.8-dev'.
The name of the operating system on which the PHP parser is executing; e.g. 'Linux'.
A true value.
A false value.
Denotes an error other than a parsing error from which recovery is not possible.
Denotes a condition where PHP knows something is wrong, but will continue anyway; these can be caught by the script itself. An example would be an invalid regexp in ereg().
The parser choked on invalid syntax in the script file. Recovery is not possible.
Something happened which may or may not be an error. Execution continues. Examples include using an unquoted string as a hash index, or accessing a variable which has not been set.
All of the E_* constants rolled into one. If used with error_reporting(), will cause any and all problems noticed by PHP to be reported.
The E_* constants are typically used with the error_reporting() function for setting the error reporting level. See all these constants at Error handling.
You can define additional constants using the define() function.
Note that these are constants, not C-style macros; only valid scalar data may be represented by a constant.
Expressions are the most important building stones of PHP. In PHP, almost anything you write is an expression. The simplest yet most accurate way to define an expression is "anything that has a value".
The most basic forms of expressions are constants and variables. When you type "$a = 5", you're assigning '5' into $a. '5', obviously, has the value 5, or in other words '5' is an expression with the value of 5 (in this case, '5' is an integer constant).
After this assignment, you'd expect $a's value to be 5 as well, so if you wrote $b = $a, you'd expect it to behave just as if you wrote $b = 5. In other words, $a is an expression with the value of 5 as well. If everything works right, this is exactly what will happen.
Slightly more complex examples for expressions are functions. For instance, consider the following function:
Assuming you're familiar with the concept of functions (if you're not, take a look at the chapter about functions), you'd assume that typing $c = foo() is essentially just like writing $c = 5, and you're right. Functions are expressions with the value of their return value. Since foo() returns 5, the value of the expression 'foo()' is 5. Usually functions don't just return a static value but compute something.
Of course, values in PHP don't have to be integers, and very often they aren't. PHP supports three scalar value types: integer values, floating point values and string values (scalar values are values that you can't 'break' into smaller pieces, unlike arrays, for instance). PHP also supports two composite (non-scalar) types: arrays and objects. Each of these value types can be assigned into variables or returned from functions.
So far, users of PHP/FI 2 shouldn't feel any change. However, PHP takes expressions much further, in the same way many other languages do. PHP is an expression-oriented language, in the sense that almost everything is an expression. Consider the example we've already dealt with, '$a = 5'. It's easy to see that there are two values involved here, the value of the integer constant '5', and the value of $a which is being updated to 5 as well. But the truth is that there's one additional value involved here, and that's the value of the assignment itself. The assignment itself evaluates to the assigned value, in this case 5. In practice, it means that '$a = 5', regardless of what it does, is an expression with the value 5. Thus, writing something like '$b = ($a = 5)' is like writing '$a = 5; $b = 5;' (a semicolon marks the end of a statement). Since assignments are parsed in a right to left order, you can also write '$b = $a = 5'.
Another good example of expression orientation is pre- and post-increment and decrement. Users of PHP/FI 2 and many other languages may be familiar with the notation of variable++ and variable--. These are increment and decrement operators. In PHP/FI 2, the statement '$a++' has no value (is not an expression), and thus you can't assign it or use it in any way. PHP enhances the increment/decrement capabilities by making these expressions as well, like in C. In PHP, like in C, there are two types of increment - pre-increment and post-increment. Both pre-increment and post-increment essentially increment the variable, and the effect on the variable is idential. The difference is with the value of the increment expression. Pre-increment, which is written '++$variable', evaluates to the incremented value (PHP increments the variable before reading its value, thus the name 'pre-increment'). Post-increment, which is written '$variable++' evaluates to the original value of $variable, before it was incremented (PHP increments the variable after reading its value, thus the name 'post-increment').
A very common type of expressions are comparison expressions. These expressions evaluate to either 0 or 1, meaning FALSE or TRUE (respectively). PHP supports > (bigger than), >= (bigger than or equal to), == (equal), != (not equal), < (smaller than) and <= (smaller than or equal to). These expressions are most commonly used inside conditional execution, such as if statements.
The last example of expressions we'll deal with here is combined operator-assignment expressions. You already know that if you want to increment $a by 1, you can simply write '$a++' or '++$a'. But what if you want to add more than one to it, for instance 3? You could write '$a++' multiple times, but this is obviously not a very efficient or comfortable way. A much more common practice is to write '$a = $a + 3'. '$a + 3' evaluates to the value of $a plus 3, and is assigned back into $a, which results in incrementing $a by 3. In PHP, as in several other languages like C, you can write this in a shorter way, which with time would become clearer and quicker to understand as well. Adding 3 to the current value of $a can be written '$a += 3'. This means exactly "take the value of $a, add 3 to it, and assign it back into $a". In addition to being shorter and clearer, this also results in faster execution. The value of '$a += 3', like the value of a regular assignment, is the assigned value. Notice that it is NOT 3, but the combined value of $a plus 3 (this is the value that's assigned into $a). Any two-place operator can be used in this operator-assignment mode, for example '$a -= 5' (subtract 5 from the value of $a), '$b *= 7' (multiply the value of $b by 7), etc.
There is one more expression that may seem odd if you haven't seen it in other languages, the ternary conditional operator:
If the value of the first subexpression is true (non-zero), then it the second subexpression is evaluated, and that is the result of the conditional expression. Otherwise, the third subexpression is evaluated, and that is the value.The following example should help you understand pre- and post-increment and expressions in general a bit better:
function double($i) {
return $i*2;
}
$b = $a = 5; /* assign the value five into the variable $a and $b */
$c = $a++; /* post-increment, assign original value of $a
(5) to $c */
$e = $d = ++$b; /* pre-increment, assign the incremented value of
$b (6) to $d and $e */
/* at this point, both $d and $e are equal to 6 */
$f = double($d++); /* assign twice the value of $d before
the increment, 2*6 = 12 to $f */
$g = double(++$e); /* assign twice the value of $e after
the increment, 2*7 = 14 to $g */
$h = $g += 10; /* first, $g is incremented by 10 and ends with the
value of 24. the value of the assignment (24) is
then assigned into $h, and $h ends with the value
of 24 as well. */
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In the beginning of the chapter we said that we'll be describing the various statement types, and as promised, expressions can be statements. However, not every expression is a statement. In this case, a statement has the form of 'expr' ';' that is, an expression followed by a semicolon. In '$b=$a=5;', $a=5 is a valid expression, but it's not a statement by itself. '$b=$a=5;' however is a valid statement.
One last thing worth mentioning is the truth value of expressions. In many events, mainly in conditional execution and loops, you're not interested in the specific value of the expression, but only care about whether it means TRUE or FALSE (PHP doesn't have a dedicated boolean type). The truth value of expressions in PHP is calculated in a similar way to perl. Any numeric non-zero numeric value is TRUE, zero is FALSE. Be sure to note that negative values are non-zero and are thus considered TRUE! The empty string and the string "0" are FALSE; all other strings are TRUE. With non-scalar values (arrays and objects) - if the value contains no elements it's considered FALSE, otherwise it's considered TRUE.
PHP provides a full and powerful implementation of expressions, and documenting it entirely goes beyond the scope of this manual. The above examples should give you a good idea about what expressions are and how you can construct useful expressions. Throughout the rest of this manual we'll write expr to indicate any valid PHP expression.
Remember basic arithmetic from school? These work just like those.
Table 10-1. Arithmetic Operators
| Example | Name | Result |
|---|---|---|
| $a + $b | Addition | Sum of $a and $b. |
| $a - $b | Subtraction | Difference of $a and $b. |
| $a * $b | Multiplication | Product of $a and $b. |
| $a / $b | Division | Quotient of $a and $b. |
| $a % $b | Modulus | Remainder of $a divided by $b. |
The division operator ("/") returns an integer value (the result of an integer division) if the two operands are integers (or strings that get converted to integers) and the quotient is an integer. If either operand is a floating-point value, or the operation results in a non-integer value, a floating-point value is returned.
The basic assignment operator is "=". Your first inclination might be to think of this as "equal to". Don't. It really means that the the left operand gets set to the value of the expression on the rights (that is, "gets set to").
The value of an assignment expression is the value assigned. That is, the value of "$a = 3" is 3. This allows you to do some tricky things:
In addition to the basic assignment operator, there are "combined operators" for all of the binary arithmetic and string operators that allow you to use a value in an expression and then set its value to the result of that expression. For example:
$a = 3;
$a += 5; // sets $a to 8, as if we had said: $a = $a + 5;
$b = "Hello ";
$b .= "There!"; // sets $b to "Hello There!", just like $b = $b . "There!";
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Note that the assignment copies the original variable to the new one (assignment by value), so changes to one will not affect the other. This may also have relevance if you need to copy something like a large array inside a tight loop. PHP 4 supports assignment by reference, using the $var = &$othervar; syntax, but this is not possible in PHP 3. 'Assignment by reference' means that both variables end up pointing at the same data, and nothing is copied anywhere. To learn more about references, please read References explained.
Bitwise operators allow you to turn specific bits within an integer on or off.
Table 10-2. Bitwise Operators
| Example | Name | Result |
|---|---|---|
| $a & $b | And | Bits that are set in both $a and $b are set. |
| $a | $b | Or | Bits that are set in either $a or $b are set. |
| $a ^ $b | Xor | Bits that are set in $a or $b but not both are set. |
| ~ $a | Not | Bits that are set in $a are not set, and vice versa. |
| $a << $b | Shift left | Shift the bits of $a $b steps to the left (each step means "multiply by two") |
| $a >> $b | Shift right | Shift the bits of $a $b steps to the right (each step means "divide by two") |
Comparison operators, as their name implies, allow you to compare two values.
Table 10-3. Comparison Operators
| Example | Name | Result |
|---|---|---|
| $a == $b | Equal | True if $a is equal to $b. |
| $a === $b | Identical | True if $a is equal to $b, and they are of the same type. (PHP 4 only) |
| $a != $b | Not equal | True if $a is not equal to $b. |
| $a !== $b | Not identical | True if $a is not equal to $b, or they are not of the same type. (PHP 4 only) |
| $a < $b | Less than | True if $a is strictly less than $b. |
| $a > $b | Greater than | True if $a is strictly greater than $b. |
| $a <= $b | Less than or equal to | True if $a is less than or equal to $b. |
| $a >= $b | Greater than or equal to | True if $a is greater than or equal to $b. |
Another conditional operator is the "?:" (or ternary) operator, which operates as in C and many other languages.
This expression evaluates to expr2 if expr1 evaluates to true, and expr3 if expr1 evaluates to false.PHP supports one error control operator: the at sign (@). When prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored.
If the track_errors feature is enabled, any error message generated by the expression will be saved in the global variable $php_errormsg. This variable will be overwritten on each error, so check early if you want to use it.
<?php
/* Intentional SQL error (extra quote): */
$res = @mysql_query ("select name, code from 'namelist") or
die ("Query failed: error was '$php_errormsg'");
?>
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See also error_reporting().
| Warning |
Currently the "@" error-control operator prefix will even disable error reporting for critical errors that will terminate script execution. Among other things, this means that if you use "@" to suppress errors from a certain function and either it isn't available or has been mistyped, the script will die right there with no indication as to why. |
PHP supports one execution operator: backticks (``). Note that these are not single-quotes! PHP will attempt to execute the contents of the backticks as a shell command; the output will be returned (i.e., it won't simply be dumped to output; it can be assigned to a variable).
See also system(), passthru(), exec(), popen(), and escapeshellcmd().
PHP supports C-style pre- and post-increment and decrement operators.
Table 10-4. Increment/decrement Operators
| Example | Name | Effect |
|---|---|---|
| ++$a | Pre-increment | Increments $a by one, then returns $a. |
| $a++ | Post-increment | Returns $a, then increments $a by one. |
| --$a | Pre-decrement | Decrements $a by one, then returns $a. |
| $a-- | Post-decrement | Returns $a, then decrements $a by one. |
Here's a simple example script:
<?php
echo "<h3>Postincrement</h3>";
$a = 5;
echo "Should be 5: " . $a++ . "<br>\n";
echo "Should be 6: " . $a . "<br>\n";
echo "<h3>Preincrement</h3>";
$a = 5;
echo "Should be 6: " . ++$a . "<br>\n";
echo "Should be 6: " . $a . "<br>\n";
echo "<h3>Postdecrement</h3>";
$a = 5;
echo "Should be 5: " . $a-- . "<br>\n";
echo "Should be 4: " . $a . "<br>\n";
echo "<h3>Predecrement</h3>";
$a = 5;
echo "Should be 4: " . --$a . "<br>\n";
echo "Should be 4: " . $a . "<br>\n";
?>
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Table 10-5. Logical Operators
| Example | Name | Result |
|---|---|---|
| $a and $b | And | True if both $a and $b are true. |
| $a or $b | Or | True if either $a or $b is true. |
| $a xor $b | Or | True if either $a or $b is true, but not both. |
| ! $a | Not | True if $a is not true. |
| $a && $b | And | True if both $a and $b are true. |
| $a || $b | Or | True if either $a or $b is true. |
The reason for the two different variations of "and" and "or" operators is that they operate at different precedences. (See Operator Precedence.)
The precedence of an operator specifies how "tightly" it binds two expressions together. For example, in the expression 1 + 5 * 3, the answer is 16 and not 18 because the multiplication ("*") operator has a higher precedence than the addition ("+") operator. Parentheses may be used to force precedence, if necessary. For instance: (1 + 5) * 3 evaluates to 18.
The following table lists the precedence of operators with the lowest-precedence operators listed first.
Table 10-6. Operator Precedence
| Associativity | Operators |
|---|---|
| left | , |
| left | or |
| left | xor |
| left | and |
| right | |
| left | = += -= *= /= .= %= &= |= ^= ~= <<= >>= |
| left | ? : |
| left | || |
| left | && |
| left | | |
| left | ^ |
| left | & |
| non-associative | == != === !== |
| non-associative | < <= > >= |
| left | << >> |
| left | + - . |
| left | * / % |
| right | ! ~ ++ -- (int) (double) (string) (array) (object) @ |
| right | [ |
| non-associative | new |
There are two string operators. The first is the concatenation operator ('.'), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator ('.='), which appends the argument on the right side to the argument on the left side. Please read Assignment Operators for more information.
Any PHP script is built out of a series of statements. A statement can be an assignment, a function call, a loop, a conditional statement of even a statement that does nothing (an empty statement). Statements usually end with a semicolon. In addition, statements can be grouped into a statement-group by encapsulating a group of statements with curly braces. A statement-group is a statement by itself as well. The various statement types are described in this chapter.
The if construct is one of the most important features of many languages, PHP included. It allows for conditional execution of code fragments. PHP features an if structure that is similar to that of C:
As described in the section about expressions, expr is evaluated to its truth value. If expr evaluates to TRUE, PHP will execute statement, and if it evaluates to FALSE - it'll ignore it.
The following example would display a is bigger than b if $a is bigger than $b:
Often you'd want to have more than one statement to be executed conditionally. Of course, there's no need to wrap each statement with an if clause. Instead, you can group several statements into a statement group. For example, this code would display a is bigger than b if $a is bigger than $b, and would then assign the value of $a into $b:
If statements can be nested indefinitely within other if statements, which provides you with complete flexibility for conditional execution of the various parts of your program.
Often you'd want to execute a statement if a certain condition is met, and a different statement if the condition is not met. This is what else is for. else extends an if statement to execute a statement in case the expression in the if statement evaluates to FALSE. For example, the following code would display a is bigger than b if $a is bigger than $b, and a is NOT bigger than b otherwise:
The else statement is only executed if the if expression evaluated to FALSE, and if there were any elseif expressions - only if they evaluated to FALSE as well (see elseif).elseif, as its name suggests, is a combination of if and else. Like else, it extends an if statement to execute a different statement in case the original if expression evaluates to FALSE. However, unlike else, it will execute that alternative expression only if the elseif conditional expression evaluates to TRUE. For example, the following code would display a is bigger than b, a equal to b or a is smaller than b:
if ($a > $b) {
print "a is bigger than b";
} elseif ($a == $b) {
print "a is equal to b";
} else {
print "a is smaller than b";
}
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There may be several elseifs within the same if statement. The first elseif expression (if any) that evaluates to true would be executed. In PHP, you can also write 'else if' (in two words) and the behavior would be identical to the one of 'elseif' (in a single word). The syntactic meaning is slightly different (if you're familiar with C, this is the same behavior) but the bottom line is that both would result in exactly the same behavior.
The elseif statement is only executed if the preceding if expression and any preceding elseif expressions evaluated to FALSE, and the current elseif expression evaluated to TRUE.
PHP offers an alternative syntax for some of its control structures; namely, if, while, for, foreach, and switch. In each case, the basic form of the alternate syntax is to change the opening brace to a colon (:) and the closing brace to endif;, endwhile;, endfor;, endforeach;, or endswitch;, respectively.
In the above example, the HTML block "A = 5" is nested within an if statement written in the alternative syntax. The HTML block would be displayed only if $a is equal to 5.
The alternative syntax applies to else and elseif as well. The following is an if structure with elseif and else in the alternative format:
while loops are the simplest type of loop in PHP. They behave just like their C counterparts. The basic form of a while statement is:
The meaning of a while statement is simple. It tells PHP to execute the nested statement(s) repeatedly, as long as the while expression evaluates to TRUE. The value of the expression is checked each time at the beginning of the loop, so even if this value changes during the execution of the nested statement(s), execution will not stop until the end of the iteration (each time PHP runs the statements in the loop is one iteration). Sometimes, if the while expression evaluates to FALSE from the very beginning, the nested statement(s) won't even be run once.
Like with the if statement, you can group multiple statements within the same while loop by surrounding a group of statements with curly braces, or by using the alternate syntax:
The following examples are identical, and both print numbers from 1 to 10:
do..while loops are very similar to while loops, except the truth expression is checked at the end of each iteration instead of in the beginning. The main difference from regular while loops is that the first iteration of a do..while loop is guarenteed to run (the truth expression is only checked at the end of the iteration), whereas it's may not necessarily run with a regular while loop (the truth expression is checked at the beginning of each iteration, if it evaluates to FALSE right from the beginning, the loop execution would end immediately).
There is just one syntax for do..while loops:
The above loop would run one time exactly, since after the first iteration, when truth expression is checked, it evaluates to FALSE ($i is not bigger than 0) and the loop execution ends.
Advanced C users may be familiar with a different usage of the do..while loop, to allow stopping execution in the middle of code blocks, by encapsulating them with do..while(0), and using the break statement. The following code fragment demonstrates this:
do {
if ($i < 5) {
print "i is not big enough";
break;
}
$i *= $factor;
if ($i < $minimum_limit) {
break;
}
print "i is ok";
...process i...
} while(0);
|
Don't worry if you don't understand this right away or at all. You can code scripts and even powerful scripts without using this `feature'.
for loops are the most complex loops in PHP. They behave like their C counterparts. The syntax of a for loop is:
The first expression (expr1) is evaluated (executed) once unconditionally at the beginning of the loop.
In the beginning of each iteration, expr2 is evaluated. If it evaluates to TRUE, the loop continues and the nested statement(s) are executed. If it evaluates to FALSE, the execution of the loop ends.
At the end of each iteration, expr3 is evaluated (executed).
Each of the expressions can be empty. expr2 being empty means the loop should be run indefinitely (PHP implicitly considers it as TRUE, like C). This may not be as useless as you might think, since often you'd want to end the loop using a conditional break statement instead of using the for truth expression.
Consider the following examples. All of them display numbers from 1 to 10:
/* example 1 */
for ($i = 1; $i <= 10; $i++) {
print $i;
}
/* example 2 */
for ($i = 1;;$i++) {
if ($i > 10) {
break;
}
print $i;
}
/* example 3 */
$i = 1;
for (;;) {
if ($i > 10) {
break;
}
print $i;
$i++;
}
/* example 4 */
for ($i = 1; $i <= 10; print $i, $i++) ;
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Of course, the first example appears to be the nicest one (or perhaps the fourth), but you may find that being able to use empty expressions in for loops comes in handy in many occasions.
PHP also supports the alternate "colon syntax" for for loops.
Other languages have a foreach statement to traverse an array or hash. PHP 3 has no such construct; PHP 4 does (see foreach). In PHP 3, you can combine while with the list() and each() functions to achieve the same effect. See the documentation for these functions for an example.
PHP 4 (not PHP 3) includes a foreach construct, much like perl and some other languages. This simply gives an easy way to iterate over arrays. There are two syntaxes; the second is a minor but useful extension of the first:
The first form loops over the array given by array_expression. On each loop, the value of the current element is assigned to $value and the internal array pointer is advanced by one (so on the next loop, you'll be looking at the next element).
The second form does the same thing, except that the current element's key will be assigned to the variable $key on each loop.
Note: When foreach first starts executing, the internal array pointer is automatically reset to the first element of the array. This means that you do not need to call reset() before a foreach loop.
Note: Also note that foreach operates on a copy of the specified array, not the array itself, therefore the array pointer is not modified like with the each construct.
You may have noticed that the following are functionally identical:
reset ($arr);
while (list(, $value) = each ($arr)) {
echo "Value: $value<br>\n";
}
foreach ($arr as $value) {
echo "Value: $value<br>\n";
}
|
reset ($arr);
while (list($key, $value) = each ($arr)) {
echo "Key: $key; Value: $value<br>\n";
}
foreach ($arr as $key => $value) {
echo "Key: $key; Value: $value<br>\n";
}
|
Some more examples to demonstrate usages:
/* foreach example 1: value only */
$a = array (1, 2, 3, 17);
foreach ($a as $v) {
print "Current value of \$a: $v.\n";
}
/* foreach example 2: value (with key printed for illustration) */
$a = array (1, 2, 3, 17);
$i = 0; /* for illustrative purposes only */
foreach($a as $v) {
print "\$a[$i] => $k.\n";
}
/* foreach example 3: key and value */
$a = array (
"one" => 1,
"two" => 2,
"three" => 3,
"seventeen" => 17
);
foreach($a as $k => $v) {
print "\$a[$k] => $v.\n";
}
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break ends execution of the current for, while, or switch structure.
break accepts an optional numeric argument which tells it how many nested enclosing structures are to be broken out of.
$arr = array ('one', 'two', 'three', 'four', 'stop', 'five');
while (list (, $val) = each ($arr)) {
if ($val == 'stop') {
break; /* You could also write 'break 1;' here. */
}
echo "$val<br>\n";
}
/* Using the optional argument. */
$i = 0;
while (++$i) {
switch ($i) {
case 5:
echo "At 5<br>\n";
break 1; /* Exit only the switch. */
case 10:
echo "At 10; quitting<br>\n";
break 2; /* Exit the switch and the while. */
default:
break;
}
}
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continue is used within looping structures to skip the rest of the current loop iteration and continue execution at the beginning of the next iteration.
continue accepts an optional numeric argument which tells it how many levels of enclosing loops it should skip to the end of.
while (list ($key, $value) = each ($arr)) {
if (!($key % 2)) { // skip odd members
continue;
}
do_something_odd ($value);
}
$i = 0;
while ($i++ < 5) {
echo "Outer<br>\n";
while (1) {
echo "ááMiddle<br>\n";
while (1) {
echo "ááInner<br>\n";
continue 3;
}
echo "This never gets output.<br>\n";
}
echo "Neither does this.<br>\n";
}
|
The switch statement is similar to a series of IF statements on the same expression. In many occasions, you may want to compare the same variable (or expression) with many different values, and execute a different piece of code depending on which value it equals to. This is exactly what the switch statement is for.
The following two examples are two different ways to write the same thing, one using a series of if statements, and the other using the switch statement:
if ($i == 0) {
print "i equals 0";
}
if ($i == 1) {
print "i equals 1";
}
if ($i == 2) {
print "i equals 2";
}
switch ($i) {
case 0:
print "i equals 0";
break;
case 1:
print "i equals 1";
break;
case 2:
print "i equals 2";
break;
}
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It is important to understand how the switch statement is executed in order to avoid mistakes. The switch statement executes line by line (actually, statement by statement). In the beginning, no code is executed. Only when a case statement is found with a value that matches the value of the switch expression does PHP begin to execute the statements. PHP continues to execute the statements until the end of the switch block, or the first time it sees a break statement. If you don't write a break statement at the end of a case's statement list, PHP will go on executing the statements of the following case. For example:
Here, if $i equals to 0, PHP would execute all of the print statements! If $i equals to 1, PHP would execute the last two print statements, and only if $i equals to 2, you'd get the 'expected' behavior and only 'i equals 2' would be displayed. So, it's important not to forget break statements (even though you may want to avoid supplying them on purpose under certain circumstances).
In a switch statement, the condition is evaluated only once and the result is compared to each case statement. In an elseif statement, the condition is evaluated again. If your condition is more complicated than a simple compare and/or is in a tight loop, a switch may be faster.
The statement list for a case can also be empty, which simply passes control into the statement list for the next case.
switch ($i) {
case 0:
case 1:
case 2:
print "i is less than 3 but not negative";
break;
case 3:
print "i is 3";
}
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A special case is the default case. This case matches anything that wasn't matched by the other cases. For example:
switch ($i) {
case 0:
print "i equals 0";
break;
case 1:
print "i equals 1";
break;
case 2:
print "i equals 2";
break;
default:
print "i is not equal to 0, 1 or 2";
}
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The case expression may be any expression that evaluates to a simple type, that is, integer or floating-point numbers and strings. Arrays or objects cannot be used here unless they are dereferenced to a simple type.
The alternative syntax for control structures is supported with switches. For more information, see Alternative syntax for control structures .
The require() statement replaces itself with the specified file, much like the C preprocessor's #include works.
If "URL fopen wrappers" are enabled in PHP (which they are in the default configuration), you can specify the file to be require()ed using an URL instead of a local pathname. See Remote files and fopen() for more information.
An important note about how this works is that when a file is include()ed or require()ed, parsing drops out of PHP mode and into HTML mode at the beginning of the target file, and resumes PHP mode again at the end. For this reason, any code inside the target file which should be executed as PHP code must be enclosed within valid PHP start and end tags.
require() is not actually a function in PHP; rather, it is a language construct. It is subject to some different rules than functions are. For instance, require() is not subject to any containing control structures. For another, it does not return any value; attempting to read a return value from a require() call results in a parse error.
Unlike include(), require() will always read in the target file, even if the line it's on never executes. If you want to conditionally include a file, use include(). The conditional statement won't affect the require(). However, if the line on which the require() occurs is not executed, neither will any of the code in the target file be executed.
Similarly, looping structures do not affect the behaviour of require(). Although the code contained in the target file is still subject to the loop, the require() itself happens only once.
This means that you can't put a require() statement inside of a loop structure and expect it to include the contents of a different file on each iteration. To do that, use an include() statement.
When a file is require()ed, the code it contains inherits the variable scope of the line on which the require() occurs. Any variables available at that line in the calling file will be available within the called file. If the require() occurs inside a function within the calling file, then all of the code contained in the called file will behave as though it had been defined inside that function.
If the require()ed file is called via HTTP using the fopen wrappers, and if the target server interprets the target file as PHP code, variables may be passed to the require()ed file using an URL request string as used with HTTP GET. This is not strictly speaking the same thing as require()ing the file and having it inherit the parent file's variable scope; the script is actually being run on the remote server and the result is then being included into the local script.
/* This example assumes that someserver is configured to parse .php
* files and not .txt files. Also, 'works' here means that the variables
* $varone and $vartwo are available within the require()ed file. */
/* Won't work; file.txt wasn't handled by someserver. */
require ("http://someserver/file.txt?varone=1&vartwo=2");
/* Won't work; looks for a file named 'file.php?varone=1&vartwo=2'
* on the local filesystem. */
require ("file.php?varone=1&vartwo=2");
/* Works. */
require ("http://someserver/file.php?varone=1&vartwo=2");
$varone = 1;
$vartwo = 2;
require ("file.txt"); /* Works. */
require ("file.php"); /* Works. */
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In PHP 3, it is possible to execute a return statement inside a require()ed file, as long as that statement occurs in the global scope of the require()ed file. It may not occur within any block (meaning inside braces ({}). In PHP 4, however, this ability has been discontinued. If you need this functionality, see include().
See also include(), require_once(), include_once(), readfile(), and virtual().
The include() statement includes and evaluates the specified file.
If "URL fopen wrappers" are enabled in PHP (which they are in the default configuration), you can specify the file to be include()ed using an URL instead of a local pathname. See Remote files and fopen() for more information.
An important note about how this works is that when a file is include()ed or require()ed, parsing drops out of PHP mode and into HTML mode at the beginning of the target file, and resumes again at the end. For this reason, any code inside the target file which should be executed as PHP code must be enclosed within valid PHP start and end tags.
This happens each time the include() statement is encountered, so you can use an include() statement within a looping structure to include a number of different files.
$files = array ('first.inc', 'second.inc', 'third.inc');
for ($i = 0; $i < count($files); $i++) {
include $files[$i];
}
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include() differs from require() in that the include statement is re-evaluated each time it is encountered (and only when it is being executed), whereas the require() statement is replaced by the required file when it is first encountered, whether the contents of the file will be evaluated or not (for example, if it is inside an if statement whose condition evaluated to false).
Because include() is a special language construct, you must enclose it within a statement block if it is inside a conditional block.
/* This is WRONG and will not work as desired. */
if ($condition)
include($file);
else
include($other);
/* This is CORRECT. */
if ($condition) {
include($file);
} else {
include($other);
}
|
In both PHP 3 and PHP 4, it is possible to execute a return statement inside an include()ed file, in order to terminate processing in that file and return to the script which called it. Some differences in the way this works exist, however. The first is that in PHP 3, the return may not appear inside a block unless it's a function block, in which case the return applies to that function and not the whole file. In PHP 4, however, this restriction does not exist. Also, PHP 4 allows you to return values from include()ed files. You can take the value of the include() call as you would a normal function. This generates a parse error in PHP 3.
Example 11-1. include() in PHP 3 and PHP 4 Assume the existence of the following file (named test.inc) in the same directory as the main file:
Assume that the main file (main.html) contains the following:
When main.html is called in PHP 3, it will generate a parse error on line 2; you can't take the value of an include() in PHP 3. In PHP 4, however, the result will be:
Now, assume that main.html has been altered to contain the following:
In PHP 4, the output will be:
The above parse error is a result of the fact that the return statement is enclosed in a non-function block within test.inc. When the return is moved outside of the block, the output is:
The spurious '27' is due to the fact that PHP 3 does not support returning values from files like that. |
When a file is include()ed, the code it contains inherits the variable scope of the line on which the include() occurs. Any variables available at that line in the calling file will be available within the called file. If the include() occurs inside a function within the calling file, then all of the code contained in the called file will behave as though it had been defined inside that function.
If the include()ed file is called via HTTP using the fopen wrappers, and if the target server interprets the target file as PHP code, variables may be passed to the include()ed file using an URL request string as used with HTTP GET. This is not strictly speaking the same thing as include()ing the file and having it inherit the parent file's variable scope; the script is actually being run on the remote server and the result is then being included into the local script.
/* This example assumes that someserver is configured to parse .php
* files and not .txt files. Also, 'works' here means that the variables
* $varone and $vartwo are available within the include()ed file. */
/* Won't work; file.txt wasn't handled by someserver. */
include ("http://someserver/file.txt?varone=1&vartwo=2");
/* Won't work; looks for a file named 'file.php?varone=1&vartwo=2'
* on the local filesystem. */
include ("file.php?varone=1&vartwo=2");
/* Works. */
include ("http://someserver/file.php?varone=1&vartwo=2");
$varone = 1;
$vartwo = 2;
include ("file.txt"); /* Works. */
include ("file.php"); /* Works. */
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See also require(), require_once(), include_once(), readfile(), and virtual().
The require_once() statement replaces itself with the specified file, much like the C preprocessor's #include works, and in that respect is similar to the require() statement. The main difference is that in an inclusion chain, the use of require_once() will assure that the code is added to your script only once, and avoid clashes with variable values or function names that can happen.
For example, if you create the following 2 include files utils.inc and foolib.inc
Example 11-4. cause_error_require.php
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GLOBALS ARE NICE
this is requiring globals.inc again which is also
required in foolib.inc
Running goodTea: Oolong tea tastes good!
Printing foo:
Array
(
[0] => 1
[1] => Array
(
[0] => complex
[1] => quaternion
)
)
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Also note that, analogous to the behavior of the #include of the C preprocessor, this statement acts at "compile time", e.g. when the script is parsed and before it is executed, and should not be used for parts of the script that need to be inserted dynamically during its execution. You should use include_once() or include() for that purpose.
For more examples on using require_once() and include_once(), look at the PEAR code included in the latest PHP source code distributions.
See also: require(), include(), include_once(), get_required_files(), get_included_files(), readfile(), and virtual().
The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the important difference that if the code from a file has already been included, it will not be included again.
As mentioned in the require_once() description, the include_once() should be used in the cases in which the same file might be included and evaluated more than once during a particular execution of a script, and you want to be sure that it is included exactly once to avoid problems with function redefinitions, variable value reassignments, etc.
For more examples on using require_once() and include_once(), look at the PEAR code included in the latest PHP source code distributions.
include_once() was added in PHP 4.0.1pl2
See also: require(), include(), require_once(), get_required_files(), get_included_files(), readfile(), and virtual().
A function may be defined using syntax such as the following:
Any valid PHP code may appear inside a function, even other functions and class definitions.
In PHP 3, functions must be defined before they are referenced. No such requirement exists in PHP 4.
PHP does not support function overloading, nor is it possible to undefine or redefine previously-declared functions.
PHP 3 does not support variable numbers of arguments to functions, although default arguments are supported (see Default argument values for more information). PHP 4 supports both: see Variable-length argument lists and the function references for func_num_args(), func_get_arg(), and func_get_args() for more information.
Information may be passed to functions via the argument list, which is a comma-delimited list of variables and/or constants.
PHP supports passing arguments by value (the default), passing by reference, and default argument values. Variable-length argument lists are supported only in PHP 4 and later; see Variable-length argument lists and the function references for func_num_args(), func_get_arg(), and func_get_args() for more information. A similar effect can be achieved in PHP 3 by passing an array of arguments to a function:
By default, function arguments are passed by value (so that if you change the value of the argument within the function, it does not get changed outside of the function). If you wish to allow a function to modify its arguments, you must pass them by reference.
If you want an argument to a function to always be passed by reference, you can prepend an ampersand (&) to the argument name in the function definition:
function add_some_extra(&$string) {
$string .= 'and something extra.';
}
$str = 'This is a string, ';
add_some_extra($str);
echo $str; // outputs 'This is a string, and something extra.'
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If you wish to pass a variable by reference to a function which does not do this by default, you may prepend an ampersand to the argument name in the function call:
A function may define C++-style default values for scalar arguments as follows:
function makecoffee ($type = "cappucino") {
return "Making a cup of $type.\n";
}
echo makecoffee ();
echo makecoffee ("espresso");
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The output from the above snippet is:
Making a cup of cappucino.
Making a cup of espresso.
|
The default value must be a constant expression, not (for example) a variable or class member.
Note that when using default arguments, any defaults should be on the right side of any non-default arguments; otherwise, things will not work as expected. Consider the following code snippet:
function makeyogurt ($type = "acidophilus", $flavour) {
return "Making a bowl of $type $flavour.\n";
}
echo makeyogurt ("raspberry"); // won't work as expected
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The output of the above example is:
Warning: Missing argument 2 in call to makeyogurt() in
/usr/local/etc/httpd/htdocs/php3test/functest.html on line 41
Making a bowl of raspberry .
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Now, compare the above with this:
function makeyogurt ($flavour, $type = "acidophilus") {
return "Making a bowl of $type $flavour.\n";
}
echo makeyogurt ("raspberry"); // works as expected
|
The output of this example is:
Making a bowl of acidophilus raspberry.
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PHP 4 has support for variable-length argument lists in user-defined functions. This is really quite easy, using the func_num_args(), func_get_arg(), and func_get_args() functions.
No special syntax is required, and argument lists may still be explicitly provided with function definitions and will behave as normal.
Values are returned by using the optional return statement. Any type may be returned, including lists and objects.
You can't return multiple values from a function, but similar results can be obtained by returning a list.
To return a reference from a function, you have to use the reference operator & in both the function declaration and when assigning the returned value to a variable:
The old_function statement allows you to declare a function using a syntax identical to PHP/FI2 (except you must replace 'function' with 'old_function'.
This is a deprecated feature, and should only be used by the PHP/FI2->PHP 3 convertor.
| Warning |
Functions declared as old_function cannot be called from PHP's internal code. Among other things, this means you can't use them in functions such as usort(), array_walk(), and register_shutdown_function(). You can get around this limitation by writing a wrapper function (in normal PHP 3 form) to call the old_function. |
PHP supports the concept of variable functions. This means that if a variable name has parentheses appended to it, PHP will look for a function with the same name as whatever the variable evaluates to, and will attempt to execute it. Among other things, this can be used to implement callbacks, function tables, and so forth.
A class is a collection of variables and functions working with these variables. A class is defined using the following syntax:
<?php
class Cart {
var $items; // Items in our shopping cart
// Add $num articles of $artnr to the cart
function add_item ($artnr, $num) {
$this->items[$artnr] += $num;
}
// Take $num articles of $artnr out of the cart
function remove_item ($artnr, $num) {
if ($this->items[$artnr] > $num) {
$this->items[$artnr] -= $num;
return true;
} else {
return false;
}
}
}
?>
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This defines a class named Cart that consists of an associative array of articles in the cart and two functions to add and remove items from this cart.
Note: In PHP 4, only constant initializers for var variables are allowed. Use constructors for non-constant initializers.
Classes are types, that is, they are blueprints for actual variables. You have to create a variable of the desired type with the new operator.
This creates an object $cart of the class Cart. The function add_item() of that object is being called to add 1 item of article number 10 to the cart.
Classes can be extensions of other classes. The extended or derived class has all variables and functions of the base class and what you add in the extended definition. This is done using the extends keyword. Multiple inheritance is not supported.
This defines a class Named_Cart that has all variables and functions of Cart plus an additional variable $owner and an additional function set_owner(). You create a named cart the usual way and can now set and get the carts owner. You can still use normal cart functions on named carts:
$ncart = new Named_Cart; // Create a named cart
$ncart->set_owner ("kris"); // Name that cart
print $ncart->owner; // print the cart owners name
$ncart->add_item ("10", 1); // (inherited functionality from cart)
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Within functions of a class the variable $this means this object. You have to use $this->something to access any variable or function named something within your current object.
Constructors are functions in a class that are automatically called when you create a new instance of a class. A function becomes a constructor when it has the same name as the class.
This defines a class Auto_Cart that is a Cart plus a constructor which initializes the cart with one item of article number "10" each time a new Auto_Cart is being made with "new". Constructors can also take arguments and these arguments can be optional, which makes them much more useful.
class Constructor_Cart extends Cart {
function Constructor_Cart ($item = "10", $num = 1) {
$this->add_item ($item, $num);
}
}
// Shop the same old boring stuff.
$default_cart = new Constructor_Cart;
// Shop for real...
$different_cart = new Constructor_Cart ("20", 17);
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| Caution |
For derived classes, the constructor of the parent class is not automatically called when the derived class's constructor is called. |
References in PHP are means to call same variable content with different names. They are not like C pointers, they are symbol table aliases. Note that in PHP, variable names and variable content are different, so same content can have different names. The most close analogy is Unix filenames and files - variable names are directory entries, while variable contents is the file itself. References can be thought of as hardlinking in Unix filesystem.
PHP references allow you to make two variables to refer to the same content. Meaning, when you do:
it means that $a and $b point to the same variable.Note: $a and $b are completely equal here, that's not $a is pointing to $b or vice versa, that's $a and $b pointing to the same place.
The same syntax can be used with functions, that return references, and with new operator (in PHP 4.0.4 and later):
Note: Unless you use the syntax above, the result of $bar = new fooclass() will not be the same variable as $this in the constructor, meaning that if you have used reference to $this in the constructor, you should use reference assignment, or you get two different objects.
The second thing references do is to pass variables by-reference. This is done by making local function variable and caller variable to be reference to the same content. Example:
will make $a to be 6. This happens because in the function foo the variable $var refers to the same content as $a. See also more detailed explanations about passing by reference.The third thing reference can do is return by reference.
As said above, references aren't pointers. That means, the following construct won't do what you expect:
What will happen that $var in foo will be bound with $bar in caller, but then it will be re-bound with $GLOBALS["baz"]. There's no way to bind $bar in the caller to something else using reference mechanism, since $bar is not available in the function foo (it is represented by $var, but $var has only variable contents and not name-to-value binding in the calling symbol table).
You can pass variable to function by reference, so that function could modify its arguments. The sytax is as follows:
Note that there's no reference sign on function call - only on function definition. Function definition alone is enough to correctly pass the argument by reference.Following things can be passed by reference:
Variable, i.e. foo($a)
New statement, i.e. foo(new foobar())
Reference, returned from a function, i.e.:
See also explanations about returning by reference.Any other expression should not be passed by reference, as the result is undefined. For example, the following examples of passing by reference are invalid:
These requirements are for PHP 4.0.4 and later.Returning by-reference it is useful when you want to use a function to find which variable a reference should be bound to. When returning references, use this syntax:
In this example, the property of the object returned by the find_var function would be set, not the copy, as it would be without using reference syntax.Note: Unlike parameter passing, here you have to use & in both places - to indicate that you return by-reference, not a copy as usual, and to indicate that reference binding, rather than usual assignment, should be done for $foo.
When you unset the reference, you just break the binding between variable name and variable content. This does not mean that variable content will be destroyed. For example:
won't unset $b, just $a.Again, it might be useful to think about this as analogous to Unix unlink call.
Many syntax constructs in PHP are implemented via referencing mechanisms, so everything told above about reference binding also apply to these constructs. Some constructs, like passing and returning by-reference, are mentioned above. Other constructs that use references are:
When you declare variable as global $var you are in fact creating reference to a global variable. That means, this is the same as:
That means, for example, that unsetting $var won't unset global variable.
There are several types of errors and warnings in PHP. They are:
Table 15-1. PHP error types
| Value | Constant | Description | Note |
|---|---|---|---|
| 1 | E_ERROR | fatal run-time errors | |
| 2 | E_WARNING | run-time warnings (non fatal errors) | |
| 4 | E_PARSE | compile-time parse errors | |
| 8 | E_NOTICE | run-time notices (less serious than warnings) | |
| 16 | E_CORE_ERROR | fatal errors that occur during PHP's initial startup | PHP 4 only |
| 32 | E_CORE_WARNING | warnings (non fatal errors) that occur during PHP's initial startup | PHP 4 only |
| 64 | E_COMPILE_ERROR | fatal compile-time errors | PHP 4 only |
| 128 | E_COMPILE_WARNING | compile-time warnings (non fatal errors) | PHP 4 only |
| 256 | E_USER_ERROR | user-generated error message | PHP 4 only |
| 512 | E_USER_WARNING | user-generated warning message | PHP 4 only |
| 1024 | E_USER_NOTICE | user-generated notice message | PHP 4 only |
| E_ALL | all of the above, as supported |
The above values (either numerical or symbolic) are used to build up a bitmask that specifies which errors to report. You can use the bitwise operators to combine these values or mask out certain types of errors. Note that only '|', '~', '!', and '&' will be understood within php.ini, however, and that no bitwise operators will be understood within php3.ini.
In PHP 4, the default error_reporting setting is E_ALL & ~E_NOTICE, meaning to display all errors and warnings which are not E_NOTICE-level. In PHP 3, the default setting is (E_ERROR | E_WARNING | E_PARSE), meaning the same thing. Note, however, that since constants are not supported in PHP 3's php3.ini, the error_reporting setting there must be numeric; hence, it is 7.
The initial setting can be changed in the ini file with the error_reporting directive, in your Apache httpd.conf file with the php_error_reporting (php3_error_reporting for PHP 3) directive, and lastly it may be set at runtime within a script by using the error_reporting() function.
| Warning |
When upgrading code or servers from PHP 3 to PHP 4 you should check these settings and calls to error_reporting() or you might disable reporting the new error types, especially E_COMPILE_ERROR. This may lead to empty documents without any feedback of what happened or where to look for the problem. |
All PHP expressions can also be called with the "@" prefix, which turns off error reporting for that particular expression. If an error occurred during such an expression and the track_errors feature is enabled, you can find the error message in the global variable $php_errormsg.
| Warning |
Currently the @ error-control operator prefix will even disable error reporting for critical errors that will terminate script execution. Among other things, this means that if you use @ to suppress errors from a certain function and either it isn't available or has been mistyped, the script will die right there with no indication as to why. |
Below we can see an example of using the error handling capabilities in PHP. We define a error handling function which logs the information into a file (using an XML format), and e-mails the developer in case a critical error in the logic happens.
Example 15-1. Using error handling in a script
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See also error_reporting(), error_log(), set_error_handler(), restore_error_handler(), trigger_error(), user_error()
PHP is not limited to creating just HTML output. It can also be used to create and manipulate image files in a variety of different image formats, including gif, png, jpg, wbmp, and xpm. Even more convenient, php can output image streams directly to a browser. You will need to compile PHP with the GD library of image functions for this to work. GD and PHP may also require other libraries, depending on which image formats you want to work with. GD stopped supporting Gif images in version 1.6.
Example 16-1. PNG creation with PHP
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The HTTP Authentication hooks in PHP are only available when it is running as an Apache module and is hence not available in the CGI version. In an Apache module PHP script, it is possible to use the Header() function to send an "Authentication Required" message to the client browser causing it to pop up a Username/Password input window. Once the user has filled in a username and a password, the URL containing the PHP script will be called again with the variables, $PHP_AUTH_USER, $PHP_AUTH_PW and $PHP_AUTH_TYPE set to the user name, password and authentication type respectively. Only "Basic" authentication is supported at this point. See the Header() function for more information.
An example script fragment which would force client authentication on a page would be the following:
Example 17-1. HTTP Authentication example
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Instead of simply printing out the $PHP_AUTH_USER and $PHP_AUTH_PW, you would probably want to check the username and password for validity. Perhaps by sending a query to a database, or by looking up the user in a dbm file.
Watch out for buggy Internet Explorer browsers out there. They seem very picky about the order of the headers. Sending the WWW-Authenticate header before the HTTP/1.0 401 header seems to do the trick for now.
In order to prevent someone from writing a script which reveals the password for a page that was authenticated through a traditional external mechanism, the PHP_AUTH variables will not be set if external authentication is enabled for that particular page. In this case, the $REMOTE_USER variable can be used to identify the externally-authenticated user.
Note, however, that the above does not prevent someone who controls a non-authenticated URL from stealing passwords from authenticated URLs on the same server.
Both Netscape and Internet Explorer will clear the local browser window's authentication cache for the realm upon receiving a server response of 401. This can effectively "log out" a user, forcing them to re-enter their username and password. Some people use this to "time out" logins, or provide a "log-out" button.
Example 17-2. HTTP Authentication example forcing a new name/password
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This behavior is not required by the HTTP Basic authentication standard, so you should never depend on this. Testing with Lynx has shown that Lynx does not clear the authentication credentials with a 401 server response, so pressing back and then forward again will open the resource (as long as the credential requirements haven't changed).
Also note that this does not work using Microsoft's IIS server and the CGI version of PHP due to a limitation of IIS.
PHP transparently supports HTTP cookies. Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set cookies using the setcookie() function. Cookies are part of the HTTP header, so setcookie() must be called before any output is sent to the browser. This is the same limitation that header() has.
Any cookies sent to you from the client will automatically be turned into a PHP variable just like GET and POST method data. If you wish to assign multiple values to a single cookie, just add [] to the cookie name. For more details see the setcookie() function.
PHP is capable of receiving file uploads from any RFC-1867 compliant browser (which includes Netscape Navigator 3 or later, Microsoft Internet Explorer 3 with a patch from Microsoft, or later without a patch). This feature lets people upload both text and binary files. With PHP's authentication and file manipulation functions, you have full control over who is allowed to upload and what is to be done with the file once it has been uploaded.
Note that PHP also supports PUT-method file uploads as used by Netscape Composer and W3C's Amaya clients. See the PUT Method Support for more details.
A file upload screen can be built by creating a special form which looks something like this:
In PHP 3, the following variables will be defined within the destination script upon a successful upload, assuming that register_globals is turned on in php3.ini. If track_vars is turned on, they will also be available in PHP 3 within the global array $HTTP_POST_VARS. Note that the following variable names assume the use of the file upload name 'userfile', as used in the example above:
$userfile - The temporary filename in which the uploaded file was stored on the server machine.
$userfile_name - The original name or path of the file on the sender's system.
$userfile_size - The size of the uploaded file in bytes.
$userfile_type - The mime type of the file if the browser provided this information. An example would be "image/gif".
In PHP 4, the behaviour is slightly different, in that the new global array $HTTP_POST_FILES is provided to contain the uploaded file information. This is still only available if track_vars is turned on, but track_vars is always turned on in versions of PHP after PHP 4.0.2.
The contents of $HTTP_POST_FILES are as follows. Note that this assumes the use of the file upload name 'userfile', as used in the example above:
The original name of the file on the client machine.
The mime type of the file, if the browser provided this information. An example would be "image/gif".
The size, in bytes, of the uploaded file.
The temporary filename of the file in which the uploaded file was stored on the server.
Files will by default be stored in the server's default temporary directory, unless another location has been given with the upload_tmp_dir directive in php.ini. The server's default directory can be changed by setting the environment variable TMPDIR in the environment in which PHP runs. Setting it using putenv() from within a PHP script will not work. This environment variable can also be used to make sure that other operations are working on uploaded files, as well.
Example 19-2. Validating file uploads The following examples are for versions of PHP 3 greater than 3.0.16, and versions of PHP 4 greater than 4.0.2. See the function entries for is_uploaded_file() and move_uploaded_file().
For earlier versions of PHP, you'll need to do something like the following.
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The PHP script which receives the uploaded file should implement whatever logic is necessary for determining what should be done with the uploaded file. You can for example use the $file_size variable to throw away any files that are either too small or too big. You could use the $file_type variable to throw away any files that didn't match a certain type criteria. Whatever the logic, you should either delete the file from the temporary directory or move it elsewhere.
The file will be deleted from the temporary directory at the end of the request if it has not been moved away or renamed.
The MAX_FILE_SIZE item cannot specify a file size greater than the file size that has been set in the upload_max_filesize in the PHP 3.ini file or the corresponding php3_upload_max_filesize Apache .conf directive. The default is 2 Megabytes.
Not validating which file you operate on may mean that users can access sensitive information in other directories.
Please note that the CERN httpd seems to strip off everything starting at the first whitespace in the content-type mime header it gets from the client. As long as this is the case, CERN httpd will not support the file upload feature.
It is possible to upload multiple files simultaneously and have the information organized automatically in arrays for you. To do so, you need to use the same array submission syntax in the HTML form as you do with multiple selects and checkboxes:
Note: Support for multiple file uploads was added in version 3.0.10.
When the above form is submitted, the arrays $userfile, $userfile_name, and $userfile_size will be formed in the global scope (as well as in $HTTP_POST_FILES ($HTTP_POST_VARS in PHP 3)). Each of these will be a numerically indexed array of the appropriate values for the submitted files.
For instance, assume that the filenames /home/test/review.html and /home/test/xwp.out are submitted. In this case, $userfile_name[0] would contain the value review.html, and $userfile_name[1] would contain the value xwp.out. Similarly, $userfile_size[0] would contain review.html's filesize, and so forth.
$userfile['name'][0], $userfile['tmp_name'][0], $userfile['size'][0], and $userfile['type'][0] are also set.
PHP provides support for the HTTP PUT method used by clients such as Netscape Composer and W3C Amaya. PUT requests are much simpler than a file upload and they look something like this:
This would normally mean that the remote client would like to save the content that follows as: /path/filename.html in your web tree. It is obviously not a good idea for Apache or PHP to automatically let everybody overwrite any files in your web tree. So, to handle such a request you have to first tell your web server that you want a certain PHP script to handle the request. In Apache you do this with the Script directive. It can be placed almost anywhere in your Apache configuration file. A common place is inside a <Directory> block or perhaps inside a <Virtualhost> block. A line like this would do the trick:
This tells Apache to send all PUT requests for URIs that match the context in which you put this line to the put.php3 script. This assumes, of course, that you have PHP enabled for the .php3 extension and PHP is active.
Inside your put.php3 file you would then do something like this:
This would copy the file to the location requested by the remote client. You would probably want to perform some checks and/or authenticate the user before performing this file copy. The only trick here is that when PHP sees a PUT-method request it stores the uploaded file in a temporary file just like those handled but the POST-method. When the request ends, this temporary file is deleted. So, your PUT handling PHP script has to copy that file somewhere. The filename of this temporary file is in the $PHP_PUT_FILENAME variable, and you can see the suggested destination filename in the $REQUEST_URI (may vary on non-Apache web servers). This destination filename is the one that the remote client specified. You do not have to listen to this client. You could, for example, copy all uploaded files to a special uploads directory.
As long as support for the "URL fopen wrapper" is enabled when you configure PHP (which it is unless you explicitly pass the --disable-url-fopen-wrapper flag to configure (for versions up to 4.0.3) or set allow_url_fopen to off in php.ini (for newer versions), you can use HTTP and FTP URLs with most functions that take a filename as a parameter, including the require() and include() statements.
For example, you can use this to open a file on a remote web server, parse the output for the data you want, and then use that data in a database query, or simply to output it in a style matching the rest of your website.
Example 20-1. Getting the title of a remote page
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You can also write to files on an FTP as long you connect as a user with the correct access rights, and the file doesn't exist already. To connect as a user other than 'anonymous', you need to specify the username (and possibly password) within the URL, such as 'ftp://user:password@ftp.example.com/path/to/file'. (You can use the same sort of syntax to access files via HTTP when they require Basic authentication.)
Note: You might get the idea from the example above to use this technique to write to a remote log, but as mentioned above, you can only write to a new file using the URL fopen() wrappers. To do distributed logging like that, you should take a look at syslog().
Note: The following applies to 3.0.7 and later.
Internally in PHP a connection status is maintained. There are 3 possible states:
0 - NORMAL
1 - ABORTED
2 - TIMEOUT
When a PHP script is running normally the NORMAL state, is active. If the remote client disconnects the ABORTED state flag is turned on. A remote client disconnect is usually caused by the user hitting his STOP button. If the PHP-imposed time limit (see set_time_limit()) is hit, the TIMEOUT state flag is turned on.
You can decide whether or not you want a client disconnect to cause your script to be aborted. Sometimes it is handy to always have your scripts run to completion even if there is no remote browser receiving the output. The default behaviour is however for your script to be aborted when the remote client disconnects. This behaviour can be set via the ignore_user_abort php3.ini directive as well as through the corresponding php3_ignore_user_abort Apache .conf directive or with the ignore_user_abort() function. If you do not tell PHP to ignore a user abort and the user aborts, your script will terminate. The one exception is if you have registered a shutdown function using register_shutdown_function(). With a shutdown function, when the remote user hits his STOP button, the next time your script tries to output something PHP will detect that the connection has been aborted and the shutdown function is called. This shutdown function will also get called at the end of your script terminating normally, so to do something different in case of a client diconnect you can use the connection_aborted() function. This function will return true if the connection was aborted.
Your script can also be terminated by the built-in script timer. The default timeout is 30 seconds. It can be changed using the max_execution_time php3.ini directive or the corresponding php3_max_execution_time Apache .conf directive as well as with the set_time_limit() function. When the timer expires the script will be aborted and as with the above client disconnect case, if a shutdown function has been registered it will be called. Within this shutdown function you can check to see if a timeout caused the shutdown function to be called by calling the connection_timeout() function. This function will return true if a timeout caused the shutdown function to be called.
One thing to note is that both the ABORTED and the TIMEOUT states can be active at the same time. This is possible if you tell PHP to ignore user aborts. PHP will still note the fact that a user may have broken the connection, but the script will keep running. If it then hits the time limit it will be aborted and your shutdown function, if any, will be called. At this point you will find that connection_timeout() and connection_aborted() return true. You can also check both states in a single call by using the connection_status(). This function returns a bitfield of the active states. So, if both states are active it would return 3, for example.
Persistent connections are SQL links that do not close when the execution of your script ends. When a persistent connection is requested, PHP checks if there's already an identical persistent connection (that remained open from earlier) - and if it exists, it uses it. If it does not exist, it creates the link. An 'identical' connection is a connection that was opened to the same host, with the same username and the same password (where applicable).
People who aren't thoroughly familiar with the way web servers work and distribute the load may mistake persistent connects for what they're not. In particular, they do not give you an ability to open 'user sessions' on the same SQL link, they do not give you an ability to build up a transaction efficently, and they don't do a whole lot of other things. In fact, to be extremely clear about the subject, persistent connections don't give you any functionality that wasn't possible with their non-persistent brothers.
Why?
This has to do with the way web servers work. There are three ways in which your web server can utilize PHP to generate web pages.
The first method is to use PHP as a CGI "wrapper". When run this way, an instance of the PHP interpreter is created and destroyed for every page request (for a PHP page) to your web server. Because it is destroyed after every request, any resources that it acquires (such as a link to an SQL database server) are closed when it is destroyed. In this case, you do not gain anything from trying to use persistent connections -- they simply don't persist.
The second, and most popular, method is to run PHP as a module in a multiprocess web server, which currently only includes Apache. A multiprocess server typically has one process (the parent) which coordinates a set of processes (its children) who actually do the work of serving up web pages. When each request comes in from a a client, it is handed off to one of the children that is not already serving another client. This means that when the same client makes a second request to the server, it may be serviced by a different child process than the first time. What a persistent connection does for you in this case it make it so each child process only needs to connect to your SQL server the first time that it serves a page that makes us of such a connection. When another page then requires a connection to the SQL server, it can reuse the connection that child established earlier.
The last method is to use PHP as a plug-in for a multithreaded web server. Currently this is only theoretical -- PHP does not yet work as a plug-in for any multithreaded web servers. Work is progressing on support for ISAPI, WSAPI, and NSAPI (on Windows), which will all allow PHP to be used as a plug-in on multithreaded servers like Netscape FastTrack, Microsoft's Internet Information Server (IIS), and O'Reilly's WebSite Pro. When this happens, the behavior will be essentially the same as for the multiprocess model described before.
If persistent connections don't have any added functionality, what are they good for?
The answer here is extremely simple -- efficiency. Persistent connections are good if the overhead to create a link to your SQL server is high. Whether or not this overhead is really high depends on many factors. Like, what kind of database it is, whether or not it sits on the same computer on which your web server sits, how loaded the machine the SQL server sits on is and so forth. The bottom line is that if that connection overhead is high, persistent connections help you considerably. They cause the child process to simply connect only once for its entire lifespan, instead of every time it processes a page that requires connecting to the SQL server. This means that for every child that opened a persistent connection will have its own open persistent connection to the server. For example, if you had 20 different child processes that ran a script that made a persistent connection to your SQL server, you'd have 20 different connections to the SQL server, one from each child.
Note, however, that this can have some drawbacks if you are using a database with connection limits that are exceeded by persistant child connections. If your database has a limit of 16 simultaneous connections, and in the course of a busy server session, 17 child threads attempt to connect, one will not be able to. If there are bugs in your scripts which do not allow the connections to shut down (such as infinite loops), a database with only 32 connections may be rapidly swamped. Check your database documentation for information on handling abandoned or idle connections.
An important summary. Persistent connections were designed to have one-to-one mapping to regular connections. That means that you should always be able to replace persistent connections with non-persistent connections, and it won't change the way your script behaves. It may (and probably will) change the efficiency of the script, but not its behavior!
(PHP 3>= 3.0.4, PHP 4 )
apache_lookup_uri -- Perform a partial request for the specified URI and return all info about itThis performs a partial request for a URI. It goes just far enough to obtain all the important information about the given resource and returns this information in a class. The properties of the returned class are:
| status |
| the_request |
| status_line |
| method |
| content_type |
| handler |
| uri |
| filename |
| path_info |
| args |
| boundary |
| no_cache |
| no_local_copy |
| allowed |
| send_bodyct |
| bytes_sent |
| byterange |
| clength |
| unparsed_uri |
| mtime |
| request_time |
Note: Apache_lookup_uri() only works when PHP is installed as an Apache module.
Apache_note() is an Apache-specific function which gets and sets values in a request's notes table. If called with one argument, it returns the current value of note note_name. If called with two arguments, it sets the value of note note_name to note_value and returns the previous value of note note_name.
This function returns an associative array of all the HTTP headers in the current request.
Note: You can also get at the value of the common CGI variables by reading them from the environment, which works whether or not you are using PHP as an Apache module. Use phpinfo() to see a list of all of the environment variables defined this way.
This example will display all the request headers for the current request.
Note: Getallheaders() is currently only supported when PHP runs as an Apache module.
Virtual() is an Apache-specific function which is equivalent to <!--#include virtual...--> in mod_include. It performs an Apache sub-request. It is useful for including CGI scripts or .shtml files, or anything else that you would parse through Apache. Note that for a CGI script, the script must generate valid CGI headers. At the minimum that means it must generate a Content-type header. For PHP files, you need to use include() or require(); virtual() cannot be used to include a document which is itself a PHP file.
ascii2ebcdic() is an Apache-specific function which is available only on EBCDIC based operating systems (OS/390, BS2000). It translates the ASCII encoded string ascii_str to its equivalent EBCDIC representation (binary safe), and returns the result.
See also the reverse function ebcdic2ascii()
ebcdic2ascii() is an Apache-specific function which is available only on EBCDIC based operating systems (OS/390, BS2000). It translates the EBCDIC encoded string ebcdic_str to its equivalent ASCII representation (binary safe), and returns the result.
See also the reverse function ascii2ebcdic()
These functions allow you to interact with and manipulate arrays in various ways. Arrays are essential for storing, managing, and operating on sets of variables.
Simple and multi-dimensional arrays are supported, and may be either user created or created by another function. There are specific database handling functions for populating arrays from database queries, and several functions return arrays.
See also is_array(), explode(), implode(), split() and join().
Returns an array of the parameters. The parameters can be given an index with the => operator.
Note: Array() is a language construct used to represent literal arrays, and not a regular function.
Syntax "index => values", separated by commas, define index and values. index may be of type string or numeric. When index is omitted, a integer index is automatically generated, starting at 0. If index is an integer, next generated index will be the biggest integer index + 1. Note that when two identical index are defined, the last overwrite the first.
The following example demonstrates how to create a two-dimensional array, how to specify keys for associative arrays, and how to skip-and-continue numeric indices in normal arrays.
This example creates a 1-based array.
See also: list().
Array_count_values() returns an array using the values of the input array as keys and their frequency in input as values.
Array_diff() returns an array containing all the values of array1 that are not present in any of the other arguments. Note that keys are preserved.
This makes $result have array ("blue");
See also array_intersect().
Array_intersect() returns an array containing all the values of array1 that are present in all the arguments. Note that keys are preserved.
This makes $result have array ("a" => "green", "red");
See also array_diff().
Array_keys() returns the keys, numeric and string, from the input array.
If the optional search_value is specified, then only the keys for that value are returned. Otherwise, all the keys from the input are returned.
Note: This function was added to PHP 4, below is an implementation for those still using PHP 3.
See also array_values().
Array_merge() merges the elements of two or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.
If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays have the same numeric key, the later value will not overwrite the original value, but will be appended.
Resulting array will be array("color" => "green", 2, 4, "a", "b", "shape" => "trapezoid", 4).
See also array_merge_recursive().
Array_merge_recursive() merges the elements of two or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.
If the input arrays have the same string keys, then the values for these keys are merged together into an array, and this is done recursively, so that if one of the values is an array itself, the function will merge it with a corresponding entry in another array too. If, however, the arrays have the same numeric key, the later value will not overwrite the original value, but will be appended.
Resulting array will be array ("color" => array ("favorite" => array ("red", "green"), "blue"), 5, 10).
See also array_merge().
Array_multisort() can be used to sort several arrays at once or a multi-dimensional array according by one of more dimensions. It maintains key association when sorting.
The input arrays are treated as columns of a table to be sorted by rows - this resembles the functionality of SQL ORDER BY clause. The first array is the primary one to sort by. The rows (values) in that array that compare the same are sorted by the next input array, and so on.
The argument structure of this function is a bit unusual, but flexible. The very first argument has to be an array. Subsequently, each argument can be either an array or a sorting flag from the following lists.
Sorting order flags:
SORT_ASC - sort in ascending order
SORT_DESC - sort in descending order
Sorting type flags:
SORT_REGULAR - compare items normally
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings
No two sorting flags of the same type can be specified after each array. The sortings flags specified after an array argument apply only to that array - they are reset to default SORT_ASC and SORT_REGULAR after before each new array argument.
Returns true on success, false on failure.
In this example, after sorting, the first array will contain 10, "a", 100, 100. The second array will contain 1, 1, 2, "3". The entries in the second array corresponding to the identical entries in the first array (100 and 100) were sorted as well.
In this example, after sorting, the first array will contain 10, 100, 100, "a" (it was sorted as strings in ascending order), and the second one will contain 1, 3, "2", 1 (sorted as numbers, in descending order).
Array_pad() returns a copy of the input padded to size specified by pad_size with value pad_value. If pad_size is positive then the array is padded on the right, if it's negative then on the left. If the absolute value of pad_size is less than or equal to the length of the input then no padding takes place.
Array_pop() pops and returns the last value of the array, shortening the array by one element.
After this, $stack has only 2 elements: "orange" and "apple", and $fruit has "raspberry".
See also array_push(), array_shift(), and array_unshift().
Array_push() treats array as a stack, and pushes the passed variables onto the end of array. The length of array increases by the number of variables pushed. Has the same effect as:
$array[] = $var;
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Returns the new number of elements in the array.
This example would result in $stack having 4 elements: 1, 2, "+", and 3.
See also: array_pop(), array_shift(), and array_unshift().
Array_rand() is rather useful when you want to pick one or more random entries out of an array. It takes an input array and an optional argument num_req which specifies how many entries you want to pick - if not specified, it defaults to 1.
If you are picking only one entry, array_rand() returns the key for a random entry. Otherwise, it returns an array of keys for the random entries. This is done so that you can pick random keys as well as values out of the array.
Don't forget to call srand() to seed the random number generator.
Array_reverse() takes input array and returns a new array with the order of the elements reversed.
This makes $result have array (array ("green", "red"), 4.0, "php").
Array_shift() shifts the first value of the array off and returns it, shortening the array by one element and moving everything down.
This would result in $args having one element "-f" left, and $opt being "-v".
See also array_unshift(), array_push(), and array_pop().
Array_slice() returns a sequence of elements from the array specified by the offset and length parameters.
If offset is positive, the sequence will start at that offset in the array. If offset is negative, the sequence will start that far from the end of the array.
If length is given and is positive, then the sequence will have that many elements in it. If length is given and is negative then the sequence will stop that many elements from the end of the array. If it is omitted, then the sequence will have everything from offset up until the end of the array.
Example 1. Array_slice() examples
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See also array_splice().
Array_splice() removes the elements designated by offset and length from the input array, and replaces them with the elements of the replacement array, if supplied.
If offset is positive then the start of removed portion is at that offset from the beginning of the input array. If offset is negative then it starts that far from the end of the input array.
If length is omitted, removes everything from offset to the end of the array. If length is specified and is positive, then that many elements will be removed. If length is specified and is negative then the end of the removed portion will be that many elements from the end of the array. Tip: to remove everything from offset to the end of the array when replacement is also specified, use count($input) for length.
If replacement array is specified, then the removed elements are replaced with elements from this array. If offset and length are such that nothing is removed, then the elements from the replacement array are inserted in the place specified by the offset. Tip: if the replacement is just one element it is not necessary to put array() around it, unless the element is an array itself.
The following equivalences hold:
array_push ($input, $x, $y) array_splice ($input, count ($input), 0,
array ($x, $y))
array_pop ($input) array_splice ($input, -1)
array_shift ($input) array_splice ($input, 0, 1)
array_unshift ($input, $x, $y) array_splice ($input, 0, 0, array ($x, $y))
$a[$x] = $y array_splice ($input, $x, 1, $y)
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Returns the array consisting of removed elements.
Example 1. Array_splice() examples
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See also array_slice().
Array_unique() takes input array and returns a new array without duplicate values. Note that keys are preserved.
This makes $result have array ("a" => "green", "red", "blue");.
Array_unshift() prepends passed elements to the front of the array. Note that the list of elements is prepended as a whole, so that the prepended elements stay in the same order.
Returns the new number of elements in the array.
This would result in $queue having 5 elements: "p4", "p5", "p6", "p1", and "p3".
See also array_shift(), array_push(), and array_pop().
Applies the function named by func to each element of arr. func will be passed array value as the first parameter and array key as the second parameter. If userdata is supplied, it will be passed as the third parameter to the user function.
If func requires more than two or three arguments, depending on userdata, a warning will be generated each time array_walk() calls func. These warnings may be suppressed by prepending the '@' sign to the array_walk() call, or by using error_reporting().
Note: If func needs to be working with the actual values of the array, specify that the first parameter of func should be passed by reference. Then any changes made to those elements will be made in the array itself.
Note: Passing the key and userdata to func was added in 4.0.
In PHP 4 reset() needs to be called as necessary since array_walk() does not reset the array by default.
Example 1. Array_walk() example
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This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant.
This example would display:
The fruits have been sorted in reverse alphabetical order, and the index associated with each element has been maintained.
You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().
This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant.
This example would display:
The fruits have been sorted in alphabetical order, and the index associated with each element has been maintained.
You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().
Compact() takes a variable number of parameters. Each parameter can be either a string containing the name of the variable, or an array of variable names. The array can contain other arrays of variable names inside it; compact() handles it recursively.
For each of these, compact() looks for a variable with that name in the current symbol table and adds it to the output array such that the variable name becomes the key and the contents of the variable become the value for that key. In short, it does the opposite of extract(). It returns the output array with all the variables added to it.
Any strings that are not set will simply be skipped.
See also extract().
Returns the number of elements in var, which is typically an array (since anything else will have one element).
Returns 1 if the variable is not an array.
Returns 0 if the variable is not set.
| Warning |
Count() may return 0 for a variable that isn't set, but it may also return 0 for a variable that has been initialized with an empty array. Use isset() to test if a variable is set. |
See also: sizeof(), isset(), and is_array().
Every array has an internal pointer to its "current" element, which is initialized to the first element inserted into the array.
The current() function simply returns the array element that's currently being pointed by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list, current() returns false.
| Warning |
If the array contains empty elements (0 or "", the empty string) then this function will return false for these elements as well. This makes it impossible to determine if you are really at the end of the list in such an array using current(). To properly traverse an array that may contain empty elements, use the each() function. |
Returns the current key and value pair from the array array and advances the array cursor. This pair is returned in a four-element array, with the keys 0, 1, key, and value. Elements 0 and key contain the key name of the array element, and 1 and value contain the data.
If the internal pointer for the array points past the end of the array contents, each() returns false.
Example 1. Each() examples
$bar now contains the following key/value pairs:
$bar now contains the following key/value pairs:
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Each() is typically used in conjunction with list() to traverse an array; for instance, $HTTP_POST_VARS:
After each() has executed, the array cursor will be left on the next element of the array, or on the last element if it hits the end of the array.
See also key(), list(), current(), reset(), next(), and prev().
This function is used to import variables from an array into the current symbol table. It takes associative array var_array and treats keys as variable names and values as variable values. For each key/value pair it will create a variable in the current symbol table, subject to extract_type and prefix parameters.
Extract() checks for colissions with existing variables. The way collisions are treated is determined by extract_type. It can be one of the following values:
If there is a collision, overwrite the existing variable.
If there is a collision, don't overwrite the existing variable.
If there is a collision, prefix the new variable with prefix.
Prefix all variables with prefix.
If extract_type is not specified, it is assumed to be EXTR_OVERWRITE.
Note that prefix is only required if extract_type is EXTR_PREFIX_SAME or EXTR_PREFIX_ALL.
Extract() checks each key to see if it constitues a valid variable name, and if it does only then does it proceed to import it.
A possible use for extract is to import into symbol table variables contained in an associative array returned by wddx_deserialize().
Example 1. Extract() example
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The above example will produce:
blue, large, sphere, medium
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The $size wasn't overwritten, becaus we specified EXTR_PREFIX_SAME, which resulted in $wddx_size being created. If EXTR_SKIP was specified, then $wddx_size wouldn't even have been created. EXTR_OVERWRITE would have cause $size to have value "medium", and EXTR_PREFIX_ALL would result in new variables being named $wddx_color, $wddx_size, and $wddx_shape.
You must use an associative array, a numerically indexed array will not produce results.
See also: compact().
Searches haystack for needle and returns true if it is found in the array, false otherwise.
Sorts an array by key in reverse order, maintaining key to data correlations. This is useful mainly for associative arrays.
This example would display:
You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().
See also asort(), arsort(), ksort() sort(), natsort()and rsort().
Sorts an array by key, maintaining key to data correlations. This is useful mainly for associative arrays.
This example would display:
You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().
See also asort(), arsort(), sort(), natsort(), and rsort().
Note: The second parameter was added in PHP 4.
Like array(), this is not really a function, but a language construct. list() is used to assign a list of variables in one operation.
Example 1. List() example
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This function implements a sort algorithm that orders alphanumeric strings in the way a human being would. This is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in sort()) can be seen below:
The code above will generate the following output:
Standard sorting
Array
(
[0] => img1.png
[1] => img10.png
[2] => img12.png
[3] => img2.png
)
Natural order sorting
Array
(
[3] => img1.png
[2] => img2.png
[1] => img10.png
[0] => img12.png
)
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See also natcasesort(), strnatcmp() and strnatcasecmp().
This function implements a sort algorithm that orders alphanumeric strings in the way a human being would. This is described as a "natural ordering".
natcasesort() is a case insensitive version of natsort(). See natsort() for an example of the difference between this algorithm and the regular computer string sorting algorithms.
For more infomation see: Martin Pool's Natural Order String Comparison page.
See also sort(), natsort(), strnatcmp() and strnatcasecmp().
Returns the array element in the next place that's pointed by the internal array pointer, or false if there are no more elements.
Next() behaves like current(), with one difference. It advances the internal array pointer one place forward before returning the element. That means it returns the next array element and advances the internal array pointer by one. If advancing the internal array pointer results in going beyond the end of the element list, next() returns false.
| Warning |
If the array contains empty elements, or elements that have a key value of 0 then this function will return false for these elements as well. To properly traverse an array which may contain empty elements or elements with key values of 0 see the each() function. |
Returns the array element in the previous place that's pointed by the internal array pointer, or false if there are no more elements.
| Warning |
If the array contains empty elements then this function will return false for these elements as well. To properly traverse an array which may contain empty elements see the each() function. |
Prev() behaves just like next(), except it rewinds the internal array pointer one place instead of advancing it.
Range() returns an array of integers from low to high, inclusive.
See shuffle() for an example of its use.
Reset() rewinds array's internal pointer to the first element.
Reset() returns the value of the first array element.
This function sorts an array in reverse order (highest to lowest).
This example would display:
The fruits have been sorted in reverse alphabetical order.
You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().
This function shuffles (randomizes the order of the elements in) an array. You must use srand() to seed this function.
See also arsort(), asort(), ksort(), rsort(), sort() and usort().
This function sorts an array. Elements will be arranged from lowest to highest when this function has completed.
This example would display:
The fruits have been sorted in alphabetical order.
The optional second parameter sort_flags may be used to modify the sorting behavior using theese valies:
Sorting type flags:
SORT_REGULAR - compare items normally
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings
See also: arsort(), asort(), ksort(), natsort(), natcasesort(), rsort(), usort(), array_multisort(), and uksort().
Note: The second parameter was added in PHP 4.
(PHP 3>= 3.0.4, PHP 4 )
uasort -- Sort an array with a user-defined comparison function and maintain index associationThis function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant. The comparison function is user-defined.
See also: usort(), uksort(), sort(), asort(), arsort(), ksort() and rsort().
This function will sort the keys of an array using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.
This example would display:
See also: usort(), uasort(), sort(), asort(), arsort(), ksort(), natsort() and rsort().
This function will sort an array by its values using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.
The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second. If two members compare as equal, their order in the sorted array is undefined.
This example would display:
Note: Obviously in this trivial case the rsort() function would be more appropriate.
Example 2. Usort() example using multi-dimensional array
|
When sorting a multi-dimensional array, $a and $b contain references to the first index of the array.
This example would display:
| Warning |
The underlying quicksort function in some C libraries (such as on Solaris systems) may cause PHP to crash if the comparison function does not return consistent values. |
See also: uasort(), uksort(), sort(), asort(), arsort(),ksort(), natsort(), and rsort().
The aspell() functions allows you to check the spelling on a word and offer suggestions.
Note: aspell works only with very old (up to .27.* or so) versions of aspell library. Neither this module, nor those versions of aspell library are supported any longer. If you want to use spell-checking capabilities in php, use pspell instead. It uses pspell library and works with newer versions of aspell.
You need the aspell library, available from: http://aspell.sourceforge.net/.
Aspell_new() opens up a new dictionary and returns the dictionary link identifier for use in other aspell functions.
Aspell_check() checks the spelling of a word and returns true if the spelling is correct, false if not.
(PHP 3>= 3.0.7, PHP 4 )
aspell_check_raw -- Check a word without changing its case or trying to trim itAspell_check_raw() checks the spelling of a word, without changing its case or trying to trim it in any way and returns true if the spelling is correct, false if not.
These functions are only available if PHP was configured with --enable-bcmath.
Note: Due to changes in the licensing, the BCMATH library is distributed separate from the standard PHP source distribution. You can download the tar-gzipped archive at the url: http://www.php.net/extra/number4.tar.gz. Read the file README.BCMATH in the PHP distribution for more information.
Adds the left operand to the right operand and returns the sum in a string. The optional scale parameter is used to set the number of digits after the decimal place in the result.
See also bcsub().
Compares the left operand to the right operand and returns the result as an integer. The optional scale parameter is used to set the number of digits after the decimal place which will be used in the comparion. The return value is 0 if the two operands are equal. If the left operand is larger than the right operand the return value is +1 and if the left operand is less than the right operand the return value is -1.
Divides the left operand by the right operand and returns the result. The optional scale sets the number of digits after the decimal place in the result.
See also bcmul().
Multiply the left operand by the right operand and returns the result. The optional scale sets the number of digits after the decimal place in the result.
See also bcdiv().
Raise x to the power y. The optional scale can be used to set the number of digits after the decimal place in the result.
See also bcsqrt().
This function sets the default scale parameter for all subsequent bc math functions that do not explicitly specify a scale parameter.
Return the square root of the operand. The optional scale parameter sets the number of digits after the decimal place in the result.
See also bcpow().
Subtracts the right operand from the left operand and returns the result in a string. The optional scale parameter is used to set the number of digits after the decimal place in the result.
See also bcadd().
The calendar functions are only available if you have compiled the calendar extension, found in either the "dl" or "ext" subdirectories of your PHP source code. Please see the README file before using it.
The calendar extension presents a series of functions to simplify converting between different calendar formats. The intermediary or standard it is based on is the Julian Day Count. The Julian Day Count is a count of days starting way earlier than any date most people would need to track (somewhere around 4000bc). To convert between calendar systems, you must first convert to Julian Day Count, then to the calendar system of your choice. Julian Day Count is very different from the Julian Calendar! For more information on calendar systems visit http://genealogy.org/~scottlee/cal-overview.html. Excerpts from this page are included in these instructions, and are in quotes.
Converts Julian Day Count to a string containing the Gregorian date in the format of "month/day/year".
Valid Range for Gregorian Calendar 4714 B.C. to 9999 A.D.
Although this software can handle dates all the way back to 4714 B.C., such use may not be meaningful. The Gregorian calendar was not instituted until October 15, 1582 (or October 5, 1582 in the Julian calendar). Some countries did not accept it until much later. For example, Britain converted in 1752, The USSR in 1918 and Greece in 1923. Most European countries used the Julian calendar prior to the Gregorian.
Converts Julian Day Count to a string containing the Julian Calendar Date in the format of "month/day/year".
Valid Range for Julian Calendar 4713 B.C. to 9999 A.D.
Although this software can handle dates all the way back to 4713 B.C., such use may not be meaningful. The calendar was created in 46 B.C., but the details did not stabilize until at least 8 A.D., and perhaps as late at the 4th century. Also, the beginning of a year varied from one culture to another - not all accepted January as the first month.
Valid Range Although this software can handle dates all the way back to the year 1 (3761 B.C.), such use may not be meaningful.
The Jewish calendar has been in use for several thousand years, but in the early days there was no formula to determine the start of a month. A new month was started when the new moon was first observed.
(PHP 3, PHP 4 )
FrenchToJD -- Converts a date from the French Republican Calendar to a Julian Day CountConverts a date from the French Republican Calendar to a Julian Day Count.
These routines only convert dates in years 1 through 14 (Gregorian dates 22 September 1792 through 22 September 1806). This more than covers the period when the calendar was in use.
Returns a string containing a month name. mode tells this function which calendar to convert the Julian Day Count to, and what type of month names are to be returned.
(PHP 3>= 3.0.9, PHP 4 >= 4.0RC2)
easter_date -- Get UNIX timestamp for midnight on Easter of a given yearReturns the UNIX timestamp corresponding to midnight on Easter of the given year. If no year is specified, the current year is assumed.
Warning: This function will generate a warning if the year is outside of the range for UNIX timestamps (i.e. before 1970 or after 2037).
The date of Easter Day was defined by the Council of Nicaea in AD325 as the Sunday after the first full moon which falls on or after the Spring Equinox. The Equinox is assumed to always fall on 21st March, so the calculation reduces to determining the date of the full moon and the date of the following Sunday. The algorithm used here was introduced around the year 532 by Dionysius Exiguus. Under the Julian Calendar (for years before 1753) a simple 19-year cycle is used to track the phases of the Moon. Under the Gregorian Calendar (for years after 1753 - devised by Clavius and Lilius, and introduced by Pope Gregory XIII in October 1582, and into Britain and its then colonies in September 1752) two correction factors are added to make the cycle more accurate.
(The code is based on a C program by Simon Kershaw, <webmaster@ely.anglican.org>)
See easter_days() for calculating Easter before 1970 or after 2037.
(PHP 3>= 3.0.9, PHP 4 >= 4.0RC2)
easter_days -- Get number of days after March 21 on which Easter falls for a given yearReturns the number of days after March 21 on which Easter falls for a given year. If no year is specified, the current year is assumed.
This function can be used instead of easter_date() to calculate Easter for years which fall outside the range of UNIX timestamps (i.e. before 1970 or after 2037).
The date of Easter Day was defined by the Council of Nicaea in AD325 as the Sunday after the first full moon which falls on or after the Spring Equinox. The Equinox is assumed to always fall on 21st March, so the calculation reduces to determining the date of the full moon and the date of the following Sunday. The algorithm used here was introduced around the year 532 by Dionysius Exiguus. Under the Julian Calendar (for years before 1753) a simple 19-year cycle is used to track the phases of the Moon. Under the Gregorian Calendar (for years after 1753 - devised by Clavius and Lilius, and introduced by Pope Gregory XIII in October 1582, and into Britain and its then colonies in September 1752) two correction factors are added to make the cycle more accurate.
(The code is based on a C program by Simon Kershaw, <webmaster@ely.anglican.org>)
See also easter_date().
Return the Julian Day for a UNIX timestamp (seconds since 1.1.1970), or for the current day if no timestamp is given.
See also jdtounix().
Note: This function is only available in PHP versions after PHP4RC1.
This function will return a UNIX timestamp corresponding to the Julian Day given in jday or false if jday is not inside the UNIX epoch (Gregorian years between 1970 and 2037 or 2440588 <= jday <= 2465342 )
See also jdtounix().
Note: This function is only available in PHP versions after PHP4RC1.
These functions interface the CCVS API, allowing you to directly work with CCVS from your PHP scripts. CCVS is RedHat's solution to the "middle-man" in credit card processing. It lets you directly address the credit card clearing houses via your *nix box and a modem. Using the CCVS module for PHP, you can process credit cards directly through CCVS via your PHP Scripts. The following references will outline the process.
To enable CCVS Support in PHP, first verify your CCVS installation directory. You will then need to configure PHP with the --with-ccvs option. If you use this option without specifying the path to your CCVS installation, PHP Will attempt to look in the default CCVS Install location (/usr/local/ccvs). If CCVS is in a non-standard location, run configure with: --with-ccvs=$ccvs_path, where $ccvs_path is the path to your CCVS installation. Please note that CCVS support requires that $ccvs_path/lib and $ccvs_path/include exist, and include cv_api.h under the include directory and libccvs.a under the lib directory.
Additionally, a ccvsd process will need to be running for the configurations you intend to use in your PHP scripts. You will also need to make sure the PHP Processes are running under the same user as your CCVS was installed as (e.g. if you installed CCVS as user 'ccvs', your PHP processes must run as 'ccvs' as well.)
Additional information about CCVS can be found at http://www.redhat.com/products/ccvs.
This documentation section is being worked on. Until then, RedHat maintains slightly outdated but still useful documentation at http://www.redhat.com/products/ccvs/support/CCVS3.3docs/ProgPHP.html.
These functions are only available on the Windows version of PHP. These functions have been added in PHP 4.
com_load() creates a new COM component and returns a reference to it. Returns false on failiure.
Com_invoke() invokes a method of the COM component referenced by com_object. Returns false on error, returns the function_name's return value on success.
Returns the value of the property of the COM component referenced by com_object. Returns false on error.
These functions allow you to obtain information about classes and instance objects. You can obtain the name of the class to which a object belongs, as well as its member properties and methods. Using these functions, you can find out not only the class membership of an object, but also its parentage (i.e. what class is the object class extending).
In this example, we first define a base class and an extension of the class. The base class describes a general vegetable, whether it is edible or not and what is its color. The subclass Spinach adds a method to cook it and another to find out if it is cooked.
Example 1. classes.inc
|
We then instantiate 2 objects from these classes and print out information about them, including their class parentage. We also define some utility functions, mainly to have a nice printout of the variables.
Example 2. test_script.php
|
One important thing to note in the example above is that the object $leafy is an instance of the class Spinach which is a subclass of Vegetable, therefore the last part of the script above will output:
Calls a the method referred by method_name from the user defined obj object. An example of usage is below, where we define a class, instantiate an object and use call_user_method() to call indirectly its print_info method.
<?php
class Country {
var $NAME;
var $TLD;
function Country($name, $tld) {
$this->NAME = $name;
$this->TLD = $tld;
}
function print_info($prestr="") {
echo $prestr."Country: ".$this->NAME."\n";
echo $prestr."Top Level Domain: ".$this->TLD."\n";
}
}
$cntry = new Country("Peru","pe");
echo "* Calling the object method directly\n";
$cntry->print_info();
echo "\n* Calling the same method indirectly\n";
call_user_method ("print_info", $cntry, "\t");
?>
|
See also call_user_func().
This function returns true if the class given by class_name has been defined, false otherwise.
This function returns the name of the class of which the object obj is an instance.
See also get_parent_class(), is_subclass_of()
This function returns an array of method names defined for the class specified by class_name.
See also get_class_vars(), get_object_vars()
This function will return an array of default properties of the class.
See also get_class_methods(), get_object_vars()
This function returns an array of the names of the declared classes in the current script.
Note: In PHP 4.0.1pl2, three extra classes are returned at the beginning of the array: stdClass (defined in Zend/zend.c), OverloadedTestClass (defined in ext/standard/basic_functions.c) and Directory (defined in ext/standard/dir.c).
This function returns an associative array of defined object properties for the specified object obj. If variables declared in the class of which the obj is an instance, have not been assigned a value, those will not be returned in the array.
Example 1. Use of get_object_vars()
|
See also get_class_methods(), get_class_vars()
This function returns the name of the parent class to the class of which the object obj is an instance.
See also get_class(), is_subclass_of()
(PHP 4 >= 4.0b4)
is_subclass_of -- Determines if an object belongs to a subclass of the specified classThis function returns true if the object obj, belongs to a class which is a subclass of superclass, false otherwise.
See also get_class(), get_parent_class()
ClibPDF lets you create PDF documents with PHP. It is available at FastIO but it isn't free software. You should definitely read the licence before you start playing with ClibPDF. If you cannot fullfil the licence agreement consider using pdflib by Thomas Merz, which is also very powerful. ClibPDF functionality and API is similar to Thomas Merz's pdflib but, according to FastIO, ClibPDF is faster and creates smaller documents. This may have changed with the new version 2.0 of pdflib. A simple benchmark (the pdfclock.c example from pdflib 2.0 turned into a php script) actually shows no difference in speed at all. The file size is also similar if compression is turned off. So, try them both and see which one does the job for you.
This documentation should be read alongside the ClibPDF manual since it explains the library in much greater detail.
Many functions in the native ClibPDF and the PHP module, as well as in pdflib, have the same name. All functions except for cpdf_open() take the handle for the document as their first parameter.
Currently this handle is not used internally since ClibPDF does not support the creation of several PDF documents at the same time. Actually, you should not even try it, the results are unpredictable. I can't oversee what the consequences in a multi threaded environment are. According to the author of ClibPDF this will change in one of the next releases (current version when this was written is 1.10). If you need this functionality use the pdflib module.
Note: The function cpdf_set_font() has changed since PHP 3 to support asian fonts. The encoding parameter is no longer an integer but a string.
One big advantage of ClibPDF over pdflib used to be the possibility to create the pdf document completely in memory without using temporary files. It also provides the ability to pass coordinates in a predefined unit length. This is a handy feature but can be simulated with pdf_translate().
Another nice feature of ClibPDF is the fact that any page can be modified at any time even if a new page has been already opened. The function cpdf_set_current_page() allows to leave the current page and presume modifying an other page.
Most of the functions are fairly easy to use. The most difficult part is probably creating a very simple PDF document at all. The following example should help you to get started. It creates a document with one page. The page contains the text "Times-Roman" in an outlined 30pt font. The text is underlined.
Example 1. Simple ClibPDF Example
|
The pdflib distribution contains a more complex example which creates a series of pages with an analog clock. Here is that example converted into PHP using the ClibPDF extension:
Example 2. pdfclock example from pdflib 2.0 distribution
|
void cpdf_global_set_document_limits
(int maxpages, int maxfonts, int maximages, int maxannotations, int maxobjects)
The cpdf_global_set_document_limits() function sets several document limits. This function has to be called before cpdf_open() to take effect. It sets the limits for any document open afterwards.
See also cpdf_open().
The cpdf_set_creator() function sets the creator of a pdf document.
See also cpdf_set_subject(), cpdf_set_title(), cpdf_set_keywords().
The cpdf_set_title() function sets the title of a pdf document.
See also cpdf_set_subject(), cpdf_set_creator(), cpdf_set_keywords().
The cpdf_set_subject() function sets the subject of a pdf document.
See also cpdf_set_title(), cpdf_set_creator(), cpdf_set_keywords().
The cpdf_set_keywords() function sets the keywords of a pdf document.
See also cpdf_set_title(), cpdf_set_creator(), cpdf_set_subject().
The cpdf_open() function opens a new pdf document. The first parameter turns document compression on if it is unequal to 0. The second optional parameter sets the file in which the document is written. If it is omitted the document is created in memory and can either be written into a file with the cpdf_save_to_file() or written to standard output with cpdf_output_buffer().
Note: The return value will be needed in further versions of ClibPDF as the first parameter in all other functions which are writing to the pdf document.
The ClibPDF library takes the filename "-" as a synonym for stdout. If PHP is compiled as an apache module this will not work because the way ClibPDF outputs to stdout does not work with apache. You can solve this problem by skipping the filename and using cpdf_output_buffer() to output the pdf document.
See also cpdf_close(), cpdf_output_buffer().
The cpdf_close() function closes the pdf document. This should be the last function even after cpdf_finalize(), cpdf_output_buffer() and cpdf_save_to_file().
See also cpdf_open().
void cpdf_page_init (int pdf document, int page number, int orientation, double height, double width [, double unit])
The cpdf_page_init() function starts a new page with height height and width width. The page has number page number and orientation orientation. orientation can be 0 for portrait and 1 for landscape. The last optional parameter unit sets the unit for the coordinate system. The value should be the number of postscript points per unit. Since one inch is equal to 72 points, a value of 72 would set the unit to one inch. The default is also 72.
See also cpdf_set_current_page().
The cpdf_finalize_page() function ends the page with page number page number.
This function is only for saving memory. A finalized page takes less memory but cannot be modified anymore.
See also cpdf_page_init().
The cpdf_finalize() function ends the document. You still have to call cpdf_close()
See also cpdf_close().
The cpdf_output_buffer() function outputs the pdf document to stdout. The document has to be created in memory which is the case if cpdf_open() has been called with no filename parameter.
See also cpdf_open().
The cpdf_save_to_file() function outputs the pdf document into a file if it has been created in memory.
This function is not needed if the pdf document has been open by specifying a filename as a parameter of cpdf_open().
See also cpdf_output_buffer(), cpdf_open().
The cpdf_set_current_page() function set the page on which all operations are performed. One can switch between pages until a page is finished with cpdf_finalize_page().
See also cpdf_finalize_page().
The cpdf_begin_text() function starts a text section. It must be ended with cpdf_end_text().
See also cpdf_end_text().
The cpdf_end_text() function ends a text section which was started with cpdf_begin_text().
See also cpdf_begin_text().
The cpdf_show() function outputs the string in text at the current position.
See also cpdf_text(), cpdf_begin_text(), cpdf_end_text().
The cpdf_show_xy() function outputs the string text at position with coordinates (x-coor, y-coor).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
Note: The function cpdf_show_xy() is identical to cpdf_text() without the optional parameters.
See also cpdf_text().
void cpdf_text (int pdf document, string text, double x-coor, double y-coor [, int mode [, double orientation [, int alignmode]]])
The cpdf_text() function outputs the string text at position with coordinates (x-coor, y-coor).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit. The optional parameter orientation is the rotation of the text in degree. The optional parameter alignmode determines how the text is aligned.
See the ClibPDF documentation for possible values.
See also cpdf_show_xy().
The cpdf_set_font() function sets the current font face, font size and encoding. Currently only the standard postscript fonts are supported.
The last parameter encoding can take the following values: "MacRomanEncoding", "MacExpertEncoding", "WinAnsiEncoding", and "NULL". "NULL" stands for the font's built-in encoding.
See the ClibPDF Manual for more information, especially how to support asian fonts.
The cpdf_set_leading() function sets the distance between text lines. This will be used if text is output by cpdf_continue_text().
See also cpdf_continue_text().
The cpdf_set_text_rendering() function determines how text is rendered.
The possible values for mode are 0=fill text, 1=stroke text, 2=fill and stroke text, 3=invisible, 4=fill text and add it to clipping path, 5=stroke text and add it to clipping path, 6=fill and stroke text and add it to clipping path, 7=add it to clipping path.
The cpdf_set_text_matrix() function sets a matrix which describes a transformation applied on the current text font.
The cpdf_set_text_pos() function sets the position of text for the next cpdf_show() function call.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_show(), cpdf_text().
The cpdf_set_char_spacing() function sets the spacing between characters.
See also cpdf_set_word_spacing(), cpdf_set_leading().
The cpdf_set_word_spacing() function sets the spacing between words.
See also cpdf_set_char_spacing(), cpdf_set_leading().
The cpdf_continue_text() function outputs the string in text in the next line.
See also cpdf_show_xy(), cpdf_text(), cpdf_set_leading(), cpdf_set_text_pos().
The cpdf_stringwidth() function returns the width of the string in text. It requires a font to be set before.
See also cpdf_set_font().
The cpdf_save() function saves the current enviroment. It works like the postscript command gsave. Very useful if you want to translate or rotate an object without effecting other objects.
See also cpdf_restore().
The cpdf_restore() function restores the enviroment saved with cpdf_save(). It works like the postscript command grestore. Very useful if you want to translate or rotate an object without effecting other objects.
See also cpdf_save().
The cpdf_translate() function set the origin of coordinate system to the point (x-coor, y-coor).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
The cpdf_setlinejoin() function set the linejoin parameter between a value of 0 and 2. 0 = miter, 1 = round, 2 = bevel.
The cpdf_setlinecap() function set the linecap parameter between a value of 0 and 2. 0 = butt end, 1 = round, 2 = projecting square.
The cpdf_setmiterlimit() function set the miter limit to a value greater or equal than 1.
The cpdf_setdash() function set the dash pattern white white units and black black units. If both are 0 a solid line is set.
The cpdf_newpath() starts a new path on the document given by the pdf_document parameter.
The cpdf_moveto() function set the current point to the coordinates x-coor and y-coor.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
The cpdf_rmoveto() function set the current point relative to the coordinates x-coor and y-coor.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_moveto().
void cpdf_curveto (int pdf document, double x1, double y1, double x2, double y2, double x3, double y3 [, int mode])
The cpdf_curveto() function draws a Bezier curve from the current point to the point (x3, y3) using (x1, y1) and (x2, y2) as control points.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_moveto(), cpdf_rmoveto(), cpdf_rlineto(), cpdf_lineto().
The cpdf_lineto() function draws a line from the current point to the point with coordinates (x-coor, y-coor).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_moveto(), cpdf_rmoveto(), cpdf_curveto().
The cpdf_rlineto() function draws a line from the current point to the relative point with coordinates (x-coor, y-coor).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_moveto(), cpdf_rmoveto(), cpdf_curveto().
The cpdf_circle() function draws a circle with center at point (x-coor, y-coor) and radius radius.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_arc().
void cpdf_arc (int pdf document, double x-coor, double y-coor, double radius, double start, double end [, int mode])
The cpdf_arc() function draws an arc with center at point (x-coor, y-coor) and radius radius, starting at angle start and ending at angle end.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_circle().
void cpdf_rect (int pdf document, double x-coor, double y-coor, double width, double height [, int mode])
The cpdf_rect() function draws a rectangle with its lower left corner at point (x-coor, y-coor). This width is set to widgth. This height is set to height.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
The cpdf_stroke() function draws a line along current path.
See also cpdf_closepath(), cpdf_closepath_stroke().
The cpdf_closepath_stroke() function is a combination of cpdf_closepath() and cpdf_stroke(). Than clears the path.
See also cpdf_closepath(), cpdf_stroke().
The cpdf_fill() function fills the interior of the current path with the current fill color.
See also cpdf_closepath(), cpdf_stroke(), cpdf_setgray_fill(), cpdf_setgray(), cpdf_setrgbcolor_fill(), cpdf_setrgbcolor().
The cpdf_fill_stroke() function fills the interior of the current path with the current fill color and draws current path.
See also cpdf_closepath(), cpdf_stroke(), cpdf_fill(), cpdf_setgray_fill(), cpdf_setgray(), cpdf_setrgbcolor_fill(), cpdf_setrgbcolor().
The cpdf_closepath_fill_stroke() function closes, fills the interior of the current path with the current fill color and draws current path.
See also cpdf_closepath(), cpdf_stroke(), cpdf_fill(), cpdf_setgray_fill(), cpdf_setgray(), cpdf_setrgbcolor_fill(), cpdf_setrgbcolor().
The cpdf_setgray_fill() function sets the current gray value to fill a path.
See also cpdf_setrgbcolor_fill().
The cpdf_setgray_stroke() function sets the current drawing color to the given gray value.
See also cpdf_setrgbcolor_stroke().
The cpdf_setgray_stroke() function sets the current drawing and filling color to the given gray value.
See also cpdf_setrgbcolor_stroke(), cpdf_setrgbcolor_fill().
void cpdf_setrgbcolor_fill (int pdf document, double red value, double green value, double blue value)
The cpdf_setrgbcolor_fill() function sets the current rgb color value to fill a path.
See also cpdf_setrgbcolor_stroke(), cpdf_setrgbcolor().
void cpdf_setrgbcolor_stroke (int pdf document, double red value, double green value, double blue value)
The cpdf_setrgbcolor_stroke() function sets the current drawing color to the given rgb color value.
See also cpdf_setrgbcolor_fill(), cpdf_setrgbcolor().
(PHP 3>= 3.0.8, PHP 4 >= 4.0b4)
cpdf_setrgbcolor -- Sets drawing and filling color to rgb color valueThe cpdf_setrgbcolor_stroke() function sets the current drawing and filling color to the given rgb color value.
See also cpdf_setrgbcolor_stroke(), cpdf_setrgbcolor_fill().
The cpdf_add_outline() function adds a bookmark with text text that points to the current page.
The cpdf_set_page_animation() function set the transition between following pages.
The value of transition can be
| 0 for none, |
| 1 for two lines sweeping across the screen reveal the page, |
| 2 for multiple lines sweeping across the screen reveal the page, |
| 3 for a box reveals the page, |
| 4 for a single line sweeping across the screen reveals the page, |
| 5 for the old page dissolves to reveal the page, |
| 6 for the dissolve effect moves from one screen edge to another, |
| 7 for the old page is simply replaced by the new page (default) |
The value of duration is the number of seconds between page flipping.
int cpdf_import_jpeg (int pdf document, string file name, double x-coor, double y-coor, double angle, double width, double height, double x-scale, double y-scale [, int
mode])
The cpdf_import_jpeg() function opens an image stored in the file with the name file name. The format of the image has to be jpeg. The image is placed on the current page at position (x-coor, y-coor). The image is rotated by angle degres.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_place_inline_image().
void cpdf_place_inline_image (int pdf document, int image, double x-coor, double y-coor, double angle, double width, double height [, int
mode])
The cpdf_place_inline_image() function places an image created with the php image functions on the page at postion (x-coor, y-coor). The image can be scaled at the same time.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_import_jpeg().
void cpdf_add_annotation (int pdf document, double llx, double lly, double urx, double ury, string title, string content [, int
mode])
The cpdf_add_annotation() adds a note with the lower left corner at (llx, lly) and the upper right corner at (urx, ury).
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
PHP supports libcurl, a library, created by Daniel Stenberg, that allows you to connect and communicate to many different types of servers with many different types of protocols. libcurl currently supports the http, https, ftp, gopher, telnet, dict, file, and ldap protocols. libcurl also supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading (this can also be done with PHP's ftp extension), HTTP form based upload, proxies, cookies and user+password authentication.
In order to use the CURL functions you need to install the CURL package. PHP requires that you use CURL 7.0.2-beta or higher. PHP will not work with any version of CURL below version 7.0.2-beta.
To use PHP's CURL support you must also compile PHP --with-curl[=DIR] where DIR is the location of the directory containing the lib and include directories. In the "include" directory there should be a folder named "curl" which should contain the easy.h and curl.h files. There should be a file named "libcurl.a" located in the "lib" directory.
These functions have been added in PHP 4.0.2.
Once you've compiled PHP with CURL support, you can begin using the curl functions. The basic idea behind the CURL functions is that you initialize a CURL session using the curl_init(), then you can set all your options for the transfer via the curl_exec() and then you finish off your session using the curl_close(). Here is an example that uses the CURL functions to fetch the PHP homepage into a file:
The curl_init() will initialize a new session and return a CURL handle for use with the curl_setopt(), curl_exec(), and curl_close() functions. If the optional url parameter is supplied then the CURLOPT_URL option will be set to the value of the parameter. You can manually set this using the curl_setopt() function.
See also: curl_close(), curl_setopt()
The curl_setopt() function will set options for a CURL session identified by the ch parameter. The option parameter is the option you want to set, and the value is the value of the option given by the option.
The value should be a long for the following options (specified in the option parameter):
CURLOPT_INFILESIZE: When you are uploading a file to a remote site, this option should be used to tell PHP what the expected size of the infile will be.
CURLOPT_VERBOSE: Set this option to a non-zero value if you want CURL to report everything that is happening.
CURLOPT_HEADER: Set this option to a non-zero value if you want the header to be included in the output.
CURLOPT_NOPROGRESS: Set this option to a non-zero value if you don't want PHP to display a progress meter for CURL transfers
Note: PHP automatically sets this option to a non-zero parameter, this should only be changed for debugging purposes.
CURLOPT_NOBODY: Set this option to a non-zero value if you don't want the body included with the output.
CURLOPT_FAILONERROR: Set this option to a non-zero value if you want PHP to fail silently if the HTTP code returned is greater than 300. The default behaviour is to return the page normally, ignoring the code.
CURLOPT_UPLOAD: Set this option to a non-zero value if you want PHP to prepare for an upload.
CURLOPT_POST: Set this option to a non-zero value if you want PHP to do a regular HTTP POST. This POST is a normal application/x-www-from-urlencoded kind, most commonly used by HTML forms.
CURLOPT_FTPLISTONLY: Set this option to a non-zero value and PHP will just list the names of an FTP directory.
CURLOPT_FTPAPPEND: Set this option to a non-zero value and PHP will append to the remote file instead of overwriting it.
CURLOPT_NETRC: Set this option to a non-zero value and PHP will scan your ~./netrc file to find your username and password for the remote site that you're establishing a connection with.
CURLOPT_FOLLOWLOCATION: Set this option to a non-zero value to follow any "Location: " header that the server sends as a part of the HTTP header (note this is recursive, PHP will follow as many "Location: " headers that it is sent.)
CURLOPT_PUT: Set this option a non-zero value to HTTP PUT a file. The file to PUT must be set with the CURLOPT_INFILE and CURLOPT_INFILESIZE.
CURLOPT_MUTE: Set this option to a non-zero value and PHP will be completely silent with regards to the CURL functions.
CURLOPT_TIMEOUT: Pass a long as a parameter that contains the maximum time, in seconds, that you'll allow the curl functions to take.
CURLOPT_LOW_SPEED_LIMIT: Pass a long as a parameter that contains the transfer speed in bytes per second that the transfer should be below during CURLOPT_LOW_SPEED_TIME seconds for PHP to consider it too slow and abort.
CURLOPT_LOW_SPEED_TIME: Pass a long as a parameter that contains the time in seconds that the transfer should be below the CURLOPT_LOW_SPEED_LIMIT for PHP to consider it too slow and abort.
CURLOPT_RESUME_FROM: Pass a long as a parameter that contains the offset, in bytes, that you want the transfer to start from.
CURLOPT_SSLVERSION: Pass a long as a parameter that contains the SSL version (2 or 3) to use. By default PHP will try and determine this by itself, although, in some cases you must set this manually.
CURLOPT_TIMECONDITION: Pass a long as a parameter that defines how the CURLOPT_TIMEVALUE is treated. You can set this parameter to TIMECOND_IFMODSINCE or TIMECOND_ISUNMODSINCE. This is a HTTP-only feature.
CURLOPT_TIMEVALUE: Pass a long as a parameter that is the time in seconds since January 1st, 1970. The time will be used as specified by the CURLOPT_TIMEVALUE option, or by default the TIMECOND_IFMODSINCE will be used.
The value parameter should be a string for the following values of the option parameter:
CURLOPT_URL: This is the URL that you want PHP to fetch. You can also set this option when initializing a session with the curl_init() function.
CURLOPT_USERPWD: Pass a string formatted in the [username]:[password] manner, for PHP to use for the connection. connection.
CURLOPT_PROXYUSERPWD: Pass a string formatted in the [username]:[password] format for connection to the HTTP proxy.
CURLOPT_RANGE: Pass the specified range you want. It should be in the "X-Y" format, where X or Y may be left out. The HTTP transfers also support several intervals, seperated with commas as in X-Y,N-M.
CURLOPT_POSTFIELDS: Pass a string containing the full data to post in an HTTP "POST" operation.
CURLOPT_REFERER: Pass a string containing the "referer" header to be used in an HTTP request.
CURLOPT_USERAGENT: Pass a string containing the "user-agent" header to be used in an HTTP request.
CURLOPT_FTPPORT: Pass a string containing the which will be used to get the IP address to use for the ftp "POST" instruction. The POST instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a hostname, a network interface name (under UNIX), or just a plain '-' to use the systems default IP address.
CURLOPT_COOKIE: Pass a string containing the content of the cookie to be set in the HTTP header.
CURLOPT_SSLCERT: Pass a string containing the filename of PEM formatted certificate.
CURLOPT_SSLCERTPASSWD: Pass a string containing the password required to use the CURLOPT_SSLCERT certificate.
CURLOPT_COOKIEFILE: Pass a string containing the name of the file containing the cookiee data. The cookie file can be in Netscape format, or just plain HTTP-style headers dumped into a file.
CURLOPT_CUSTOMREQUEST: Pass a string to be used instead of GET or HEAD when doing an HTTP request. This is useful for doing DELETE or another, more obscure, HTTP request.
Note: Don't do this without making sure your server supports the command first.
The following options expect a file descriptor that is obtained by using the fopen() function:
CURLOPT_FILE: The file where the output of your transfer should be placed, the default is STDOUT.
CURLOPT_INFILE: The file where the input of your transfer comes from.
CURLOPT_WRITEHEADER: The file to write the header part of the output into.
CURLOPT_STDERR: The file to write errors to instead of stderr.
This function is should be called after you initialize a CURL session and all the options for the session are set. Its purpose is simply to execute the predefined CURL session (given by the ch).
This functions closes a CURL session and frees all ressources. The CURL handle, ch, is also deleted.
These functions are only available if the interpreter has been compiled with the --with-cybercash=[DIR]. These functions have been added in PHP 4.
The function returns an associative array with the elements "errcode" and, if "errcode" is false, "outbuff" (string), "outLth" (long) and "macbuff" (string).
The function returns an associative array with the elements "errcode" and, if "errcode" is false, "outbuff" (string), "outLth" (long) and "macbuff" (string).
These functions build the foundation for accessing Berkeley DB style databases.
This is a general abstraction layer for several file-based databases. As such, functionality is limited to a subset of features modern databases such as Sleepycat Software's DB2 support. (This is not to be confused with IBM's DB2 software, which is supported through the ODBC functions.)
The behaviour of various aspects depend on the implementation of the underlying database. Functions such as dba_optimize() and dba_sync() will do what they promise for one database and will do nothing for others.
To add support for any of the following handlers, add the specified --with configure switch to your PHP configure line:
Dbm is the oldest (original) type of Berkeley DB style databases. You should avoid it, if possible. We do not support the compatibility functions built into DB2 and gdbm, because they are only compatible on the source code level, but cannot handle the original dbm format. (--with-dbm)
Ndbm is a newer type and more flexible than dbm. It still has most of the arbitrary limits of dbm (therefore it is deprecated). (--with-ndbm)
Gdbm is the GNU database manager. (--with-gdbm)
DB2 is Sleepycat Software's DB2. It is described as "a programmatic toolkit that provides high-performance built-in database support for both standalone and client/server applications." (--with-db2)
DB3 is Sleepycat Software's DB3. (--with-db3)
Cdb is "a fast, reliable, lightweight package for creating and reading constant databases." It is from the author of qmail and can be found here. Since it is constant, we support only reading operations. (--with-cdb)
DBA is binary safe and does not have any arbitrary limits. It inherits all limits set by the underlying database implementation.
All file-based databases must provide a way of setting the file mode of a new created database, if that is possible at all. The file mode is commonly passed as the fourth argument to dba_open() or dba_popen().
You can access all entries of a database in a linear way by using the dba_firstkey() and dba_nextkey() functions. You may not change the database while traversing it.
Example 2. Traversing a database
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Dba_close() closes the established database and frees all resources specified by handle.
handle is a database handle returned by dba_open().
Dba_close() does not return any value.
See also: dba_open() and dba_popen()
dba_delete() deletes the entry specified by key from the database specified with handle.
key is the key of the entry which is deleted.
handle is a database handle returned by dba_open().
dba_delete() returns true or false, if the entry is deleted or not deleted, respectively.
See also: dba_exists(), dba_fetch(), dba_insert(), and dba_replace().
Dba_exists() checks whether the specified key exists in the database specified by handle.
Key is the key the check is performed for.
Handle is a database handle returned by dba_open().
Dba_exists() returns true or false, if the key is found or not found, respectively.
See also: dba_fetch(), dba_delete(), dba_insert(), and dba_replace().
Dba_fetch() fetches the data specified by key from the database specified with handle.
Key is the key the data is specified by.
Handle is a database handle returned by dba_open().
Dba_fetch() returns the associated string or false, if the key/data pair is found or not found, respectively.
See also: dba_exists(), dba_delete(), dba_insert(), and dba_replace().
Dba_firstkey() returns the first key of the database specified by handle and resets the internal key pointer. This permits a linear search through the whole database.
Handle is a database handle returned by dba_open().
Dba_firstkey() returns the key or false depending on whether it succeeds or fails, respectively.
See also: Dba_nextkey()
dba_insert() inserts the entry described with key and value into the database specified by handle. It fails, if an entry with the same key already exists.
key is the key of the entry to be inserted.
value is the value to be inserted.
handle is a database handle returned by dba_open().
dba_insert() returns true or false, depending on whether it succeeds of fails, respectively.
See also: dba_exists() dba_delete() dba_fetch() dba_replace()
dba_nextkey() returns the next key of the database specified by handle and increments the internal key pointer.
handle is a database handle returned by dba_open().
dba_nextkey() returns the key or false depending on whether it succeeds or fails, respectively.
See also: dba_firstkey()
dba_popen() establishes a persistent database instance for path with mode using handler.
path is commonly a regular path in your filesystem.
mode is "r" for read access, "w" for read/write access to an already existing database, "c" for read/write access and database creation if it doesn't currently exist, and "n" for create, truncate and read/write access.
handler is the name of the handler which shall be used for accessing path. It is passed all optional parameters given to dba_popen() and can act on behalf of them.
dba_popen() returns a positive handler id or false, in the case the open is successful or fails, respectively.
See also: dba_open() dba_close()
dba_open() establishes a database instance for path with mode using handler.
path is commonly a regular path in your filesystem.
mode is "r" for read access, "w" for read/write access to an already existing database, "c" for read/write access and database creation if it doesn't currently exist, and "n" for create, truncate and read/write access.
handler is the name of the handler which shall be used for accessing path. It is passed all optional parameters given to dba_open() and can act on behalf of them.
dba_open() returns a positive handler id or false, in the case the open is successful or fails, respectively.
See also: dba_popen() dba_close()
dba_optimize() optimizes the underlying database specified by handle.
handle is a database handle returned by dba_open().
dba_optimize() returns true or false, if the optimization succeeds or fails, respectively.
See also: dba_sync()
dba_replace() replaces or inserts the entry described with key and value into the database specified by handle.
key is the key of the entry to be inserted.
value is the value to be inserted.
handle is a database handle returned by dba_open().
dba_replace() returns true or false, depending on whether it succeeds of fails, respectively.
See also: dba_exists(), dba_delete(), dba_fetch(), and dba_insert().
dba_sync() synchronizes the database specified by handle. This will probably trigger a physical write to disk, if supported.
handle is a database handle returned by dba_open().
dba_sync() returns true or false, if the synchronization succeeds or fails, respectively.
See also: dba_optimize()
Returns true if the date given is valid; otherwise returns false. Checks the validity of the date formed by the arguments. A date is considered valid if:
year is between 1 and 32767 inclusive
month is between 1 and 12 inclusive
Day is within the allowed number of days for the given month. Leap years are taken into consideration.
Returns a string formatted according to the given format string using the given timestamp or the current local time if no timestamp is given.
The following characters are recognized in the format string:
a - "am" or "pm"
A - "AM" or "PM"
B - Swatch Internet time
d - day of the month, 2 digits with leading zeros; i.e. "01" to "31"
D - day of the week, textual, 3 letters; i.e. "Fri"
F - month, textual, long; i.e. "January"
g - hour, 12-hour format without leading zeros; i.e. "1" to "12"
G - hour, 24-hour format without leading zeros; i.e. "0" to "23"
h - hour, 12-hour format; i.e. "01" to "12"
H - hour, 24-hour format; i.e. "00" to "23"
i - minutes; i.e. "00" to "59"
I (capital i) - "1" if Daylight Savings Time, "0" otherwise.
j - day of the month without leading zeros; i.e. "1" to "31"
l (lowercase 'L') - day of the week, textual, long; i.e. "Friday"
L - boolean for whether it is a leap year; i.e. "0" or "1"
m - month; i.e. "01" to "12"
M - month, textual, 3 letters; i.e. "Jan"
n - month without leading zeros; i.e. "1" to "12"
s - seconds; i.e. "00" to "59"
S - English ordinal suffix, textual, 2 characters; i.e. "th", "nd"
t - number of days in the given month; i.e. "28" to "31"
T - Timezone setting of this machine; i.e. "MDT"
U - seconds since the epoch
w - day of the week, numeric, i.e. "0" (Sunday) to "6" (Saturday)
Y - year, 4 digits; i.e. "1999"
y - year, 2 digits; i.e. "99"
z - day of the year; i.e. "0" to "365"
Z - timezone offset in seconds (i.e. "-43200" to "43200")
It is possible to use date() and mktime() together to find dates in the future or the past.
Example 2. Date() and mktime() example
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To format dates in other languages, you should use the setlocale() and strftime() functions.
Returns an associative array containing the date information of the timestamp as the following array elements:
"seconds" - seconds
"minutes" - minutes
"hours" - hours
"mday" - day of the month
"wday" - day of the week, numeric
"mon" - month, numeric
"year" - year, numeric
"yday" - day of the year, numeric; i.e. "299"
"weekday" - day of the week, textual, full; i.e. "Friday"
"month" - month, textual, full; i.e. "January"
This is an interface to gettimeofday(2). It returns an associative array containing the data returned from the system call.
"sec" - seconds
"usec" - microseconds
"minuteswest" - minutes west of Greenwich
"dsttime" - type of dst correction
Identical to the date() function except that the time returned is Greenwich Mean Time (GMT). For example, when run in Finland (GMT +0200), the first line below prints "Jan 01 1998 00:00:00", while the second prints "Dec 31 1997 22:00:00".
See also date(), mktime(), and gmmktime().
(PHP 3>= 3.0.12, PHP 4 >= 4.0RC2)
gmstrftime -- Format a GMT/CUT time/date according to locale settingsBehaves the same as strftime() except that the time returned is Greenwich Mean Time (GMT). For example, when run in Eastern Standard Time (GMT -0500), the first line below prints "Dec 31 1998 20:00:00", while the second prints "Jan 01 1999 01:00:00".
See also strftime().
The localtime() function returns an array identical to that of the structure returned by the C function call. The first argument to localtime() is the timestamp, if this is not given the current time is used. The second argument to the localtime() is the is_associative, if this is set to 0 or not supplied than the array is returned as a regular, numerically indexed array. If the argument is set to 1 then localtime() is an associative array containing all the different elements of the structure returned by the C function call to localtime. The names of the different keys of the associative array are as follows:
"tm_sec" - seconds
"tm_min" - minutes
"tm_hour" - hour
"tm_mday" - day of the month
"tm_mon" - month of the year
"tm_year" - Year, not y2k compliant
"tm_wday" - Day of the week
"tm_yday" - Day of the year
"tm_isdst" - Is daylight savings time in effect
Returns the string "msec sec" where sec is the current time measured in the number of seconds since the Unix Epoch (0:00:00 January 1, 1970 GMT), and msec is the microseconds part. This function is only available on operating systems that support the gettimeofday() system call.
See also time().
Warning: Note the strange order of arguments, which differs from the order of arguments in a regular UNIX mktime() call and which does not lend itself well to leaving out parameters from right to left (see below). It is a common error to mix these values up in a script.
Returns the Unix timestamp corresponding to the arguments given. This timestamp is a long integer containing the number of seconds between the Unix Epoch (January 1 1970) and the time specified.
Arguments may be left out in order from right to left; any arguments thus omitted will be set to the current value according to the local date and time.
Is_dst can be set to 1 if the time is during daylight savings time, 0 if it is not, or -1 (the default) if it is unknown whether the time is within daylight savings time or not.
Note: Is_dst was added in 3.0.10.
Mktime() is useful for doing date arithmetic and validation, as it will automatically calculate the correct value for out-of-range input. For example, each of the following lines produces the string "Jan-01-1998".
The last day of any given month can be expressed as the "0" day of the next month, not the -1 day. Both of the following examples will produce the string "The last day in Feb 2000 is: 29".
Date with year, month and day equal to zero is considered illegal (otherwise it what be regarded as 30.11.1999, which would be strange behaviour).
Returns a string formatted according to the given format string using the given timestamp or the current local time if no timestamp is given. Month and weekday names and other language dependent strings respect the current locale set with setlocale().
The following conversion specifiers are recognized in the format string:
%a - abbreviated weekday name according to the current locale
%A - full weekday name according to the current locale
%b - abbreviated month name according to the current locale
%B - full month name according to the current locale
%c - preferred date and time representation for the current locale
%C - century number (the year divided by 100 and truncated to an integer, range 00 to 99)
%d - day of the month as a decimal number (range 00 to 31)
%D - same as %m/%d/%y
%e - day of the month as a decimal number, a single digit is preceded by a space (range ' 1' to '31')
%h - same as %b
%H - hour as a decimal number using a 24-hour clock (range 00 to 23)
%I - hour as a decimal number using a 12-hour clock (range 01 to 12)
%j - day of the year as a decimal number (range 001 to 366)
%m - month as a decimal number (range 01 to 12)
%M - minute as a decimal number
%n - newline character
%p - either `am' or `pm' according to the given time value, or the corresponding strings for the current locale
%r - time in a.m. and p.m. notation
%R - time in 24 hour notation
%S - second as a decimal number
%t - tab character
%T - current time, equal to %H:%M:%S
%u - weekday as a decimal number [1,7], with 1 representing Monday
%U - week number of the current year as a decimal number, starting with the first Sunday as the first day of the first week
%V - The ISO 8601:1988 week number of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week.
%W - week number of the current year as a decimal number, starting with the first Monday as the first day of the first week
%w - day of the week as a decimal, Sunday being 0
%x - preferred date representation for the current locale without the time
%X - preferred time representation for the current locale without the date
%y - year as a decimal number without a century (range 00 to 99)
%Y - year as a decimal number including the century
%Z - time zone or name or abbreviation
%% - a literal `%' character
See also setlocale() and mktime() and the Open Group specification of strftime().
Returns the current time measured in the number of seconds since the Unix Epoch (January 1 1970 00:00:00 GMT).
See also date().
(PHP 3>= 3.0.12, PHP 4 >= 4.0b2)
strtotime -- Parse about any english textual datetime description into a UNIX timestampThese functions allow you to access records stored in dBase-format (dbf) databases.
There is no support for indexes or memo fields. There is no support for locking, too. Two concurrent webserver processes modifying the same dBase file will very likely ruin your database.
Unlike SQL databases, dBase "databases" cannot change the database definition afterwards. Once the file is created, the database definition is fixed. There are no indexes that speed searching or otherwise organize your data. dBase files are simple sequential files of fixed length records. Records are appended to the end of the file and delete records are kept until you call dbase_pack()().
We recommend that you do not use dBase files as your production database. Choose any real SQL server instead; MySQL or Postgres are common choices with PHP. dBase support is here to allow you to import and export data to and from your web database, since the file format is commonly understood with Windows spreadsheets and organizers. Import and export of data is about all that dBase support is good for.
The fields parameter is an array of arrays, each array describing the format of one field in the database. Each field consists of a name, a character indicating the field type, a length, and a precision.
The types of fields available are:
Boolean. These do not have a length or precision.
Memo. (Note that these aren't supported by PHP.) These do not have a length or precision.
Date (stored as YYYYMMDD). These do not have a length or precision.
Number. These have both a length and a precision (the number of digits after the decimal point).
String.
If the database is successfully created, a dbase_identifier is returned, otherwise false is returned.
Example 1. Creating a dBase database file
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The flags correspond to those for the open() system call. (Typically 0 means read-only, 1 means write-only, and 2 means read and write.)
Returns a dbase_identifier for the opened database, or false if the database couldn't be opened.
Packs the specified database (permanently deleting all records marked for deletion using dbase_delete_record().
Adds the data in the record to the database. If the number of items in the supplied record isn't equal to the number of fields in the database, the operation will fail and false will be returned.
Replaces the data associated with the record record_number with the data in the record in the database. If the number of items in the supplied record is not equal to the number of fields in the database, the operation will fail and false will be returned.
dbase_record_number is an integer which spans from 1 to the number of records in the database (as returned by dbase_numrecords()).
Marks record to be deleted from the database. To actually remove the record from the database, you must also call dbase_pack().
Returns the data from record in an array. The array is indexed starting at 0, and includes an associative member named 'deleted' which is set to 1 if the record has been marked for deletion (see dbase_delete_record().
Each field is converted to the appropriate PHP type. (Dates are left as strings.)
(PHP 3>= 3.0.4, PHP 4 )
dbase_get_record_with_names -- Gets a record from a dBase database as an associative arrayReturns the data from record in an associative array. The array also includes an associative member named 'deleted' which is set to 1 if the record has been marked for deletion (see dbase_delete_record().
Each field is converted to the appropriate PHP type. (Dates are left as strings.)
Returns the number of fields (columns) in the specified database. Field numbers are between 0 and dbase_numfields($db)-1, while record numbers are between 1 and dbase_numrecords($db).
These functions allow you to store records stored in a dbm-style database. This type of database (supported by the Berkeley DB, GDBM, and some system libraries, as well as a built-in flatfile library) stores key/value pairs (as opposed to the full-blown records supported by relational databases).
The first argument is the full-path filename of the DBM file to be opened and the second is the file open mode which is one of "r", "n", "c" or "w" for read-only, new (implies read-write, and most likely will truncate an already-existing database of the same name), create (implies read-write, and will not truncate an already-existing database of the same name) and read-write respectively.
Returns an identifer to be passed to the other DBM functions on success, or false on failure.
If NDBM support is used, NDBM will actually create filename.dir and filename.pag files. GDBM only uses one file, as does the internal flat-file support, and Berkeley DB creates a filename.db file. Note that PHP does its own file locking in addition to any file locking that may be done by the DBM library itself. PHP does not delete the .lck files it creates. It uses these files simply as fixed inodes on which to do the file locking. For more information on DBM files, see your Unix man pages, or obtain GNU's GDBM.
Adds the value to the database with the specified key.
Returns -1 if the database was opened read-only, 0 if the insert was successful, and 1 if the specified key already exists. (To replace the value, use dbmreplace().)
Replaces the value for the specified key in the database.
This will also add the key to the database if it didn't already exist.
Deletes the value for key in the database.
Returns false if the key didn't exist in the database.
Returns the first key in the database. Note that no particular order is guaranteed since the database may be built using a hash-table, which doesn't guarantee any ordering.
Returns the next key after key. By calling dbmfirstkey() followed by successive calls to dbmnextkey() it is possible to visit every key/value pair in the dbm database. For example:
Changes PHP's current directory to directory. Returns FALSE if unable to change directory, TRUE otherwise.
A pseudo-object oriented mechanism for reading a directory. The given directory is opened. Two properties are available once directory has been opened. The handle property can be used with other directory functions such as readdir(), rewinddir() and closedir(). The path property is set to path the directory that was opened. Three methods are available: read, rewind and close.
Closes the directory stream indicated by dir_handle. The stream must have previously been opened by opendir().
Returns a directory handle to be used in subsequent closedir(), readdir(), and rewinddir() calls.
Returns the filename of the next file from the directory. The filenames are not returned in any particular order.
Note that readdir() will return the . and .. entries. If you don't want these, simply strip them out:
These functions are only available if PHP was configured with --with-dom=[DIR], using the GNOME xml library. You will need at least libxml-2.0.0 (the beta version will not work). These functions have been added in PHP 4.
This module defines the following constants:
Table 1. XML constants
| Constant | Value | Description |
|---|---|---|
| XML_ELEMENT_NODE | 1 | |
| XML_ATTRIBUTE_NODE | 2 | |
| XML_TEXT_NODE | 3 | |
| XML_CDATA_SECTION_NODE | 4 | |
| XML_ENTITY_REF_NODE | 5 | |
| XML_ENTITY_NODE | 6 | |
| XML_PI_NODE | 7 | |
| XML_COMMENT_NODE | 8 | |
| XML_DOCUMENT_NODE | 9 | |
| XML_DOCUMENT_TYPE_NODE | 10 | |
| XML_DOCUMENT_FRAG_NODE | 11 | |
| XML_NOTATION_NODE | 12 | |
| XML_GLOBAL_NAMESPACE | 1 | |
| XML_LOCAL_NAMESPACE | 2 |
This module defines a number of classes. The DOM XML functions return a parsed tree of the XML document with each node being an object belonging to one of these classes.
The function parses the XML document in str and returns an object of class "Dom document", having the properties "doc" (resource), "version" (string) and "type" (long).
The function parses the XML document in the file named filename and returns an object of class "Dom document", having the properties "doc" (resource), "version" (string).
These are functions dealing with error handling and logging. They allow you to define your own error handling rules, as well as modify the way the errors can be logged. This allows you to change and enhance error reporting to suit your needs.
With the logging functions, you can send messages directly to other machines, to an email (or email to pager gateway!), to system logs, etc., so you can selectively log and monitor the most important parts of your applications and websites.
The error reporting functions allow you to customize what level and kind of error feedback is given, ranging from simple notices to customized functions returned during errors.
Sends an error message to the web server's error log, a TCP port or to a file. The first parameter, message, is the error message that should be logged. The second parameter, message_type says where the message should go:
Table 1. error_log() log types
| 0 | message is sent to PHP's system logger, using the Operating System's system logging mechanism or a file, depending on what the error_log configuration directive is set to. |
| 1 | message is sent by email to the address in the destination parameter. This is the only message type where the fourth parameter, extra_headers is used. This message type uses the same internal function as Mail() does. |
| 2 | message is sent through the PHP debugging connection. This option is only available if remote debugging has been enabled. In this case, the destination parameter specifies the host name or IP address and optionally, port number, of the socket receiving the debug information. |
| 3 | message is appended to the file destination. |
Example 1. error_log() examples
|
Sets PHP's error reporting level and returns the old level. The error reporting level is either a bitmask, or named constant. Using named constants is strongly encouraged to ensure compatibility for future versions. As error levels are added, the range of integers increases, so older integer-based error levels will not always behave as expected.
Example 1. Error Integer changes
|
Table 1. error_reporting() bit values
| constant | value |
|---|---|
| 1 | E_ERROR |
| 2 | E_WARNING |
| 4 | E_PARSE |
| 8 | E_NOTICE |
| 16 | E_CORE_ERROR |
| 32 | E_CORE_WARNING |
| 64 | E_COMPILE_ERROR |
| 128 | E_COMPILE_WARNING |
| 256 | E_USER_ERROR |
| 512 | E_USER_WARNING |
| 1024 | E_USER_NOTICE |
Example 2. error_reporting() examples
|
Used after changing the error handler function using set_error_handler(), to revert to the previous error handler (which could be the built-in or a user defined function)
See also error_reporting(), set_error_handler(), trigger_error(), user_error()
Sets a user function (error_handler) to handle errors in a script. Returns the previously defined error handler (if any), or false on error. This function can be used for defining your own way of handling errors during runtime, for example in applications in which you need to do cleanup of data/files when a critical error happens, or when you need to trigger an error under certain conditions (using trigger_error())
The user function needs to accept 2 parameters: the error code, and a string describing the error. From PHP 4.0.2, an additional 3 optional parameters are supplied: the filename in which the error occured, the line number in which the error occured, and the context in which the error occured (an array that points to the active symbol table at the point the error occurred).
The example below shows the handling of internal execptions by triggering errors and handling them with a user defined function:
Example 1. Error handling with set_error_handler() and trigger_error()
|
vector a
Array
(
[0] => 2
[1] => 3
[2] => foo
[3] => 5.5
[4] => 43.3
[5] => 21.11
)
----
vector b - a warning (b = log(PI) * a)
<b>WARNING</b> [1024] Value at position 2 is not a number, using 0 (zero)<br>
Array
(
[0] => 2.2894597716988
[1] => 3.4341896575482
[2] => 0
[3] => 6.2960143721717
[4] => 49.566804057279
[5] => 24.165247890281
)
----
vector c - an error
<b>ERROR</b> [512] Incorrect input vector, array of values expected<br>
NULL
----
vector d - fatal error
<b>FATAL</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br>
Fatal error in line 36 of file trigger_error.php, PHP 4.0.2 (Linux)<br>
Aborting...<br>
|
It is important to remember that the standard PHP error handler is completely bypassed. error_reporting() settings will have no effect and your error handler will be called regardless - however you are still able to read the current value of error_reporting() and act appropriately. Of particular note is that this value will be 0 if the statement that caused the error was prepended by the @ error-control operator.
Also note that it is your responsibility to die() if necessary. If the error-handler function returns, script execution will continue with the next statement after the one that caused an error.
See also error_reporting(), restore_error_handler(), trigger_error(), user_error()
Used to trigger a user error condition, it can be used by in conjunction with the built-in error handler, or with a user defined function that has been set as the new error handler (set_error_handler()). It only works with the E_USER family of constants, and will default to E_USER_NOTICE.
This function is useful when you need to generate a particular response to an exception at runtime. For example:
Note: See set_error_handler() for a more extensive example.
See also error_reporting(), set_error_handler(), restore_error_handler(), user_error()
This is an alias for the function trigger_error().
See also error_reporting(), set_error_handler(), restore_error_handler(), and trigger_error()
These functions allow read-only access to data stored in filePro databases.
filePro is a registered trademark of Fiserv, Inc. You can find more information about filePro at http://www.fileproplus.com/.
This reads and verifies the map file, storing the field count and info.
No locking is done, so you should avoid modifying your filePro database while it may be opened in PHP.
Returns the number of fields (columns) in the opened filePro database.
See also filepro().
Given a string containing a path to a file, this function will return the base name of the file.
On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/).
See also: dirname()
Attempts to change the group of the file filename to group. Only the superuser may change the group of a file arbitrarily; other users may change the group of a file to any group of which that user is a member.
Returns true on success; otherwise returns false.
Note: This function does not work on Windows systems
Attempts to change the mode of the file specified by filename to that given in mode.
Note that mode is not automatically assumed to be an octal value, so strings (such as "g+w") will not work properly. To ensure the expected operation, you need to prefix mode with a zero (0):
chmod ("/somedir/somefile", 755); // decimal; probably incorrect
chmod ("/somedir/somefile", "u+rwx,go+rx"); // string; incorrect
chmod ("/somedir/somefile", 0755); // octal; correct value of mode
|
Returns true on success and false otherwise.
Note: This function does not work on Windows systems
Attempts to change the owner of the file filename to user user. Only the superuser may change the owner of a file.
Returns true on success; otherwise returns false.
See also chown() and chmod().
Note: This function does not work on Windows systems
Invoking the stat or lstat system call on most systems is quite expensive. Therefore, the result of the last call to any of the status functions (listed below) is stored for use on the next such call using the same filename. If you wish to force a new status check, for instance if the file is being checked many times and may change or disappear, use this function to clear the results of the last call from memory.
This value is only cached for the lifetime of a single request.
Affected functions include stat(), lstat(), file_exists(), is_writeable(), is_readable(), is_executable(), is_file(), is_dir(), is_link(), filectime(), fileatime(), filemtime(), fileinode(), filegroup(), fileowner(), filesize(), filetype(), and fileperms().
Makes a copy of a file. Returns true if the copy succeeded, false otherwise.
See also: rename().
This is a dummy manual entry to satisfy those people who are looking for unlink() or unset() in the wrong place.
See also: unlink() to delete files, unset() to delete variables.
Given a string containing a path to a file, this function will return the name of the directory.
On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/).
See also: basename()
Given a string containing a directory, this function will return the number of bytes available on the corresponding filesystem or disk partition.
The file pointed to by fp is closed.
Returns true on success and false on failure.
The file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen().
Returns true if the file pointer is at EOF or an error occurs; otherwise returns false.
The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen().
This function forces a write of all buffered output to the to the resource pointed to by the file handle fp. Returns true if succesful, false otherwise.
The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen().
Returns a string containing a single character read from the file pointed to by fp. Returns FALSE on EOF.
The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen().
See also fread(), fopen(), popen(), fsockopen(), and fgets().
Similar to fgets() except that fgetcsv() parses the line it reads for fields in CSV format and returns an array containing the fields read. The field delimiter is a comma, unless you specify another delimiter with the optional third parameter.
Fp must be a valid file pointer to a file successfully opened by fopen(), popen(), or fsockopen()
Length must be greater than the longest line to be found in the CSV file (allowing for trailing line-end characters).
Fgetcsv() returns false on error, including end of file.
N.B. A blank line in a CSV file will be returned as an array comprising a single null field, and will not be treated as an error.
Example 1. Fgetcsv() example - Read and print entire contents of a CSV file
|
Returns a string of up to length - 1 bytes read from the file pointed to by fp. Reading ends when length - 1 bytes have been read, on a newline (which is included in the return value), or on EOF (whichever comes first).
If an error occurs, returns false.
Common Pitfalls:
People used to the 'C' semantics of fgets should note the difference in how EOF is returned.
The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen().
A simple example follows:
See also fread(), fopen(), popen(), fgetc(), fsockopen(), and socket_set_timeout().
Identical to fgets(), except that fgetss attempts to strip any HTML and PHP tags from the text it reads.
You can use the optional third parameter to specify tags which should not be stripped.
Note: allowable_tags was added in PHP 3.0.13, PHP4B3.
See also fgets(), fopen(), fsockopen(), popen(), and strip_tags().
Identical to readfile(), except that file() returns the file in an array. Each element of the array corresponds to a line in the file, with the newline still attached.
You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.
<?php
// get a web page into an array and print it out
$fcontents = file ('http://www.php.net');
while (list ($line_num, $line) = each ($fcontents)) {
echo "<b>Line $line_num:</b> " . htmlspecialchars ($line) . "<br>\n";
}
// get a web page into a string
$fcontents = join ('', file ('http://www.php.net'));
?>
|
See also readfile(), fopen(), fsockopen(), and popen().
Returns true if the file specified by filename exists; false otherwise.
file_exists() will not work on remote files; the file to be examined must be accessible via the server's filesystem.
The results of this function are cached. See clearstatcache() for more details.
Returns the time the file was last accessed, or false in case of an error. The time is returned as a Unix timestamp.
The results of this function are cached. See clearstatcache() for more details.
Note: The atime of a file is supposed to change whenever the data blocks of a file are being read. This can be costly performancewise when an appliation regularly accesses a very large number of files or directories. Some Unix filesystems can be mounted with atime updates disabled to increase the performance of such applications; USENET news spools are a common example. On such filesystems this function will be useless.
Returns the time the file was last changed, or false in case of an error. The time is returned as a Unix timestamp.
The results of this function are cached. See clearstatcache() for more details.
Note: In most Unix filesystem, a file is considered changed, when it's Inode data is changed, that is, when the permissions, the owner, the group or other metadata from the Inode is written to. See also filemtime() (this is what you want to use when you want to create "Last Modified" footers on web pages) and fileatime().
Note: In some Unix texts the ctime of a file is being referred to as the creation time of the file. This is wrong. There is no creation time for Unix files in most Unix filesystems.
Returns the group ID of the owner of the file, or false in case of an error. The group ID is returned in numerical format, use posix_getgrgid() to resolve it to a group name.
The results of this function are cached. See clearstatcache() for more details.
Note: This function does not work on Windows systems
Returns the inode number of the file, or false in case of an error.
The results of this function are cached. See clearstatcache() for more details.
Note: This function does not work on Windows systems
Returns the time the file was last modified, or false in case of an error. The time is returned as a Unix timestamp.
The results of this function are cached. See clearstatcache() for more details.
Note: This function returns the time when the data blocks of a file were being written to, that is, the time when the content of the file was changed. Use date() on the result of this function to get a printable modification date for use in page footers.
Returns the user ID of the owner of the file, or false in case of an error. The user ID is returned in numerical format, use posix_getpwuid() to resolve it to a username.
The results of this function are cached. See clearstatcache() for more details.
Note: This function does not work on Windows systems
Returns the permissions on the file, or false in case of an error.
The results of this function are cached. See clearstatcache() for more details.
Returns the size of the file, or false in case of an error.
The results of this function are cached. See clearstatcache() for more details.
Returns the type of the file. Possible values are fifo, char, dir, block, link, file, and unknown.
Returns false if an error occurs.
The results of this function are cached. See clearstatcache() for more details.
PHP supports a portable way of locking complete files in an advisory way (which means all accessing programs have to use the same way of locking or it will not work).
flock() operates on fp which must be an open file pointer. operation is one of the following values:
To acquire a shared lock (reader), set operation to LOCK_SH (set to 1 prior to PHP 4.0.1).
To acquire an exclusive lock (writer), set operation to LOCK_EX (set to 2 prior to PHP 4.0.1).
To release a lock (shared or exclusive), set operation to LOCK_UN (set to 3 prior to PHP 4.0.1).
If you don't want flock() to block while locking, add LOCK_NB (4 prior to PHP 4.0.1) to operation.
Flock() allows you to perform a simple reader/writer model which can be used on virtually every platform (including most Unices and even Windows). The optional 3rd argument is set to true if the lock would block (EWOULDBLOCK errno condition)
Flock() returns true on success and false on error (e.g. when a lock could not be acquired).
| Warning |
On most operation systems flock() is implemented at the process level. When using a multithreaded server API like ISAPI you cannot rely on flock() to protect files against other PHP scripts running in parallel threads of the same server instance! |
If filename begins with "http://" (not case sensitive), an HTTP 1.0 connection is opened to the specified server and a file pointer is returned to the beginning of the text of the response. A 'Host:' header is sent with the request in order to handle name-based virtual hosts.
Does not handle HTTP redirects, so you must include trailing slashes on directories.
If filename begins with "ftp://" (not case sensitive), an ftp connection to the specified server is opened and a pointer to the requested file is returned. If the server does not support passive mode ftp, this will fail. You can open files for either reading or writing via ftp (but not both simultaneously).
If filename is one of "php://stdin", "php://stdout", or "php://stderr", the corresponding stdio stream will be opened. (This was introduced in PHP 3.0.13; in earlier versions, a filename such as "/dev/stdin" or "/dev/fd/0" must be used to access the stdio streams.)
If filename begins with anything else, the file will be opened from the filesystem, and a file pointer to the file opened is returned.
If the open fails, the function returns false.
mode may be any of the following:
'r' - Open for reading only; place the file pointer at the beginning of the file.
'r+' - Open for reading and writing; place the file pointer at the beginning of the file.
'w' - Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'w+' - Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'a' - Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
'a+' - Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
You can use the optional third parameter and set it to "1", if you want to search for the file in the include_path, too.
If you are experiencing problems with reading and writing to files and you're using the server module version of PHP, remember to make sure that the files and directories you're using are accessible to the server process.
On the Windows platform, be careful to escape any backslashes used in the path to the file, or use forward slashes.
See also fclose(), fsockopen(), socket_set_timeout(), and popen().
Reads to EOF on the given file pointer and writes the results to standard output.
If an error occurs, fpassthru() returns false.
The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen(). The file is closed when fpassthru() is done reading it (leaving fp useless).
If you just want to dump the contents of a file to stdout you may want to use the readfile(), which saves you the fopen() call.
See also readfile(), fopen(), popen(), and fsockopen()
Fputs() is an alias to fwrite(), and is identical in every way. Note that the length parameter is optional and if not specified the entire string will be written.
Fread() reads up to length bytes from the file pointer referenced by fp. Reading stops when length bytes have been read or EOF is reached, whichever comes first.
// get contents of a file into a string
$filename = "/usr/local/something.txt";
$fd = fopen ($filename, "r");
$contents = fread ($fd, filesize ($filename));
fclose ($fd);
|
See also fwrite(), fopen(), fsockopen(), popen(), fgets(), fgetss(), fscanf(), file(), and fpassthru().
The function fscanf() is similar to sscanf(), but it takes its input from a file associated with handle and interprets the input according to the specified format. If only two parameters were passed to this function, the values parsed will be returned as an array. Otherwise, if optional parameters are passed, the function will return the number of assigned values. The optional parameters must be passed by reference.
See also fread(), fgets(), fgetss(), sscanf(), printf(), and sprintf().
Sets the file position indicator for the file referenced by fp.The new position, measured in bytes from the beginning of the file, is obtained by adding offset to the position specified by whence, whose values are defined as follows:
| SEEK_SET - Set position equal to offset bytes. |
| SEEK_CUR - Set position to current location plus offset. |
| SEEK_END - Set position to end-of-file plus offset. |
If whence is not specified, it is assumed to be SEEK_SET.
Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.
May not be used on file pointers returned by fopen() if they use the "http://" or "ftp://" formats.
Note: The whence argument was added after PHP 4.0 RC1.
Gathers the statistics of the file opened by the file pointer fp. This function is similar to the stat() function except that it operates on an open file pointer instead of a filename.
Returns an array with the statistics of the file with the following elements:
device
inode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated
The results of this function are cached. See clearstatcache() for more details.
Returns the position of the file pointer referenced by fp; i.e., its offset into the file stream.
If an error occurs, returns false.
The file pointer must be valid, and must point to a file successfully opened by fopen() or popen().
Takes the filepointer, fp, and truncates the file to length, size. This function returns true on success and false on failure.
fwrite() writes the contents of string to the file stream pointed to by fp. If the length argument is given, writing will stop after length bytes have been written or the end of string is reached, whichever comes first.
Note that if the length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from string.
See also fread(), fopen(), fsockopen(), popen(), and fputs().
Output using fwrite() is normally buffered at 8K. This means that if there are two processess wanting to write to the same output stream (a file), each is paused after 8K of data to allow the other to write. set_file_buffer() sets the buffering for write operations on the given filepointer fp to buffer bytes. If buffer is 0 then write operations are unbuffered. This ensures that all writes with fwrite() are completed before other processes are allowed to write to that output stream.
The function returns 0 on success, or EOF if the request cannot be honored.
The following example demonstrates how to use set_file_buffer() to create an unbuffered stream.
Returns true if the filename exists and is a directory.
The results of this function are cached. See clearstatcache() for more details.
Returns true if the filename exists and is executable.
The results of this function are cached. See clearstatcache() for more details.
Returns true if the filename exists and is a regular file.
The results of this function are cached. See clearstatcache() for more details.
Returns true if the filename exists and is a symbolic link.
The results of this function are cached. See clearstatcache() for more details.
See also is_dir() and is_file().
Note: This function does not work on Windows systems
Returns true if the filename exists and is readable.
Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account.
The results of this function are cached. See clearstatcache() for more details.
See also is_writeable().
Returns true if the filename exists and is writeable. The filename argument may be a directory name allowing you to check if a directory is writeable.
Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account.
The results of this function are cached. See clearstatcache() for more details.
See also is_readable().
(PHP 3>= 3.0.17, PHP 4 >= 4.0.3)
is_uploaded_file -- Tells whether the file was uploaded via HTTP POST.This function is available only in versions of PHP 3 after PHP 3.0.16, and in versions of PHP 4 after 4.0.2.
Returns true if the file named by filename was uploaded via HTTP POST. This is useful to help ensure that a malicious user hasn't tried to trick the script into working on files upon which it should not be working--for instance, /etc/passwd.
This sort of check is especially important if there is any chance that anything done with uploaded files could reveal their contents to the user, or even to other users on the same system.
See also move_uploaded_file(), and the section Handling file uploads for a simple usage example.
Link() creates a hard link.
See also the symlink() to create soft links, and readlink() along with linkinfo().
Note: This function does not work on Windows systems
Linkinfo() returns the st_dev field of the UNIX C stat structure returned by the lstat system call. This function is used to verify if a link (pointed to by path) really exists (using the same method as the S_ISLNK macro defined in stat.h). Returns 0 or FALSE in case of error.
See also symlink(), link(), and readlink().
Note: This function does not work on Windows systems
Attempts to create the directory specified by pathname.
Note that you probably want to specify the mode as an octal number, which means it should have a leading zero.
Returns true on success and false on failure.
See also rmdir().
This function is available only in versions of PHP 3 after PHP 3.0.16, and in versions of PHP 4 after 4.0.2.
This function checks to ensure that the file designated by filename is a valid upload file (meaning that it was uploaded via PHP's HTTP POST upload mechanism). If the file is valid, it will be moved to the filename given by destination.
If filename is not a valid upload file, then no action will occur, and move_uploaded_file() will return false.
If filename is a valid upload file, but cannot be moved for some reason, no action will occur, and move_uploaded_file() will return false. Additionally, a warning will be issued.
This sort of check is especially important if there is any chance that anything done with uploaded files could reveal their contents to the user, or even to other users on the same system.
See also is_uploaded_file(), and the section Handling file uploads for a simple usage example.
Closes a file pointer to a pipe opened by popen().
The file pointer must be valid, and must have been returned by a successful call to popen().
Returns the termination status of the process that was run.
See also popen().
Opens a pipe to a process executed by forking the command given by command.
Returns a file pointer identical to that returned by fopen(), except that it is unidirectional (may only be used for reading or writing) and must be closed with pclose(). This pointer may be used with fgets(), fgetss(), and fputs().
If an error occurs, returns false.
See also pclose().
Reads a file and writes it to standard output.
Returns the number of bytes read from the file. If an error occurs, false is returned and unless the function was called as @readfile, an error message is printed.
If filename begins with "http://" (not case sensitive), an HTTP 1.0 connection is opened to the specified server and the text of the response is written to standard output.
Does not handle HTTP redirects, so you must include trailing slashes on directories.
If filename begins with "ftp://" (not case sensitive), an ftp connection to the specified server is opened and the requested file is written to standard output. If the server does not support passive mode ftp, this will fail.
If filename begins with neither of these strings, the file will be opened from the filesystem and its contents written to standard output.
You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.
See also fpassthru(), file(), fopen(), include(), require(), and virtual().
Readlink() does the same as the readlink C function and returns the contents of the symbolic link path or 0 in case of error.
See also symlink(), readlink() and linkinfo().
Note: This function does not work on Windows systems
Sets the file position indicator for fp to the beginning of the file stream.
If an error occurs, returns 0.
The file pointer must be valid, and must point to a file successfully opened by fopen().
Attempts to remove the directory named by pathname. The directory must be empty, and the relevant permissions must permit. this.
If an error occurs, returns 0.
See also mkdir().
Gathers the statistics of the file named by filename.
Returns an array with the statistics of the file with the following elements:
device
inode
inode protection mode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated
The results of this function are cached. See clearstatcache() for more details.
Gathers the statistics of the file or symbolic link named by filename. This function is identical to the stat() function except that if the filename parameter is a symbolic link, the status of the symbolic link is returned, not the status of the file pointed to by the symbolic link.
Returns an array with the statistics of the file with the following elements:
device
inode
inode protection mode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated
The results of this function are cached. See clearstatcache() for more details.
realpath() expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path and return the canonicalized absolute pathname. The resulting path will have no symbolic link, '/./' or '/../' components.
symlink() creates a symbolic link from the existing target with the specified name link.
See also link() to create hard links, and readlink() along with linkinfo().
Note: This function does not work on Windows systems.
Creates a unique temporary filename in the specified directory. If the directory does not exist, tempnam() may generate a filename in the system's temporary directory.
The behaviour of the tempnam() function is system dependent. On Windows the TMP environment variable will override the dir parameter, on Linux the TMPDIR environment variable has precedence, while SVR4 will always use your dir parameter if the directory it points to exists. Consult your system documentation on the tempnam(3) function if in doubt.
Returns the new temporary filename, or the null string on failure.
Note: This function's behavior changed in 4.0.3. The temporary file is also created to avoid a race condition where the file might appear in the filesystem between the time the string was generated and before the the script gets around to creating the file.
See also tmpfile().
Creates a temporary file with an unique name in write mode, returning a file handle similar to the one returned by fopen(). The file is automatically removed when closed (using fclose()), or when the script ends.
For details, consult your system documentation on the tmpfile(3) function, as well as the stdio.h header file.
See also tempnam().
Attempts to set the modification time of the file named by filename to the value given by time. If the option time is not given, uses the present time.
If the file does not exist, it is created.
Returns true on success and false otherwise.
Umask() sets PHP's umask to mask & 0777 and returns the old umask. When PHP is being used as a server module, the umask is restored when each request is finished.
Umask() without arguments simply returns the current umask.
Note: This function may not work on Windows systems.
Deletes filename. Similar to the Unix C unlink() function.
Returns 0 or FALSE on an error.
See also rmdir() for removing directories.
Note: This function may not work on Windows systems.
Forms Data Format (FDF) is a format for handling forms within PDF documents. You should read the documentation at http://partners.adobe.com/asn/developer/acrosdk/forms.html for more information on what FDF is and how it is used in general.
Note: If you run into problems configuring php with fdftk support, check whether the header file FdfTk.h and the library libFdfTk.so are at the right place. They should be in fdftk-dir/include and fdftk-dir/lib. This will not be the case if you just unpack the FdfTk distribution.
The general idea of FDF is similar to HTML forms. The diffence is basically the format how data is transmitted to the server when the submit button is pressed (this is actually the Form Data Format) and the format of the form itself (which is the Portable Document Format, PDF). Processing the FDF data is one of the features provided by the fdf functions. But there is more. One may as well take an existing PDF form and populated the input fields with data without modifying the form itself. In such a case one would create a FDF document (fdf_create()) set the values of each input field (fdf_set_value()) and associate it with a PDF form (fdf_set_file()). Finally it has to be sent to the browser with MimeType application/vnd.fdf. The Acrobat reader plugin of your browser recognizes the MimeType, reads the associated PDF form and fills in the data from the FDF document.
If you look at an FDF-document with a text editor you will find a catalogue object with the name FDF. Such an object may contain a number of entries like Fields, F, Status etc.. The most commonly used entries are Fields whicht points to a list of input fields, and F which contains the filename of the PDF-document this data belongs to. Those entries are referred to in the FDF documention as /F-Key or /Status-Key. Modifying this entries is done by functions like fdf_set_file() and fdf_set_status(). Fields are modified with fdf_set_value(), fdf_set_opt() etc..
The following examples shows just the evaluation of form data.
Example 1. Evaluating a FDF document
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The fdf_open() function opens a file with form data. This file must contain the data as returned from a PDF form. Currently, the file has to be created 'manually' by using fopen() and writing the content of HTTP_FDF_DATA with fwrite() into it. A mechanism like for HTML form data where for each input field a variable is created does not exist.
See also fdf_close().
The fdf_create() creates a new FDF document. This function is needed if one would like to populate input fields in a PDF document with data.
Example 1. Populating a PDF document
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See also fdf_close(), fdf_save(), fdf_open().
The fdf_save() function saves a FDF document. The FDF Toolkit provides a way to output the document to stdout if the parameter filename is '.'. This does not work if PHP is used as an apache module. In such a case one will have to write to a file and use e.g. fpassthru(). to output it.
See also fdf_close() and example for fdf_create().
The fdf_set_value() function sets the value of a field. The last parameter determines if the field value is to be converted to a PDF Name (isName = 1) or set to a PDF String (isName = 0).
See also fdf_get_value().
The fdf_next_field_name() function returns the name of the field after the field in fieldname or the field name of the first field if the second paramter is NULL.
See also fdf_set_field(), fdf_get_field().
boolean fdf_set_ap (int fdf_document, string field_name, int face, string filename, int page_number)
The fdf_set_ap() function sets the appearance of a field (i.e. the value of the /AP key). The possible values of face are 1=FDFNormalAP, 2=FDFRolloverAP, 3=FDFDownAP.
The fdf_set_file() sets the value of the /F key. The /F key is just a reference to a PDF form which is to be populated with data. In a web environment it is a URL (e.g. http:/testfdf/resultlabel.pdf).
See also fdf_get_file() and example for fdf_create().
The fdf_set_flags() sets certain flags of the given field fieldname.
See also fdf_set_opt().
boolean fdf_set_submit_form_action (int fdf_document, string fieldname, int trigger, string script, int flags)
The fdf_set_submit_form_action() sets a submit form action for the given field fieldname.
See also fdf_set_javascript_action().
The fdf_set_javascript_action() sets a javascript action for the given field fieldname.
See also fdf_set_submit_form_action().
FTP stands for File Transfer Protocol.
The following constants are defined when using the FTP module: FTP_ASCII and FTP_BINARY.
Example 1. ftp() example
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Returns a FTP stream on success, false on error.
ftp_connect() opens up a FTP connection to the specified host. The port parameter specifies an alternate port to connect to. If it is omitted or zero, then the default FTP port, 21, will be used.
Returns the newly created directory name on success, false on error.
Creates the specified directory.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
ftp_rawlist -- Returns a detailed list of files in the given directory.ftp_rawlist() executes the FTP LIST command, and returns the result as an array. Each array element corresponds to one line of text. The output is not parsed in any way. The system type identifier returned by ftp_systype() can be used to determine how the results should be interpreted.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
ftp_systype -- Returns the system type identifier of the remote FTP server.Returns true on success, false on error.
ftp_pasv() turns on passive mode if the pasv parameter is true (it turns off passive mode if pasv is false.) In passive mode, data connections are initiated by the client, rather than by the server.
Returns true on success, false on error.
ftp_get() retrieves remote_file from the FTP server, and saves it to local_file locally. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
ftp_fget -- Downloads a file from the FTP server and saves to an open file.Returns true on success, false on error.
ftp_fget() retrieves remote_file from the FTP server, and writes it to the given file pointer, fp. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.
Returns true on success, false on error.
ftp_put() stores local_file on the FTP server, as remote_file. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.
Returns true on success, false on error.
ftp_fput() uploads the data from the file pointer fp until end of file. The results are stored in remote_file on the FTP server. The transfer mode specified must be either FTP_ASCII or FTP_BINARY
Returns the file size on success, or -1 on error.
ftp_size() returns the size of a file. If an error occurs, of if the file does not exist, -1 is returned. Not all servers support this feature.
Returns a UNIX timestamp on success, or -1 on error.
ftp_mdtm() checks the last-modified time for a file, and returns it as a UNIX timestamp. If an error occurs, or the file does not exist, -1 is returned. Note that not all servers support this feature.
Note: ftp_mdtm() does not work with directories.
Returns true on success, false on error.
ftp_rename() renames the file specified by from to the new name to
Returns true on success, false on error.
ftp_delete() deletes the file specified by path from the FTP server.
Returns true on success, false on error.
ftp_site() sends the command specified by cmd to the FTP server. SITE commands are not standardized, and vary from server to server. They are useful for handling such things as file permissions and group membership.
Creates an anonymous function from the parameters passed, and returns a unique name for it. Usually the args will be passed as a single quote delimited string, and this is also recommended for the code. The reason for using single quoted strings, is to protect the variable names from parsing, otherwise, if you use double quotes there will be a need to escape the variable names, e.g. \$avar.
You can use this function, to (for example) create a function from information gathered at run time:
Example 1. Creating an anonymous function with create_function()
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Example 2. Making a general processing function with create_function()
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Using the first array of anonymous functions
parameters: 2.3445, M_PI
some trig: -1.6291725057799
a hypotenuse: 3.9199852871011
b*a^2 = 4.8103313314525
min(b^2+a, a^2,b) = 8.6382729035898
ln(a/b) = 0.27122299212594
Using the second array of anonymous functions
** "Twas the night" and "Twas brilling and the slithy toves"
** Look the same to me! (looking at the first 3 chars)
CRCs: -725381282 , 1908338681
similar(a,b) = 11(45.833333333333%)
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Example 3. Using anonymous functions as callback functions
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Returns the argument which is at the arg_num'th offset into a user-defined function's argument list. Function arguments are counted starting from zero. Func_get_arg() will generate a warning if called from outside of a function definition.
If arg_num is greater than the number of arguments actually passed, a warning will be generated and func_get_arg() will return FALSE.
<?php
function foo() {
$numargs = func_num_args();
echo "Number of arguments: $numargs<br>\n";
if ($numargs >= 2) {
echo "Second argument is: " . func_get_arg (1) . "<br>\n";
}
}
foo (1, 2, 3);
?>
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Func_get_arg() may be used in conjunction with func_num_args() and func_get_args() to allow user-defined functions to accept variable-length argument lists.
Note: This function was added in PHP 4.
Returns an array in which each element is the corresponding member of the current user-defined function's argument list. Func_get_args() will generate a warning if called from outside of a function definition.
<?php
function foo() {
$numargs = func_num_args();
echo "Number of arguments: $numargs<br>\n";
if ($numargs >= 2) {
echo "Second argument is: " . func_get_arg (1) . "<br>\n";
}
$arg_list = func_get_args();
for ($i = 0; $i < $numargs; $i++) {
echo "Argument $i is: " . $arg_list[$i] . "<br>\n";
}
}
foo (1, 2, 3);
?>
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Func_get_args() may be used in conjunction with func_num_args() and func_get_arg() to allow user-defined functions to accept variable-length argument lists.
Note: This function was added in PHP 4.
Returns the number of arguments passed into the current user-defined function. Func_num_args() will generate a warning if called from outside of a function definition.
<?php
function foo() {
$numargs = func_num_args();
echo "Number of arguments: $numargs\n";
}
foo (1, 2, 3); // Prints 'Number of arguments: 3'
?>
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Func_num_args() may be used in conjunction with func_get_arg() and func_get_args() to allow user-defined functions to accept variable-length argument lists.
Note: This function was added in PHP 4.
Checks the list of defined functions for function_name. Returns true if the given function name was found, false otherwise.
if (function_exists('imap_open')) {
echo "IMAP functions are available.<br>\n";
} else {
echo "IMAP functions are not available.<br>\n";
}
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See also method_exists().
The gettext functions implement a NLS (Native Language Support) API which can be used to internationalize your PHP applications. Please see the GNU gettext documentation for a thorough explanation of these functions.
This function allows you to override the current domain for a single message lookup. It also allows you to specify a category.
The dgettext() function allows you to override the current domain for a single message lookup.
This function returns a translated string if one is found in the translation table, or the submitted message if not found. You may use an underscore character as an alias to this function.
This function sets the domain to search within when calls are made to gettext(), usually the named after an application. The previous default domain is returned. Call it with no parameters to get the current setting without changing it.
These functions allow you to work with arbitrary-length integers using GNU MP library. In order to have these functions available, you must compile PHP with GMP support by using the --with-gmp option.
You can download the GMP library from http://www.swox.com/gmp/. This site also has the GMP manual available.
You will need GMP version 2 or better to use these functions. Some functions may require more recent version of the GMP library.
These functions have been added in PHP 4.0.4.
Note: Most GMP functions accept GMP number arguments, defined as resource below. However, most of these functions will accept also numeric and string arguments, given it's possible to convert the latter to number. Also, if there's faster function that can operate on integer arguments, it would be used instead of slower function when supplied arguments are integers. This is done transparently, so the bottom line is that you can use integers in every function that expects GMP number. See also gmp_init() function.
This will calculate factiorial of 1000 (pretty big number) very fast.
Creates a GMP number from integer or string. String representation can be decimal or hexadecimal. In the latter case, the string should start with 0x.
Note: It is not necessary to call this function if you want to use integer or string in place of GMP number in GMP functions, like gmp_add(). Function arguments are automatically converted to GMP numbers, if such conversion is possible and needed, using the same rules as gmp_init().
This function allows to convert GMP number to integer.
| Warning |
This function returns useful result only if the number actually fits the PHP integer (i.e., signed long type). If you want just to print the GMP number, use gmp_strval(). |
Convert GMP number to string representation in base base. The default base is 10. Allowed values for the base are from 2 to 36.
Add two GMP numbers. The result will be GMP number representing the sum of the arguments.
Divides a by b and returns the integer result. The result rounding is defined by the round, which can have the following values:
GMP_ROUND_ZERO: The result is truncated towards 0.
GMP_ROUND_PLUSINF: The result is rounded towards +infinity.
GMP_ROUND_MINUSINF: The result is rounded towards -infinity.
This function can also be called as gmp_div().
See also gmp_div_r(), gmp_div_qr()
Calculates remainder of the integer division of n by d. The remainder has the sign of the n argument, if not zero.
See the gmp_div_q() function for description of the round argument.
See also gmp_div_q(), gmp_div_qr()
The function divides n by d and returns array, with the first element being [n/d] (the integer result of the division) and the second being (n - [n/d] * d) (the remainder of the division).
See the gmp_div_q() function for description of the round argument.
See also gmp_div_q(), gmp_div_r().
Divides n by d, using fast "exact division" algorithm. This function produces correct results only when it is known in advance that d divides n.
Returns array where first element is the integer square root of a (see also gmp_sqrt()), and the second is the remainder (i.e., the difference between a and the first element squared).
Returns true if a is a prefect square, false otherwise.
See also: gmp_sqrt(), gmp_sqrtrm().
Calculate (base raised into power exp) modulo mod. If exp is negative, result is undefined.
If this function returns 0, a is definitely not prime. If it returns 1, then a is "probably" prime. If it returns 2, then a is surely prime. Reasonable values of reps vary from 5 to 10 (default being 10); a higher value lowers the probability for a non-prime to pass as a "probable" prime.
The function uses Miller-Rabin's probabilistic test.
Calculate greatest common divisor of a and b. The result is always positive even if either of or both input operands are negative.
Calculates g, s, and t, such that a*s + b*t = g = gcd(a,b), where gcd is gretest common divisor. Returns array with respective elements g, s and t.
Generate a random number. The number will be up to limiter words long. If limiter is negative, negative numbers are generated.
Sets bit index in a. set_clear defines if the bit is set to 0 or 1. By default the bit is set to 1.
Scans a, starting with bit start, towards more significant bits, until the first clear bit is found. Returns the index of the found bit.
Scans a, starting with bit start, towards more significant bits, until the first set bit is found. Returns the index of the found bit.
These functions let you manipulate the output sent back to the remote browser right down to the HTTP protocol level.
The Header() function is used at the top of an HTML file to send raw HTTP header strings. See the HTTP 1.1 Specification for more information on raw http headers. Note: Remember that the Header() function must be called before any actual output is sent either by normal HTML tags or from PHP. It is a very common error to read code with include() or with auto_prepend and have spaces or empty lines in this code that force output before header() is called.
There are two special-case header calls. The first is the "Location" header. Not only does it send this header back to the browser, it also returns a REDIRECT status code to Apache. From a script writer's point of view this should not be important, but for people who understand Apache internals it is important to understand.
header ("Location: http://www.php.net"); /* Redirect browser
to PHP web site */
exit; /* Make sure that code below does
not get executed when we redirect. */
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The second special-case is any header that starts with the string, "HTTP/" (case is not significant). For example, if you have your ErrorDocument 404 Apache directive pointed to a PHP script, it would be a good idea to make sure that your PHP script is actually generating a 404. The first thing you do in your script should then be:
PHP scripts often generate dynamic HTML that must not be cached by the client browser or any proxy caches between the server and the client browser. Many proxies and clients can be forced to disable caching with
header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
// always modified
header ("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header ("Pragma: no-cache"); // HTTP/1.0
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See also headers_sent()
This function returns true if the HTTP headers have already been sent, false otherwise.
See also header()
int setcookie (string name [, string
value [, int
expire [, string
path [, string
domain [, int
secure]]]]])
Setcookie() defines a cookie to be sent along with the rest of the header information. Cookies must be sent before any other headers are sent (this is a restriction of cookies, not PHP). This requires you to place calls to this function before any <html> or <head> tags.
All the arguments except the name argument are optional. If only the name argument is present, the cookie by that name will be deleted from the remote client. You may also replace any argument with an empty string ("") in order to skip that argument. The expire and secure arguments are integers and cannot be skipped with an empty string. Use a zero (0) instead. The expire argument is a regular Unix time integer as returned by the time() or mktime() functions. The secure indicates that the cookie should only be transmitted over a secure HTTPS connection.
Common Pitfalls:
Cookies will not become visible until the next loading of a page that the cookie should be visible for.
Cookies must be deleted with the same parameters as they were set with.
In PHP 3, multiple calls to setcookie() in the same script will be performed in reverse order. If you are trying to delete one cookie before inserting another you should put the insert before the delete. In PHP 4, multiple calls to setcookie() are performed in the order called.
Some examples follow how to send cookies:
Examples follow how to delete cookies send in previous example:
Note that the value portion of the cookie will automatically be urlencoded when you send the cookie, and when it is received, it is automatically decoded and assigned to a variable by the same name as the cookie name. To see the contents of our test cookie in a script, simply use one of the following examples:
You may also set array cookies by using array notation in the cookie name. This has the effect of setting as many cookies as you have array elements, but when the cookie is received by your script, the values are all placed in an array with the cookie's name:
setcookie ("cookie[three]", "cookiethree");
setcookie ("cookie[two]", "cookietwo");
setcookie ("cookie[one]", "cookieone");
if (isset ($cookie)) {
while (list ($name, $value) = each ($cookie)) {
echo "$name == $value<br>\n";
}
}
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For more information on cookies, see Netscape's cookie specification at http://www.netscape.com/newsref/std/cookie_spec.html.
Microsoft Internet Explorer 4 with Service Pack 1 applied does not correctly deal with cookies that have their path parameter set.
Netscape Communicator 4.05 and Microsoft Internet Explorer 3.x appear to handle cookies incorrectly when the path and time are not set.
Hyperwave has been developed at IICM in Graz. It started with the name Hyper-G and changed to Hyperwave when it was commercialised (If I remember properly it was in 1996).
Hyperwave is not free software. The current version, 4.1, is available at www.hyperwave.com. A time limited version can be ordered for free (30 days).
Hyperwave is an information system similar to a database (HIS, Hyperwave Information Server). Its focus is the storage and management of documents. A document can be any possible piece of data that may as well be stored in file. Each document is accompanied by its object record. The object record contains meta data for the document. The meta data is a list of attributes which can be extended by the user. Certain attributes are always set by the Hyperwave server, other may be modified by the user. An attribute is a name/value pair of the form name=value. The complete object record contains as many of those pairs as the user likes. The name of an attribute does not have to be unique, e.g. a title may appear several times within an object record. This makes sense if you want to specify a title in several languages. In such a case there is a convention, that each title value is preceded by the two letter language abbreviation followed by a colon, e.g. 'en:Title in English' or 'ge:Titel in deutsch'. Other attributes like a description or keywords are potential candidates. You may also replace the language abbreviation by any other string as long as it separated by colon from the rest of the attribute value.
Each object record has native a string representation with each name/value pair separated by a newline. The Hyperwave extension also knows a second representation which is an associated array with the attribute name being the key. Multilingual attribute values itself form another associated array with the key being the language abbreviation. Actually any multiple attribute forms an associated array with the string left to the colon in the attribute value being the key. (This is not fully implemented. Only the attributes Title, Description and Keyword are treated properly yet.)
Besides the documents, all hyper links contained in a document are stored as object records as well. Hyper links which are in a document will be removed from it and stored as individual objects, when the document is inserted into the database. The object record of the link contains information about where it starts and where it ends. In order to gain the original document you will have to retrieve the plain document without the links and the list of links and reinsert them (The functions hw_pipedocument() and hw_gettext() do this for you. The advantage of separating links from the document is obvious. Once a document to which a link is pointing to changes its name, the link can easily be modified accordingly. The document containing the link is not affected at all. You may even add a link to a document without modifying the document itself.
Saying that hw_pipedocument() and hw_gettext() do the link insertion automatically is not as simple as it sounds. Inserting links implies a certain hierarchy of the documents. On a web server this is given by the file system, but Hyperwave has its own hierarchy and names do not reflect the position of an object in that hierarchy. Therefore creation of links first of all requires a mapping from the Hyperwave hierarchy and namespace into a web hierarchy respective web namespace. The fundamental difference between Hyperwave and the web is the clear distinction between names and hierarchy in Hyperwave. The name does not contain any information about the objects position in the hierarchy. In the web the name also contains the information on where the object is located in the hierarchy. This leads to two possibles ways of mapping. Either the Hyperwave hierarchy and name of the Hyperwave object is reflected in the URL or the name only. To make things simple the second approach is used. Hyperwave object with name 'my_object' is mapped to 'http://host/my_object' disregarding where it resides in the Hyperwave hierarchy. An object with name 'parent/my_object' could be the child of 'my_object' in the Hyperwave hierarchy, though in a web namespace it appears to be just the opposite and the user might get confused. This can only be prevented by selecting reasonable object names.
Having made this decision a second problem arises. How do you involve PHP? The URL http://host/my_object will not call any PHP script unless you tell your web server to rewrite it to e.g. 'http://host/php3_script/my_object' and the script 'php3_script' evaluates the $PATH_INFO variable and retrieves the object with name 'my_object' from the Hyperwave server. Their is just one little drawback which can be fixed easily. Rewriting any URL would not allow any access to other document on the web server. A PHP script for searching in the Hyperwave server would be impossible. Therefore you will need at least a second rewriting rule to exclude certain URLS like all e.g. starting with http://host/Hyperwave. This is basically sharing of a namespace by the web and Hyperwave server.
Based on the above mechanism links are insert into documents.
It gets more complicated if PHP is not run as a server module or CGI script but as a standalone application e.g. to dump the content of the Hyperwave server on a CD-ROM. In such a case it makes sense to retain the Hyperwave hierarchy and map in onto the file system. This conflicts with the object names if they reflect its own hierarchy (e.g. by choosing names including '/'). Therefore '/' has to be replaced by another character, e.g. '_'. to be continued.
The network protocol to communicate with the Hyperwave server is called HG-CSP (Hyper-G Client/Server Protocol). It is based on messages to initiate certain actions, e.g. get object record. In early versions of the Hyperwave Server two native clients (Harmony, Amadeus) were provided for communication with the server. Those two disappeared when Hyperwave was commercialised. As a replacement a so called wavemaster was provided. The wavemaster is like a protocol converter from HTTP to HG-CSP. The idea is to do all the administration of the database and visualisation of documents by a web interface. The wavemaster implements a set of placeholders for certain actions to customise the interface. This set of placeholders is called the PLACE Language. PLACE lacks a lot of features of a real programming language and any extension to it only enlarges the list of placeholders. This has led to the use of JavaScript which IMO does not make life easier.
Adding Hyperwave support to PHP should fill in the gap of a missing programming language for interface customisation. It implements all the messages as defined by the HG-CSP but also provides more powerful commands to e.g. retrieve complete documents.
Hyperwave has its own terminology to name certain pieces of information. This has widely been taken over and extended. Almost all functions operate on one of the following data types.
object ID: An unique integer value for each object in the Hyperwave server. It is also one of the attributes of the object record (ObjectID). Object ids are often used as an input parameter to specify an object.
object record: A string with attribute-value pairs of the form attribute=value. The pairs are separated by a carriage return from each other. An object record can easily be converted into an object array with hw_object2array(). Several functions return object records. The names of those functions end with obj.
object array: An associated array with all attributes of an object. The key is the attribute name. If an attribute occurs more than once in an object record it will result in another indexed or associated array. Attributes which are language depended (like the title, keyword, description) will form an associated array with the key set to the language abbreviation. All other multiple attributes will form an indexed array. PHP functions never return object arrays.
hw_document: This is a complete new data type which holds the actual document, e.g. HTML, PDF etc. It is somewhat optimised for HTML documents but may be used for any format.
Several functions which return an array of object records do also return an associated array with statistical information about them. The array is the last element of the object record array. The statistical array contains the following entries:
Number of object records with attribute PresentationHints set to Hidden.
Number of object records with attribute PresentationHints set to CollectionHead.
Number of object records with attribute PresentationHints set to FullCollectionHead.
Index in array of object records with attribute PresentationHints set to CollectionHead.
Index in array of object records with attribute PresentationHints set to FullCollectionHead.
Total: Number of object records.
The Hyperwave extension is best used when PHP is compiled as an Apache module. In such a case the underlying Hyperwave server can be hidden from users almost completely if Apache uses its rewriting engine. The following instructions will explain this.
Since PHP with Hyperwave support built into Apache is intended to replace the native Hyperwave solution based on Wavemaster I will assume that the Apache server will only serve as a Hyperwave web interface. This is not necessary but it simplifies the configuration. The concept is quite simple. First of all you need a PHP script which evaluates the PATH_INFO variable and treats its value as the name of a Hyperwave object. Let's call this script 'Hyperwave'. The URL http://your.hostname/Hyperwave/name_of_object would than return the Hyperwave object with the name 'name_of_object'. Depending on the type of the object the script has to react accordingly. If it is a collection, it will probably return a list of children. If it is a document it will return the mime type and the content. A slight improvement can be achieved if the Apache rewriting engine is used. From the users point of view it would be more straight forward if the URL http://your.hostname/name_of_object would return the object. The rewriting rule is quite easy:
Now every URL relates to an object in the Hyperwave server. This causes a simple to solve problem. There is no way to execute a different script, e.g. for searching, than the 'Hyperwave' script. This can be fixed with another rewriting rule like the following: This will reserve the directory /usr/local/apache/htdocs/hw for additional scripts and other files. Just make sure this rule is evaluated before the one above. There is just a little drawback: all Hyperwave objects whose name starts with 'hw/' will be shadowed. So, make sure you don't use such names. If you need more directories, e.g. for images just add more rules or place them all in one directory. Finally, don't forget to turn on the rewriting engine with My experiences have shown that you will need the following scripts:to return the object itself
to allow searching
to identify yourself
to set your profile
one for each additional function like to show the object attributes, to show information about users, to show the status of the server, etc.
There are still some things todo:
The hw_InsertDocument has to be split into hw_InsertObject() and hw_PutDocument().
The names of several functions are not fixed, yet.
Most functions require the current connection as its first parameter. This leads to a lot of typing, which is quite often not necessary if there is just one open connection. A default connection will improve this.
Conversion form object record into object array needs to handle any multiple attribute.
Converts an object_array into an object record. Multiple attributes like 'Title' in different languages are treated properly.
See also hw_objrec2array().
Returns an array of object ids. Each id belongs to a child of the collection with ID objectID. The array contains all children both documents and collections.
Returns an array of object records. Each object record belongs to a child of the collection with ID objectID. The array contains all children both documents and collections.
Returns false if connection is not a valid connection index, otherwise true. Closes down the connection to a Hyperwave server with the given connection index.
Opens a connection to a Hyperwave server and returns a connection index on success, or false if the connection could not be made. Each of the arguments should be a quoted string, except for the port number. The username and password arguments are optional and can be left out. In such a case no identification with the server will be done. It is similar to identify as user anonymous. This function returns a connection index that is needed by other Hyperwave functions. You can have multiple connections open at once. Keep in mind, that the password is not encrypted.
See also hw_pConnect().
Copies the objects with object ids as specified in the second parameter to the collection with the id destination id.
The value return is the number of copied objects.
See also hw_mv().
Deletes the object with the given object id in the second parameter. It will delete all instances of the object.
Returns TRUE if no error occurs otherwise FALSE.
See also hw_mv().
Returns the object record of the document.
For backward compatibility, hw_DocumentAttributes() is also accepted. This is deprecated, however.
See also hw_Document_BodyTag(), and hw_Document_Size().
Returns the BODY tag of the document. If the document is an HTML document the BODY tag should be printed before the document.
See also hw_Document_Attributes(), and hw_Document_Size().
For backward compatibility, hw_DocumentBodyTag() is also accepted. This is deprecated, however.
Returns the content of the document. If the document is an HTML document the content is everything after the BODY tag. Information from the HEAD and BODY tag is in the stored in the object record.
See also hw_Document_Attributes(), hw_Document_Size(), and hw_DocumentSetContent().
Sets or replaces the content of the document. If the document is an HTML document the content is everything after the BODY tag. Information from the HEAD and BODY tag is in the stored in the object record. If you provide this information in the content of the document too, the Hyperwave server will change the object record accordingly when the document is inserted. Probably not a very good idea. If this functions fails the document will retain its old content.
See also hw_Document_Attributes(), hw_Document_Size(), and hw_Document_Content().
Returns the size in bytes of the document.
See also hw_Document_BodyTag(), and hw_Document_Attributes().
For backward compatibility, hw_DocumentSize() is also accepted. This is deprecated, however.
Returns a string containing the last error message or 'No Error'. If false is returned, this function failed. The message relates to the last command.
Uploads the text document to the server. The object record of the document may not be modified while the document is edited. This function will only works for pure text documents. It will not open a special data connection and therefore blocks the control connection during the transfer.
See also hw_PipeDocument(), hw_FreeDocument(), hw_Document_BodyTag(), hw_Document_Size(), hw_Output_Document(), hw_GetText().
Returns the last error number. If the return value is 0 no error has occurred. The error relates to the last command.
Returns an indexed array of object ids. Each object id belongs to a parent of the object with ID objectID.
Returns an indexed array of object records plus an associated array with statistical information about the object records. The associated array is the last entry of the returned array. Each object record belongs to a parent of the object with ID objectID.
Returns an array of object ids. Each object ID belongs to a child collection of the collection with ID objectID. The function will not return child documents.
See also hw_GetChildren(), and hw_GetChildDocColl().
Returns an array of object records. Each object records belongs to a child collection of the collection with ID objectID. The function will not return child documents.
See also hw_ChildrenObj(), and hw_GetChildDocCollObj().
Returns a remote document. Remote documents in Hyperwave notation are documents retrieved from an external source. Common remote documents are for example external web pages or queries in a database. In order to be able to access external sources throught remote documents Hyperwave introduces the HGI (Hyperwave Gateway Interface) which is similar to the CGI. Currently, only ftp, http-servers and some databases can be accessed by the HGI. Calling hw_GetRemote() returns the document from the external source. If you want to use this function you should be very familiar with HGIs. You should also consider to use PHP instead of Hyperwave to access external sources. Adding database support by a Hyperwave gateway should be more difficult than doing it in PHP.
See also hw_GetRemoteChildren().
Returns the children of a remote document. Children of a remote document are remote documents itself. This makes sense if a database query has to be narrowed and is explained in Hyperwave Programmers' Guide. If the number of children is 1 the function will return the document itself formated by the Hyperwave Gateway Interface (HGI). If the number of children is greater than 1 it will return an array of object record with each maybe the input value for another call to hw_GetRemoteChildren(). Those object records are virtual and do not exist in the Hyperwave server, therefore they do not have a valid object ID. How exactely such an object record looks like is up to the HGI. If you want to use this function you should be very familiar with HGIs. You should also consider to use PHP instead of Hyperwave to access external sources. Adding database support by a Hyperwave gateway should be more difficult than doing it in PHP.
See also hw_GetRemote().
Returns the object records of all anchors pointing to the object with ID objectID. The object can either be a document or an anchor of type destination.
See also hw_GetAnchors().
Returns the object record for the object with ID objectID if the second parameter is an integer. If the second parameter is an array of integer the function will return an array of object records. In such a case the last parameter is also evaluated which is a query string.
The query string has the following syntax:
<expr> ::= "(" <expr> ")" |
"!" <expr> | /* NOT */
<expr> "||" <expr> | /* OR */
<expr> "&&" <expr> | /* AND */
<attribute> <operator> <value>
<attribute> ::= /* any attribute name (Title, Author, DocumentType ...) */
<operator> ::= "=" | /* equal */
"<" | /* less than (string compare) */
">" | /* greater than (string compare) */
"~" /* regular expression matching */
The query allows to further select certain objects from the list of given objects. Unlike the other query functions, this query may use not indexed attributes. How many object records are returned depends on the query and if access to the object is allowed.
See also hw_GetAndLock(), and hw_GetObjectByQuery().
Returns the object record for the object with ID objectID. It will also lock the object, so other users cannot access it until it is unlocked.
See also hw_Unlock(), and hw_GetObject().
Returns the document with object ID objectID. If the document has anchors which can be inserted, they will be inserted already. The optional parameter rootID/prefix can be a string or an integer. If it is an integer it determines how links are inserted into the document. The default is 0 and will result in links that are constructed from the name of the link's destination object. This is useful for web applications. If a link points to an object with name 'internet_movie' the HTML link will be <A HREF="/internet_movie">. The actual location of the source and destination object in the document hierachy is disregarded. You will have to set up your web browser, to rewrite that URL to for example '/my_script.php3/internet_movie'. 'my_script.php3' will have to evaluate $PATH_INFO and retrieve the document. All links will have the prefix '/my_script.php3/'. If you do not want this you can set the optional parameter rootID/prefix to any prefix which is used instead. Is this case it has to be a string.
If rootID/prefix is an integer and unequal to 0 the link is constructed from all the names starting at the object with the id rootID/prefix separated by a slash relative to the current object. If for example the above document 'internet_movie' is located at 'a-b-c-internet_movie' with '-' being the seperator between hierachy levels on the Hyperwave server and the source document is located at 'a-b-d-source' the resulting HTML link would be: <A HREF="../c/internet_movie">. This is useful if you want to download the whole server content onto disk and map the document hierachy onto the file system.
This function will only work for pure text documents. It will not open a special data connection and therefore blocks the control connection during the transfer.
See also hw_PipeDocument(), hw_FreeDocument(), hw_Document_BodyTag(), hw_Document_Size(), and hw_Output_Document().
Searches for objects on the whole server and returns an array of object ids. The maximum number of matches is limited to max_hits. If max_hits is set to -1 the maximum number of matches is unlimited.
The query will only work with indexed attributes.
See also hw_GetObjectByQueryObj().
Searches for objects on the whole server and returns an array of object records. The maximum number of matches is limited to max_hits. If max_hits is set to -1 the maximum number of matches is unlimited.
The query will only work with indexed attributes.
See also hw_GetObjectByQuery().
Searches for objects in collection with ID objectID and returns an array of object ids. The maximum number of matches is limited to max_hits. If max_hits is set to -1 the maximum number of matches is unlimited.
The query will only work with indexed attributes.
See also hw_GetObjectByQueryCollObj().
Searches for objects in collection with ID objectID and returns an array of object records. The maximum number of matches is limited to max_hits. If max_hits is set to -1 the maximum number of matches is unlimited.
The query will only work with indexed attributes.
See also hw_GetObjectByQueryColl().
Returns array of object ids for child documents of a collection.
See also hw_GetChildren(), and hw_GetChildColl().
Returns an array of object records for child documents of a collection.
See also hw_ChildrenObj(), and hw_GetChildCollObj().
Returns an array of object records with anchors of the document with object ID objectID.
Moves the objects with object ids as specified in the second parameter from the collection with id source id to the collection with the id destination id. If the destination id is 0 the objects will be unlinked from the source collection. If this is the last instance of that object it will be deleted. If you want to delete all instances at once, use hw_deleteobject().
The value return is the number of moved objects.
See also hw_cp(), and hw_deleteobject().
Identifies as user with username and password. Identification is only valid for the current session. I do not thing this function will be needed very often. In most cases it will be easier to identify with the opening of the connection.
See also hw_Connect().
array hw_incollections (int connection, array object_id_array, array collection_id_array, int return_collections)
Checks whether a set of objects (documents or collections) specified by the object_id_array is part of the collections listed in collection_id_array. When the fourth parameter return_collections is 0, the subset of object ids that is part of the collections (i.e., the documents or collections that are children of one or more collections of collection ids or their subcollections, recursively) is returned as an array. When the fourth parameter is 1, however, the set of collections that have one or more objects of this subset as children are returned as an array. This option allows a client to, e.g., highlight the part of the collection hierarchy that contains the matches of a previous query, in a graphical overview.
Returns information about the current connection. The returned string has the following format: <Serverstring>, <Host>, <Port>, <Username>, <Port of Client>, <Byte swapping>
Inserts a new collection with attributes as in object_array into collection with object ID objectID.
Inserts a new document with attributes as in object_record into collection with object ID parentID. This function inserts either an object record only or an object record and a pure ascii text in text if text is given. If you want to insert a general document of any kind use hw_insertdocument() instead.
See also hw_InsertDocument(), and hw_InsColl().
Uploads a document into the collection with parent_id. The document has to be created before with hw_NewDocument(). Make sure that the object record of the new document contains at least the attributes: Type, DocumentType, Title and Name. Possibly you also want to set the MimeType. The functions returns the object id of the new document or false.
See also hw_PipeDocument().
Inserts an object into the server. The object can be any valid hyperwave object. See the HG-CSP documentation for a detailed information on how the parameters have to be.
Note: If you want to insert an Anchor, the attribute Position has always been set either to a start/end value or to 'invisible'. Invisible positions are needed if the annotation has no correspondig link in the annotation text.
See also hw_PipeDocument(), hw_InsertDocument(), hw_InsDoc(), and hw_InsColl().
Maps a global object id on any hyperwave server, even those you did not connect to with hw_connect(), onto a virtual object id. This virtual object id can then be used as any other object id, e.g. to obtain the object record with hw_getobject(). The server id is the first part of the global object id (GOid) of the object which is actually the IP number as an integer.
Note: In order to use this function you will have to set the F_DISTRIBUTED flag, which can currently only be set at compile time in hg_comm.c. It is not set by default. Read the comment at the beginning of hg_comm.c
This command allows to remove, add, or modify individual attributes of an object record. The object is specified by the Object ID object_to_change. The first array remove is a list of attributes to remove. The second array add is a list of attributes to add. In order to modify an attribute one will have to remove the old one and add a new one. hw_modifyobject() will always remove the attributes before it adds attributes unless the value of the attribute to remove is not a string or array.
The last parameter determines if the modification is performed recursively. 1 means recurive modification. If some of the objects cannot be modified they will be skiped without notice. hw_error() may not indicate an error though some of the objects could not be modified.
The keys of both arrays are the attributes name. The value of each array element can either be an array, a string or anything else. If it is an array each attribute value is constructed by the key of each element plus a colon and the value of each element. If it is a string it is taken as the attribute value. An empty string will result in a complete removal of that attribute. If the value is neither a string nor an array but something else, e.g. an integer, no operation at all will be performed on the attribute. This is neccessary if you want to to add a completely new attribute not just a new value for an existing attribute. If the remove array contained an empty string for that attribute, the attribute would be tried to be removed which would fail since it doesn't exist. The following addition of a new value for that attribute would also fail. Setting the value for that attribute to e.g. 0 would not even try to remove it and the addition will work.
If you would like to change the attribute 'Name' with the current value 'books' into 'articles' you will have to create two arrays and call hw_modifyobject().
Note: Multilingual attributes, e.g. 'Title', can be modified in two ways. Either by providing the attributes value in its native form 'language':'title' or by providing an array with elements for each language as described above. The above example would than be:
Note: This will remove all attributes with the name 'Title' and adds a new 'Title' attribute. This comes in handy if you want to remove attributes recursively.
Note: If you need to delete all attributes with a certain name you will have to pass an empty string as the attribute value.
Note: Only the attributes 'Title', 'Description' and 'Keyword' will properly handle the language prefix. If those attributes don't carry a language prefix, the prefix 'xx' will be assigned.
Note: The 'Name' attribute is somewhat special. In some cases it cannot be complete removed. You will get an error message 'Change of base attribute' (not clear when this happens). Therefore you will always have to add a new Name first and than remove the old one.
Note: You may not suround this function by calls to hw_getandlock() and hw_unlock(). hw_modifyobject() does this internally.
Returns TRUE if no error occurs otherwise FALSE.
Returns a new Hyperwave document with document data set to document_data and object record set to object_record. The length of the document_data has to passed in document_sizeThis function does not insert the document into the Hyperwave server.
See also hw_FreeDocument(), hw_Document_Size(), hw_Document_BodyTag(), hw_Output_Document(), and hw_InsertDocument().
Converts an object_record into an object array. The keys of the resulting array are the attributes names. Multi-value attributes like 'Title' in different languages form its own array. The keys of this array are the left part to the colon of the attribute value. This left part must be two characters long. Other multi-value attributes without a prefix form an indexed array. If the optional parameter is missing the attributes 'Title', 'Description' and 'Keyword' are treated as language attributes and the attributes 'Group', 'Parent' and 'HtmlAttr' as non-prefixed multi-value attributes. By passing an array holding the type for each attribute you can alter this behaviour. The array is an associated array with the attribute name as its key and the value being one of HW_ATTR_LANG or HW_ATTR_NONE
See also hw_array2objrec().
Prints the document without the BODY tag.
For backward compatibility, hw_OutputDocument() is also accepted. This is deprecated, however.
Returns a connection index on success, or false if the connection could not be made. Opens a persistent connection to a Hyperwave server. Each of the arguments should be a quoted string, except for the port number. The username and password arguments are optional and can be left out. In such a case no identification with the server will be done. It is similar to identify as user anonymous. This function returns a connection index that is needed by other Hyperwave functions. You can have multiple persistent connections open at once.
See also hw_Connect().
Returns the Hyperwave document with object ID objectID. If the document has anchors which can be inserted, they will have been inserted already. The document will be transfered via a special data connection which does not block the control connection.
See also hw_GetText() for more on link insertion, hw_FreeDocument(), hw_Document_Size(), hw_Document_BodyTag(), and hw_Output_Document().
Returns the object ID of the hyperroot collection. Currently this is always 0. The child collection of the hyperroot is the root collection of the connected server.
Returns an array of users currently logged into the Hyperwave server. Each entry in this array is an array itself containing the elements id, name, system, onSinceDate, onSinceTime, TotalTime and self. 'self' is 1 if this entry belongs to the user who initianted the request.
To get these functions to work, you have to compile PHP with --with-icap. That requires the icap library to be installed. Grab the latest version from http://icap.chek.com/ and compile and install it.
Returns an ICAP stream on success, false on error.
icap_open() opens up an ICAP connection to the specified calendar store. If the optional options is specified, passes the options to that mailbox also.
Icap_fetch_event() fetches an event from the calendar stream specified by event_id.
Returns an event object consisting of:
int id - ID of that event.
int public - TRUE if the event if public, FALSE if it is private.
string category - Category string of the event.
string title - Title string of the event.
string description - Description string of the event.
int alarm - number of minutes before the event to send an alarm/reminder.
object start - Object containing a datetime entry.
object end - Object containing a datetime entry.
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
Returns an array of event ID's that are between the two given datetimes.
Icap_list_events() function takes in a beginning datetime and an end datetime for a calendar stream. An array of event id's that are between the given datetimes are returned.
All datetime entries consist of an object that contains:
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
Icap_store_event() Stores an event into an ICAP calendar. An event object consists of:
int public - 1 if public, 0 if private;
string caegory - Category string of the event.
string title - Title string of the event.
string description - Description string of the event.
int alarm - Number of minutes before the event to sned out an alarm.
datetime start - datetime object of the start of the event.
datetime end - datetime object of the end of the event.
All datetime entries consist of an object that contains:
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
Returns true on success and false on error.
Icap_snooze() turns on an alarm for a calendar event specified by the uid.
Returns true.
(PHP 4 >= 4.0b4)
icap_list_alarms -- Return a list of events that has an alarm triggered at the given datetimeReturns an array of event ID's that has an alarm going off at the given datetime.
Icap_list_alarms() function takes in a datetime for a calendar stream. An array of event id's that has an alarm should be going off at the datetime are returned.
All datetime entries consist of an object that contains:
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
You can use the image functions in PHP to get the size of JPEG, GIF, PNG, and SWF images, and if you have the GD library (available at http://www.boutell.com/gd/) you will also be able to create and manipulate images.
The format of images you are able to manipulate depend on the version of gd you install, and any other libraries gd might need to access those image formats. Versions of gd older than gd-1.6 support gif format images, and do not support png, where versions greater than gd-1.6 support png, not gif.
In order to read and write images in jpeg format, you will need to obtain and install jpeg-6b (available at ftp://ftp.uu.net/graphics/jpeg/), and then recompile gd to make use of jpeg-6b. You will also have to compile PHP with --with-jpeg-dir=/path/to/jpeg-6b.
To add support for Type 1 fonts, you can install t1lib (available at ftp://ftp.neuroinformatik.ruhr-uni-bochum.de/pub/software/t1lib/), and then add --with-t1lib[=dir].
The GetImageSize() function will determine the size of any GIF, JPG, PNG or SWF image file and return the dimensions along with the file type and a height/width text string to be used inside a normal HTML IMG tag.
Returns an array with 4 elements. Index 0 contains the width of the image in pixels. Index 1 contains the height. Index 2 a flag indicating the type of the image. 1 = GIF, 2 = JPG, 3 = PNG, 4 = SWF. Index 3 is a text string with the correct "height=xxx width=xxx" string that can be used directly in an IMG tag.
The optional imageinfo parameter allows you to extract some extended information from the image file. Currently this will return the diffrent JPG APP markers in an associative Array. Some Programs use these APP markers to embedd text information in images. A very common one in to embed IPTC http://www.iptc.org/ information in the APP13 marker. You can use the iptcparse() function to parse the binary APP13 marker into something readable.
Note: This function does not require the GD image library.
ImageArc() draws a partial ellipse centered at cx, cy (top left is 0, 0) in the image represented by im. W and h specifies the ellipse's width and height respectively while the start and end points are specified in degrees indicated by the s and e. arguments.
ImageChar() draws the first character of c in the image identified by id with its upper-left at x,y (top left is 0, 0) with the color col. If font is 1, 2, 3, 4 or 5, a built-in font is used (with higher numbers corresponding to larger fonts).
See also imageloadfont().
ImageCharUp() draws the character c vertically in the image identified by im at coordinates x, y (top left is 0, 0) with the color col. If font is 1, 2, 3, 4 or 5, a built-in font is used.
See also imageloadfont().
ImageColorAllocate() returns a color identifier representing the color composed of the given RGB components. The im argument is the return from the imagecreate() function. ImageColorAllocate() must be called to create each color that is to be used in the image represented by im.
The ImageColorDeAllocate() function de-allocates a color previously allocated with the ImageColorAllocate() function.
Returns the index of the color of the pixel at the specified location in the image.
See also imagecolorset() and imagecolorsforindex().
Returns the index of the color in the palette of the image which is "closest" to the specified RGB value.
The "distance" between the desired color and each color in the palette is calculated as if the RGB values represented points in three-dimensional space.
See also imagecolorexact().
Returns the index of the specified color in the palette of the image.
If the color does not exist in the image's palette, -1 is returned.
See also imagecolorclosest().
(PHP 3>= 3.0.2, PHP 4 )
ImageColorResolve -- Get the index of the specified color or its closest possible alternativeThis function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.
See also imagecolorclosest().
The ImageGammaCorrect() function applies gamma correction to a gd image stream (im) given an input gamma, the parameter inputgamma and an output gamma, the parameter outputgamma.
This sets the specified index in the palette to the specified color. This is useful for creating flood-fill-like effects in paletted images without the overhead of performing the actual flood-fill.
See also imagecolorat().
This returns an associative array with red, green, and blue keys that contain the appropriate values for the specified color index.
See also imagecolorat() and imagecolorexact().
This returns the number of colors in the specified image's palette.
See also imagecolorat() and imagecolorsforindex().
ImageColorTransparent() sets the transparent color in the im image to col. Im is the image identifier returned by ImageCreate() and col is a color identifier returned by ImageColorAllocate().
The identifier of the new (or current, if none is specified) transparent color is returned.
int
ImageCopy
(int
dst_im, int
src_im, int
dst_x, int
dst_y, int
src_x, int
src_y, int
src_w, int
src_h)
Copy a part of src_im onto dst_im starting at the x,y coordinates src_x, src_y with a width of src_w and a height of src_h. The portion defined will be copied onto the x,y coordinates, dst_x and dst_y.
int imagecopyresized (int dst_im, int src_im, int dstX, int dstY, int srcX, int srcY, int dstW, int dstH, int srcW, int srcH)
ImageCopyResized() copies a rectangular portion of one image to another image. Dst_im is the destination image, src_im is the source image identifier. If the source and destination coordinates and width and heights differ, appropriate stretching or shrinking of the image fragment will be performed. The coordinates refer to the upper left corner. This function can be used to copy regions within the same image (if dst_im is the same as src_im) but if the regions overlap the results will be unpredictable.
ImageCreate() returns an image identifier representing a blank image of size x_size by y_size.
Example 1. Creating a new GD image stream and outputting an image.
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ImageCreateFromGif() returns an image identifier representing the image obtained from the given filename.
ImageCreateFromGif() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error GIF:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com)
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Note: Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library.
ImageCreateFromJPEG() returns an image identifier representing the image obtained from the given filename.
ImagecreateFromJPEG() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error JPEG:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com )
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ImageCreateFromPNG() returns an image identifier representing the image obtained from the given filename.
ImageCreateFromPNG() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error PNG:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com)
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ImageDashedLine() draws a dashed line from x1, y1 to x2, y2 (top left is 0, 0) in image im of color col.
See also ImageLine().
ImageDestroy() frees any memory associated with image im. Im is the image identifier returned by the ImageCreate() function.
ImageFill() performs a flood fill starting at coordinate x, y (top left is 0, 0) with color col in the image im.
ImageFilledPolygon() creates a filled polygon in image im. Points is a PHP array containing the polygon's vertices, ie. points[0] = x0, points[1] = y0, points[2] = x1, points[3] = y1, etc. Num_points is the total number of vertices.
ImageFilledRectangle() creates a filled rectangle of color col() in image im starting at upper left coordinates x1, y1 and ending at bottom right coordinates x2, y2. 0, 0 is the top left corner of the image.
ImageFillToBorder() performs a flood fill whose border color is defined by border. The starting point for the fill is x, y (top left is 0, 0) and the region is filled with color col.
Returns the pixel height of a character in the specified font.
See also ImageFontWidth() and ImageLoadFont().
Returns the pixel width of a character in font.
See also ImageFontHeight() and ImageLoadFont().
ImageGIF() creates the GIF file in filename from the image im. The im argument is the return from the imagecreate() function.
The image format will be GIF87a unless the image has been made transparent with ImageColorTransparent(), in which case the image format will be GIF89a.
The filename argument is optional, and if left off, the raw image stream will be output directly. By sending an image/gif content-type using header(), you can create a PHP script that outputs GIF images directly.
Note: Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library.
The following code snippet allows you to write more portable PHP applications by auto-detecting the type of GD support which is available. Replace the sequence Header("Content-type: image/gif"); ImageGif($im); by the more flexible sequence:
<?php if (function_exists("imagegif")) { Header("Content-type: image/gif"); ImageGif($im); } elseif (function_exists("imagejpeg")) { Header("Content-type: image/jpeg"); ImageJpeg($im, "", 0.5); } elseif (function_exists("imagepng")) { Header("Content-type: image/png"); ImagePng($im); } else die("No image support in this PHP server"); ?>
Note: As of version 3.0.18 and 4.0.2 you can use the function imagetypes() in place of function_exists() for checking the presence of the various supported image formats:
See also ImagePng(), ImageJpeg(), ImageTypes().
The ImagePng() outputs a GD image stream (im) in PNG format to standard output (usually the browser) or, if a filename is given by the filename it outputs the image to the file.
See also ImageGif(), ImageJpeg(), ImageTypes().
ImageJPEG() creates the JPEG file in filename from the image im. The im argument is the return from the ImageCreate() function.
The filename argument is optional, and if left off, the raw image stream will be output directly. To skip the filename argument in order to provide a quality argument just use an empty string (''). By sending an image/jpeg content-type using header(), you can create a PHP script that outputs JPEG images directly.
Note: JPEG support is only available in PHP if PHP was compiled against GD-1.8 or later.
See also ImagePng(), ImageGif(), ImageTypes().
ImageInterlace() turns the interlace bit on or off. If interlace is 1 the im image will be interlaced, and if interlace is 0 the interlace bit is turned off.
This functions returns whether the interlace bit is set for the image.
ImageLine() draws a line from x1, y1 to x2, y2 (top left is 0, 0) in image im of color col.
See also ImageCreate() and ImageColorAllocate().
ImageLoadFont() loads a user-defined bitmap font and returns an identifier for the font (that is always greater than 5, so it will not conflict with the built-in fonts).
The font file format is currently binary and architecture dependent. This means you should generate the font files on the same type of CPU as the machine you are running PHP on.
Table 1. Font file format
| byte position | C data type | description |
|---|---|---|
| byte 0-3 | int | number of characters in the font |
| byte 4-7 | int | value of first character in the font (often 32 for space) |
| byte 8-11 | int | pixel width of each character |
| byte 12-15 | int | pixel height of each character |
| byte 16- | char | array with character data, one byte per pixel in each character, for a total of (nchars*width*height) bytes. |
See also ImageFontWidth() and ImageFontHeight().
ImagePolygon() creates a polygon in image id. Points is a PHP array containing the polygon's vertices, ie. points[0] = x0, points[1] = y0, points[2] = x1, points[3] = y1, etc. Num_points is the total number of vertices.
See also imagecreate().
(PHP 3>= 3.0.9, PHP 4 >= 4.0RC1)
ImagePSBBox -- Give the bounding box of a text rectangle using PostScript Type1 fontsSize is expressed in pixels.
Space allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative.
Tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative.
Angle is in degrees.
Parameters space and tightness are expressed in character space units, where 1 unit is 1/1000th of an em-square.
Parameters space, tightness, and angle are optional.
The bounding box is calculated using information available from character metrics, and unfortunately tends to differ slightly from the results achieved by actually rasterizing the text. If the angle is 0 degrees, you can expect the text to need 1 pixel more to every direction.
This function returns an array containing the following elements:
See also imagepstext().
Loads a character encoding vector from from a file and changes the fonts encoding vector to it. As a PostScript fonts default vector lacks most of the character positions above 127, you'll definitely want to change this if you use an other language than english. The exact format of this file is described in T1libs documentation. T1lib comes with two ready-to-use files, IsoLatin1.enc and IsoLatin2.enc.
If you find yourself using this function all the time, a much better way to define the encoding is to set ps.default_encoding in the configuration file to point to the right encoding file and all fonts you load will automatically have the right encoding.
In the case everything went right, a valid font index will be returned and can be used for further purposes. Otherwise the function returns false and prints a message describing what went wrong.
See also ImagePSFreeFont().
Extend or condense a font (font_index), if the value of the extend parameter is less than one you will be condensing the font.
Slant a font given by the font_index parameter with a slant of the value of the slant parameter.
(PHP 3>= 3.0.9, PHP 4 >= 4.0RC1)
ImagePSText -- To draw a text string over an image using PostScript Type1 fontsarray imagepstext (int image, string text, int font, int size, int foreground, int background, int x, int y [, int
space [, int
tightness [, float
angle [, int
antialias_steps]]]])
Size is expressed in pixels.
Foreground is the color in which the text will be painted. Background is the color to which the text will try to fade in with antialiasing. No pixels with the color background are actually painted, so the background image does not need to be of solid color.
The coordinates given by x, y will define the origin (or reference point) of the first character (roughly the lower-left corner of the character). This is different from the ImageString(), where x, y define the upper-right corner of the first character. Refer to PostScipt documentation about fonts and their measuring system if you have trouble understanding how this works.
Space allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative.
Tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative.
Angle is in degrees.
Antialias_steps allows you to control the number of colours used for antialiasing text. Allowed values are 4 and 16. The higher value is recommended for text sizes lower than 20, where the effect in text quality is quite visible. With bigger sizes, use 4. It's less computationally intensive.
Parameters space and tightness are expressed in character space units, where 1 unit is 1/1000th of an em-square.
Parameters space, tightness, angle and antialias are optional.
This function returns an array containing the following elements:
See also imagepsbbox().
ImageRectangle() creates a rectangle of color col in image im starting at upper left coordinate x1, y1 and ending at bottom right coordinate x2, y2. 0, 0 is the top left corner of the image.
ImageSetPixel() draws a pixel at x, y (top left is 0, 0) in image im of color col.
See also ImageCreate() and ImageColorAllocate().
ImageString() draws the string s in the image identified by im at coordinates x, y (top left is 0, 0) in color col. If font is 1, 2, 3, 4 or 5, a built-in font is used.
See also ImageLoadFont().
ImageStringUp() draws the string s vertically in the image identified by im at coordinates x, y (top left is 0, 0) in color col. If font is 1, 2, 3, 4 or 5, a built-in font is used.
See also ImageLoadFont().
ImageSX() returns the width of the image identified by im.
See also ImageCreate() and ImageSY().
ImageSY() returns the height of the image identified by im.
See also ImageCreate() and ImageSX().
This function calculates and returns the bounding box in pixels for a TrueType text.
The string to be measured.
The font size in pixels.
The name of the TrueType font file. (Can also be an URL.)
Angle in degrees in which text will be measured.
| 0 | lower left corner, X position |
| 1 | lower left corner, Y position |
| 2 | lower right corner, X position |
| 3 | lower right corner, Y position |
| 4 | upper right corner, X position |
| 5 | upper right corner, Y position |
| 6 | upper left corner, X position |
| 7 | upper left corner, Y position |
This function requires both the GD library and the FreeType library.
See also ImageTTFText().
array imagettftext (int im, int size, int angle, int x, int y, int col, string fontfile, string text)
ImageTTFText() draws the string text in the image identified by im, starting at coordinates x, y (top left is 0, 0), at an angle of angle in color col, using the TrueType font file identified by fontfile.
The coordinates given by x, y will define the basepoint of the first character (roughly the lower-left corner of the character). This is different from the ImageString(), where x, y define the upper-right corner of the first character.
Angle is in degrees, with 0 degrees being left-to-right reading text (3 o'clock direction), and higher values representing a counter-clockwise rotation. (i.e., a value of 90 would result in bottom-to-top reading text).
Fontfile is the path to the TrueType font you wish to use.
Text is the text string which may include UTF-8 character sequences (of the form: {) to access characters in a font beyond the first 255.
Col is the color index. Using the negative of a color index has the effect of turning off antialiasing.
ImageTTFText() returns an array with 8 elements representing four points making the bounding box of the text. The order of the points is upper left, upper right, lower right, lower left. The points are relative to the text regardless of the angle, so "upper left" means in the top left-hand corner when you see the text horizontallty.
This example script will produce a black GIF 400x30 pixels, with the words "Testing..." in white in the font Arial.
Example 1. ImageTTFText
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This function requires both the GD library and the FreeType library.
See also ImageTTFBBox().
This function returns a bit-field corresponding to the image formats supported by the version of GD linked into PHP. The following bits are returned, IMG_GIF | IMG_JPG | IMG_PNG | IMG_WBMP. To check for PNG support, for example, do this:
The read_exif_data() function reads the EXIF headers from a JPEG image file. It returns an associative array where the indexes are the Exif header names and the values are the values associated with those Exif headers. Exif headers tend to be present in JPEG images generated by digital cameras, but unfortunately each digital camera maker has a different idea of how to actually tag their images, so you can't always rely on a specific Exif header being present.
Example 1. read_exif_data
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Note: This function is only available in PHP 4 compiled using --enable-exif
This function does not require the GD image library.
To get these functions to work, you have to compile PHP with --with-imap. That requires the c-client library to be installed. Grab the latest version from ftp://ftp.cac.washington.edu/imap/ and compile it. Then copy c-client/c-client.a to /usr/local/lib/libc-client.a or some other directory on your link path and copy c-client/rfc822.h, mail.h and linkage.h to /usr/local/include or some other directory in your include path.
Note that these functions are not limited to the IMAP protocol, despite their name. The underlying c-client library also supports NNTP, POP3 and local mailbox access methods.
This document can't go into detail on all the topics touched by the provided functions. Further information is provided by the documentation of the c-client library source (docs/internal.txt). and the following RFC documents:
RFC821: Simple Mail Transfer Protocol (SMTP).
RFC822: Standard for ARPA internet text messages.
RFC2060: Internet Message Access Protocol (IMAP) Version 4rev1.
RFC1939: Post Office Protocol Version 3 (POP3).
RFC977: Network News Transfer Protocol (NNTP).
RFC2076: Common Internet Message Headers.
RFC2045 , RFC2046 , RFC2047 , RFC2048 & RFC2049: Multipurpose Internet Mail Extensions (MIME).
Returns true on sucess, false on error.
imap_append() appends a string message to the specified mailbox mbox. If the optional flags is specified, writes the flags to that mailbox also.
When talking to the Cyrus IMAP server, you must use "\r\n" as your end-of-line terminator instead of "\n" or the operation will fail.
Example 1. imap_append() example
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imap_base64() function decodes BASE-64 encoded text (see RFC2045, Section 6.8). The decoded message is returned as a string.
See also imap_binary().
imap_body() returns the body of the message, numbered msg_number in the current mailbox. The optional flags are a bit mask with one or more of the following:
FT_UID - The msgno is a UID
FT_PEEK - Do not set the \Seen flag if not already set
FT_INTERNAL - The return string is in internal format, will not canonicalize to CRLF.
imap_body() will only return a verbatim copy of the message body. To extract single parts of a multipart MIME-encoded message you have to use imap_fetch_structure() to analyze its structure and imap_fetch_body() to extract a copy of a single body component.
Returns information about the current mailbox. Returns FALSE on failure.
The imap_check() function checks the current mailbox status on the server and returns the information in an object with following properties:
Date - last change of mailbox contents
Driver - protocol used to access this mailbox: POP3, IMAP, NNTP
Mailbox - the mailbox name
Nmsgs - number of messages in the mailbox
Recent - number of recent messages in the mailbox
Close the imap stream. Takes an optional flag CL_EXPUNGE, which will silently expunge the mailbox before closing, removing all messages marked for deletion.
imap_createmailbox() creates a new mailbox specified by mbox. Names containing international characters should be encoded by imap_utf7_encode()
Returns true on success and false on error.
See also imap_renamemailbox(), imap_deletemailbox() and imap_open() for the format of mbox names.
Example 1. imap_createmailbox() example
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Returns true.
imap_delete() function marks message pointed by msg_number for deletion. The optional flags parameter only has a single option, FT_UID, which tells the function to treat the msg_number argument as a UID. Messages marked for deletion will stay in the mailbox until either imap_expunge() is called or imap_close() is called with the optional parameter CL_EXPUNGE.
Example 1. Imap_delete() Beispiel
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imap_deletemailbox() deletes the specified mailbox (see imap_open() for the format of mbox names).
Returns true on success and false on error.
See also imap_createmailbox(), imap_renamemailbox(), and imap_open() for the format of mbox.
imap_expunge() deletes all the messages marked for deletion by imap_delete(), imap_mail_move(), or imap_setflag_full().
Returns true.
This function causes a fetch of a particular section of the body of the specified messages as a text string and returns that text string. The section specification is a string of integers delimited by period which index into a body part list as per the IMAP4 specification. Body parts are not decoded by this function.
The options for imap_fetchbody() is a bitmask with one or more of the following:
FT_UID - The msg_number is a UID
FT_PEEK - Do not set the \Seen flag if not already set
FT_INTERNAL - The return string is in "internal" format, without any attempt to canonicalize CRLF.
This function fetches all the structured information for a given message. The optional flags parameter only has a single option, FT_UID, which tells the function to treat the msg_number argument as a UID. The returned object includes the envelope, internal date, size, flags and body structure along with a similar object for each mime attachement. The structure of the returned objects is as follows:
Table 1. Returned Objects for imap_fetchstructure()
| type | Primary body type |
| encoding | Body transfer encoding |
| ifsubtype | True if there is a subtype string |
| subtype | MIME subtype |
| ifdescription | True if there is a description string |
| description | Content description string |
| ifid | True if there is an identification string |
| id | Identification string |
| lines | Number of lines |
| bytes | Number of bytes |
| ifdisposition | True if there is a disposition string |
| disposition | Disposition string |
| ifdparameters | True if the dparameters array exists |
| dparameters | Disposition parameter array |
| ifparameters | True if the parameters array exists |
| parameters | MIME parameters array |
| parts | Array of objects describing each message part |
dparameters is an array of objects where each object has an "attribute" and a "value" property.
Parameter is an array of objects where each object has an "attributte" and a "value" property.
Parts is an array of objects identical in structure to the top-level object, with the limitation that it cannot contain further 'parts' objects.
object imap_headerinfo (int imap_stream, int msg_number [, int
fromlength [, int
subjectlength [, string
defaulthost]]])This function returns an object of various header elements.
remail, date, Date, subject, Subject, in_reply_to, message_id,
newsgroups, followup_to, references
message flags:
Recent - 'R' if recent and seen,
'N' if recent and not seen,
' ' if not recent
Unseen - 'U' if not seen AND not recent,
' ' if seen OR not seen and recent
Answered -'A' if answered,
' ' if unanswered
Deleted - 'D' if deleted,
' ' if not deleted
Draft - 'X' if draft,
' ' if not draft
Flagged - 'F' if flagged,
' ' if not flagged
NOTE that the Recent/Unseen behavior is a little odd. If you want to
know if a message is Unseen, you must check for
Unseen == 'U' || Recent == 'N'
toaddress (full to: line, up to 1024 characters)
to[] (returns an array of objects from the To line, containing):
personal
adl
mailbox
host
fromaddress (full from: line, up to 1024 characters)
from[] (returns an array of objects from the From line, containing):
personal
adl
mailbox
host
ccaddress (full cc: line, up to 1024 characters)
cc[] (returns an array of objects from the Cc line, containing):
personal
adl
mailbox
host
bccaddress (full bcc line, up to 1024 characters)
bcc[] (returns an array of objects from the Bcc line, containing):
personal
adl
mailbox
host
reply_toaddress (full reply_to: line, up to 1024 characters)
reply_to[] (returns an array of objects from the Reply_to line,
containing):
personal
adl
mailbox
host
senderaddress (full sender: line, up to 1024 characters)
sender[] (returns an array of objects from the sender line, containing):
personal
adl
mailbox
host
return_path (full return-path: line, up to 1024 characters)
return_path[] (returns an array of objects from the return_path line,
containing):
personal
adl
mailbox
host
udate (mail message date in unix time)
fetchfrom (from line formatted to fit fromlength
characters)
fetchsubject (subject line formatted to fit subjectlength characters)
object imap_header (int imap_stream, int msg_number [, int
fromlength [, int
subjectlength [, string
defaulthost]]])This is an alias to imap_headerinfo() and is identical to this in any way.
This function returns an object of various header elements, similar to imap_header(), except without the flags and other elements that come from the IMAP server.
Returns an array containing the names of the mailboxes. See imap_getmailboxes() for a description of ref and pattern.
Example 1. imap_listmailbox() example
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(PHP 3>= 3.0.12, PHP 4 >= 4.0b4)
imap_getmailboxes -- Read the list of mailboxes, returning detailed information on each oneReturns an array of objects containing mailbox information. Each object has the attributes name, specifying the full name of the mailbox; delimiter, which is the hierarchy delimiter for the part of the hierarchy this mailbox is in; and attributes. Attributes is a bitmask that can be tested against:
LATT_NOINFERIORS - This mailbox has no "children" (there are no mailboxes below this one).
LATT_NOSELECT - This is only a container, not a mailbox - you cannot open it.
LATT_MARKED - This mailbox is marked. Only used by UW-IMAPD.
LATT_UNMARKED - This mailbox is not marked. Only used by UW-IMAPD.
Mailbox names containing international Characters outside the printable ASCII range will be encoded and may be decoded by imap_utf7_decode().
ref should normally be just the server specification as described in imap_open(), and pattern specifies where in the mailbox hierarchy to start searching. If you want all mailboxes, pass '*' for pattern.
There are two special characters you can pass as part of the pattern: '*' and '%'. '*' means to return all mailboxes. If you pass pattern as '*', you will get a list of the entire mailbox hierarchy. '%' means to return the current level only. '%' as the pattern parameter will return only the top level mailboxes; '~/mail/%' on UW_IMAPD will return every mailbox in the ~/mail directory, but none in subfolders of that directory.
Example 1. imap_getmailboxes() example
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See also imap_getsubscribed().
Returns an array of all the mailboxes that you have subscribed. This is almost identical to imap_listmailbox(), but will only return mailboxes the user you logged in as has subscribed.
This function is identical to imap_getmailboxes(), except that it only returns mailboxes that the user is subscribed to.
Returns true on success and false on error.
Copies mail messages specified by msglist to specified mailbox. msglist is a range not just message numbers (as described in RFC2060).
Flags is a bitmask of one or more of
CP_UID - the sequence numbers contain UIDS
CP_MOVE - Delete the messages from the current mailbox after copying
Moves mail messages specified by msglist to specified mailbox. msglist is a range not just message numbers (as described in RFC2060).
Flags is a bitmask and may contain the single option
CP_UID - the sequence numbers contain UIDS
Returns true on success and false on error.
Returns an IMAP stream on success and false on error. This function can also be used to open streams to POP3 and NNTP servers, but some functions and features are not available on IMAP servers.
A mailbox name consists of a server part and a mailbox path on this server. The special name INBOX stands for the current users personal mailbox. The server part, which is enclosed in '{' and '}', consists of the servers name or ip address, a protocol secification (beginning with '/') and an optional port specifier beginnung with ':'. The server part is mandatory in all mailbox parameters. Mailbox names that contain international characters besides those in the printable ASCII space have to be encoded with imap_utf7_encode().
The options are a bit mask with one or more of the following:
OP_READONLY - Open mailbox read-only
OP_ANONYMOUS - Dont use or update a .newsrc for news (NNTP only)
OP_HALFOPEN - For IMAP and NNTP names, open a connection but dont open a mailbox
CL_EXPUNGE - Expunge mailbox automatically upon mailbox close
To connect to an IMAP server running on port 143 on the local machine, do the following:
To connect to a POP3 server on port 110 on the local server, use: To connect to an NNTP server on port 119 on the local server, use: To connect to a remote server replace "localhost" with the name or the IP address of the server you want to connect to.
Example 1. imap_open() example
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Returns true if the stream is still alive, false otherwise.
imap_ping() function pings the stream to see it is still active. It may discover new mail; this is the preferred method for a periodic "new mail check" as well as a "keep alive" for servers which have inactivity timeout. (As PHP scripts do not tend to run that long, i can hardly imagine that this function will be usefull to anyone.)
This function renames on old mailbox to new mailbox (see imap_open() for the format of mbox names).
Returns true on success and false on error.
See also imap_createmailbox(), imap_deletemailbox(), and imap_open() for the format of mbox.
This function reopens the specified stream to a new mailbox on an IMAP or NNTP server.
The options are a bit mask with one or more of the following:
OP_READONLY - Open mailbox read-only
OP_ANONYMOUS - Dont use or update a .newsrc for news (NNTP only)
OP_HALFOPEN - For IMAP and NNTP names, open a connection but dont open a mailbox.
CL_EXPUNGE - Expunge mailbox automatically upon mailbox close (see also imap_delete() and imap_expunge())
Returns true on success and false on error.
This function removes the deletion flag for a specified message, which is set by imap_delete() or imap_mail_move().
Returns true on success and false on error.
Convert a quoted-printable string to an 8 bit string (according to RFC2045, section 6.7).
Returns an 8 bit (binary) string.
See also imap_8bit().
Convert an 8bit string to a quoted-printable string (according to RFC2045, section 6.7).
Returns a quoted-printable string.
See also imap_qprint().
Convert an 8bit string to a base64 string (according to RFC2045, Section 6.8).
Returns a base64 string.
See also imap_base64().
(PHP 3, PHP 4 )
imap_scanmailbox -- Read the list of mailboxes, takes a string to search for in the text of the mailboxReturns an array containing the names of the mailboxes that have string in the text of the mailbox. This function is similar to imap_listmailbox(), but it will additionally check for the presence of the string content inside the mailbox data. See imap_getmailboxes() for a description of ref and pattern.
Returns information about the current mailbox. Returns FALSE on failure.
The imap_mailboxmsginfo() function checks the current mailbox status on the server. It is similar to imap_status(), but will additionally sum up the size of all messages in the mailbox, which will take some additional time to execute. It returns the information in an object with following properties.
Table 1. Mailbox properties
| Date | date of last change |
| Driver | driver |
| Mailbox | name of the mailbox |
| Nmsgs | number of messages |
| Recent | number of recent messages |
| Unread | number of unread messages |
| Deleted | number of deleted messages |
| Size | mailbox size |
Example 1. imap_mailboxmsginfo() example
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(PHP 3>= 3.0.2, PHP 4 )
imap_rfc822_write_address -- Returns a properly formatted email address given the mailbox, host, and personal info.Returns a properly formatted email address as defined in RFC822 given the mailbox, host, and personal info.
This function parses the address string as defined in RFC822 and for each address, returns an array of objects. The objects properties are:
mailbox - the mailbox name (username)
host - the host name
personal - the personal name
adl - at domain source route
Example 1. imap_rfc822_parse_adrlist() example
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This function causes a store to add the specified flag to the flags set for the messages in the specified sequence.
The flags which you can set are "\\Seen", "\\Answered", "\\Flagged", "\\Deleted", "\\Draft", and "\\Recent" (as defined by RFC2060).
The options are a bit mask with one or more of the following:
This function causes a store to delete the specified flag to the flags set for the messages in the specified sequence. The flags which you can unset are "\\Seen", "\\Answered", "\\Flagged", "\\Deleted", "\\Draft", and "\\Recent" (as defined by RFC2060).
The options are a bit mask with one or more of the following:
Returns an array of message numbers sorted by the given parameters.
Reverse is 1 for reverse-sorting.
Criteria can be one (and only one) of the following:
SORTDATE message Date
SORTARRIVAL arrival date
SORTFROM mailbox in first From address
SORTSUBJECT message Subject
SORTTO mailbox in first To address
SORTCC mailbox in first cc address
SORTSIZE size of message in octets
The flags are a bitmask of one or more of the following:
This function causes a fetch of the complete, unfiltered RFC822 format header of the specified message as a text string and returns that text string.
The options are:
FT_UID The msgno argument is a UID
FT_INTERNAL The return string is in "internal" format,
without any attempt to canonicalize to CRLF
newlines
FT_PREFETCHTEXT The RFC822.TEXT should be pre-fetched at the
same time. This avoids an extra RTT on an
IMAP connection if a full message text is
desired (e.g. in a "save to local file"
operation)
(PHP 3>= 3.0.3, PHP 4 )
imap_uid -- This function returns the UID for the given message sequence numberThis function returns the UID for the given message sequence number. An UID is an unique identifier that will not change over time while a message sequence number may change whenever the content of the mailbox changes. This function is the inverse of imap_msgno().
(PHP 3>= 3.0.3, PHP 4 )
imap_msgno -- This function returns the message sequence number for the given UIDThis function returns the message sequence number for the given UID. It is the inverse of imap_uid().
(PHP 3>= 3.0.12, PHP 4 >= 4.0b4)
imap_search -- This function returns an array of messages matching the given search criteriaThis function performs a search on the mailbox currently opened in the given imap stream. criteria is a string, delimited by spaces, in which the following keywords are allowed. Any multi-word arguments (eg. FROM "joey smith") must be quoted.
ALL - return all messages matching the rest of the criteria
ANSWERED - match messages with the \\ANSWERED flag set
BCC "string" - match messages with "string" in the Bcc: field
BEFORE "date" - match messages with Date: before "date"
BODY "string" - match messages with "string" in the body of the message
CC "string" - match messages with "string" in the Cc: field
DELETED - match deleted messages
FLAGGED - match messages with the \\FLAGGED (sometimes referred to as Important or Urgent) flag set
FROM "string" - match messages with "string" in the From: field
KEYWORD "string" - match messages with "string" as a keyword
NEW - match new messages
OLD - match old messages
ON "date" - match messages with Date: matching "date"
RECENT - match messages with the \\RECENT flag set
SEEN - match messages that have been read (the \\SEEN flag is set)
SINCE "date" - match messages with Date: after "date"
SUBJECT "string" - match messages with "string" in the Subject:
TEXT "string" - match messages with text "string"
TO "string" - match messages with "string" in the To:
UNANSWERED - match messages that have not been answered
UNDELETED - match messages that are not deleted
UNFLAGGED - match messages that are not flagged
UNKEYWORD "string" - match messages that do not have the keyword "string"
UNSEEN - match messages which have not been read yet
For example, to match all unanswered messages sent by Mom, you'd use: "UNANSWERED FROM mom". Searches appear to be case insensitive. This list of criteria is from a reading of the UW c-client source code and may be uncomplete or inaccurate (see also RFC2060, section 6.4.4).
Valid values for flags are SE_UID, which causes the returned array to contain UIDs instead of messages sequence numbers.
(PHP 3>= 3.0.12, PHP 4 >= 4.0b4)
imap_last_error -- This function returns the last IMAP error (if any) that occurred during this page requestThis function returns the full text of the last IMAP error message that occurred on the current page. The error stack is untouched; calling imap_last_error() subsequently, with no intervening errors, will return the same error.
(PHP 3>= 3.0.12, PHP 4 >= 4.0b4)
imap_errors -- This function returns all of the IMAP errors (if any) that have occurred during this page request or since the error stack was reset.This function returns an array of all of the IMAP error messages generated since the last imap_errors() call, or the beginning of the page. When imap_errors() is called, the error stack is subsequently cleared.
(PHP 3>= 3.0.12, PHP 4 >= 4.0b4)
imap_alerts -- This function returns all IMAP alert messages (if any) that have occurred during this page request or since the alert stack was resetThis function returns an array of all of the IMAP alert messages generated since the last imap_alerts() call, or the beginning of the page. When imap_alerts() is called, the alert stack is subsequently cleared. The IMAP specification requires that these messages be passed to the user.
(PHP 3>= 3.0.4, PHP 4 )
imap_status -- This function returns status information on a mailbox other than the current oneThis function returns an object containing status information. Valid flags are:
SA_MESSAGES - set status->messages to the number of messages in the mailbox
SA_RECENT - set status->recent to the number of recent messages in the mailbox
SA_UNSEEN - set status->unseen to the number of unseen (new) messages in the mailbox
SA_UIDNEXT - set status->uidnext to the next uid to be used in the mailbox
SA_UIDVALIDITY - set status->uidvalidity to a constant that changes when uids for the mailbox may no longer be valid
SA_ALL - set all of the above
status->flags is also set, which contains a bitmask which can be checked against any of the above constants.
Example 1. imap_status() example
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Decodes modified UTF-7 text into 8bit data.
Returns the decoded 8bit data, or false if the input string was not valid modified UTF-7. This function is needed to decode mailbox names that contain international characters outside of the printable ASCII range. The modified UTF-7 encoding is defined in RFC 2060, section 5.1.3 (original UTF-7 was defned in RFC1642).
Converts 8bit data to modified UTF-7 text. This is needed to encode mailbox names that contain international characters outside of the printable ASCII range. The modified UTF-7 encoding is defined in RFC 2060, section 5.1.3 (original UTF-7 was defned in RFC1642).
Returns the modified UTF-7 text.
(PHP 3>= 3.0.4, PHP 4 )
imap_fetch_overview -- Read an overview of the information in the headers of the given messageThis function fetches mail headers for the given sequence and returns an overview of their contents. sequence will contain a sequence of message indices or UIDs, if flags contains FT_UID. The returned value is an array of objects describing one message header each:
subject - the messages subject
from - who sent it
date - when was it sent
message_id - Message-ID
references - is a reference to this message id
size - size in bytes
uid - UID the message has in the mailbox
msgno - message sequence number in the maibox
recent - this message is flagged as recent
flagged - this message is flagged
answered - this message is flagged as answered
deleted - this message is flagged for deletion
seen - this message is flagged as already read
draft - this message is flagged as being a draft
Example 1. imap_fetch_overview() example
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imap_mime_header_decode() function decodes MIME message header extensions that are non ASCII text (see RFC2047) The decoded elements are returned in an array of objects, where each object has two properties, "charset" & "text". If the element hasn't been encoded, and in other words is in plain US-ASCII,the "charset" property of that element is set to "default".
In the above example we would have two elements, whereas the first element had previously been encoded with ISO-8859-1, and the second element would be plain US-ASCII.
(PHP 3>= 3.0.5, PHP 4 )
imap_mail_compose -- Create a MIME message based on given envelope and body sections
Example 1. imap_mail_compose() example
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The Informix driver for Informix (IDS) 7.x, SE 7.x, Universal Server (IUS) 9.x and IDS 2000 is implemented in "ifx.ec" and "php3_ifx.h" in the informix extension directory. IDS 7.x support is fairly complete, with full support for BYTE and TEXT columns. IUS 9.x support is partly finished: the new data types are there, but SLOB and CLOB support is still under construction.
Configuration notes: You need a version of ESQL/C to compile the PHP Informix driver. ESQL/C versions from 7.2x on should be OK. ESQL/C is now part of the Informix Client SDK.
Make sure that the "INFORMIXDIR" variable has been set, and that $INFORMIXDIR/bin is in your PATH before you run the "configure" script.
The configure script will autodetect the libraries and include directories, if you run "configure --with_informix=yes". You can overide this detection by specifying "IFX_LIBDIR", "IFX_LIBS" and "IFX_INCDIR" in the environment. The configure script will also try to detect your Informix server version. It will set the "HAVE_IFX_IUS" conditional compilation variable if your Informix version >= 9.00.
Runtime considerations: Make sure that the Informix environment variables INFORMIXDIR and INFORMIXSERVER are available to the PHP ifx driver, and that the INFORMIX bin directory is in the PATH. Check this by running a script that contains a call to phpinfo()() before you start testing. The phpinfo()() output should list these environment variables. This is true for both CGI php and Apache mod_php. You may have to set these environment variables in your Apache startup script.
The Informix shared libraries should also be available to the loader (check LD_LINBRARY_PATH or ld.so.conf/ldconfig).
Some notes on the use of BLOBs (TEXT and BYTE columns): BLOBs are normally addressed by BLOB identifiers. Select queries return a "blob id" for every BYTE and TEXT column. You can get at the contents with "string_var = ifx_get_blob($blob_id);" if you choose to get the BLOBs in memory (with : "ifx_blobinfile(0);"). If you prefer to receive the content of BLOB columns in a file, use "ifx_blobinfile(1);", and "ifx_get_blob($blob_id);" will get you the filename. Use normal file I/O to get at the blob contents.
For insert/update queries you must create these "blob id's" yourself with "ifx_create_blob();". You then plug the blob id's into an array, and replace the blob columns with a question mark (?) in the query string. For updates/inserts, you are responsible for setting the blob contents with ifx_update_blob().
The behaviour of BLOB columns can be altered by configuration variables that also can be set at runtime :
configuration variable : ifx.textasvarchar
configuration variable : ifx.byteasvarchar
runtime functions :
ifx_textasvarchar(0) : use blob id's for select queries with TEXT columns
ifx_byteasvarchar(0) : use blob id's for select queries with BYTE columns
ifx_textasvarchar(1) : return TEXT columns as if they were VARCHAR columns, so that you don't need to use blob id's for select queries.
ifx_byteasvarchar(1) : return BYTE columns as if they were VARCHAR columns, so that you don't need to use blob id's for select queries.
configuration variable : ifx.blobinfile
runtime function :
ifx_blobinfile_mode(0) : return BYTE columns in memory, the blob id lets you get at the contents.
ifx_blobinfile_mode(1) : return BYTE columns in a file, the blob id lets you get at the file name.
If you set ifx_text/byteasvarchar to 1, you can use TEXT and BYTE columns in select queries just like normal (but rather long) VARCHAR fields. Since all strings are "counted" in PHP, this remains "binary safe". It is up to you to handle this correctly. The returned data can contain anything, you are responsible for the contents.
If you set ifx_blobinfile to 1, use the file name returned by ifx_get_blob(..) to get at the blob contents. Note that in this case YOU ARE RESPONSIBLE FOR DELETING THE TEMPORARY FILES CREATED BY INFORMIX when fetching the row. Every new row fetched will create new temporary files for every BYTE column.
The location of the temporary files can be influenced by the environment variable "blobdir", default is "." (the current directory). Something like : putenv(blobdir=tmpblob"); will ease the cleaning up of temp files accidentally left behind (their names all start with "blb").
Automatically trimming "char" (SQLCHAR and SQLNCHAR) data: This can be set with the configuration variable
ifx.charasvarchar : if set to 1 trailing spaces will be automatically trimmed, to save you some "chopping".
NULL values: The configuration variable ifx.nullformat (and the runtime function ifx_nullformat()) when set to true will return NULL columns as the string "NULL", when set to false they return the empty string. This allows you to discriminate between NULL columns and empty columns.
Returns a connection identifier on success, or FALSE on error.
ifx_connect() establishes a connection to an Informix server. All of the arguments are optional, and if they're missing, defaults are taken from values supplied in configuration file (ifx.default_host for the host (Informix libraries will use INFORMIXSERVER environment value if not defined), ifx.default_user for user, ifx.default_password for the password (none if not defined).
In case a second call is made to ifx_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling ifx_close().
See also ifx_pconnect(), and ifx_close().
Returns: A positive Informix persistent link identifier on success, or false on error
ifx_pconnect() acts very much like ifx_connect() with two major differences.
This function behaves exactly like ifx_connect() when PHP is not running as an Apache module. First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.
Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (ifx_close() will not close links established by ifx_pconnect()).
This type of links is therefore called 'persistent'.
See also: ifx_connect().
Returns: always true.
ifx_close() closes the link to an Informix database that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
Note that this isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
ifx_close() will not close persistent links generated by ifx_pconnect().
See also: ifx_connect(), and ifx_pconnect().
Returns: A positive Informix result identifier on success, or false on error.
A "result_id" resource used by other functions to retrieve the query results. Sets "affected_rows" for retrieval by the ifx_affected_rows() function.
ifx_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if ifx_connect() was called, and use it.
Executes query on connection conn_id. For "select-type" queries a cursor is declared and opened. The optional cursor_type parameter allows you to make this a "scroll" and/or "hold" cursor. It's a bitmask and can be either IFX_SCROLL, IFX_HOLD, or both or'ed together. Non-select queries are "execute immediate". IFX_SCROLL and IFX_HOLD are symbolic constants and as such shouldn't be between quotes. I you omit this parameter the cursor is a normal sequential cursor.
For either query type the number of (estimated or real) affected rows is saved for retrieval by ifx_affected_rows().
If you have BLOB (BYTE or TEXT) columns in an update query, you can add a blobidarray parameter containing the corresponding "blob ids", and you should replace those columns with a "?" in the query text.
If the contents of the TEXT (or BYTE) column allow it, you can also use "ifx_textasvarchar(1)" and "ifx_byteasvarchar(1)". This allows you to treat TEXT (or BYTE) columns just as if they were ordinary (but long) VARCHAR columns for select queries, and you don't need to bother with blob id's.
With ifx_textasvarchar(0) or ifx_byteasvarchar(0) (the default situation), select queries will return BLOB columns as blob id's (integer value). You can get the value of the blob as a string or file with the blob functions (see below).
See also: ifx_connect().
Example 1. Show all rows of the "orders" table as a html table
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Example 2. Insert some values into the "catalog" table
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Returns a integer result_id for use by ifx_do(). Sets affected_rows for retrieval by the ifx_affected_rows() function.
Prepares query on connection conn_id. For "select-type" queries a cursor is declared and opened. The optional cursor_type parameter allows you to make this a "scroll" and/or "hold" cursor. It's a bitmask and can be either IFX_SCROLL, IFX_HOLD, or both or'ed together.
For either query type the estimated number of affected rows is saved for retrieval by ifx_affected_rows().
If you have BLOB (BYTE or TEXT) columns in the query, you can add a blobidarray parameter containing the corresponding "blob ids", and you should replace those columns with a "?" in the query text.
If the contents of the TEXT (or BYTE) column allow it, you can also use "ifx_textasvarchar(1)" and "ifx_byteasvarchar(1)". This allows you to treat TEXT (or BYTE) columns just as if they were ordinary (but long) VARCHAR columns for select queries, and you don't need to bother with blob id's.
With ifx_textasvarchar(0) or ifx_byteasvarchar(0) (the default situation), select queries will return BLOB columns as blob id's (integer value). You can get the value of the blob as a string or file with the blob functions (see below).
See also: ifx_do().
Returns TRUE on success, FALSE on error.
Executes a previously prepared query or opens a cursor for it.
Does NOT free result_id on error.
Also sets the real number of ifx_affected_rows() for non-select statements for retrieval by ifx_affected_rows()
See also: ifx_prepare(). There is a example.
The Informix error codes (SQLSTATE & SQLCODE) formatted as follows :
x [SQLSTATE = aa bbb SQLCODE=cccc]
where x = space : no error
E : error
N : no more data
W : warning
? : undefined
If the "x" character is anything other than space, SQLSTATE and SQLCODE describe the error in more detail.
See the Informix manual for the description of SQLSTATE and SQLCODE
Returns in a string one character describing the general results of a statement and both SQLSTATE and SQLCODE associated with the most recent SQL statement executed. The format of the string is "(char) [SQLSTATE=(two digits) (three digits) SQLCODE=(one digit)]". The first character can be ' ' (space) (success), 'W' (the statement caused some warning), 'E' (an error happened when executing the statement) or 'N' (the statement didn't return any data).
See also: ifx_errormsg()
Returns the Informix error message associated with the most recent Informix error, or, when the optional "errorcode" param is present, the error message corresponding to "errorcode".
See also: ifx_error()
result_id is a valid result id returned by ifx_query() or ifx_prepare().
Returns the number of rows affected by a query associated with result_id.
For inserts, updates and deletes the number is the real number (sqlerrd[2]) of affected rows. For selects it is an estimate (sqlerrd[0]). Don't rely on it. The database server can never return the actual number of rows that will be returned by a SELECT because it has not even begun fetching them at this stage (just after the "PREPARE" when the optimizer has determined the query plan).
Useful after ifx_prepare() to limit queries to reasonable result sets.
See also: ifx_num_rows()
Example 1. Informix affected rows
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result_id is a valid result id returned by ifx_query() or ifx_prepare().
Returns a pseudo-row (assiociative array) with sqlca.sqlerrd[0] ... sqlca.sqlerrd[5] after the query associated with result_id.
For inserts, updates and deletes the values returned are those as set by the server after executing the query. This gives access to the number of affected rows and the serial insert value. For SELECTs the values are those saved after the PREPARE statement. This gives access to the *estimated* number of affected rows. The use of this function saves the overhead of executing a "select dbinfo('sqlca.sqlerrdx')" query, as it retrieves the values that were saved by the ifx driver at the appropriate moment.
Example 1. Retrieve Informix sqlca.sqlerrd[x] values
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Returns an associative array that corresponds to the fetched row, or false if there are no more rows.
Blob columns are returned as integer blob id values for use in ifx_get_blob() unless you have used ifx_textasvarchar(1) or ifx_byteasvarchar(1), in which case blobs are returned as string values. Returns FALSE on error
result_id is a valid resultid returned by ifx_query() or ifx_prepare() (select type queries only!).
position is an optional parameter for a "fetch" operation on "scroll" cursors: "NEXT", "PREVIOUS", "CURRENT", "FIRST", "LAST" or a number. If you specify a number, an "absolute" row fetch is executed. This parameter is optional, and only valid for SCROLL cursors.
ifx_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0, with the column name as key.
Subsequent calls to ifx_fetch_row() would return the next row in the result set, or false if there are no more rows.
Example 1. Informix fetch rows
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Returns the number of rows fetched or FALSE on error.
Formats all rows of the result_id query into a html table. The optional second argument is a string of <table> tag options
Example 1. Informix results as HTML table
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Returns an associative array with fieldnames as key and the SQL fieldtypes as data for query with result_id. Returns FALSE on error.
Returns an associative array with fieldnames as key and the SQL fieldproperties as data for a query with result_id. Returns FALSE on error.
Returns the Informix SQL fieldproperies of every field in the query as an associative array. Properties are encoded as: "SQLTYPE;length;precision;scale;ISNULLABLE" where SQLTYPE = the Informix type like "SQLVCHAR" etc. and ISNULLABLE = "Y" or "N".
Returns the number of columns in query for result_id or FALSE on error
After preparing or executing a query, this call gives you the number of columns in the query.
Gives the number of rows fetched so far for a query with result_id after a ifx_query() or ifx_do() query.
Deletes the charobject for the given char object-id bid. Returns FALSE on error otherwise TRUE.
Updates the content of the char object for the given char object bid. content is a string with new data. Returns FALSE on error otherwise TRUE.
Creates an blob object.
type: 1 = TEXT, 0 = BYTE
mode: 0 = blob-object holds the content in memory, 1 = blob-object holds the content in file.
param: if mode = 0: pointer to the content, if mode = 1: pointer to the filestring.
Return FALSE on error, otherwise the new blob object-id.
Duplicates the given blob object. bid is the ID of the blob object.
Returns FALSE on error otherwise the new blob object-id.
Deletes the blobobject for the given blob object-id bid. Returns FALSE on error otherwise TRUE.
Updates the content of the blob object for the given blob object bid. content is a string with new data. Returns FALSE on error otherwise TRUE.
Set the default blob mode for all select queries. Mode "0" means save Byte-Blobs in memory, and mode "1" means save Byte-Blobs in a file.
Sets the default text mode for all select-queries. Mode "0" will return a blob id, and mode "1" will return a varchar with text content.
Sets the default byte mode for all select-queries. Mode "0" will return a blob id, and mode "1" will return a varchar with text content.
Sets the default return value of a NULL-value on a fetch row. Mode "0" returns "", and mode "1" returns "NULL".
Creates an slob object and opens it. Modes: 1 = LO_RDONLY, 2 = LO_WRONLY, 4 = LO_APPEND, 8 = LO_RDWR, 16 = LO_BUFFER, 32 = LO_NOBUFFER -> or-mask. You can also use constants named IFX_LO_RDONLY, IFX_LO_WRONLY etc. Return FALSE on error otherwise the new slob object-id.
Deletes the slob object. bid is the Id of the slob object. Returns FALSE on error otherwise TRUE.
Deletes the slob object on the given slob object-id bid. Return FALSE on error otherwise TRUE.
Opens an slob object. bid should be an existing slob id. Modes: 1 = LO_RDONLY, 2 = LO_WRONLY, 4 = LO_APPEND, 8 = LO_RDWR, 16 = LO_BUFFER, 32 = LO_NOBUFFER -> or-mask. Returns FALSE on error otherwise the new slob object-id.
Returns the current file or seek position of an open slob object bid should be an existing slob id. Return FALSE on error otherwise the seek position.
Sets the current file or seek position of an open slob object. bid should be an existing slob id. Modes: 0 = LO_SEEK_SET, 1 = LO_SEEK_CUR, 2 = LO_SEEK_END and offset is an byte offset. Return FALSE on error otherwise the seek position.
Reads nbytes of the slob object. bid is a existing slob id and nbytes is the number of bytes zu read. Return FALSE on error otherwise the string.
InterBase is a popular database put out by Borland/Inprise. More information about InterBase is available at http://www.interbase.com/. Oh, by the way, InterBase just joined the open source movement!
int ibase_connect (string database [, string
username [, string
password [, string
charset [, int
buffers [, int
dialect [, string
role]]]]]])
Establishes a connection to an InterBase server. The database argument has to be a valid path to database file on the server it resides on. If the server is not local, it must be prefixed with either 'hostname:' (TCP/IP), '//hostname/' (NetBEUI) or 'hostname@' (IPX/SPX), depending on the connection protocol used. username and password can also be specified with PHP configuration directives ibase.default_user and ibase.default_password. charset is the default character set for a database. buffers is the number of database buffers to allocate for the server-side cache. If 0 or omitted, server chooses its own default. dialect selects the default SQL dialect for any statement executed within a connection, and it defaults to the highest one supported by client libraries.
In case a second call is made to ibase_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned. The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling ibase_close().
Note: buffers was added in PHP4-RC2.
Note: dialect was added in PHP4-RC2. It is functional only with InterBase 6 and versions higher than that.
Note: role was added in PHP4-RC2. It is functional only with InterBase 5 and versions higher than that.
See also: ibase_pconnect().
int ibase_pconnect (string database [, string
username [, string
password [, string
charset [, int
buffers [, int
dialect [, string
role]]]]]])
ibase_pconnect() acts very much like ibase_connect() with two major differences. First, when connecting, the function will first try to find a (persistent) link that's already opened with the same parameters. If one is found, an identifier for it will be returned instead of opening a new connection. Second, the connection to the InterBase server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (ibase_close() will not close links established by ibase_pconnect()). This type of link is therefore called 'persistent'.
Note: buffers was added in PHP4-RC2.
Note: dialect was added in PHP4-RC2. It is functional only with InterBase 6 and versions higher than that.
Note: role was added in PHP4-RC2. It is functional only with InterBase 5 and versions higher than that.
See also ibase_connect() for the meaning of parameters passed to this function. They are exactly the same.
Closes the link to an InterBase database that's associated with a connection id returned from ibase_connect(). If the connection id is omitted, the last opened link is assumed. Default transaction on link is committed, other transactions are rolled back.
Performs a query on an InterBase database, returning a result identifier for use with ibase_fetch_row(), ibase_fetch_object(), ibase_free_result() and ibase_free_query().
Note: Although this function supports variable binding to parameter placeholders, there is not very much meaning using this capability with it. For real life use and an example, see ibase_prepare() and ibase_execute().
Returns the next row specified by the result identifier obtained using the ibase_query().
Fetches a row as a pseudo-object from a result_id obtained either by ibase_query() or ibase_execute().
<php
$dbh = ibase_connect ($host, $username, $password);
$stmt = 'SELECT * FROM tblname';
$sth = ibase_query ($dbh, $stmt);
while ($row = ibase_fetch_object ($sth)) {
print $row->email . "\n";
}
ibase_close ($dbh);
?>
|
See also ibase_fetch_row().
Returns an array with information about a field after a select query has been run. The array is in the form of name, alias, relation, length, type.
// helio@helio.com.br 08-Dec-2000 02:53
$rs=ibase_query("Select * from something");
$coln = ibase_num_fields($rs);
for ($i=0 ; $i < $coln ; $i++) {
$col_info = ibase_field_info($rs, $i);
echo "name: ".$col_info['name']."\n";
echo "alias: ".$col_info['alias']."\n";
echo "relation: ".$col_info['relation']."\n";
echo "length: ".$col_info['length']."\n";
echo "type: ".$col_info['type']."\n";
}
|
(PHP 3>= 3.0.6, PHP 4 )
ibase_prepare -- Prepare a query for later binding of parameter placeholders and executionPrepare a query for later binding of parameter placeholders and execution (via ibase_execute()).
Execute a query prepared by ibase_prepare(). This is a lot more effective than using ibase_query() if you are repeating a same kind of query several times with only some parameters changing.
(PHP 3>= 3.0.6, PHP 4 )
ibase_timefmt -- Sets the format of timestamp, date and time type columns returned from queriesSets the format of timestamp, date or time type columns returned from queries. Internally, the columns are formatted by c-function strftime(), so refer to it's documentation regarding to the format of the string. columntype is one of the constants IBASE_TIMESTAMP, IBASE_DATE and IBASE_TIME. If omitted, defaults to IBASE_TIMESTAMP for backwards compatibility.
<?php
// InterBase 6 TIME-type columns will be returned in
// the form '05 hours 37 minutes'.
ibase_timefmt("%H hours %M minutes", IBASE_TIME);
?>
|
You can also set defaults for these formats with PHP configuration directives ibase.timestampformat, ibase.dateformat and ibase.timeformat.
Note: columntype was added in PHP 4.0. It has any meaning only with InterBase version 6 and higher.
Note: A backwards incompatible change happened in PHP 4.0 when PHP configuration directive ibase.timeformat was renamed to ibase.timestampformat and directives ibase.dateformat and ibase.timeformat were added, so that the names would match better their functionality.
Returns an integer containing the number of fields in a result set.
<?php
$dbh = ibase_connect ($host, $username, $password);
$stmt = 'SELECT * FROM tblname';
$sth = ibase_query ($dbh, $stmt);
if (ibase_num_fields($sth) > 0) {
while ($row = ibase_fetch_object ($sth)) {
print $row->email . "\n";
}
} else {
die ("No Results were found for your query");
}
ibase_close ($dbh);
?>
|
See also: ibase_field_info().
Note: Ibase_num_fields() is currently not functional in PHP 4.
These functions allow you to access Ingres II database servers.
In order to have these functions available, you must compile php with Ingres support by using the --with-ingres option. You need the Open API library and header files included with Ingres II. If the II_SYSTEM environment variable isn't correctly set you may have to use --with-ingres=DIR to specify your Ingres installation directory.
When using this extension with Apache, if Apache does not start and complains with "PHP Fatal error: Unable to start ingres_ii module in Unknown on line 0" then make sure the environement variable II_SYSTEM is correctly set. Adding "export II_SYSTEM="/home/ingres/II" in the script that starts Apache, just before launching httpd, should be fine.
Note: If you already used PHP extensions to access other database servers, note that Ingres doesn't allow concurrent queries and/or transaction over one connection, thus you won't find any result or transaction handle in this extension. The result of a query must be treated before sending another query, and a transaction must be commited or rolled back before opening another transaction (which is automaticaly done when sending the first query).
Returns a Ingres II link resource on success, or false on failure.
ingres_connect() opens a connection with the Ingres database designated by database, which follows the syntax [node_id::]dbname[/svr_class].
If some parameters are missing, ingres_connect() uses the values in php.ini for ingres.default_database, ingres.default_user and ingres.default_password.
The connection is closed when the script ends or when ingres_close() is called on this link.
All the other ingres functions use the last opened link as a default, so you need to store the returned value only if you use more than one link at a time.
See also ingres_pconnect(), and ingres_close().
Returns a Ingres II link resource on success, or false on failure.
See ingres_connect() for parameters details and examples. There are only 2 differences between ingres_pconnect() and ingres_connect() : First, when connecting, the function will first try to find a (persistent) link that's already opened with the same parameters. If one is found, an identifier for it will be returned instead of opening a new connection. Second, the connection to the Ingres server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (ingres_close() will not close links established by ingres_pconnect()). This type of link is therefore called 'persistent'.
See also ingres_connect(), and ingres_close().
Returns true on success, or false on failure.
ingres_close() closes the connection to the Ingres server that's associated with the specified link. If the link parameter isn't specified, the last opened link is used.
ingres_close() isn't usually necessary, as it won't close persistent connections and all non-persistent connections are automatically closed at the end of the script.
See also ingres_connect(), and ingres_pconnect().
Returns true on success, or false on failure.
ingres_query() sends the given query to the Ingres server. This query must be a valid SQL query (see the Ingres SQL reference guide)
The query becomes part of the currently open transaction. If there is no open transaction, ingres_query() opens a new transaction. To close the transaction, you can either call ingres_commit() to commit the changes made to the database or ingres_rollback() to cancel these changes. When the script ends, any open transaction is rolled back (by calling ingres_rollback()). You can also use ingres_autocommit() before opening a new transaction to have every SQL query immediatly commited.
Some types of SQL queries can't be sent with this function :
close (see ingres_close()).
commit (see ingres_commit()).
connect (see ingres_connect()).
disconnect (see ingres_close()).
get dbevent
prepare to commit
rollback (see ingres_rollback()).
savepoint
set autocommit (see ingres_autocommit()).
all cursor related queries are unsupported
See also ingres_fetch_array(), ingres_fetch_object(), ingres_fetch_row(), ingres_commit(), ingres_rollback() and ingres_autocommit().
For delete, insert or update queries, ingres_num_rows() returns the number of rows affected by the query. For other queries, ingres_num_rows() returns the number of rows in the query's result.
Note: This function is mainly meant to get the number of rows modified in the database. If this function is called before using ingres_fetch_array(), ingres_fetch_object() or ingres_fetch_row() the server will delete the result's data and the script won't be able to get them.
You should instead retrieve the result's data using one of these fetch functions in a loop until it returns false, indicating that no more results are available.
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_num_fields() returns the number of fields in the results returned by the Ingres server after a call to ingres_query()
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_name() returns the name of a field in a query result, or false on failure.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_type() returns the type of a field in a query result, or false on failure. Examples of types returned are "IIAPI_BYTE_TYPE", "IIAPI_CHA_TYPE", "IIAPI_DTE_TYPE", "IIAPI_FLT_TYPE", "IIAPI_INT_TYPE", "IIAPI_VCH_TYPE". Some of these types can map to more than one SQL type depending on the length of the field (see ingres_field_length()). For example "IIAPI_FLT_TYPE" can be a float4 or a float8. For detailed information, see the Ingres/OpenAPI User Guide - Appendix C.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_nullable() returns true if the field can be set to the NULL value and false if it can't.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_length() returns the length of a field. This is the number of bytes used by the server to store the field. For detailed information, see the Ingres/OpenAPI User Guide - Appendix C.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_precision() returns the precision of a field. This value is used only for decimal, float and money SQL data types. For detailed information, see the Ingres/OpenAPI User Guide - Appendix C.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_field_scale() returns the scale of a field. This value is used only for the decimal SQL data type. For detailed information, see the Ingres/OpenAPI User Guide - Appendix C.
index is the number of the field and must be between 1 and the value given by ingres_num_fields().
See also ingres_query(), ingres_fetch_array(), ingres_fetch_object() and ingres_fetch_row().
ingres_fetch_array() Returns an array that corresponds to the fetched row, or false if there are no more rows.
This function is an extended version of ingres_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must use the numeric index of the column or make an alias for the column.
ingres_query(select t1.f1 as foo t2.f1 as bar from t1, t2);
$result = ingres_fetch_array();
$foo = $result["foo"];
$bar = $result["bar"];
|
result_type can be II_NUM for enumerated array, II_ASSOC for associative array, or II_BOTH (default).
Speed-wise, the function is identical to ingres_fetch_object(), and almost as quick as ingres_fetch_row() (the difference is insignificant).
See also ingres_query(), ingres_num_fields(), ingres_field_name(), ingres_fetch_object() and ingres_fetch_row().
ingres_fetch_row() returns an array that corresponds to the fetched row, or false if there are no more rows. Each result column is stored in an array offset, starting at offset 1.
Subsequent call to ingres_fetch_row() would return the next row in the result set, or false if there are no more rows.
See also ingres_num_fields(), ingres_query(), ingres_fetch_array() and ingres_fetch_object().
ingres_fetch_object() Returns an object that corresponds to the fetched row, or false if there are no more rows.
This function is similar to ingres_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
The optional argument result_type is a constant and can take the following values: II_ASSOC, II_NUM, and II_BOTH.
Speed-wise, the function is identical to ingres_fetch_array(), and almost as quick as ingres_fetch_row() (the difference is insignificant).
See also ingres_query(), ingres_num_fields(), ingres_field_name(), ingres_fetch_array() and ingres_fetch_row().
ingres_rollback() rolls back the currently open transaction, actualy canceling all changes made to the database during the transaction.
This closes the transaction. A new one can be open by sending a query with ingres_query().
See also ingres_query(), ingres_commit() and ingres_autocommit().
ingres_commit() commits the currently open transaction, making all changes made to the database permanent.
This closes the transaction. A new one can be open by sending a query with ingres_query().
You can also have the server commit automaticaly after every query by calling ingres_autocommit() before opening the transaction.
See also ingres_query(), ingres_rollback() and ingres_autocommit().
ingres_autocommit() is called before opening a transaction (before the first call to ingres_query() or just after a call to ingres_rollback() or ingres_autocommit()) to switch the "autocommit" mode of the server on or off (when the script begins the autocommit mode is off).
When the autocommit mode is on, every query is automaticaly commited by the server, as if ingres_commit() was called after every call to ingres_query().
See also ingres_query(), ingres_rollback() and ingres_commit().
LDAP is the Lightweight Directory Access Protocol, and is a protocol used to access "Directory Servers". The Directory is a special kind of database that holds information in a tree structure.
The concept is similar to your hard disk directory structure, except that in this context, the root directory is "The world" and the first level subdirectories are "countries". Lower levels of the directory structure contain entries for companies, organisations or places, while yet lower still we find directory entries for people, and perhaps equipment or documents.
To refer to a file in a subdirectory on your hard disk, you might use something like
/usr/local/myapp/docs
The forwards slash marks each division in the reference, and the sequence is read from left to right.
The equivalent to the fully qualified file reference in LDAP is the "distinguished name", referred to simply as "dn". An example dn might be.
cn=John Smith,ou=Accounts,o=My Company,c=US
The comma marks each division in the reference, and the sequence is read from right to left. You would read this dn as ..
country = US
organization = My Company
organizationalUnit = Accounts
commonName = John Smith
In the same way as there are no hard rules about how you organise the directory structure of a hard disk, a directory server manager can set up any structure that is meaningful for the purpose. However, there are some conventions that are used. The message is that you can not write code to access a directory server unless you know something about its structure, any more than you can use a database without some knowledge of what is available.
Retrieve information for all entries where the surname starts with "S" from a directory server, displaying an extract with name and email address.
Example 1. LDAP search example
|
You will need to get and compile LDAP client libraries from either the University of Michigan ldap-3.3 package or the Netscape Directory SDK 3.0. You will also need to recompile PHP with LDAP support enabled before PHP's LDAP calls will work.
Before you can use the LDAP calls you will need to know ..
The name or address of the directory server you will use
The "base dn" of the server (the part of the world directory that is held on this server, which could be "o=My Company,c=US")
Whether you need a password to access the server (many servers will provide read access for an "anonymous bind" but require a password for anything else)
The typical sequence of LDAP calls you will make in an application will follow this pattern:
ldap_connect() // establish connection to server
|
ldap_bind() // anonymous or authenticated "login"
|
do something like search or update the directory
and display the results
|
ldap_close() // "logout"
Lots of information about LDAP can be found at
The Netscape SDK contains a helpful Programmer's Guide in .html format.
returns true on success and false on error.
The ldap_add() function is used to add entries in the LDAP directory. The DN of the entry to be added is specified by dn. Array entry specifies the information about the entry. The values in the entries are indexed by individual attributes. In case of multiple values for an attribute, they are indexed using integers starting with 0.
Example 1. Complete example with authenticated bind
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Binds to the LDAP directory with specified RDN and password. Returns true on success and false on error.
ldap_bind() does a bind operation on the directory. bind_rdn and bind_password are optional. If not specified, anonymous bind is attempted.
Returns true on success, false on error.
ldap_close() closes the link to the LDAP server that's associated with the specified link_identifier.
This call is internally identical to ldap_unbind(). The LDAP API uses the call ldap_unbind(), so perhaps you should use this in preference to ldap_close().
Returns true if value matches otherwise returns false. Returns -1 on error.
ldap_compare() is used to compare value of attribute to value of same attribute in LDAP directory entry specified with dn.
The following example demonstrates how to check whether or not given password matches the one defined in DN specified entry.
Example 1. Complete example of password check
|
Note: ldap_compare() can NOT be used to compare BINARY values!
Note: This function was added in 4.0.2.
Returns a positive LDAP link identifier on success, or false on error.
ldap_connect() establishes a connection to a LDAP server on a specified hostname and port. Both the arguments are optional. If no arguments are specified then the link identifier of the already opened link will be returned. If only hostname is specified, then the port defaults to 389.
If you are using OpenLDAP 2.x.x you can specify a URL instead of the hostname. To use LDAP with SSL, compile OpenLDAP 2.x.x with SSL support, configure PHP with SSL, and use ldaps://hostname/ as host parameter. The port parameter is not used when using URLs. URL and SSL support were added in 4.0.4.
Returns number of entries in the result or false on error.
ldap_count_entries() returns the number of entries stored in the result of previous search operations. result_identifier identifies the internal ldap result.
Returns true on success and false on error.
ldap_delete() function delete a particular entry in LDAP directory specified by dn.
ldap_dn2ufn() function is used to turn a DN into a more user-friendly form, stripping off type names.
(PHP 3>= 3.0.13, PHP 4 >= 4.0RC2)
ldap_err2str -- Convert LDAP error number into string error messagereturns string error message.
This function returns the string error message explaining the error number errno. While LDAP errno numbers are standardized, different libraries return different or even localized textual error messages. Never check for a specific error message text, but always use an error number to check.
See also ldap_errno() and ldap_error().
(PHP 3>= 3.0.12, PHP 4 >= 4.0RC2)
ldap_errno -- Return the LDAP error number of the last LDAP commandreturn the LDAP error number of the last LDAP command for this link.
This function returns the standardized error number returned by the last LDAP command for the given link identifier. This number can be converted into a textual error message using ldap_err2str().
Unless you lower your warning level in your php3.ini sufficiently or prefix your LDAP commands with @ (at) characters to suppress warning output, the errors generated will also show up in your HTML output.
Example 1. Generating and catching an error
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see also ldap_err2str() and ldap_error().
(PHP 3>= 3.0.12, PHP 4 >= 4.0RC2)
ldap_error -- Return the LDAP error message of the last LDAP commandreturns string error message.
This function returns the string error message explaining the error generated by the last LDAP command for the given link identifier. While LDAP errno numbers are standardized, different libraries return different or even localized textual error messages. Never check for a specific error message text, but always use an error number to check.
Unless you lower your warning level in your php3.ini sufficiently or prefix your LDAP commands with @ (at) characters to suppress warning output, the errors generated will also show up in your HTML output.
see also ldap_err2str() and ldap_errno().
ldap_explode_dn() function is used to split the a DN returned by ldap_get_dn() and breaks it up into its component parts. Each part is known as Relative Distinguished Name, or RDN. ldap_explode_dn() returns an array of all those components. with_attrib is used to request if the RDNs are returned with only values or their attributes as well. To get RDNs with the attributes (i.e. in attribute=value format) set with_attrib to 0 and to get only values set it to 1.
Returns the first attribute in the entry on success and false on error.
Similar to reading entries, attributes are also read one by one from a particular entry. ldap_first_attribute() returns the first attribute in the entry pointed by the entry identifier. Remaining attributes are retrieved by calling ldap_next_attribute() successively. ber_identifier is the identifier to internal memory location pointer. It is passed by reference. The same ber_identifier is passed to the ldap_next_attribute() function, which modifies that pointer.
see also ldap_get_attributes()
Returns the result entry identifier for the first entry on success and false on error.
Entries in the LDAP result are read sequentially using the ldap_first_entry() and ldap_next_entry() functions. ldap_first_entry() returns the entry identifier for first entry in the result. This entry identifier is then supplied to lap_next_entry() routine to get successive entries from the result.
see also ldap_get_entries().
Returns true on success and false on error.
ldap_free_result() frees up the memory allocated internally to store the result and pointed by the result_identifier. All result memory will be automatically freed when the script terminates.
Typically all the memory allocated for the ldap result gets freed at the end of the script. In case the script is making successive searches which return large result sets, ldap_free_result() could be called to keep the runtime memory usage by the script low.
Returns a complete entry information in a multi-dimensional array on success and false on error.
ldap_get_attributes() function is used to simplify reading the attributes and values from an entry in the search result. The return value is a multi-dimensional array of attributes and values.
Having located a specific entry in the directory, you can find out what information is held for that entry by using this call. You would use this call for an application which "browses" directory entries and/or where you do not know the structure of the directory entries. In many applications you will be searching for a specific attribute such as an email address or a surname, and won't care what other data is held.
return_value["count"] = number of attributes in the entry
return_value[0] = first attribute
return_value[n] = nth attribute
return_value["attribute"]["count"] = number of values for attribute
return_value["attribute"][0] = first value of the attribute
return_value["attribute"][i] = ith value of the attribute
Example 1. Show the list of attributes held for a particular directory entry
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see also ldap_first_attribute() and ldap_next_attribute()
Returns the DN of the result entry and false on error.
ldap_get_dn() function is used to find out the DN of an entry in the result.
Returns a complete result information in a multi-dimenasional array on success and false on error.
ldap_get_entries() function is used to simplify reading multiple entries from the result and then reading the attributes and multiple values. The entire information is returned by one function call in a multi-dimensional array. The structure of the array is as follows.
The attribute index is converted to lowercase. (Attributes are case-insensitive for directory servers, but not when used as array indices)
return_value["count"] = number of entries in the result
return_value[0] : refers to the details of first entry
return_value[i]["dn"] = DN of the ith entry in the result
return_value[i]["count"] = number of attributes in ith entry
return_value[i][j] = jth attribute in the ith entry in the result
return_value[i]["attribute"]["count"] = number of values for
attribute in ith entry
return_value[i]["attribute"][j] = jth value of attribute in ith entry
see also ldap_first_entry() and ldap_next_entry()
Sets retval to the value of the specified option, and returns true on success and false on error.
The parameter option can be one of: LDAP_OPT_DEREF, LDAP_OPT_SIZELIMIT, LDAP_OPT_TIMELIMIT, LDAP_OPT_PROTOCOL_VERSION, LDAP_OPT_ERROR_NUMBER, LDAP_OPT_REFERRALS, LDAP_OPT_RESTART, LDAP_OPT_HOST_NAME, LDAP_OPT_ERROR_STRING, LDAP_OPT_MATCHED_DN. These are described in draft-ietf-ldapext-ldap-c-api-xx.txt
This function is only available when using OpenLDAP 2.x.x OR Netscape Directory SDK x.x, and was added in PHP 4.0.4
See also ldap_set_option().
Returns an array of values for the attribute on success and false on error.
ldap_get_values() function is used to read all the values of the attribute in the entry in the result. entry is specified by the result_entry_identifier. The number of values can be found by indexing "count" in the resultant array. Individual values are accessed by integer index in the array. The first index is 0.
This call needs a result_entry_identifier, so needs to be preceded by one of the ldap search calls and one of the calls to get an individual entry.
You application will either be hard coded to look for certain attributes (such as "surname" or "mail") or you will have to use the ldap_get_attributes() call to work out what attributes exist for a given entry.
LDAP allows more than one entry for an attribute, so it can, for example, store a number of email addresses for one person's directory entry all labeled with the attribute "mail"
return_value["count"] = number of values for attribute
return_value[0] = first value of attribute
return_value[i] = ith value of attribute
Example 1. List all values of the "mail" attribute for a directory entry
|
Returns an array of values for the attribute on success and false on error.
ldap_get_values_len() function is used to read all the values of the attribute in the entry in the result. entry is specified by the result_entry_identifier. The number of values can be found by indexing "count" in the resultant array. Individual values are accessed by integer index in the array. The first index is 0.
This function is used exactly like ldap_get_values() except that it handles binary data and not string data.
Note: This function was added in 4.0.
int ldap_list (int link_identifier, string base_dn, string filter [, array
attributes [, int
attrsonly [, int
sizelimit [, int
timelimit [, int
deref]]]]])
Returns a search result identifier or false on error.
ldap_list() performs the search for a specified filter on the directory with the scope LDAP_SCOPE_ONELEVEL.
LDAP_SCOPE_ONELEVEL means that the search should only return information that is at the level immediately below the base dn given in the call. (Equivalent to typing "ls" and getting a list of files and folders in the current working directory.)
This call takes 5 optional parameters. See ldap_search() notes.
Note: These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.
Example 1. Produce a list of all organizational units of an organization
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Returns true on success and false on error.
ldap_modify() function is used to modify the existing entries in the LDAP directory. The structure of the entry is same as in ldap_add().
returns true on success and false on error.
This function adds attribute(s) to the specified dn. It performs the modification at the attribute level as opposed to the object level. Object-level additions are done by the ldap_add() function.
returns true on success and false on error.
This function removes attribute(s) from the specified dn. It performs the modification at the attribute level as opposed to the object level. Object-level deletions are done by the ldap_del() function.
returns true on success and false on error.
This function replaces attribute(s) from the specified dn. It performs the modification at the attribute level as opposed to the object level. Object-level modifications are done by the ldap_modify() function.
Returns the next attribute in an entry on success and false on error.
ldap_next_attribute() is called to retrieve the attributes in an entry. The internal state of the pointer is maintained by the ber_identifier. It is passed by reference to the function. The first call to ldap_next_attribute() is made with the result_entry_identifier returned from ldap_first_attribute().
see also ldap_get_attributes()
Returns entry identifier for the next entry in the result whose entries are being read starting with ldap_first_entry(). If there are no more entries in the result then it returns false.
ldap_next_entry() function is used to retrieve the entries stored in the result. Successive calls to the ldap_next_entry() return entries one by one till there are no more entries. The first call to ldap_next_entry() is made after the call to ldap_first_entry() with the result_identifier as returned from the ldap_first_entry().
see also ldap_get_entries()
int ldap_read (int link_identifier, string base_dn, string filter [, array
attributes [, int
attrsonly [, int
sizelimit [, int
timelimit [, int
deref]]]]])
Returns a search result identifier or false on error.
ldap_read() performs the search for a specified filter on the directory with the scope LDAP_SCOPE_BASE. So it is equivalent to reading an entry from the directory.
An empty filter is not allowed. If you want to retrieve absolutely all information for this entry, use a filter of "objectClass=*". If you know which entry types are used on the directory server, you might use an appropriate filter such as "objectClass=inetOrgPerson".
This call takes 5 optional parameters. See ldap_search() notes.
Note: These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.
int ldap_search (int link_identifier, string base_dn, string filter [, array
attributes [, int
attrsonly [, int
sizelimit [, int
timelimit [, int
deref]]]]])
Returns a search result identifier or false on error.
ldap_search() performs the search for a specified filter on the directory with the scope of LDAP_SCOPE_SUBTREE. This is equivalent to searching the entire directory. base_dn specifies the base DN for the directory.
There is a optional fourth parameter, that can be added to restrict the attributes and values returned by the server to just those required. This is much more efficient than the default action (which is to return all attributes and their associated values). The use of the fourth parameter should therefore be considered good practice.
The fourth parameter is a standard PHP string array of the required attributes, eg array("mail","sn","cn") Note that the "dn" is always returned irrespective of which attributes types are requested.
Note too that some directory server hosts will be configured to return no more than a preset number of entries. If this occurs, the server will indicate that it has only returned a partial results set. This occurs also if the sixth parameter sizelimit has been used to limit the count of fetched entries.
The fifth parameter attrsonly should be set to 1 if only attribute types are wanted. If set to 0 both attributes types and attribute values are fetched which is the default behaviour.
With the sixth parameter sizelimit it is possible to limit the count of entries fetched. Setting this to 0 means no limit. NOTE: This parameter can NOT override server-side preset sizelimit. You can set it lower though.
The seventh parameter timelimit sets the number of seconds how long is spend on the search. Setting this to 0 means no limit. NOTE: This parameter can NOT override server-side preset timelimit. You can set it lower though.
The eigth parameter deref specifies how aliases should be handled during the search. It can be one of the following:
LDAP_DEREF_NEVER - (default) aliases are never dereferenced.
LDAP_DEREF_SEARCHING - aliases should be dereferenced during the search but not when locating the base object of the search.
LDAP_DEREF_FINDING - aliases should be dereferenced when locating the base object but not during the search.
LDAP_DEREF_ALWAYS - aliases should be dereferenced always.
These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.
The search filter can be simple or advanced, using boolean operators in the format described in the LDAP doumentation (see the Netscape Directory SDK for full information on filters).
The example below retrieves the organizational unit, surname, given name and email address for all people in "My Company" where the surname or given name contains the substring $person. This example uses a boolean filter to tell the server to look for information in more than one attribute.
Example 1. LDAP search
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Sets the value of the specified option to be newval, and returns true on success and false on error.
The parameter option can be one of: LDAP_OPT_DEREF, LDAP_OPT_SIZELIMIT, LDAP_OPT_TIMELIMIT, LDAP_OPT_PROTOCOL_VERSION, LDAP_OPT_ERROR_NUMBER, LDAP_OPT_REFERRALS, LDAP_OPT_RESTART, LDAP_OPT_HOST_NAME, LDAP_OPT_ERROR_STRING, LDAP_OPT_MATCHED_DN. These are described in draft-ietf-ldapext-ldap-c-api-xx.txt
This function is only available when using OpenLDAP 2.x.x OR Netscape Directory SDK x.x, and was added in PHP 4.0.4
See also ldap_get_option().
The mail() function allows you to send mail.
Mail() automatically mails the message specified in message to the receiver specified in to. Multiple recipients can be specified by putting a comma between each address in to.
If a fourth string argument is passed, this string is inserted at the end of the header. This is typically used to add extra headers. Multiple extra headers are separated with a newline.
Example 3. Sending complex email.
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These math functions will only handle values within the range of the long and double types on your computer. If you need to handle bigger numbers, take a look at the arbitrary precision math functions.
The following values are defined as constants in PHP by the math extension:
Table 1. Math constants
| Constant | Value | Description |
|---|---|---|
| M_PI | 3.14159265358979323846 | Pi |
| M_E | 2.7182818284590452354 | e |
| M_LOG2E | 1.4426950408889634074 | log_2 e |
| M_LOG10E | 0.43429448190325182765 | log_10 e |
| M_LN2 | 0.69314718055994530942 | log_e 2 |
| M_LN10 | 2.30258509299404568402 | log_e 10 |
| M_PI_2 | 1.57079632679489661923 | pi/2 |
| M_PI_4 | 0.78539816339744830962 | pi/4 |
| M_1_PI | 0.31830988618379067154 | 1/pi |
| M_2_PI | 0.63661977236758134308 | 2/pi |
| M_SQRTPI | 1.77245385090551602729 | sqrt(pi) [4.0.2] |
| M_2_SQRTPI | 1.12837916709551257390 | 2/sqrt(pi) |
| M_SQRT2 | 1.41421356237309504880 | sqrt(2) |
| M_SQRT3 | 1.73205080756887729352 | sqrt(3) [4.0.2] |
| M_SQRT1_2 | 0.70710678118654752440 | 1/sqrt(2) |
| M_LNPI | 1.14472988584940017414 | log_e(pi) [4.0.2] |
| M_EULER | 0.57721566490153286061 | Euler constant [4.0.2] |
Returns the absolute value of number. If the argument number is float, return type is also float, otherwise it is int.
This function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result.
The function returns the result in radians, which is between -PI and PI (inclusive).
Returns a string containing number represented in base tobase. The base in which number is given is specified in frombase. Both frombase and tobase have to be between 2 and 36, inclusive. Digits in numbers with a base higher than 10 will be represented with the letters a-z, with a meaning 10, b meaning 11 and z meaning 35.
Returns the decimal equivalent of the binary number represented by the binary_string argument.
Octdec converts a binary number to a decimal number. The largest number that can be converted is 31 bits of 1's or 2147483647 in decimal.
See also the decbin() function.
Returns the next highest integer value from number. Using ceil() on integers is absolutely a waste of time.
NOTE: PHP/FI 2's ceil() returned a float. Use: $new = (double)ceil($number); to get the old behaviour.
Returns a string containing a binary representation of the given number argument. The largest number that can be converted is 2147483647 in decimal resulting to a string of 31 1's.
See also the bindec() function.
Returns a string containing a hexadecimal representation of the given number argument. The largest number that can be converted is 2147483647 in decimal resulting to "7fffffff".
See also the hexdec() function.
Returns a string containing an octal representation of the given number argument. The largest number that can be converted is 2147483647 in decimal resulting to "17777777777".
See also octdec().
This function converts number from degrees to the radian equivalent.
See also rad2deg().
Returns the next lowest integer value from number. Using floor() on integers is absolutely a waste of time.
NOTE: PHP/FI 2's floor() returned a float. Use: $new = (double)floor($number); to get the old behaviour.
Returns the maximum value that can be returned by a call to rand().
See also rand(), srand(), mt_rand(), mt_srand(), and mt_getrandmax().
Returns the decimal equivalent of the hexadecimal number represented by the hex_string argument. HexDec converts a hexadecimal string to a decimal number. The largest number that can be converted is 7fffffff or 2147483647 in decimal.
See also the dechex() function.
lcg_value() returns a pseudo random number in the range of (0, 1). The function combines two CGs with periods of 2^31 - 85 and 2^31 - 249. The period of this function is equal to the product of both primes.
max() returns the numerically highest of the parameter values.
If the first parameter is an array, max() returns the highest value in that array. If the first parameter is an integer, string or double, you need at least two parameters and max() returns the biggest of these values. You can compare an unlimited number of values.
If one or more of the values is a double, all the values will be treated as doubles, and a double is returned. If none of the values is a double, all of them will be treated as integers, and an integer is returned.
Min() returns the numerically lowest of the parameter values.
If the first parameter is an array, min() returns the lowest value in that array. If the first parameter is an integer, string or double, you need at least two parameters and min() returns the lowest of these values. You can compare an unlimited number of values.
If one or more of the values is a double, all the values will be treated as doubles, and a double is returned. If none of the values is a double, all of them will be treated as integers, and an integer is returned.
Many random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand() function. mt_rand() function is a drop-in replacement for this. It uses a random number generator with known characteristics, the Mersenne Twister, which will produce random numbers that should be suitable for seeding some kinds of cryptography (see the home pages for details) and is four times faster than what the average libc provides. The Homepage of the Mersenne Twister can be found at http://www.math.keio.ac.jp/~matumoto/emt.html, and an optimized version of the MT source is available from http://www.scp.syr.edu/~marc/hawk/twister.html .
If called without the optional min, max arguments mt_rand() returns a pseudo-random value between 0 and RAND_MAX. If you want a random number between 5 and 15 (inclusive), for example, use mt_rand (5, 15).
Remember to seed the random number generator before use with mt_srand().
Note: In versions before 3.0.7 the meaning of max was range. To get the same results in these versions the short example should be mt_rand (5, 11) to get a random number between 5 and 15.
See also mt_srand(), mt_getrandmax(), srand(), rand() and getrandmax().
Seeds the random number generator with seed.
// seed with microseconds since last "whole" second
mt_srand ((double) microtime() * 1000000);
$randval = mt_rand();
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See also mt_rand(), mt_getrandmax(), srand(), rand(), and getrandmax().
Returns the maximum value that can be returned by a call to mt_rand().
See also mt_rand(), mt_srand() rand(), srand(), and getrandmax().
Number_format() returns a formatted version of number. This function accepts either one, two or four parameters (not three):
If only one parameter is given, Number will be formatted without decimals, but with a comma (",") between every group of thousands.
If two parameters are given, number will be formatted with decimals decimals with a dot (".") in front, and a comma (",") between every group of thousands.
If all four parameters are given, number will be formatted with decimals decimals, dec_point instead of a dot (".") before the decimals and thousands_sep instead of a comma (",") between every group of thousands.
Returns the decimal equivalent of the octal number represented by the octal_string argument. OctDec converts an octal string to a decimal number. The largest number that can be converted is 17777777777 or 2147483647 in decimal.
See also decoct().
If called without the optional min, max arguments rand() returns a pseudo-random value between 0 and RAND_MAX. If you want a random number between 5 and 15 (inclusive), for example, use rand (5, 15).
Remember to seed the random number generator before use with srand().
Note: In versions before 3.0.7 the meaning of max was range. To get the same results in these versions the short example should be rand (5, 11) to get a random number between 5 and 15.
See also srand(), getrandmax(), mt_rand(), mt_srand(), and mt_getrandmax().
Returns the rounded value of val to specified precision.
Seeds the random number generator with seed.
// seed with microseconds since last "whole" second
srand ((double) microtime() * 1000000);
$randval = rand();
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See also rand(), getrandmax(), mt_rand(), mt_srand(), and mt_getrandmax().
MCAL stands for Modular Calendar Access Library.
Libmcal is a C library for accessing calendars. It's written to be very modular, with plugable drivers. MCAL is the calendar equivalent of the IMAP module for mailboxes.
With mcal support, a calendar stream can be opened much like the mailbox stream with the IMAP support. Calendars can be local file stores, remote ICAP servers, or other formats that are supported by the mcal library.
Calendar events can be pulled up, queried, and stored. There is also support for calendar triggers (alarms) and reoccuring events.
With libmcal, central calendar servers can be accessed and used, removing the need for any specific database or local file programming.
To get these functions to work, you have to compile PHP with --with-mcal. That requires the mcal library to be installed. Grab the latest version from http://mcal.chek.com/ and compile and install it.
The following constants are defined when using the MCAL module: MCAL_SUNDAY, MCAL_MONDAY, MCAL_TUESDAY, MCAL_WEDNESDAY, MCAL_THURSDAY, MCAL_FRIDAY, MCAL_SATURDAY, MCAL_RECUR_NONE, MCAL_RECUR_DAILY, MCAL_RECUR_WEEKLY, MCAL_RECUR_MONTHLY_MDAY, MCAL_RECUR_MONTHLY_WDAY, MCAL_RECUR_YEARLY, MCAL_JANUARY, MCAL_FEBRUARY, MCAL_MARCH, MCAL_APRIL, MCAL_MAY, MCAL_JUNE, MCAL_JULY, MCAL_AUGUGT, MCAL_SEPTEMBER, MCAL_OCTOBER, MCAL_NOVEMBER, and MCAL_DECEMBER. Most of the functions use an internal event structure that is unique for each stream. This alleviates the need to pass around large objects between functions. There are convenience functions for setting, initializing, and retrieving the event structure values.
Returns an MCAL stream on success, false on error.
mcal_open() opens up an MCAL connection to the specified calendar store. If the optional options is specified, passes the options to that mailbox also. The streams internal event structure is also initialized upon connection.
Returns an MCAL stream on success, false on error.
mcal_popen() opens up an MCAL connection to the specified calendar store. If the optional options is specified, passes the options to that mailbox also. The streams internal event structure is also initialized upon connection.
Reopens an MCAL stream to a new calendar.
mcal_reopen() reopens an MCAL connection to the specified calendar store. If the optional options is specified, passes the options to that mailbox also.
mcal_fetch_event() fetches an event from the calendar stream specified by id.
Returns an event object consisting of:
int id - ID of that event.
int public - TRUE if the event if public, FALSE if it is private.
string category - Category string of the event.
string title - Title string of the event.
string description - Description string of the event.
int alarm - number of minutes before the event to send an alarm/reminder.
object start - Object containing a datetime entry.
object end - Object containing a datetime entry.
int recur_type - recurrence type
int recur_interval - recurrence interval
datetime recur_enddate - recurrence end date
int recur_data - recurrence data
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
int alarm - minutes before event to send an alarm
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_list_events -- Return a list of IDs for a date or a range of dates.Returns an array of ID's that are between the start and end dates, or if just a stream is given, uses the start and end dates in the global event structure.
mcal_list_events() function takes in an beginning date and an optional end date for a calendar stream. An array of event id's that are between the given dates or the internal event dates are returned.
mcal_append_event() Stores the global event into an MCAL calendar for the given stream.
Returns the id of the newly inserted event.
mcal_store_event() Stores the modifications to the current global event for the given stream.
Returns true on success and false on error.
mcal_snooze() turns off an alarm for a calendar event specified by the id.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_list_alarms -- Return a list of events that has an alarm triggered at the given datetimearray mcal_list_events (int mcal_stream [, int
begin_year [, int
begin_month [, int
begin_day [, int
end_year [, int
end_month [, int
end_day]]]]]])
Returns an array of event ID's that has an alarm going off between the start and end dates, or if just a stream is given, uses the start and end dates in the global event structure.
mcal_list_events() function takes in an optional beginning date and an end date for a calendar stream. An array of event id's that are between the given dates or the internal event dates are returned.
mcal_event_init() initializes a streams global event structure. this effectively sets all elements of the structure to 0, or the default settings.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_category -- Sets the category of the streams global event structuremcal_event_set_category() sets the streams global event structure's category to the given string.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_title -- Sets the title of the streams global event structuremcal_event_set_title() sets the streams global event structure's title to the given string.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_description -- Sets the description of the streams global event structuremcal_event_set_description() sets the streams global event structure's description to the given string.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_start -- Sets the start date and time of the streams global event structureint mcal_event_set_start (int stream, int year, int month [, int
day [, int
hour [, int
min [, int
sec]]]])
mcal_event_set_start() sets the streams global event structure's start date and time to the given values.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_end -- Sets the end date and time of the streams global event structureint mcal_event_set_end (int stream, int year, int month [, int
day [, int
hour [, int
min [, int
sec]]]])
mcal_event_set_end() sets the streams global event structure's end date and time to the given values.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_alarm -- Sets the alarm of the streams global event structuremcal_event_set_alarm() sets the streams global event structure's alarm to the given minutes before the event.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_class -- Sets the class of the streams global event structuremcal_event_set_class() sets the streams global event structure's class to the given value. The class is either 1 for public, or 0 for private.
Returns true.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_is_leap_year -- Returns if the given year is a leap year or notmcal_days_in_month() Returns the number of days in the given month, taking into account if the given year is a leap year or not.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_date_valid -- Returns true if the given year, month, day is a valid datemcal_date_valid() Returns true if the given year, month and day is a valid date, false if not.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_time_valid -- Returns true if the given year, month, day is a valid timemcal_time_valid() Returns true if the given hour, minutes and seconds is a valid time, false if not.
mcal_date_compare() Compares the two given dates, returns <0, 0, >0 if a<b, a==b, a>b respectively.
mcal_next_recurrence() returns an object filled with the next date the event occurs, on or after the supplied date. Returns empty date field if event does not occur or something is invalid. Uses weekstart to determine what day is considered the beginning of the week.
(PHP 3>= 3.0.15, PHP 4 >= 4.0RC1)
mcal_event_set_recur_none -- Sets the recurrence of the streams global event structuremcal_event_set_recur_none() sets the streams global event structure to not recur (event->recur_type is set to MCAL_RECUR_NONE).
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_recur_daily -- Sets the recurrence of the streams global event structuremcal_event_set_recur_daily() sets the streams global event structure's recurrence to the given value to be reoccuring on a daily basis, ending at the given date.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_recur_weekly -- Sets the recurrence of the streams global event structureint
mcal_event_set_recur_weekly
(int stream, int year, int month, int day, int interval, int weekdays)
mcal_event_set_recur_weekly() sets the streams global event structure's recurrence to the given value to be reoccuring on a weekly basis, ending at the given date.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_recur_monthly_mday -- Sets the recurrence of the streams global event structuremcal_event_set_recur_monthly_mday() sets the streams global event structure's recurrence to the given value to be reoccuring on a monthly by month day basis, ending at the given date.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_recur_monthly_wday -- Sets the recurrence of the streams global event structuremcal_event_set_recur_monthly_wday() sets the streams global event structure's recurrence to the given value to be reoccuring on a monthly by week basis, ending at the given date.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_event_set_recur_yearly -- Sets the recurrence of the streams global event structuremcal_event_set_recur_yearly() sets the streams global event structure's recurrence to the given value to be reoccuring on a yearly basis,ending at the given date.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
mcal_fetch_current_stream_event -- Returns an object containing the current streams event structuremcal_event_fetch_current_stream_event() returns the current stream's event structure as an object containing:
int id - ID of that event.
int public - TRUE if the event if public, FALSE if it is private.
string category - Category string of the event.
string title - Title string of the event.
string description - Description string of the event.
int alarm - number of minutes before the event to send an alarm/reminder.
object start - Object containing a datetime entry.
object end - Object containing a datetime entry.
int recur_type - recurrence type
int recur_interval - recurrence interval
datetime recur_enddate - recurrence end date
int recur_data - recurrence data
int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
int alarm - minutes before event to send an alarm
(PHP 3>= 3.0.15, PHP 4 >= 4.0RC1)
mcal_event_add_attribute -- Adds an attribute and a value to the streams global event structuremcal_event_add_attribute() adds an attribute to the stream's global event structure with the value given by "value".
These functions work using mcrypt.
This is an interface to the mcrypt library, which supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes. Additionally, it supports RC6 and IDEA which are considered "non-free".
If you linked against libmcrypt 2.4.x, the following additional block algorithms are supported: CAST, LOKI97, RIJNDAEL, SAFERPLUS, SERPENT and the following stream ciphers: ENIGMA (crypt), PANAMA, RC4 and WAKE. With libmcrypt 2.4.x another cipher mode is also available; nOFB.
To use it, download libmcrypt-x.x.tar.gz from here and follow the included installation instructions. You need to compile PHP with the --with-mcrypt parameter to enable this extension. Make sure you compile libmcrypt with the option --disable-posix-threads.
Mcrypt can be used to encrypt and decrypt using the above mentioned ciphers. If you linked against libmcrypt-2.2.x, the four important mcrypt commands (mcrypt_cfb(), mcrypt_cbc(), mcrypt_ecb(), and mcrypt_ofb()) can operate in both modes which are named MCRYPT_ENCRYPT and MCRYPT_DECRYPT, respectively.
If you linked against libmcrypt 2.4.x, these functions are still available, but it is recommended that you use the advanced functions.
Example 2. Encrypt an input value with TripleDES under 2.4.x in ECB mode
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Mcrypt can operate in four block cipher modes (CBC, OFB, CFB, and ECB). If linked against libmcrypt-2.4.x mcrypt can also operate in the block cipher mode nOFB and in STREAM mode. Then there are also constants in the form MCRYPT_MODE_mode for use with several functions. We will outline the normal use for each of these modes. For a more complete reference and discussion see Applied Cryptography by Schneier (ISBN 0-471-11709-9).
ECB (electronic codebook) is suitable for random data, such as encrypting other keys. Since data there is short and random, the disadvantages of ECB have a favorable negative effect.
CBC (cipher block chaining) is especially suitable for encrypting files where the security is increased over ECB significantly.
CFB (cipher feedback) is the best mode for encrypting byte streams where single bytes must be encrypted.
OFB (output feedback, in 8bit) is comparable to CFB, but can be used in applications where error propagation cannot be tolerated. It's insecure (because it operates in 8bit mode) so it is not recommended to use it.
nOFB (output feedback, in nbit) is comparable to OFB, but more secure because it operates on the block size of the algorithm.
STREAM is an extra mode to include some stream algorithms like WAKE or RC4.
PHP does not support encrypting/decrypting bit streams currently. As of now, PHP only supports handling of strings.
For a complete list of supported ciphers, see the defines at the end of mcrypt.h. The general rule with the mcrypt-2.2.x API is that you can access the cipher from PHP with MCRYPT_ciphername. With the mcrypt-2.4.x API these constants also work, but it is possible to specify the name of the cipher as a string with a call to mcrypt_module_open().
Here is a short list of ciphers which are currently supported by the mcrypt extension. If a cipher is not listed here, but is listed by mcrypt as supported, you can safely assume that this documentation is outdated.
MCRYPT_3DES
MCRYPT_ARCFOUR_IV (libmcrypt 2.4.x only)
MCRYPT_ARCFOUR (libmcrypt 2.4.x only)
MCRYPT_BLOWFISH
MCRYPT_CAST_128
MCRYPT_CAST_256
MCRYPT_CRYPT
MCRYPT_DES
MCRYPT_DES_COMPAT (libmcrypt 2.2.x only)
MCRYPT_ENIGMA (libmcrypt 2.4.x only, alias for MCRYPT_CRYPT)
MCRYPT_GOST
MCRYPT_IDEA (non-free)
MCRYPT_LOKI97 (libmcrypt 2.4.x only)
MCRYPT_MARS (libmcrypt 2.4.x only, non-free)
MCRYPT_PANAMA (libmcrypt 2.4.x only)
MCRYPT_RIJNDAEL_128 (libmcrypt 2.4.x only)
MCRYPT_RIJNDAEL_192 (libmcrypt 2.4.x only)
MCRYPT_RIJNDAEL_256 (libmcrypt 2.4.x only)
MCRYPT_RC2
MCRYPT_RC4 (libmcrypt 2.2.x only)
MCRYPT_RC6 (libmcrypt 2.4.x only)
MCRYPT_RC6_128 (libmcrypt 2.2.x only)
MCRYPT_RC6_192 (libmcrypt 2.2.x only)
MCRYPT_RC6_256 (libmcrypt 2.2.x only)
MCRYPT_SAFER64
MCRYPT_SAFER128
MCRYPT_SAFERPLUS (libmcrypt 2.4.x only)
MCRYPT_SERPENT (libmcrypt 2.4.x only)
MCRYPT_SERPENT_128 (libmcrypt 2.2.x only)
MCRYPT_SERPENT_192 (libmcrypt 2.2.x only)
MCRYPT_SERPENT_256 (libmcrypt 2.2.x only)
MCRYPT_SKIPJACK (libmcrypt 2.4.x only)
MCRYPT_TEAN (libmcrypt 2.2.x only)
MCRYPT_THREEWAY
MCRYPT_TRIPLEDES (libmcrypt 2.4.x only)
MCRYPT_TWOFISH (for older mcrypt 2.x versions, or mcrypt 2.4.x )
MCRYPT_TWOFISH128 (TWOFISHxxx are available in newer 2.x versions, but not in the 2.4.x versions)
MCRYPT_TWOFISH192
MCRYPT_TWOFISH256
MCRYPT_WAKE (libmcrypt 2.4.x only)
MCRYPT_XTEA (libmcrypt 2.4.x only)
You must (in CFB and OFB mode) or can (in CBC mode) supply an initialization vector (IV) to the respective cipher function. The IV must be unique and must be the same when decrypting/encrypting. With data which is stored encrypted, you can take the output of a function of the index under which the data is stored (e.g. the MD5 key of the filename). Alternatively, you can transmit the IV together with the encrypted data (see chapter 9.3 of Applied Cryptography by Schneier (ISBN 0-471-11709-9) for a discussion of this topic).
Mcrypt_get_cipher_name() is used to get the name of the specified cipher.
Mcrypt_get_cipher_name() takes the cipher number as an argument (libmcrypt 2.2.x) or takes the cipher name as an argument (libmcrypt 2.4.x) and returns the name of the cipher or false, if the cipher does not exist.
The above example will produce:
3DES
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The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_get_block_size() is used to get the size of a block of the specified cipher.
Mcrypt_get_block_size() takes one or two arguments, the cipher and module, and returns the size in bytes.
See also: mcrypt_get_key_size().
The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_get_key_size() is used to get the size of a key of the specified cipher.
Mcrypt_get_key_size() takes one or two arguments, the cipher and module, and returns the size in bytes.
See also: mcrypt_get_block_size().
(PHP 3>= 3.0.8, PHP 4 )
mcrypt_create_iv -- Create an initialization vector (IV) from a random sourceMcrypt_create_iv() is used to create an IV.
mcrypt_create_iv() takes two arguments, size determines the size of the IV, source specifies the source of the IV.
The source can be MCRYPT_RAND (system random number generator), MCRYPT_DEV_RANDOM (read data from /dev/random) and MCRYPT_DEV_URANDOM (read data from /dev/urandom). If you use MCRYPT_RAND, make sure to call srand() before to initialize the random number generator.
The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_cbc() encrypts or decrypts (depending on mode) the data with cipher and key in CBC cipher mode and returns the resulting string.
Cipher is one of the MCRYPT_ciphername constants.
Key is the key supplied to the algorithm. It must be kept secret.
Data is the data which shall be encrypted/decrypted.
Mode is MCRYPT_ENCRYPT or MCRYPT_DECRYPT.
IV is the optional initialization vector.
See also: mcrypt_cfb(), mcrypt_ecb(), and mcrypt_ofb().
The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_cfb() encrypts or decrypts (depending on mode) the data with cipher and key in CFB cipher mode and returns the resulting string.
Cipher is one of the MCRYPT_ciphername constants.
Key is the key supplied to the algorithm. It must be kept secret.
Data is the data which shall be encrypted/decrypted.
Mode is MCRYPT_ENCRYPT or MCRYPT_DECRYPT.
IV is the initialization vector.
See also: mcrypt_cbc(), mcrypt_ecb(), and mcrypt_ofb().
The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_ecb() encrypts or decrypts (depending on mode) the data with cipher and key in ECB cipher mode and returns the resulting string.
Cipher is one of the MCRYPT_ciphername constants.
Key is the key supplied to the algorithm. It must be kept secret.
Data is the data which shall be encrypted/decrypted.
Mode is MCRYPT_ENCRYPT or MCRYPT_DECRYPT.
See also: mcrypt_cbc(), mcrypt_cfb(), and mcrypt_ofb().
The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_ofb() encrypts or decrypts (depending on mode) the data with cipher and key in OFB cipher mode and returns the resulting string.
Cipher is one of the MCRYPT_ciphername constants.
Key is the key supplied to the algorithm. It must be kept secret.
Data is the data which shall be encrypted/decrypted.
Mode is MCRYPT_ENCRYPT or MCRYPT_DECRYPT.
IV is the initialization vector.
See also: mcrypt_cbc(), mcrypt_cfb(), and mcrypt_ecb().
Mcrypt_list_algorithms() is used to get an array of all supported algorithms in the
lib_dir. Mcrypt_list_algorithms() takes as optional parameter a directory which specifies the directory where all algorithms are located. If not specifies, the value of the mcrypt.algorithms_dir php.ini directive is used.
The above example will produce a list with all supported algorithms in the "/usr/local/lib/libmcrypt" directory.
Mcrypt_list_modes() is used to get an array of all supported modes in the lib_dir.
Mcrypt_list_modes() takes as optional parameter a directory which specifies the directory where all modes are located. If not specifies, the value of the mcrypt.modes_dir php.ini directive is used.
The above example will produce a list with all supported algorithms in the default mode directory. If it is not set with the ini directive mcrypt.modes_dir, the default directory of mcrypt is used (which is /usr/local/lib/libmcrypt).
(PHP 4 >= 4.0.2)
mcrypt_get_iv_size -- Returns the size of the IV belonging to a specific cipher/mode combinationThe first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x.
Mcrypt_get_iv_size() returns the size of the Initialisation Vector (IV) in bytes. On error the function returns FALSE. If the IV is ignored in the specified cipher/mode combination zero is returned.
Cipher is one of the MCRYPT_ciphername constants of the name of the algorithm as string.
Mode is one of the MCRYPT_MODE_modename constants of one of "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
Td is the algorithm specified.
Mcrypt_encrypt() encrypts the data and returns the encrypted data.
Cipher is one of the MCRYPT_ciphername constants of the name of the algorithm as string.
Key is the key with which the data will be encrypted. If it's smaller that the required keysize, it is padded with '\0'. It is better not to use ASCII strings for keys. It is recommended to use the mhash functions to create a key from a string.
Data is the data that will be encrypted with the given cipher and mode. If the size of the data is not n * blocksize, the data will be padded with '\0'. The returned crypttext can be larger that the size of the data that is given by data.
Mode is one of the MCRYPT_MODE_modename constants of one of "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
The IV parameter is used for the initialisation in CBC, CFB, OFB modes, and in some algorithms in STREAM mode. If you do not supply an IV, while it is needed for an algorithm, the function issues a warning and uses an IV with all bytes set to '\0'.
Example 1. Mcrypt_encrypt() Example
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42
64
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Mcrypt_decrypt() decrypts the data and returns the unencrypted data.
Cipher is one of the MCRYPT_ciphername constants of the name of the algorithm as string.
Key is the key with which the data is encrypted. If it's smaller that the required keysize, it is padded with '\0'.
Data is the data that will be decrypted with the given cipher and mode. If the size of the data is not n * blocksize, the data will be padded with '\0'.
Mode is one of the MCRYPT_MODE_modename constants of one of "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
The IV parameter is used for the initialisation in CBC, CFB, OFB modes, and in some algorithms in STREAM mode. If you do not supply an IV, while it is needed for an algorithm, the function issues a warning and uses an IV with all bytes set to '\0'.
(PHP 4 >= 4.0.2)
mcrypt_module_open -- This function opens the module of the algorithm and the mode to be usedresource mcrypt_module_open (string algorithm, string algorithm_directory, string mode, string mode_directory)
This function opens the module of the algorithm and the mode to be used. The name of the algorithm is specified in algorithm, eg "twofish" or is one of the MCRYPT_ciphername constants. The library is closed by calling mcrypt_module_close(), but there is no need to call that function if mcrypt_generic_end() is called. Normally it returns an encryption descriptor, or FALSE on error.
The algorithm_directory and mode_directory are used to locate the encryption modules. When you supply a directory name, it is used. When you set one of these to the empty string (""), the value set by the mcrypt.algorithms_dir or mcrypt.modes_dir ini-directive is used. When these are not set, the default directory are used that are compiled in into libmcrypt (usally /usr/local/lib/libmcrypt).
The maximum length of the key should be the one obtained by calling mcrypt_enc_get_key_size() and every value smaller than this is legal. The IV should normally have the size of the algorithms block size, but you must obtain the size by calling mcrypt_enc_get_iv_size(). IV is ignored in ECB. IV MUST exist in CFB, CBC, STREAM, nOFB and OFB modes. It needs to be random and unique (but not secret). The same IV must be used for encryption/decryption. If you do not want to use it you should set it to zeros, but this is not recommended. The function returns (-1) on error.
You need to call this function before every mcrypt_generic() or mdecrypt_generic().
This function encrypts data. The data is padded with "\0" to make sure the length of the data is n * blocksize. This function returns the encrypted data. Note that the length of the returned string can in fact be longer then the input, due to the padding of the data.
This function decrypts data. Note that the length of the returned string can in fact be longer then the unencrypted string, due to the padding of the data.
Example 1. Mdecrypt_generic() Example
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This function terminates encryption specified by the encryption descriptor (td). Actually it clears all buffers, and closes all the modules used. Returns FALSE on error, or TRUE on succes.
This function runs the self test on the algorithm specified by the descriptor td. If the self test succeeds it returns zero. In case of an error, it returns 1.
(PHP 4 >= 4.0.2)
mcrypt_enc_is_block_algorithm_mode -- Checks whether the encryption of the opened mode works on blocksThis function returns 1 if the mode is for use with block algorithms, otherwise it returns 0. (eg. 0 for stream, and 1 for cbc, cfb, ofb).
(PHP 4 >= 4.0.2)
mcrypt_enc_is_block_algorithm -- Checks whether the algorithm of the opened mode is a block algorithmThis function returns 1 if the algorithm is a block algorithm, or 0 if it is a stream algorithm.
This function returns 1 if the mode outputs blocks of bytes or 0 if it outputs bytes. (eg. 1 for cbc and ecb, and 0 for cfb and stream).
This function returns the block size of the algorithm specified by the encryption descriptor td in bytes.
This function returns the maximum supported key size of the algorithm specified by the encryption descriptor td in bytes.
(PHP 4 >= 4.0.2)
mcrypt_enc_get_supported_key_sizes -- Returns an array with the supported keysizes of the opened algorithmReturns an array with the key sizes supported by the algorithm specified by the encryption descriptor. If it returns an empty array then all key sizes between 1 and mcrypt_enc_get_key_size() are supported by the algorithm.
This function returns the size of the iv of the algorithm specified by the encryption descriptor in bytes. If it returns '0' then the IV is ignored in the algorithm. An IV is used in cbc, cfb and ofb modes, and in some algorithms in stream mode.
This function runs the self test on the algorithm specified. The optional lib_dir parameter can contain the location of where the algorithm module is on the system.
The function returns TRUE if the self test succeeds, or FALSE when if fails.
(PHP 4 >= 4.0.2)
mcrypt_module_is_block_algorithm_mode -- This function returns if the the specified module is a block algorithm or notThis function returns TRUE if the mode is for use with block algorithms, otherwise it returns 0. (eg. 0 for stream, and 1 for cbc, cfb, ofb). The optional lib_dir parameter can contain the location where the mode module is on the system.
(PHP 4 >= 4.0.2)
mcrypt_module_is_block_algorithm -- This function checks whether the specified algorithm is a block algorithmThis function returns TRUE if the specified algorithm is a block algorithm, or FALSE is it is a stream algorithm. The optional lib_dir parameter can contain the location where the algorithm module is on the system.
(PHP 4 >= 4.0.2)
mcrypt_module_is_block_mode -- This function returns if the the specified mode outputs blocks or notThis function returns TRUE if the mode outputs blocks of bytes or FALSE if it outputs just bytes. (eg. 1 for cbc and ecb, and 0 for cfb and stream). The optional lib_dir parameter can contain the location where the mode module is on the system.
(PHP 4 >= 4.0.2)
mcrypt_module_get_algo_block_size -- Returns the blocksize of the specified algorithmThis function returns the block size of the algorithm specified in bytes. The optional lib_dir parameter can contain the location where the mode module is on the system.
(PHP 4 >= 4.0.2)
mcrypt_module_get_algo_key_size -- Returns the maximum supported keysize of the opened modeThis function returns the maximum supported key size of the algorithm specified in bytes. The optional lib_dir parameter can contain the location where the mode module is on the system.
(unknown)
mcrypt_module_get_algo_supported_key_sizes -- Returns an array with the supported keysizes of the opened algorithmReturns an array with the key sizes supported by the specified algorithm. If it returns an empty array then all key sizes between 1 and mcrypt_module_get_algo_key_size() are supported by the algorithm. The optional lib_dir parameter can contain the location where the mode module is on the system.
These functions are intended to work with mhash.
This is an interface to the mhash library. mhash supports a wide variety of hash algorithms such as MD5, SHA1, GOST, and many others.
To use it, download the mhash distribution from its web site and follow the included installation instructions. You need to compile PHP with the --with-mhash parameter to enable this extension.
Mhash can be used to create checksums, message digests, message authentication codes, and more.
The hash is d03cb659cbf9192dcd066272249f8412
The hmac is 750c783e6ab0b503eaa86e310a5db738
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Here is a list of hashes which are currently supported by mhash. If a hash is not listed here, but is listed by mhash as supported, you can safely assume that this documentation is outdated.
MHASH_MD5
MHASH_SHA1
MHASH_HAVAL256
MHASH_HAVAL192
MHASH_HAVAL160
MHASH_HAVAL128
MHASH_RIPEMD160
MHASH_GOST
MHASH_TIGER
MHASH_CRC32
MHASH_CRC32B
Mhash_get_hash_name() is used to get the name of the specified hash.
mhash_get_hash_name() takes the hash id as an argument and returns the name of the hash or false, if the hash does not exist.
MD5
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Mhash_get_block_size() is used to get the size of a block of the specified hash.
Mhash_get_block_size() takes one argument, the hash and returns the size in bytes or false, if the hash does not exist.
Mhash_count() returns the highest available hash id. Hashes are numbered from 0 to this hash id.
Mhash() applies a hash function specified by hash to the data and returns the resulting hash (also called digest). If the key is specified it will return the resulting HMAC. HMAC is keyed hashing for message authentication, or simply a message digest that depends on the specified key. Not all algorithms supported in mhash can be used in HMAC mode and will return an error.
Mhash_keygen_s2k() generates a key that is bytes long, from a user given password. This is the Salted S2K algorithm as specified in the OpenPGP document (RFC 2440). That algorithm will use the specified hash algorithm to create the key. The salt must be different and random enough for every key you generate in order to create different keys. That salt must be known when you check the keys, thus it is a good idea to append the key to it. Salt has a fixed length of 8 bytes and will be padded with zeros if you supply less bytes. Keep in mind that user supplied passwords are not really suitable to be used as keys in cryptographic algorithms, since users normally choose keys they can write on keyboard. These passwords use only 6 to 7 bits per character (or less). It is highly recommended to use some kind of tranformation (like this function) to the user supplied key.
Returns: true on success, false on error.
Mssql_close() closes the link to a MS SQL Server database that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
Note that this isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
Mssql_close() will not close persistent links generated by mssql_pconnect().
See also: mssql_connect(), mssql_pconnect().
Returns: A positive MS SQL link identifier on success, or false on error.
Mssql_connect() establishes a connection to a MS SQL server. The servername argument has to be a valid servername that is defined in the 'interfaces' file.
In case a second call is made to mssql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mssql_close().
See also mssql_pconnect(), mssql_close().
Returns: true on success, false on failure.
Mssql_data_seek() moves the internal row pointer of the MS SQL result associated with the specified result identifier to point to the specified row number. The next call to mssql_fetch_row() would return that row.
See also: mssql_data_seek().
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
Mssql_fetch_array() is an extended version of mssql_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
An important thing to note is that using mssql_fetch_array() is NOT significantly slower than using mssql_fetch_row(), while it provides a significant added value.
For further details, also see mssql_fetch_row().
Returns an object containing field information.
Mssql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by mssql_fetch_field() is retrieved.
The properties of the object are:
name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric
See also mssql_field_seek().
Returns: An object with properties that correspond to the fetched row, or false if there are no more rows.
Mssql_fetch_object() is similar to mssql_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
Speed-wise, the function is identical to mssql_fetch_array(), and almost as quick as mssql_fetch_row() (the difference is insignificant).
See also: mssql_fetch-array() and mssql_fetch-row().
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
Mssql_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.
Subsequent call to mssql_fetch_rows() would return the next row in the result set, or false if there are no more rows.
See also: mssql_fetch_array(), mssql_fetch_object(), mssql_data_seek(), mssql_fetch_lengths(), and mssql_result().
Seeks to the specified field offset. If the next call to mssql_fetch_field() won't include a field offset, this field would be returned.
See also: mssql_fetch_field().
mssql_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script ends. You may call mssql_free_result() with the result identifier as an argument and the associated result memory will be freed.
(PHP 3, PHP 4 )
mssql_get_last_message -- Returns the last message from server (over min_message_severity?)Mssql_num_fields() returns the number of fields in a result set.
See also: mssql_db_query(), mssql_query(), mssql_fetch_field(), and mssql_num_rows().
Mssql_num_rows() returns the number of rows in a result set.
See also: mssql_db_query(), mssql_query(), and mssql_fetch_row().
Returns: A positive MS SQL persistent link identifier on success, or false on error.
Mssql_pconnect() acts very much like mssql_connect() with two major differences.
First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.
Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (mssql_close() will not close links established by mssql_pconnect()).
This type of links is therefore called 'persistent'.
Returns: A positive MS SQL result identifier on success, or false on error.
Mssql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if mssql_connect() was called, and use it.
See also: mssql_db_query(), mssql_select_db(), and mssql_connect().
Mssql_result() returns the contents of one cell from a MS SQL result set. The field argument can be the field's offset, the field's name or the field's table dot field's name (tablename.fieldname). If the column name has been aliased ('select foo as bar from...'), it uses the alias instead of the column name.
When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than mssql_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.
Recommended high-performance alternatives: mssql_fetch_row(), mssql_fetch_array(), and mssql_fetch_object().
Returns: true on success, false on error
Mssql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if mssql_connect() was called, and use it.
Every subsequent call to mssql_query() will be made on the active database.
See also: mssql_connect(), mssql_pconnect(), and mssql_query()
Returns true if client disconnected. See the Connection Handling description in the Features chapter for a complete explanation.
Returns the connection status bitfield. See the Connection Handling description in the Features chapter for a complete explanation.
Returns true if script timed out. See the Connection Handling description in the Features chapter for a complete explanation.
Defines a named constant, which is similar to a variable except:
Constants do not have a dollar sign '$' before them;
Constants may be accessed anywhere without regard to variable scoping rules;
Constants may not be redefined or undefined once they have been set; and
Constants may only evaluate to scalar values.
The name of the constant is given by name; the value is given by value.
The optional third parameter case_insensitive is also available. If the value 1 is given, then the constant will be defined case-insensitive. The default behaviour is case-sensitive; i.e. CONSTANT and Constant represent different values.
Define() returns TRUE on success and FALSE if an error occurs.
This language construct outputs a message and terminates parsing of the script. It does not return anything.
See also exit().
eval() evaluates the string given in code_str as PHP code. Among other things, this can be useful for storing code in a database text field for later execution.
There are some factors to keep in mind when using eval(). Remember that the string passed must be valid PHP code, including things like terminating statements with a semicolon so the parser doesn't die on the line after the eval(), and properly escaping things in code_str.
Also remember that variables given values under eval() will retain these values in the main script afterwards.
A return statement will terminate the evaluation of the string immediatley. In PHP 4 you may use return to return a value that will become the result of the eval() function while in PHP 3 eval() was of type void and did never return anything.
The above example will show:
This is a $string with my $name in it.
This is a cup with my coffee in it.
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This language construct terminates parsing of the script. It does not return.
See also die().
get_browser() attempts to determine the capabilities of the user's browser. This is done by looking up the browser's information in the browscap.ini file. By default, the value of $HTTP_USER_AGENT is used; however, you can alter this (i.e., look up another browser's info) by passing the optional user_agent parameter to get_browser().
The information is returned in an object, which will contain various data elements representing, for instance, the browser's major and minor version numbers and ID string; true/false values for features such as frames, JavaScript, and cookies; and so forth.
While browscap.ini contains information on many browsers, it relies on user updates to keep the database current. The format of the file is fairly self-explanatory.
The following example shows how one might list all available information retrieved about the user's browser.
The output of the above script would look something like this:
Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586)<hr>
<b>browser_name_pattern:</b> Mozilla/4\.5.*<br>
<b>parent:</b> Netscape 4.0<br>
<b>platform:</b> Unknown<br>
<b>majorver:</b> 4<br>
<b>minorver:</b> 5<br>
<b>browser:</b> Netscape<br>
<b>version:</b> 4<br>
<b>frames:</b> 1<br>
<b>tables:</b> 1<br>
<b>cookies:</b> 1<br>
<b>backgroundsounds:</b> <br>
<b>vbscript:</b> <br>
<b>javascript:</b> 1<br>
<b>javaapplets:</b> 1<br>
<b>activexcontrols:</b> <br>
<b>beta:</b> <br>
<b>crawler:</b> <br>
<b>authenticodeupdate:</b> <br>
<b>msn:</b> <br>
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In order for this to work, your browscap configuration file setting must point to the correct location of the browscap.ini file.
For more information (including locations from which you may obtain a browscap.ini file), check the PHP FAQ at http://www.php.net/FAQ.php.
The highlight_file() function prints out a syntax higlighted version of the code contained in filename using the colors defined in the built-in syntax highlighter for PHP. It returns true on success, false otherwise (PHP 4).
Example 1. Creating a source highlighting URL To setup a URL that can code hightlight any script that you pass to it, we will make use of the "ForceType" directive in Apache to generate a nice URL pattern, and use the function highlight_file() to show a nice looking code list. In your httpd.conf you can add the following:
And then make a file named "source" and put it in your web root directory.
Then you can use an URL like the one below to display a colorized version of a script located in "/path/to/script.php" in your web site.
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See also highlight_string(), show_source().
The highlight_string() function prints out a syntax highlighted version of str using the colors defined in the built-in syntax highlighter for PHP. It returns true on success, false otherwise (PHP 4).
See also highlight_file(), show_source().
(PHP 3>= 3.0.7, PHP 4 >= 4.0b4)
ignore_user_abort -- Set whether a client disconnect should abort script executionThis function sets whether a client disconnect should cause a script to be aborted. It will return the previous setting and can be called without an argument to not change the current setting and only return the current setting. See the Connection Handling section in the Features chapter for a complete description of connection handling in PHP.
(PHP 3>= 3.0.6, PHP 4 )
iptcparse -- Parse a binary IPTC http://www.iptc.org/ block into single tags.This function parses a binary IPTC block into its single tags. It returns an array using the tagmarker as an index and the value as the value. It returns false on error or if no IPTC data was found. See GetImageSize() for a sample.
Leak() leaks the specified amount of memory.
This is useful when debugging the memory manager, which automatically cleans up "leaked" memory when each request is completed.
Pack given arguments into binary string according to format. Returns binary string containing data.
The idea to this function was taken from Perl and all formatting codes work the same as there, however, there are some formatting codes that are missing such as Perl's "u" format code. The format string consists of format codes followed by an optional repeater argument. The repeater argument can be either an integer value or * for repeating to the end of the input data. For a, A, h, H the repeat count specifies how many characters of one data argument are taken, for @ it is the absolute position where to put the next data, for everything else the repeat count specifies how many data arguments are consumed and packed into the resulting binary string. Currently implemented are
a NUL-padded string
A SPACE-padded string
h Hex string, low nibble first
H Hex string, high nibble first
c signed char
C unsigned char
s signed short (always 16 bit, machine byte order)
S unsigned short (always 16 bit, machine byte order)
n unsigned short (always 16 bit, big endian byte order)
v unsigned short (always 16 bit, little endian byte order)
i signed integer (machine dependent size and byte order)
I unsigned integer (machine dependent size and byte order)
l signed long (always 32 bit, machine byte order)
L unsigned long (always 32 bit, machine byte order)
N unsigned long (always 32 bit, big endian byte order)
V unsigned long (always 32 bit, little endian byte order)
f float (machine dependent size and representation)
d double (machine dependent size and representation)
x NUL byte
X Back up one byte
@ NUL-fill to absolute position
Note that the distinction between signed and unsigned values only affects the function unpack(), where as function pack() gives the same result for signed and unsigned format codes.
Also note that PHP internally stores integral values as signed values of a machine dependent size. If you give it an unsigned integral value too large to be stored that way it is converted to a double which often yields an undesired result.
The show_source() function prints out a syntax higlighted version of the code contained in filename using the colors defined in the built-in syntax highlighter for PHP. It returns true on success, false otherwise (PHP 4).
Note: This function is an alias for the function highlight_file()
See also highlight_string(), highlight_file().
The sleep function delays program execution for the given number of seconds.
See also usleep().
Uniqid() returns a prefixed unique identifier based on the current time in microseconds. The prefix can be useful for instance if you generate identifiers simultaneously on several hosts that might happen to generate the identifier at the same microsecond. Prefix can be up to 114 characters long.
If the optional lcg parameter is true, uniqid() will add additional "combined LCG" entropy at the end of the return value, which should make the results more unique.
With an empty prefix, the returned string will be 13 characters long. If lcg is true, it will be 23 characters.
Note: The lcg parameter is only available in PHP 4 and PHP 3.0.13 and later.
If you need a unique identifier or token and you intend to give out that token to the user via the network (i.e. session cookies), it is recommended that you use something along the lines of
$token = md5 (uniqid ("")); // no random portion
$better_token = md5 (uniqid (rand())); // better, difficult to guess
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This will create a 32 character identifier (a 128 bit hex number) that is extremely difficult to predict.
Unpack() from binary string into array according to format. Returns array containing unpacked elements of binary string.
Unpack() works slightly different from Perl as the unpacked data is stored in an associative array. To accomplish this you have to name the different format codes and separate them by a slash /.
For an explanation of the format codes see also: pack()
Note that PHP internally stores integral values as signed. If you unpack a large unsigned long and it is of the same size as PHP internally stored values the result will be a negative number even though unsigned unpacking was specified.
The usleep() function delays program execution for the given number of micro_seconds.
See also sleep().
Note: This function does not work on Windows systems.
These functions allow you to access mSQL database servers. In order to have these functions available, you must compile php with msql support by using the --with-msql[=dir] option. The default location is /usr/local/Hughes.
More information about mSQL can be found at http://www.hughes.com.au/.
Returns a positive mSQL query identifier to the query result, or false on error.
msql() selects a database and executes a query on it. If the optional link identifier isn't specified, the function will try to find an open link to the mSQL server and if no such link is found it'll try to create one as if msql_connect() was called with no arguments (see msql_connect()).
Returns number of affected ("touched") rows by a specific query (i.e. the number of rows returned by a SELECT, the number of rows modified by an update, or the number of rows removed by a delete).
See also: msql_query().
Returns true on success, false on error.
msql_close() closes the link to a mSQL database that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
Note that this isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
msql_close() will not close persistent links generated by msql_pconnect().
See also: msql_connect() and msql_pconnect().
int msql_connect ([string
hostname [, string
hostname[:port] [, string
username [, string
password]]]])
Returns a positive mSQL link identifier on success, or false on error.
msql_connect() establishes a connection to a mSQL server. The hostname argument is optional, and if it's missing, localhost is assumed.
In case a second call is made to msql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling msql_close().
See also msql_pconnect(), msql_close().
msql_create_db() attempts to create a new database on the server associated with the specified link identifier.
See also: msql_drop_db().
Returns true on success, false on failure.
msql_data_seek() moves the internal row pointer of the mSQL result associated with the specified query identifier to pointer to the specifyed row number. The next call to msql_fetch_row() would return that row.
See also: msql_fetch_row().
msql_dbname() returns the database name stored in position i of the result pointer returned from the msql_listdbs() function. The msql_numrows() function can be used to determine how many database names are available.
Returns true on success, false on failure.
msql_drop_db() attempts to drop (remove) an entire database from the server associated with the specified link identifier.
See also: msql_create_db().
Errors coming back from the mSQL database backend no longer issue warnings. Instead, use these functions to retrieve the error string.
Returns an array that corresponds to the fetched row, or false if there are no more rows.
msql_fetch_array() is an extended version of msql_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
The second optional argument result_type in msql_fetch_array() is a constant and can take the following values: MSQL_ASSOC, MSQL_NUM, and MYSQL_BOTH.
Be careful if you are retrieving results from a query that may return a record that contains only one field that has a value of 0 (or an empty string, or NULL).
An important thing to note is that using msql_fetch_array() is NOT significantly slower than using msql_fetch_row(), while it provides a significant added value.
For further details, also see msql_fetch_row().
Returns an object containing field information
msql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retreived by msql_fetch_field() is retreived.
The properties of the object are:
name - column name
table - name of the table the column belongs to
not_null - 1 if the column cannot be null
primary_key - 1 if the column is a primary key
unique - 1 if the column is a unique key
type - the type of the column
See also msql_field_seek().
Returns an object with properties that correspond to the fetched row, or false if there are no more rows.
msql_fetch_object() is similar to msql_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
The optional second argument result_type in msql_fetch_array() is a constant and can take the following values: MSQL_ASSOC, MSQL_NUM, and MSQL_BOTH.
Speed-wise, the function is identical to msql_fetch_array(), and almost as quick as msql_fetch_row() (the difference is insignificant).
See also: msql_fetch_array() and msql_fetch_row().
Returns an array that corresponds to the fetched row, or false if there are no more rows.
msql_fetch_row() fetches one row of data from the result associated with the specified query identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.
Subsequent call to msql_fetch_row() would return the next row in the result set, or false if there are no more rows.
See also: msql_fetch_array(), msql_fetch_object(), msql_data_seek(), and msql_result().
msql_fieldname() returns the name of the specified field. query_identifier is the query identifier, and field is the field index. msql_fieldname($result, 2); will return the name of the second field in the result associated with the result identifier.
Seeks to the specified field offset. If the next call to msql_fetch_field() won't include a field offset, this field would be returned.
See also: msql_fetch_field().
msql_fieldtype() is similar to the msql_fieldname() function. The arguments are identical, but the field type is returned. This will be one of "int", "char" or "real".
msql_fieldflags() returns the field flags of the specified field. Currently this is either, "not null", "primary key", a combination of the two or "" (an empty string).
msql_free_result() frees the memory associated with query_identifier. When PHP completes a request, this memory is freed automatically, so you only need to call this function when you want to make sure you don't use too much memory while the script is running.
msql_list_fields() retrieves information about the given tablename. Arguments are the database name and the table name. A result pointer is returned which can be used with msql_fieldflags(), msql_fieldlen(), msql_fieldname(), and msql_fieldtype(). A query identifier is a positive integer. The function returns -1 if a error occurs. A string describing the error will be placed in $phperrmsg, and unless the function was called as @msql_list_fields() then this error string will also be printed out.
See also msql_error().
msql_list_dbs() will return a result pointer containing the databases available from the current msql daemon. Use the msql_dbname() function to traverse this result pointer.
msql_list_tables() takes a database name and result pointer much like the msql() function. The msql_tablename() function should be used to extract the actual table names from the result pointer.
msql_num_fields() returns the number of fields in a result set.
See also: msql(), msql_query(), msql_fetch_field(), and msql_num_rows().
Msql_num_rows() returns the number of rows in a result set.
See also: msql(), msql_query(), and msql_fetch_row().
int msql_pconnect ([string
hostname [, string
hostname[:port] [, string
username [, string
password]]]])
Returns a positive mSQL persistent link identifier on success, or false on error.
msql_pconnect() acts very much like msql_connect() with two major differences.
First, when connecting, the function would first try to find a (persistent) link that's already open with the same host. If one is found, an identifier for it will be returned instead of opening a new connection.
Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (msql_close() will not close links established by msql_pconnect()).
This type of links is therefore called 'persistent'.
msql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if msql_connect() was called, and use it.
Returns a positive mSQL query identifier on success, or false on error.
See also: msql(), msql_select_db(), and msql_connect().
Returns the contents of the cell at the row and offset in the specified mSQL result set.
msql_result() returns the contents of one cell from a mSQL result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (fieldname.tablename). If the column name has been aliased ('select foo as bar from ...'), use the alias instead of the column name.
When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than msql_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.
Recommended high-performance alternatives: msql_fetch_row(), msql_fetch_array(), and msql_fetch_object().
Returns true on success, false on error.
msql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if msql_connect() was called, and use it.
Every subsequent call to msql_query() will be made on the active database.
See also: msql_connect(), msql_pconnect(), and msql_query().
msql_tablename() takes a result pointer returned by the msql_list_tables() function as well as an integer index and returns the name of a table. The msql_numrows() function may be used to determine the number of tables in the result pointer.
These functions allow you to access MySQL database servers. In order to have these functions available, you must compile php with mysql support by using the --with-mysql option. If you use this option without specifying the path to mysql, php will use the built-in mysql client libraries. Users who run other applications that use mysql (for example, running php3 and php4 as concurrent apache modules, or auth-mysql) should always specify the path to mysql: --with-mysql=/path/to/mysql. This will force php to use the client libraries installed by mysql, avoiding any conflicts.
More information about MySQL can be found at http://www.mysql.com/.
Documentation for MySQL can be found at http://www.mysql.com/documentation/.
mysql_affected_rows() returns the number of rows affected by the last INSERT, UPDATE or DELETE query on the server associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
If the last query was a DELETE query with no WHERE clause, all of the records will have been deleted from the table but this function will return zero.
This command is not effective for SELECT statements, only on statements which modify records. To retrieve the number of rows returned from a SELECT, use mysql_num_rows().
mysql_change_user() changes the logged in user of the current active connection, or the connection given by the optional parameter link_identifier. If a database is specified, this will default or current database after the user has been changed. If the new user and password authorization fails, the current connected user stays active.
Note: This function was introduced in PHP 3.0.13 and requires MySQL 3.23.3 or higher.
Returns: true on success, false on error.
mysql_close() closes the connection to the MySQL server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is used.
Using mysql_close() isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
Note: mysql_close() will not close persistent links created by mysql_pconnect().
See also: mysql_connect(), and mysql_pconnect().
int mysql_connect ([string
hostname
[:port]
[:/path/to/socket] [, string
username [, string
password]]])
Returns a positive MySQL link identifier on success, or an error message on failure.
mysql_connect() establishes a connection to a MySQL server. The following defaults are assumed for missing optional parameters: host:port = 'localhost:3306', username = name of the user that owns the server process and password = empty password.
The hostname string can also include a port number. eg. "hostname:port" or a path to a socket eg. ":/path/to/socket" for the localhost.
Note: Support for ":port" was added in PHP 3.0B4.
Support for ":/path/to/socket" was added in PHP 3.0.10.
You can suppress the error message on failure by prepending '@' to the function name.
If a second call is made to mysql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().
See also mysql_pconnect(), and mysql_close().
mysql_create_db() attempts to create a new database on the server associated with the specified link identifier.
For downwards compatibility mysql_createdb() can also be used.
See also: mysql_drop_db().
Returns: true on success, false on failure.
mysql_data_seek() moves the internal row pointer of the MySQL result associated with the specified result identifier to point to the specified row number. The next call to mysql_fetch_row() would return that row.
Row_number starts at 0.
Example 1. MySQL data seek example
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mysql_db_name() takes as its first parameter the result pointer from a call to mysql_list_dbs(). The row parameter is an index into the result set.
If an error occurs, FALSE is returned. Use mysql_errno() and mysql_error() to determine the nature of the error.
For backward compatibility, mysql_dbname() is also accepted. This is deprecated, however.
Returns: A positive MySQL result identifier to the query result, or false on error.
mysql_db_query() selects a database and executes a query on it. If the optional link identifier isn't specified, the function will try to find an open link to the MySQL server and if no such link is found it'll try to create one as if mysql_connect() was called with no arguments
See also mysql_connect().
For downwards compatibility mysql() can also be used.
Returns: true on success, false on failure.
mysql_drop_db() attempts to drop (remove) an entire database from the server associated with the specified link identifier.
See also: mysql_create_db(). For downward compatibility mysql_dropdb() can also be used.
(PHP 3, PHP 4 )
mysql_errno -- Returns the numerical value of the error message from previous MySQL operationReturns the error number from the last mySQL function, or 0 (zero) if no error occurred.
Errors coming back from the mySQL database backend no longer issue warnings. Instead, use mysql_errno() to retrieve the error code. Note that this function only returns the error code from the most recently executed mySQL function (not including mysql_error() and mysql_errno()), so if you want to use it, make sure you check the value before calling another mySQL function.
<?php
mysql_connect("marliesle");
echo mysql_errno().": ".mysql_error()."<BR>";
mysql_select_db("nonexistentdb");
echo mysql_errno().": ".mysql_error()."<BR>";
$conn = mysql_query("SELECT * FROM nonexistenttable");
echo mysql_errno().": ".mysql_error()."<BR>";
?>
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See also: mysql_error()
Returns the error text from the last mySQL function, or '' (the empty string) if no error occurred.
Errors coming back from the mySQL database backend no longer issue warnings. Instead, use mysql_error() to retrieve the error text. Note that this function only returns the error text from the most recently executed mySQL function (not including mysql_error() and mysql_errno()), so if you want to use it, make sure you check the value before calling another mySQL function.
<?php
mysql_connect("marliesle");
echo mysql_errno().": ".mysql_error()."<BR>";
mysql_select_db("nonexistentdb");
echo mysql_errno().": ".mysql_error()."<BR>";
$conn = mysql_query("SELECT * FROM nonexistenttable");
echo mysql_errno().": ".mysql_error()."<BR>";
?>
|
See also: mysql_errno()
(PHP 3, PHP 4 )
mysql_fetch_array -- Fetch a result row as an associative array, a numeric array, or both.Returns an array that corresponds to the fetched row, or false if there are no more rows.
mysql_fetch_array() is an extended version of mysql_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must the numeric index of the column or make an alias for the column.
An important thing to note is that using mysql_fetch_array() is NOT significantly slower than using mysql_fetch_row(), while it provides a significant added value.
The optional second argument result_type in mysql_fetch_array() is a constant and can take the following values: MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH. (This feature was added in PHP 3.0.7)
For further details, see also mysql_fetch_row() and mysql_fetch_assoc().
Example 1. Mysql_fetch_array()
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Returns an associative array that corresponds to the fetched row, or false if there are no more rows.
mysql_fetch_assoc() is equivalent to calling mysql_fetch_array() with MYSQL_ASSOC for the optional second parameter. It only returns an associative array. This is the way mysql_fetch_array() originally worked. If you need the numeric indices as well as the associative, use mysql_fetch_array().
If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must use mysql_fetch_array() and have it return the numeric indices as well.
An important thing to note is that using mysql_fetch_assoc() is NOT significantly slower than using mysql_fetch_row(), while it provides a significant added value.
For further details, see also mysql_fetch_row() and mysql_fetch_array().
Returns an object containing field information.
mysql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by mysql_fetch_field() is retrieved.
The properties of the object are:
name - column name
table - name of the table the column belongs to
max_length - maximum length of the column
not_null - 1 if the column cannot be null
primary_key - 1 if the column is a primary key
unique_key - 1 if the column is a unique key
multiple_key - 1 if the column is a non-unique key
numeric - 1 if the column is numeric
blob - 1 if the column is a BLOB
type - the type of the column
unsigned - 1 if the column is unsigned
zerofill - 1 if the column is zero-filled
Example 1. Mysql_fetch_field()
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See also mysql_field_seek().
Returns: An array that corresponds to the lengths of each field in the last row fetched by mysql_fetch_row(), or false on error.
mysql_fetch_lengths() stores the lengths of each result column in the last row returned by mysql_fetch_row(), mysql_fetch_array(), and mysql_fetch_object() in an array, starting at offset 0.
See also: mysql_fetch_row().
Returns an object with properties that correspond to the fetched row, or false if there are no more rows.
mysql_fetch_object() is similar to mysql_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
The optional argument result_type is a constant and can take the following values: MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH.
Speed-wise, the function is identical to mysql_fetch_array(), and almost as quick as mysql_fetch_row() (the difference is insignificant).
See also: mysql_fetch_array() and mysql_fetch_row().
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
mysql_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.
Subsequent call to mysql_fetch_row() would return the next row in the result set, or false if there are no more rows.
See also: mysql_fetch_array(), mysql_fetch_object(), mysql_data_seek(), mysql_fetch_lengths(), and mysql_result().
mysql_field_flags() returns the field flags of the specified field. The flags are reported as a single word per flag separated by a single space, so that you can split the returned value using explode().
The following flags are reported, if your version of MySQL is current enough to support them: "not_null", "primary_key", "unique_key", "multiple_key", "blob", "unsigned", "zerofill", "binary", "enum", "auto_increment", "timestamp".
For downward compatibility mysql_fieldflags() can also be used.
mysql_field_name() returns the name of the specified field index. result must be a valid result identifier and field_index is the numerical offset of the field.
Note: field_index starts at 0.
e.g. The index of the third field would actually be 2, the index of the fourth field would be 3 and so on.
The above example would produce the following output:
For downwards compatibility mysql_fieldname() can also be used.
mysql_field_len() returns the length of the specified field.
For downward compatibility mysql_fieldlen() can also be used.
Seeks to the specified field offset. If the next call to mysql_fetch_field() doesn't include a field offset, the field offset specified in mysql_field_seek() will be returned.
See also: mysql_fetch_field().
Returns the name of the table that the specifed field is in.
For downward compatibility mysql_fieldtable() can also be used.
mysql_field_type() is similar to the mysql_field_name() function. The arguments are identical, but the field type is returned instead. The field type will be one of "int", "real", "string", "blob", and others as detailed in the MySQL documentation.
Example 1. mysql field types
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For downward compatibility mysql_fieldtype() can also be used.
mysql_free_result() will free all memory associated with the result identifier result.
mysql_free_result() only needs to be called if you are concerned about how much memory is being used for queries that return large result sets. All associated result memory is automatically freed at the end of the script's execution.
For downward compatibility mysql_freeresult() can also be used.
mysql_insert_id() returns the ID generated for an AUTO_INCREMENT column by the previous INSERT query using the given link_identifier. If link_identifier isn't specified, the last opened link is assumed.
mysql_insert_id() returns 0 if the previous query does not generate an AUTO_INCREMENT value. If you need to save the value for later, be sure to call mysql_insert_id() immediately after the query that generates the value.
Note: The value of the MySQL SQL function LAST_INSERT_ID() always contains the most recently generated AUTO_INCREMENT value, and is not reset between queries.
| Warning |
mysql_insert_id() converts the return type of the native MySQL C API function mysql_insert_id() to a type of long. If your AUTO_INCREMENT column has a column type of BIGINT, the value returned by mysql_insert_id() will be incorrect. Instead, use the internal MySQL SQL function LAST_INSERT_ID(). |
mysql_list_dbs() will return a result pointer containing the databases available from the current mysql daemon. Use the mysql_tablename() function to traverse this result pointer.
The above example would produce the following output:
Note: The above code would just as easily work with mysql_fetch_row() or other similar functions.
For downward compatibility mysql_listdbs() can also be used.
mysql_list_fields() retrieves information about the given tablename. Arguments are the database name and the table name. A result pointer is returned which can be used with mysql_field_flags(), mysql_field_len(), mysql_field_name(), and mysql_field_type().
A result identifier is a positive integer. The function returns -1 if a error occurs. A string describing the error will be placed in $phperrmsg, and unless the function was called as @mysql() then this error string will also be printed out.
The above example would produce the following output:
For downward compatibility mysql_listfields() can also be used.
mysql_list_tables() takes a database name and returns a result pointer much like the mysql_db_query() function. The mysql_tablename() function should be used to extract the actual table names from the result pointer.
For downward compatibility mysql_listtables() can also be used.
mysql_num_fields() returns the number of fields in a result set.
See also: mysql_db_query(), mysql_query(), mysql_fetch_field(), mysql_num_rows().
For downward compatibility mysql_numfields() can also be used.
mysql_num_rows() returns the number of rows in a result set. This command is only valid for SELECT statements. To retrieve the number of rows returned from a INSERT, UPDATE or DELETE, use mysql_affected_rows().
Example 1. mysql_num_rows example by crubel@trilizio.org ()
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See also: mysql_db_query(), mysql_query() and, mysql_fetch_row().
For downward compatibility mysql_numrows() can also be used.
int mysql_pconnect ([string
hostname
[:port]
[:/path/to/socket] [, string
username [, string
password]]])
Returns: A positive MySQL persistent link identifier on success, or false on error.
mysql_pconnect() establishes a connection to a MySQL server. The following defaults are assumed for missing optional parameters: host:port = 'localhost:3306', username = name of the user that owns the server process and password = empty password.
The hostname string can also include a port number. eg. "hostname:port" or a path to a socket eg. ":/path/to/socket" for the localhost.
Note: Support for ":port" wass added in 3.0B4.
Support for the ":/path/to/socket" was added in 3.0.10.
mysql_pconnect() acts very much like mysql_connect() with two major differences.
First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.
Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (mysql_close() will not close links established by mysql_pconnect()).
This type of links is therefore called 'persistent'.
mysql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if mysql_connect() was called with no arguments, and use it.
Note: The query string should not end with a semicolon.
mysql_query() returns TRUE (non-zero) or FALSE to indicate whether or not the query succeeded. A return value of TRUE means that the query was legal and could be executed by the server. It does not indicate anything about the number of rows affected or returned. It is perfectly possible for a query to succeed but affect no rows or return no rows.
The following query is syntactically invalid, so mysql_query() fails and returns FALSE:
The following query is semantically invalid if my_col is not a column in the table my_tbl, so mysql_query() fails and returns FALSE:
mysql_query() will also fail and return FALSE if you don't have permission to access the table(s) referenced by the query.
Assuming the query succeeds, you can call mysql_num_rows() to find out how many rows were returned for a SELECT statment or mysql_affected_rows() to find out how many rows were affected by a DELETE, INSERT, REPLACE, or UPDATE statement.
For SELECT statements, mysql_query() returns a new result identifier that you can pass to mysql_result(). When you are done with the result set, you can free the resources associated with it by calling mysql_free_result(). Although, the memory will automatically be freed at the end of the script's execution.
See also: mysql_affected_rows(), mysql_db_query(), mysql_free_result(), mysql_result(), mysql_select_db(), and mysql_connect().
mysql_result() returns the contents of one cell from a MySQL result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (fieldname.tablename). If the column name has been aliased ('select foo as bar from...'), use the alias instead of the column name.
When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than mysql_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.
Calls to mysql_result() should not be mixed with calls to other functions that deal with the result set.
Recommended high-performance alternatives: mysql_fetch_row(), mysql_fetch_array(), and mysql_fetch_object().
Returns: true on success, false on error.
mysql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if mysql_connect() was called, and use it.
Every subsequent call to mysql_query() will be made on the active database.
See also: mysql_connect(), mysql_pconnect(), and mysql_query().
For downward compatibility mysql_selectdb() can also be used.
mysql_tablename() takes a result pointer returned by the mysql_list_tables() function as well as an integer index and returns the name of a table. The mysql_num_rows() function may be used to determine the number of tables in the result pointer.
(PHP 3, PHP 4 )
checkdnsrr -- Check DNS records corresponding to a given Internet host name or IP addressSearches DNS for records of type type corresponding to host. Returns true if any records are found; returns false if no records were found or if an error occurred.
type may be any one of: A, MX, NS, SOA, PTR, CNAME, or ANY. The default is MX.
Host may either be the IP address in dotted-quad notation or the host name.
See also getmxrr(), gethostbyaddr(), gethostbyname(), gethostbynamel(), and the named(8) manual page.
Closelog() closes the descriptor being used to write to the system logger. The use of closelog() is optional.
See also define_syslog_variables(), syslog() and openlog().
Enables the internal PHP debugger, connecting it to address. The debugger is still under development.
Initializes all constants used in the syslog functions.
See also openlog(), syslog() and closelog().
int fsockopen (string [udp://]hostname, int port [, int
errno [, string
errstr [, double
timeout]]])
Initiates a stream connection in the Internet (AF_INET, using TCP or UDP) or Unix (AF_UNIX) domain. For the Internet domain, it will open a TCP socket connection to hostname on port port. hostname may in this case be either a fully qualified domain name or an IP address. For UDP connections, you need to explicitly specify the protocol: udp://hostname. For the Unix domain, hostname will be used as the path to the socket, port must be set to 0 in this case. The optional timeout can be used to set a timeout in seconds for the connect system call.
Fsockopen() returns a file pointer which may be used together with the other file functions (such as fgets(), fgetss(), fputs(), fclose(), and feof()).
If the call fails, it will return false and if the optional errno and errstr arguments are present they will be set to indicate the actual system level error that occurred on the system-level connect() call. If the returned errno is 0 and the function returned false, it is an indication that the error occurred before the connect() call. This is most likely due to a problem initializing the socket. Note that the errno and errstr arguments must be passed by reference.
Depending on the environment, the Unix domain or the optional connect timeout may not be available.
The socket will by default be opened in blocking mode. You can switch it to non-blocking mode by using socket_set_blocking().
Note: The timeout parameter was introduced in PHP 3.0.9 and UDP support was added in PHP 4.
Returns the host name of the Internet host specified by ip_address. If an error occurs, returns ip_address.
See also gethostbyname().
Returns the IP address of the Internet host specified by hostname.
See also gethostbyaddr().
(PHP 3, PHP 4 )
gethostbynamel -- Get a list of IP addresses corresponding to a given Internet host nameReturns a list of IP addresses to which the Internet host specified by hostname resolves.
See also gethostbyname(), gethostbyaddr(), checkdnsrr(), getmxrr(), and the named(8) manual page.
Searches DNS for MX records corresponding to hostname. Returns true if any records are found; returns false if no records were found or if an error occurred.
A list of the MX records found is placed into the array mxhosts. If the weight array is given, it will be filled with the weight information gathered.
See also checkdnsrr(), gethostbyname(), gethostbynamel(), gethostbyaddr(), and the named(8) manual page.
Getprotobyname() returns the protocol number associated with the protocol name as per /etc/protocols.
See also: getprotobynumber().
Getprotobynumber() returns the protocol name associated with protocol number as per /etc/protocols.
See also: getprotobyname().
Getservbyname() returns the Internet port which corresponds to service for the specified protocol as per /etc/services. protocol is either TCP or UDP.
See also: getservbyport().
Getservbyport() returns the Internet service associated with port for the specified protocol as per /etc/services. protocol is either TCP or UDP.
See also: getservbyname().
(PHP 4 >= 4.0RC1)
ip2long -- Converts a string containing an (IPv4) Internet Protocol dotted address into a proper address.The function ip2long() generates an IPv4 Internet network address from its Internet standard format (dotted string) representation.
See also: long2ip()
(PHP 4 >= 4.0RC1)
long2ip -- Converts an (IPv4) Internet network address into a string in Internet standard dotted formatThe function long2ip() generates an Internet address in dotted format (i.e.: aaa.bbb.ccc.ddd) from the proper address representation.
See also: ip2long()
Openlog() opens a connection to the system logger for a program. The string ident is added to each message. Values for option and facility are given below. The option argument is used to indicate what loggin options will be used when generating a log message. The facility argument is used to specify what type of program is logging the message. This allows you to specify (in your machine's syslog configuration) how messages coming from different facilities will be handled. The use of openlog() is optional. It will automatically be called by syslog() if necessary, in which case ident will default to false.
Table 1. Openlog() Options
| Constant | Description |
|---|---|
| LOG_CONS | if there is an error while sending data to the system logger, write directly to the system console |
| LOG_NDELAY | open the connection to the logger immediately |
| LOG_ODELAY | (default) delay openning the connection until the first message is logged |
| LOG_PERROR | print log message also to standard error |
| LOG_PID | include PID with each message |
Table 2. Openlog() Facilities
| Constant | Description |
|---|---|
| LOG_AUTH | security/authorization messages (use LOG_AUTHPRIV instead in systems where that constant is defined) |
| LOG_AUTHPRIV | security/authorization messages (private) |
| LOG_CRON | clock daemon (cron and at) |
| LOG_DAEMON | other system daemons |
| LOG_KERN | kernel messages |
| LOG_LOCAL0 ... LOG_LOCAL7 | reserved for local use |
| LOG_LPR | line printer subsystem |
| LOG_MAIL | mail subsystem |
| LOG_NEWS | USENET news subsystem |
| LOG_SYSLOG | messages generated internally by syslogd |
| LOG_USER | generic user-level messages |
| LOG_UUCP | UUCP subsystem |
See also define_syslog_variables(), syslog() and closelog().
This function behaves exactly as fsockopen() with the difference that the connection is not closed after the script finishes. It is the persistent version of fsockopen().
Returns information about an existing socket resource. Currently returns four entries in the result array:
timed_out (bool) - The socket timed out waiting for data
blocked (bool) - The socket was blocked
eof (bool) - Indicates EOF event
unread_bytes (int) - Number of bytes left in the socket buffer
See also accept_connect(), bind(), connect(), listen(), and strerror().
If mode is false, the given socket descriptor will be switched to non-blocking mode, and if true, it will be switched to blocking mode. This affects calls like fgets() that read from the socket. In non-blocking mode an fgets() call will always return right away while in blocking mode it will wait for data to become available on the socket.
This function was previously called as set_socket_blocking() but this usage is deprecated.
Sets the timeout value on socket descriptor, expressed in the sum of seconds and microseconds.
This function was previously called as set_socket_timeout() but this usage is deprecated.
See also: fsockopen() and fopen().
Syslog() generates a log message that will be distributed by the system logger. priority is a combination of the facility and the level, values for which are given in the next section. The remaining argument is the message to send, except that the two characters %m will be replaced by the error message string (strerror) corresponding to the present value of errno.
Table 1. Syslog() Priorities (in descending order)
| Constant | Description |
|---|---|
| LOG_EMERG | system is unusable |
| LOG_ALERT | action must be taken immediately |
| LOG_CRIT | critical conditions |
| LOG_ERR | error conditions |
| LOG_WARNING | warning conditions |
| LOG_NOTICE | normal, but significant, condition |
| LOG_INFO | informational message |
| LOG_DEBUG | debug-level message |
Example 1. Using syslog()
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On Windows NT, the syslog service is emulated using the Event Log.
See also define_syslog_variables(), openlog() and closelog().
In addition to normal ODBC support, the Unified ODBC functions in PHP allow you to access several databases that have borrowed the semantics of the ODBC API to implement their own API. Instead of maintaining multiple database drivers that were all nearly identical, these drivers have been unified into a single set of ODBC functions.
The following databases are supported by the Unified ODBC functions: Adabas D, IBM DB2, iODBC, Solid, and Sybase SQL Anywhere.
Please see the Installation on Unix Systems chapter for more information about configuring PHP with these databases.
Note: There is no ODBC involved when connecting to the above databases. The functions that you use to speak natively to them just happen to share the same names and syntax as the ODBC functions.
Without the OnOff parameter, this function returns auto-commit status for connection_id. True is returned if auto-commit is on, false if it is off or an error occurs.
If OnOff is true, auto-commit is enabled, if it is false auto-commit is disabled. Returns true on success, false on failure.
By default, auto-commit is on for a connection. Disabling auto-commit is equivalent with starting a transaction.
See also odbc_commit() and odbc_rollback().
(ODBC SQL types affected: BINARY, VARBINARY, LONGVARBINARY)
ODBC_BINMODE_PASSTHRU: Passthru BINARY data
ODBC_BINMODE_RETURN: Return as is
ODBC_BINMODE_CONVERT: Convert to char and return
When binary SQL data is converted to character C data, each byte (8 bits) of source data is represented as two ASCII characters. These characters are the ASCII character representation of the number in its hexadecimal form. For example, a binary 00000001 is converted to "01" and a binary 11111111 is converted to "FF".
Table 1. LONGVARBINARY handling
| binmode | longreadlen | result |
|---|---|---|
| ODBC_BINMODE_PASSTHRU | 0 | passthru |
| ODBC_BINMODE_RETURN | 0 | passthru |
| ODBC_BINMODE_CONVERT | 0 | passthru |
| ODBC_BINMODE_PASSTHRU | 0 | passthru |
| ODBC_BINMODE_PASSTHRU | >0 | passthru |
| ODBC_BINMODE_RETURN | >0 | return as is |
| ODBC_BINMODE_CONVERT | >0 | return as char |
If odbc_fetch_into() is used, passthru means that an empty string is returned for these columns.
If result_id is 0, the settings apply as default for new results.
Note: Default for longreadlen is 4096 and binmode defaults to ODBC_BINMODE_RETURN. Handling of binary long columns is also affected by odbc_longreadlen()
odbc_close() will close down the connection to the database server associated with the given connection identifier.
Note: This function will fail if there are open transactions on this connection. The connection will remain open in this case.
odbc_close_all() will close down all connections to database server(s).
Note: This function will fail if there are open transactions on a connection. This connection will remain open in this case.
Returns: true on success, false on failure. All pending transactions on connection_id are committed.
Returns an ODBC connection id or 0 (false) on error.
The connection id returned by this functions is needed by other ODBC functions. You can have multiple connections open at once. The optional fourth parameter sets the type of cursor to be used for this connection. This parameter is not normally needed, but can be useful for working around problems with some ODBC drivers.
With some ODBC drivers, executing a complex stored procedure may fail with an error similar to: "Cannot open a cursor on a stored procedure that has anything other than a single select statement in it". Using SQL_CUR_USE_ODBC may avoid that error. Also, some drivers don't support the optional row_number parameter in odbc_fetch_row(). SQL_CUR_USE_ODBC might help in that case, too.
The following constants are defined for cursortype:
SQL_CUR_USE_IF_NEEDED
SQL_CUR_USE_ODBC
SQL_CUR_USE_DRIVER
SQL_CUR_DEFAULT
For persistent connections see odbc_pconnect().
Returns false on error. Returns an ODBC result identifier if the SQL command was executed successfully.
odbc_exec() will send an SQL statement to the database server specified by connection_id. This parameter must be a valid identifier returned by odbc_connect() or odbc_pconnect().
See also: odbc_prepare() and odbc_execute() for multiple execution of SQL statements.
Executes a statement prepared with odbc_prepare(). Returns true on successful execution, false otherwise. The array arameters_array only needs to be given if you really have parameters in your statement.
Returns the number of columns in the result; false on error. result_array must be passed by reference, but it can be of any type since it will be converted to type array. The array will contain the column values starting at array index 0.
If odbc_fetch_row() was succesful (there was a row), true is returned. If there are no more rows, false is returned.
odbc_fetch_row() fetches a row of the data that was returned by odbc_do() / odbc_exec(). After odbc_fetch_row() is called, the fields of that row can be accessed with odbc_result().
If row_number is not specified, odbc_fetch_row() will try to fetch the next row in the result set. Calls to odbc_fetch_row() with and without row_number can be mixed.
To step through the result more than once, you can call odbc_fetch_row() with row_number 1, and then continue doing odbc_fetch_row() without row_number to review the result. If a driver doesn't support fetching rows by number, the row_number parameter is ignored.
odbc_field_name() will return the name of the field occupying the given column number in the given ODBC result identifier. Field numbering starts at 1. false is returned on error.
odbc_field_num() will return the number of the column slot that corresponds to the named field in the given ODBC result identifier. Field numbering starts at 1. false is returned on error.
odbc_field_type() will return the SQL type of the field referecend by number in the given ODBC result identifier. Field numbering starts at 1.
odbc_field_len() will return the length of the field referecend by number in the given ODBC result identifier. Field numbering starts at 1.
See also: odbc_field_scale() to get the scale of a floating point number.
odbc_field_precision() will return the precision of the field referecend by number in the given ODBC result identifier.
See also: odbc_field_scale() to get the scale of a floating point number.
odbc_field_precision() will return the scale of the field referecend by number in the given ODBC result identifier.
Always returns true.
odbc_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script is finished. But, if you are sure you are not going to need the result data anymore in a script, you may call odbc_free_result(), and the memory associated with result_id will be freed.
Note: If auto-commit is disabled (see odbc_autocommit()) and you call odbc_free_result() before commiting, all pending transactions are rolled back.
(ODBC SQL types affected: LONG, LONGVARBINARY) The number of bytes returned to PHP is controled by the parameter length. If it is set to 0, Long column data is passed thru to the client.
Note: Handling of LONGVARBINARY columns is also affected by odbc_binmode().
Odbc_num_fields() will return the number of fields (columns) in an ODBC result. This function will return -1 on error. The argument is a valid result identifier returned by odbc_exec().
Returns an ODBC connection id or 0 (false) on error. This function is much like odbc_connect(), except that the connection is not really closed when the script has finished. Future requests for a connection with the same dsn, user, password combination (via odbc_connect() and odbc_pconnect()) can reuse the persistent connection.
Note: Persistent connections have no effect if PHP is used as a CGI program.
For information about the optional cursor_type parameter see the odbc_connect() function. For more information on persistent connections, refer to the PHP FAQ.
Returns false on error.
Returns an ODBC result identifier if the SQL command was prepared successfully. The result identifier can be used later to execute the statement with odbc_execute().
odbc_num_rows() will return the number of rows in an ODBC result. This function will return -1 on error. For INSERT, UPDATE and DELETE statements odbc_num_rows() returns the number of rows affected. For a SELECT clause this can be the number of rows available.
Note: Using odbc_num_rows() to determine the number of rows available after a SELECT will return -1 with many drivers.
Returns the contents of the field.
field can either be an integer containing the column number of the field you want; or it can be a string containing the name of the field. For example:
The first call to odbc_result() returns the value of the third field in the current record of the query result. The second function call to odbc_result() returns the value of the field whose field name is "val" in the current record of the query result. An error occurs if a column number parameter for a field is less than one or exceeds the number of columns (or fields) in the current record. Similarly, an error occurs if a field with a name that is not one of the fieldnames of the table(s) that is(are) being queried.
Field indices start from 1. Regarding the way binary or long column data is returned refer to odbc_binmode () and odbc_longreadlen().
Returns the number of rows in the result or false on error.
Odbc_result_all() will print all rows from a result identifier produced by odbc_exec(). The result is printed in HTML table format. With the optional string argument format, additional overall table formatting can be done.
Rolls back all pending statements on connection_id. Returns true on success, false on failure.
(PHP 3>= 3.0.6, PHP 4 )
odbc_setoption -- Adjust ODBC settings. Returns false if an error occurs, otherwise true.This function allows fiddling with the ODBC options for a particular connection or query result. It was written to help find work arounds to problems in quirky ODBC drivers. You should probably only use this function if you are an ODBC programmer and understand the effects the various options will have. You will certainly need a good ODBC reference to explain all the different options and values that can be used. Different driver versions support different options.
Because the effects may vary depending on the ODBC driver, use of this function in scripts to be made publicly available is strongly discouraged. Also, some ODBC options are not available to this function because they must be set before the connection is established or the query is prepared. However, if on a particular job it can make PHP work so your boss doesn't tell you to use a commercial product, that's all that really matters.
ID is a connection id or result id on which to change the settings.For SQLSetConnectOption(), this is a connection id. For SQLSetStmtOption(), this is a result id.
Function is the ODBC function to use. The value should be 1 for SQLSetConnectOption() and 2 for SQLSetStmtOption().
Parameter option is the option to set.
Parameter param is the value for the given option.
Example 1. ODBC Setoption Examples
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(PHP 3>= 3.0.17, PHP 4 >= 4.0b4)
odbc_tables -- Get the list of table names stored in a specific data source. Returns a result identifier containing the information.int odbc_tables (int connection_id [, string qualifier [, string owner [, string name [, string types]]]])
Lists all tables in the requested range. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
TABLE_TYPE
REMARKS
The result set is ordered by TABLE_TYPE, TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.
The owner and name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).
To support enumeration of qualifiers, owners, and table types, the following special semantics for the qualifier, owner, name, and table_type are available:
If qualifier is a single percent character (%) and owner and name are empty strings, then the result set contains a list of valid qualifiers for the data source. (All columns except the TABLE_QUALIFIER column contain NULLs.)
If owner is a single percent character (%) and qualifier and name are empty strings, then the result set contains a list of valid owners for the data source. (All columns except the TABLE_OWNER column contain NULLs.)
If table_type is a single percent character (%) and qualifier, owner and name are empty strings, then the result set contains a list of valid table types for the data source. (All columns except the TABLE_TYPE column contain NULLs.)
If table_type is not an empty string, it must contain a list of comma-separated values for the types of interest; each value may be enclosed in single quotes (') or unquoted. For example, "'TABLE','VIEW'" or "TABLE, VIEW". If the data source does not support a specified table type, odbc_tables() does not return any results for that type.
See also odbc_tableprivileges() to retrieve associated privileges.
Lists tables in the requested range and the privileges associated with each table. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
GRANTOR
GRANTEE
PRIVILEGE
IS_GRANTABLE
The result set is ordered by TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.
The owner and name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).
(PHP 4 >= 4.0b4)
odbc_columns -- Lists the column names in specified tables. Returns a result identifier containing the information.int odbc_columns (int connection_id [, string qualifier [, string owner [, string table_name [, string column_name]]]])
Lists all columns in the requested range. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
COLUMN_NAME
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
RADIX
NULLABLE
REMARKS
The result set is ordered by TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.
The owner, table_name and column_name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).
See also odbc_columnprivileges() to retrieve associated privileges.
(PHP 4 >= 4.0b4)
odbc_columnprivileges -- Returns a result identifier that can be used to fetch a list of columns and associated privilegesint odbc_columnprivileges (int connection_id [, string qualifier [, string owner [, string table_name [, string column_name]]]])
Lists columns and associated privileges for the given table. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
GRANTOR
GRANTEE
PRIVILEGE
IS_GRANTABLE
The result set is ordered by TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.
The column_name argument accepts search patterns ('%' to match zero or more characters and '_' to match a single character).
(PHP 4 >= 4.0b4)
odbc_gettypeinfo -- Returns a result identifier containing information about data types supported by the data source.Retrieves information about data types supported by the data source. Returns an ODBC result identifier or false on failure. The optional argument data_type can be used to restrict the information to a single data type.
The result set has the following columns:
TYPE_NAME
DATA_TYPE
PRECISION
LITERAL_PREFIX
LITERAL_SUFFIX
CREATE_PARAMS
NULLABLE
CASE_SENSITIVE
SEARCHABLE
UNSIGNED_ATTRIBUTE
MONEY
AUTO_INCREMENT
LOCAL_TYPE_NAME
MINIMUM_SCALE
MAXIMUM_SCALE
The result set is ordered by DATA_TYPE and TYPE_NAME.
(PHP 4 >= 4.0b4)
odbc_primarykeys -- Returns a result identifier that can be used to fetch the column names that comprise the primary key for a tableReturns the column names that comprise the primary key for a table. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
COLUMN_NAME
KEY_SEQ
PK_NAME
(PHP 4 >= 4.0b4)
odbc_foreignkeys -- Returns a list of foreign keys in the specified table or a list of foreign keys in other tables that refer to the primary key in the specified tableint odbc_foreignkeys (int connection_id, string pk_qualifier, string pk_owner, string pk_table, string fk_qualifier, string fk_owner, string fk_table)
Odbc_foreignkeys() retrieves information about foreign keys. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
PKTABLE_QUALIFIER
PKTABLE_OWNER
PKTABLE_NAME
PKCOLUMN_NAME
FKTABLE_QUALIFIER
FKTABLE_OWNER
FKTABLE_NAME
FKCOLUMN_NAME
KEY_SEQ
UPDATE_RULE
DELETE_RULE
FK_NAME
PK_NAME
If pk_table contains a table name, odbc_foreignkeys() returns a result set containing the primary key of the specified table and all of the foreign keys that refer to it.
If fk_table contains a table name, odbc_foreignkeys() returns a result set containing all of the foreign keys in the specified table and the primary keys (in other tables) to which they refer.
If both pk_table and fk_table contain table names, odbc_foreignkeys() returns the foreign keys in the table specified in fk_table that refer to the primary key of the table specified in pk_table. This should be one key at most.
(PHP 4 >= 4.0b4)
odbc_procedures -- Get the list of procedures stored in a specific data source. Returns a result identifier containing the information.Lists all procedures in the requested range. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
PROCEDURE_QUALIFIER
PROCEDURE_OWNER
PROCEDURE_NAME
NUM_INPUT_PARAMS
NUM_OUTPUT_PARAMS
NUM_RESULT_SETS
REMARKS
PROCEDURE_TYPE
The owner and name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).
int odbc_procedurecolumns (int connection_id [, string qualifier [, string owner [, string proc [, string column]]]])
Returns the list of input and output parameters, as well as the columns that make up the result set for the specified procedures. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
PROCEDURE_QUALIFIER
PROCEDURE_OWNER
PROCEDURE_NAME
COLUMN_NAME
COLUMN_TYPE
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
RADIX
NULLABLE
REMARKS
The result set is ordered by PROCEDURE_QUALIFIER, PROCEDURE_OWNER, PROCEDURE_NAME and COLUMN_TYPE.
The owner, proc and column arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).
(PHP 4 >= 4.0b4)
odbc_specialcolumns -- Returns either the optimal set of columns that uniquely identifies a row in the table or columns that are automatically updated when any value in the row is updated by a transactionint odbc_specialcolumns (int connection_id, int type, string qualifier, string owner, string table, int scope, int nullable)
When the type argument is SQL_BEST_ROWID, odbc_specialcolumns() returns the column or columns that uniquely identify each row in the table.
When the type argument is SQL_ROWVER, odbc_specialcolumns() returns the optimal column or set of columns that, by retrieving values from the column or columns, allows any row in the specified table to be uniquely identified.
Returns an ODBC result identifier or false on failure.
The result set has the following columns:
SCOPE
COLUMN_NAME
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
PSEUDO_COLUMN
The result set is ordered by SCOPE.
int odbc_statistics (int connection_id, string qualifier, string owner, string table_name, int unique, int accuracy)
Get statistics about a table and it's indexes. Returns an ODBC result identifier or false on failure.
The result set has the following columns:
TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
NON_UNIQUE
INDEX_QUALIFIER
INDEX_NAME
TYPE
SEQ_IN_INDEX
COLUMN_NAME
COLLATION
CARDINALITY
PAGES
FILTER_CONDITION
The result set is ordered by NON_UNIQUE, TYPE, INDEX_QUALIFIER, INDEX_NAME and SEQ_IN_INDEX.
These functions allow you to access Oracle8 and Oracle7 databases. It uses the Oracle8 Call-Interface (OCI8). You will need the Oracle8 client libraries to use this extension.
This extension is more flexible than the standard Oracle extension. It supports binding of global and local PHP variables to Oracle placeholders, has full LOB, FILE and ROWID support and allows you to use user-supplied define variables.
Before using this extension, make sure that you have set up your oracle environment variables properly for the Oracle user, as well as your web daemon user. The variables you might need to set are as follows:
ORACLE_HOME
ORACLE_SID
LD_PRELOAD
LD_LIBRARY_PATH
NLS_LANG
ORA_NLS33
After setting up the environment variables for your webserver user, be sure to also add the webserver user (nobody, www) to the oracle group.
Example 1. OCI Hints
|
You can easily access stored procedures in the same way as you would from the commands line.
Example 2. Using Stored Procedures
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OCIDefineByName() uses fetches SQL-Columns into user-defined PHP-Variables. Be careful that Oracle user ALL-UPPERCASE column-names, whereby in your select you can also write lower-case. OCIDefineByName() expects the Column-Name to be in uppercase. If you define a variable that doesn't exists in you select statement, no error will be given!
If you need to define an abstract Datatype (LOB/ROWID/BFILE) you need to allocate it first using OCINewDescriptor() function. See also the OCIBindByName() function.
Example 1. OCIDefineByName
|
OCIBindByName() binds the PHP variable variable to the Oracle placeholder ph_name. Whether it will be used for input or output will be determined run-time, and the necessary storage space will be allocated. The length parameter sets the maximum length for the bind. If you set length to -1 OCIBindByName() will use the current length of variable to set the maximum length.
If you need to bind an abstract Datatype (LOB/ROWID/BFILE) you need to allocate it first using OCINewDescriptor() function. The length is not used for abstract Datatypes and should be set to -1. The type variable tells oracle, what kind of descriptor we want to use. Possible values are: OCI_B_FILE (Binary-File), OCI_B_CFILE (Character-File), OCI_B_CLOB (Character-LOB), OCI_B_BLOB (Binary-LOB) and OCI_B_ROWID (ROWID).
Example 1. OCIDefineByName
|
| Warning |
It is a bad idea to use magic quotes and OciBindByName() simultaneously as no quoting is needed on quoted variables and any quotes magically applied will be written into your database as OciBindByName() is not able to distinguish magically added quotings from those added by intention. |
OCILogon() returns an connection identifier needed for most other OCI calls. The optional third parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora to which you want to connect. If the optional third parameter is not specified, PHP uses the environment variables ORACLE_SID (Oracle instance) or TWO_TASK (tnsnames.ora) to determine which database to connect to.
Connections are shared at the page level when using OCILogon(). This means that commits and rollbacks apply to all open transactions in the page, even if you have created multiple connections.
This example demonstrates how the connections are shared.
Example 1. OCILogon
|
See also OCIPLogon() and OCINLogon().
(PHP 3>= 3.0.8, PHP 4 )
OCIPLogon -- Connect to an Oracle database and log on using a persistant connection. Returns a new session.OCIPLogon() creates a persistent connection to an Oracle 8 database and logs on. The optional third parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora to which you want to connect. If the optional third parameter is not specified, PHP uses the environment variables ORACLE_SID (Oracle instance) or TWO_TASK (tnsnames.ora) to determine which database to connect to.
See also OCILogon() and OCINLogon().
(PHP 3>= 3.0.8, PHP 4 )
OCINLogon -- Connect to an Oracle database and log on using a new connection. Returns a new session.OCINLogon() creates a new connection to an Oracle 8 database and logs on. The optional third parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora to which you want to connect. If the optional third parameter is not specified, PHP uses the environment variables ORACLE_SID (Oracle instance) or TWO_TASK (tnsnames.ora) to determine which database to connect to.
OCINLogon() forces a new connection. This should be used if you need to isolate a set of transactions. By default, connections are shared at the page level if using OCILogon() or at the web server process level if using OCIPLogon(). If you have multiple connections open using OCINLogon(), all commits and rollbacks apply to the specified connection only.
This example demonstrates how the connections are separated.
Example 1. OCINLogon
|
See also OCILogon() and OCIPLogon().
OCIExecute() executes a previously parsed statement. (see OCIParse(). The optional mode allows you to specify the execution-mode (default is OCI_COMMIT_ON_SUCCESS). If you don't want statements to be committed automaticly specify OCI_DEFAULT as your mode.
(PHP 3>= 3.0.7, PHP 4 )
OCINewDescriptor -- Initialize a new empty descriptor LOB/FILE (LOB is default)OCINewDescriptor() Allocates storage to hold descriptors or LOB locators. Valid values for the valid type are OCI_D_FILE, OCI_D_LOB, OCI_D_ROWID. For LOB descriptors, the methods load, save, and savefile are associated with the descriptor, for BFILE only the load method exists. See the second example usage hints.
Example 1. OCINewDescriptor
|
OCIRowCount() returns the number of rows affected for eg update-statements. This function will not tell you the number of rows that a select will return!
Example 1. OCIRowCount
|
OCINumCols() returns the number of columns in a statement
Example 1. OCINumCols
|
OCIResult() returns the data for column column in the current row (see OCIFetch()).OCIResult() will return everything as strings except for abstract types (ROWIDs, LOBs and FILEs).
OCIFetch() fetches the next row (for SELECT statements) into the internal result-buffer.
OCIFetchInto() fetches the next row (for SELECT statements) into the result array. OCIFetchInto() will overwrite the previous content of result. By default result will contain a one-based array of all columns that are not NULL.
The mode parameter allows you to change the default behaviour. You can specify more than one flag by simply adding them up (eg OCI_ASSOC+OCI_RETURN_NULLS). The known flags are:
| OCI_ASSOC Return an associative array. |
| OCI_NUM Return an numbered array starting with one. (DEFAULT) |
| OCI_RETURN_NULLS Return empty columns. |
| OCI_RETURN_LOBS Return the value of a LOB instead of the descriptor. |
OCIFetchStatement() fetches all the rows from a result into a user-defined array. OCIFetchStatement() returns the number of rows fetched.
Example 1. OCIFetchStatement
|
OCIColumnIsNULL() returns true if the returned column column in the result from the statement stmt is NULL. You can either use the column-number (1-Based) or the column-name for the col parameter.
OCIColumnName() returns the name of the column corresponding to the column number (1-based) that is passed in.
Example 1. OCIColumnName
|
See also OCINumCols(), OCIColumnType(), and OCIColumnSize().
OCIColumnSize() returns the size of the column as given by Oracle. You can either use the column-number (1-Based) or the column-name for the col parameter.
Example 1. OCIColumnSize
|
See also OCINumCols(), OCIColumnName(), and OCIColumnSize().
OCIColumnType() returns the data type of the column corresponding to the column number (1-based) that is passed in.
Example 1. OCIColumnType
|
See also OCINumCols(), OCIColumnName(), and OCIColumnSize().
OCIStatementType() returns one of the following values:
"SELECT"
"UPDATE"
"DELETE"
"INSERT"
"CREATE"
"DROP"
"ALTER"
"BEGIN"
"DECLARE"
"UNKNOWN"
Example 1. Code examples
|
(PHP 3>= 3.0.8, PHP 4 )
OCINewCursor -- Return a new cursor (Statement-Handle) - use to bind ref-cursors.OCINewCursor() allocates a new statement handle on the specified connection.
Example 1. Using a REF CURSOR from a stored procedure
|
Example 2. Using a REF CURSOR in a select statement
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OCIParse() parses the query using conn. It returns the statement identity if the query is valid, false if not. The query can be any valid SQL statement.
(PHP 3>= 3.0.7, PHP 4 )
OCIError -- Return the last error of stmt|conn|global. If no error happened returns false.OCIError() returns the last error found. If the optional stmt|conn|global is not provided, the last error encountered is returned. If no error is found, OCIError() returns false. OCIError() returns the error as an associative array. In this array, code consists the oracle error code and message the oracle errorstring.
int ora_bind (int cursor, string PHP variable name, string SQL parameter name, int length [, int type])
Returns true if the bind succeeds, otherwise false. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function binds the named PHP variable with a SQL parameter. The SQL parameter must be in the form ":name". With the optional type parameter, you can define whether the SQL parameter is an in/out (0, default), in (1) or out (2) parameter. As of PHP 3.0.1, you can use the constants ORA_BIND_INOUT, ORA_BIND_IN and ORA_BIND_OUT instead of the numbers.
ora_bind must be called after ora_parse() and before ora_exec(). Input values can be given by assignment to the bound PHP variables, after calling ora_exec() the bound PHP variables contain the output values if available.
<?php
ora_parse($curs, "declare tmp INTEGER; begin tmp := :in; :out := tmp; :x := 7.77; end;");
ora_bind($curs, "result", ":x", $len, 2);
ora_bind($curs, "input", ":in", 5, 1);
ora_bind($curs, "output", ":out", 5, 2);
$input = 765;
ora_exec($curs);
echo "Result: $result<BR>Out: $output<BR>In: $input";
?>
|
Returns true if the close succeeds, otherwise false. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function closes a data cursor opened with ora_open().
Returns the name of the field/column column on the cursor cursor. The returned name is in all uppercase letters.
Returns the Oracle data type name of the field/column column on the cursor cursor. The returned type will be one of the following:
| "VARCHAR2" |
| "VARCHAR" |
| "CHAR" |
| "NUMBER" |
| "LONG" |
| "LONG RAW" |
| "ROWID" |
| "DATE" |
| "CURSOR" |
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function commits an Oracle transaction. A transaction is defined as all the changes on a given connection since the last commit/rollback, autocommit was turned off or when the connection was established.
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function turns off automatic commit after each ora_exec().
This function turns on automatic commit after each ora_exec() on the given connection.
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function is quick combination of ora_parse(), ora_exec() and ora_fetch(). It will parse and execute a statement, then fetch the first result row.
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
See also ora_parse(),ora_exec(), and ora_fetch().
Returns an error message of the form XXX-NNNNN where XXX is where the error comes from and NNNNN identifies the error message.
Note: Support for connection ids was added in 3.0.4.
On UNIX versions of Oracle, you can find details about an error message like this: $ oerr ora 00001 00001, 00000, "unique constraint (%s.%s) violated" // *Cause: An update or insert statement attempted to insert a duplicate key // For Trusted ORACLE configured in DBMS MAC mode, you may see // this message if a duplicate entry exists at a different level. // *Action: Either remove the unique restriction or do not insert the key
Returns the numeric error code of the last executed statement on the specified cursor or connection.
Note: Support for connection ids was added in 3.0.4.
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
See also ora_parse(), ora_fetch(), and ora_do().
Returns true (a row was fetched) or false (no more rows, or an error occured). If an error occured, details can be retrieved using the ora_error() and ora_errorcode() functions. If there was no error, ora_errorcode() will return 0.
Retrieves a row of data from the specified cursor.
See also ora_parse(),ora_exec(), and ora_do().
You can fetch a row into an array with this function.
See also ora_parse(),ora_exec(), ora_fetch(), and ora_do().
Returns the column data. If an error occurs, False is returned and ora_errorcode() will return a non-zero value. Note, however, that a test for False on the results from this function may be true in cases where there is not error as well (NULL result, empty string, the number 0, the string "0").
Fetches the data for a column or function result.
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
Logs out the user and disconnects from the server.
See also ora_logon().
Establishes a connection between PHP and an Oracle database with the given username and password.
Connections can be made using SQL*Net by supplying the TNS name to user like this:
If you have character data with non-ASCII characters, you should make sure that NLS_LANG is set in your environment. For server modules, you should set it in the server's environment before starting the server.
Returns a connection index on success, or false on failure. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
Establishes a persistant connection between PHP and an Oracle database with the given username and password.
See also ora_logon().
ora_numcols() returns the number of columns in a result. Only returns meaningful values after an parse/exec/fetch sequence.
See also ora_parse(),ora_exec(), ora_fetch(), and ora_do().
Opens an Oracle cursor associated with connection.
Returns a cursor index or False on failure. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
This function parses an SQL statement or a PL/SQL block and associates it with the given cursor.
Returns 0 on success or -1 on error.
See also ora_exec(), ora_fetch(), and ora_do().
This function undoes an Oracle transaction. (See ora_commit() for the definition of a transaction.)
Returns true on success, false on error. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.
Ovrimos SQL Server, is a client/server, transactional RDBMS combined with Web capabilities and fast transactions.
Ovrimos SQL Server is available at www.ovrimos.com. To enable ovrimos support in PHP just compile php with the '--with-ovrimos' parameter to configure script. You'll need to install the sqlcli library available in the Ovrimos SQL Server distribution.
Example 1. Connect to Ovrimos SQL Server and select from a system table
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ovrimos_connect() is used to connect to the specified database.
ovrimos_connect() returns a connection id (greater than 0) or 0 for failure. The meaning of 'host' and 'port' are those used everywhere in Ovrimos APIs. 'Host' is a host name or IP address and 'db' is either a database name, or a string containing the port number.
Example 1. ovrimos_connect() Example
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ovrimos_close() is used to close the specified connection.
ovrimos_close() closes a connection to Ovrimos. This has the effect of rolling back uncommitted transactions.
ovrimos_close_all() is used to close all the connections.
ovrimos_close_all() closes all connections to Ovrimos. This has the effect of rolling back uncommitted transactions.
(PHP 4 >= 4.0.3)
ovrimos_longreadlen -- Specifies how many bytes are to be retrieved from long datatypesovrimos_longreadlen() is used to specify how many bytes are to be retrieved from long datatypes.
ovrimos_longreadlen() specifies how many bytes are to be retrieved from long datatypes (long varchar and long varbinary). Default is zero. Regardless of its taking a result_id as an argument, it currently sets this parameter for all result sets. Returns true.
ovrimos_prepare() is used to prepare an SQL statement.
ovrimos_prepare() prepares an SQL statement and returns a result_id (or false on failure).
Example 1. Connect to Ovrimos SQL Server and prepare a statement
|
ovrimos_execute() is used to execute an SQL statement.
ovrimos_execute() executes a prepared statement. Returns true or false. If the prepared statement contained parameters (question marks in the statement), the correct number of parameters should be passed in an array. Notice that I don't follow the PHP convention of placing just the name of the optional parameter inside square brackets. I couldn't bring myself on liking it.
ovrimos_cursor() is used to get the name of the cursor.
ovrimos_cursor() returns the name of the cursor. Useful when wishing to perform positioned updates or deletes.
ovrimos_exec() is used to execute an SQL statement.
ovrimos_exec() executes an SQL statement (query or update) and returns a result_id or false. Evidently, the SQL statement should not contain parameters.
ovrimos_fetch_into() is used to fetch a row from the result set.
ovrimos_fetch_into() fetches a row from the result set into 'result_array', which should be passed by reference. Which row is fetched is determined by the two last parameters. 'how' is one of 'Next' (default), 'Prev', 'First', 'Last', 'Absolute', corresponding to forward direction from current position, backward direction from current position, forward direction from the start, backward direction from the end and absolute position from the start (essentially equivalent to 'first' but needs 'rownumber'). Case is not significant. 'Rownumber' is optional except for absolute positioning. Returns true or false.
Example 1. A fetch into example
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ovrimos_fetch_row() is used to fetch a row from the result set.
ovrimos_fetch_row() fetches a row from the result set. Column values should be retrieved with other calls. Returns true or false.
Example 1. A fetch row example
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ovrimos_result() is used to retrieve the output column.
ovrimos_result() retrieves the output column specified by 'field', either as a string or as an 1-based index.
ovrimos_result_all() is used to print an HTML table containing the whole result set.
ovrimos_result_all() prints the whole result set as an HTML table. Returns true or false.
Example 1. Prepare a statement, execute, and view the result
|
Example 2. Ovrimos_result_all with meta-information
|
Example 3. ovrimos_result_all example
|
ovrimos_num_rows() is used to get the number of rows affected by update operations.
ovrimos_num_rows() returns the number of rows affected by update operations.
ovrimos_num_fields() is used to get the number of columns.
ovrimos_num_fields() returns the number of columns in a result_id resulting from a query.
ovrimos_field_name() is used to get the output column name.
ovrimos_field_name() returns the output column name at the (1-based) index specified.
ovrimos_field_type() is used to get the (numeric) type of the output column.
ovrimos_field_type() returns the (numeric) type of the output column at the (1-based) index specified.
ovrimos_field_len() is used to get the length of the output column.
ovrimos_field_len() returns the length of the output column at the (1-based) index specified.
ovrimos_field_num() is used to get the (1-based) index of the output column.
ovrimos_field_num() returns the (1-based) index of the output column specified by name, or false.
ovrimos_free_result() is used to free the result_id.
ovrimos_free_result() frees the specified result_id. Returns true.
ovrimos_commit() is used to commit the transaction.
ovrimos_commit() commits the transaction.
The Output Control functions allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputing data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo() and data between blocks of PHP code.
In the above example, the output from echo() would be stored in the output buffer until ob_end_flush() was called. In the mean time, the call to setcookie() successfully stored a cookie without causing an error. (You can not normally send headers to the browser after data has already been sent.)
See also header() and setcookie().
Flushes the output buffers of PHP and whatever backend PHP is using (CGI, a web server, etc.) This effectively tries to push all the output so far to the user's browser.
Note: flush() has no effect on the buffering scheme of your webserver or the browser on the client side.
Several servers, especially on Win32, will still buffer the output from your script until it terminates before transmitting the results to the browser.
Even the browser may buffer its input before displaying it. Netscape, for example, buffers text until it receives an end-of-line or the beginning of a tag, and it won't render tables until the </table> tag of the outermost table is seen.
This function will turn output buffering on. While output buffering is active no output is sent from the script, instead the output is stored in an internal buffer.
The contents of this internal buffer may be copied into a string variable using ob_get_contents(). To output what is stored in the internal buffer, use ob_end_flush(). Alternatively, ob_end_clean() will silently discard the buffer contents.
An optional output_callback function may be specified. This function takes a string as a parameter and returns a string. The function will be called at ob_end_flush() time and will receive the contents of the output buffer as its parameter. It must return a new output buffer as a result, which is what will be printed.
Output buffers are stackable, that is, you may call ob_start() while another ob_start() is active. Just make sure that you call ob_end_flush()() the appropriate number of times. If multiple output callback functions are active, output is being filtered sequentially through each of them in nesting order.
Example 1. Callback function example
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See also ob_get_contents(), ob_end_flush(), ob_end_clean(), and ob_implicit_flush()
This will return the contents of the output buffer or FALSE, if output buffering isn't active.
See also ob_start() and ob_get_length().
This will return the length of the contents in the output buffer or FALSE, if output buffering isnt't active.
See also ob_start() and ob_get_contents().
This function will send the contents of the output buffer (if any) and turn output buffering off. If you want to further process the buffer's contents you have to call ob_get_contents() before ob_end_flush() as the buffer contents are discarded after ob_end_flush() is called.
See also ob_start(), ob_get_contents(), and ob_end_clean().
This function discards the contents of the output buffer and turns off output buffering.
See also ob_start() and ob_end_flush().
ob_implicit_flush() will turn implicit flushing on or off (if no flag is given, it defaults to on). Implicit flushing will result in a flush operation after every output call, so that explicit calls to flush() will no longer be needed.
Turning implicit flushing on will disable output buffering, the output buffers current output will be sent as if ob_end_flush() had been called.
See also flush(), ob_start(), and ob_end_flush().
You can use the PDF functions in PHP to create PDF files if you have the PDF library by Thomas Merz (available at http://www.pdflib.com/pdflib/index.html; you will also need the JPEG library and the TIFF library to compile this. These two libs also quite often make problems when configuring php. Follow the messages of configure to fix possible problems.
Please consult the excellent documentation for pdflib shipped with the source distribution of pdflib. It provides a very good overview of what pdflib capable of doing. Most of the functions in pdflib and the PHP module have the same name. The parameters are also identical. You should also understand some of the concepts of PDF or Postscript to efficiently use this module. All lengths and coordinates are measured in Postscript points. There are generally 72 PostScript points to an inch, but this depends on the output resolution.
There is another PHP module for pdf document creation based on FastIO's. ClibPDF. It has a slightly different API. Check the ClibPDF functions section for details.
The pdf module introduces two new type of variable. It is called pdfdoc pdfdoc is a pointer to a pdf document and almost all functions need it as its first parameter.
Since the very begining of PDF support in PHP — starting with pdflib 0.6 — there has been tons of changes especially to the pdflib API. Most of these changes has been somehow covered by PHP, some has even required changes to the PHP API. Since pdflib 3.x the API seems to be stabilzed and PHP 4 has adopted the version as a minimum requirement for PDF support. The consequence will be that many functions will disappear or be replaced by alternatives sooner or later. Support for pdflib 0.6 is already completely given up. The following table list all the functions which are deprecated in PHP 4.02 and should be replaced by their new versions.
Table 1. Deprecated functions and its replacements
| Old function | Replacement |
|---|---|
| pdf_put_image() | Not needed anymore. |
| pdf_get_font() | pdf_get_value() passing "font" as the second parameter. |
| pdf_get_fontsize() | pdf_get_value() passing "fontsize" as the second parameter. |
| pdf_get_fontname() | pdf_get_parameter() passing "fontname" as the second parameter. |
| pdf_set_info_creator() | pdf_set_info() passing "Creator" as the second parameter. |
| pdf_set_info_title() | pdf_set_info() passing "Title" as the second parameter. |
| pdf_set_info_subject() | pdf_set_info() passing "Subject" as the second parameter. |
| pdf_set_info_author() | pdf_set_info() passing "Author" as the second parameter. |
| pdf_set_info_keywords() | pdf_set_info() passing "Keywords" as the second parameter. |
| pdf_set_leading() | pdf_set_value() passing "leading" as the second parameter. |
| pdf_set_text_rendering() | pdf_set_value() passing "textrendering" as the second parameter. |
| pdf_set_text_rise() | pdf_set_value() passing "textrise" as the second parameter. |
| pdf_set_horiz_scaling() | pdf_set_value() passing "horizscaling" as the second parameter. |
| pdf_set_text_matrix() | Not available anymore |
| pdf_set_char_spacing() | pdf_set_value() passing "charspacing" as the second parameter. |
| pdf_set_word_spacing() | pdf_set_value() passing "wordspacing" as the second parameter. |
| pdf_set_transition() | pdf_set_parameter() passing "transition" as the second parameter. |
| pdf_set_duration() | pdf_set_value() passing "duration" as the second parameter. |
| pdf_open_gif() | pdf_open_image_file() passing "gif" as the second parameter. |
| pdf_open_jpeg() | pdf_open_image_file() passing "jpeg" as the second parameter. |
| pdf_open_tiff() | pdf_open_image_file() passing "tiff" as the second parameter. |
| pdf_open_png() | pdf_open_image_file() passing "png" as the second parameter. |
| pdf_get_imagewidth() | pdf_get_value() passing "imagewidth" as the second parameter and the image as the third parameter. |
| pdf_get_imageheight() | pdf_get_value() passing "imageheight" as the second parameter and the image as the third parameter. |
| () | () |
Since version 3.0 of pdflib you should configure pdflib with the option --enable-shared-pdflib.
If you use pdflib 2.01 check how the lib was installed. There should be a file or a to link libpdf.so. Version 2.01 just creates a lib with the name libpdf2.01.so which cannot be found when linking the test programm in configure. You will have to create a symbolic link from libpdf.so to libpdf2.01.so.).
Version 2.20 of pdflib has introduced more changes to its API and support for chinese and japanese fonts. This unfortunately causes some changes of the pdf module of php4 (not php3). If you use pdflib 2.20 handle the in memory generation of PDF documents with care. Until pdflib 3.0 is released it might be unstable. The encoding parameter of pdf_set_font() has changed to a string. This means that instead of e.g. 4 you have to use 'winansi'.
If you use pdflib 2.30 the pdf_set_text_matrix() will have gone. It is not supported any more. In general it is a good advise to consult the release notes of the used version of pdflib for possible changes.
Any version of PHP 4 after March, 9th 2000 do not support versions of pdflib older than 3.0. PHP 3 on the other hand should not be used with version newer than 2.01.
Most of the functions are fairly easy to use. The most difficult part is probably to create a very simple pdf document at all. The following example should help to get started. It creates the file test.pdf with one page. The page contains the text "Times Roman outlined" in an outlined, 30pt font. The text is also underlined.
Example 1. Creating a PDF document with pdflib
The script getpdf.php just returns the pdf document. |
The pdflib distribution contains a more complex example which creates a serious of pages with an analog clock. This example converted into PHP using pdflib looks as the following (you can see the same example in the documentation for the clibpdf module):
Example 2. pdfclock example from pdflib distribution
The PHP script getpdf.php just outputs the pdf document.
|
The pdf_set_info() function sets an information field of a pdf document. Possible values for the fieldname are 'Subject', 'Title', 'Creator', 'Author', 'Keywords' and one user-defined name. It can be called before beginning a page.
Example 1. Setting document information
|
Note: This function replaces pdf_set_info_keywords(), pdf_set_info_title(), pdf_set_info_subject(), pdf_set_info_creator(), pdf_set_info_sybject().
The pdf_open() function opens a new pdf document. The corresponding file has to be opened with fopen() and the file descriptor passed as argument file. If you do not pass any parameters, the document will be created in memory and outputed page by page either to stdout or to the web browser.
Note: The return value is needed as the first parameter in all other functions writing to the pdf document.
See also fopen(), pdf_close().
The pdf_begin_page() function starts a new page with height height and width width. In order to create a valid document you must call this function and pdf_end_page() at least once.
See also pdf_end_page().
The pdf_end_page() function ends a page. Once a page is ended it cannot be modified anymore.
See also pdf_begin_page().
The pdf_show() function outputs the string text at the current text position using the current font.
See also pdf_show_xy(), pdf_show_boxed(), pdf_set_text_pos(), pdf_set_font().
int pdf_show_boxed (int pdf document, string text, double x-coor, double y-coor, double width, double height, string mode [, string feature])
The pdf_show_boxed() function outputs the string text in a box with its lower left position at (x-coor, y-coor). The boxes dimension is height by width. The parameter mode determines how the text is type set. If width and height are zero, the mode can be "left", "right" or "center". If width or height is unequal zero it can also be "justify" and "fulljustify".
If the parameter feature is set to "blind", the text is not shown.
Returns the number of characters that could not be processed because they did not fit into the box.
See also pdf_show(), pdf_show_xy().
The pdf_show_xy() function outputs the string text at position (x-coor, y-coor).
See also pdf_show(), pdf_show_boxed().
The pdf_set_font() function sets the current font face, font size and encoding. If you use pdflib 0.6 you will need to provide the Adobe Font Metrics (afm-files) for the font in the font path (default is ./fonts). If you use php3 or a version of pdflib older than 2.20 the fourth parameter encoding can take the following values: 0 = builtin, 1 = pdfdoc, 2 = macroman, 3 = macexpert, 4 = winansi. An encoding greater than 4 and less than 0 will default to winansi. winansi is often a good choice. If you use php4 and a version of pdflib >= 2.20 the encoding parameter has changed to a string. Use 'winansi', 'builtin', 'host', 'macroman' etc. instead. If the last parameter is set to 1 the font is embedded into the pdf document otherwise it is not. To embed a font is usually a good idea if the font is not widely spread and you cannot ensure that the person watching your document has access on fonts in the document. I font is only embedded once even if you call pdf_set_font() several times.
Note: This function has to be called after pdf_begin_page() in order to create a valid pdf document.
Note: If you reference a font in a .upr file make sure the name in the afm file and the font name are the same. Otherwise, the font will be embedded several times (Thanks to Paul Haddon for finding this.)
The pdf_set_leading() function sets the distance between text lines. This will be used if text is output by pdf_continue_text().
See also pdf_continue_text().
The pdf_set_parameter() function sets several parameters of pdflib which are of the type string.
See also pdf_get_value(), pdf_set_value(), pdf_get_parameter().
The pdf_get_parameter() function gets several parameters of pdflib which are of the type string. The function parameter modifier characterizes the parameter to get. If the modifier is not needed it has to be 0 or not passed at all.
See also pdf_get_value(), pdf_set_value(), pdf_set_parameter().
The pdf_set_value() function sets several numerical parameters of pdflib.
See also pdf_get_value(), pdf_get_parameter(), pdf_set_parameter().
The pdf_get_value() function gets several numerical parameters of pdflib. The function parameter modifier characterizes the parameter to get. If the modifier is not needed it has to be 0 or not passed at all.
See also pdf_set_value(), pdf_get_parameter(), pdf_set_parameter().
The pdf_get_image_height() function returns the heights of a pdf image in pixel.
See also pdf_open_image_file(), pdf_open_memory_image(), pdf_get_image_width().
The pdf_get_image_width() function returns the widths of a pdf image in pixel.
See also pdf_open_image_file(), pdf_open_memory_image(), pdf_get_image_height().
The pdf_set_text_rendering() function determines how text is rendered. The possible values for mode are 0=fill text, 1=stroke text, 2=fill and stroke text, 3=invisible, 4=fill text and add it to cliping path, 5=stroke text and add it to clipping path, 6=fill and stroke text and add it to cliping path, 7=add it to clipping path.
The pdf_set_text_matrix() function sets a matrix which describes a transformation applied on the current text font. The matrix has to passed as an array with six elements.
Note: This function is not available anymore since pdflib 2.3
The pdf_set_text_pos() function sets the position of text for the next pdf_show() function call.
See also pdf_show(), pdf_show_xy().
The pdf_set_char_spacing() function sets the spacing between characters.
See also pdf_set_word_spacing(), pdf_set_leading().
The pdf_set_word_spacing() function sets the spacing between words.
See also pdf_set_char_spacing(), pdf_set_leading().
The pdf_skew() function skew the coordinate system by alpha (x) and beta (y) degrees. alpha and beta may not be 90 or 270 degrees.
The pdf_continue_text() function outputs the string in text in the next line. The distance between the lines can be set with pdf_set_leading().
See also pdf_show_xy(), pdf_set_leading(), pdf_set_text_pos().
The pdf_stringwidth() function returns the width of the string in text by using the current font. It requires a font to be set before with pdf_set_font().
See also pdf_set_font().
The pdf_save() function saves the current environment. It works like the postscript command gsave. Very useful if you want to translate or rotate an object without effecting other objects. pdf_save() should always be followed by pdf_restore() to restore the environment before pdf_save().
See also pdf_restore().
The pdf_restore() function restores the environment saved with pdf_save(). It works like the postscript command grestore.
See also pdf_save().
The pdf_translate() function sets the origin of coordinate system to the point (x-coor, y-coor) relativ the current origin. The following example draws a line from (0, 0) to (200, 200) relative to the initial coordinate system. You have to set the current point after pdf_translate() and before you start drawing more objects.
The pdf_scale() function sets the scaling factor in both directions. The following example scales x and y direction by 72. The following line will therefore be drawn one inch in both directions.
The pdf_setmiterlimit() function sets the miter limit to a value greater of equal than 1.
The pdf_setdash() function sets the dash pattern white white points and black black points. If both are 0 a solid line is set.
void pdf_curveto (int pdf document, double x1, double y1, double x2, double y2, double x3, double y3)
The pdf_curveto() function draws a Bezier curve from the current point to the point (x3, y3) using (x1, y1) and (x2, y2) as control points.
See also pdf_moveto(), pdf_lineto(), pdf_stroke().
The pdf_lineto() function draws a line from the current point to the point with coordinates (x-coor, y-coor).
See also pdf_moveto(), pdf_curveto(), pdf_stroke().
The pdf_circle() function draws a circle with center at point (x-coor, y-coor) and radius radius.
See also pdf_arc(), pdf_stroke().
void pdf_arc (int pdf document, double x-coor, double y-coor, double radius, double start, double end)
The pdf_arc() function draws an arc with center at point (x-coor, y-coor) and radius radius, starting at angle start and ending at angle end.
See also pdf_circle(), pdf_stroke().
The pdf_rect() function draws a rectangle with its lower left corner at point (x-coor, y-coor). This width is set to width. This height is set to height.
See also pdf_stroke().
The pdf_closepath() function closes the current path. This means, it draws a line from current point to the point where the first line was started. Many functions like pdf_moveto(), pdf_circle() and pdf_rect() start a new path.
The pdf_stroke() function draws a line along current path. The current path is the sum of all line drawing. Without this function the line would not be drawn.
See also pdf_closepath(), pdf_closepath_stroke().
The pdf_closepath_stroke() function is a combination of pdf_closepath() and pdf_stroke(). It also clears the path.
See also pdf_closepath(), pdf_stroke().
The pdf_fill() function fills the interior of the current path with the current fill color.
See also pdf_closepath(), pdf_stroke(), pdf_setgray_fill(), pdf_setgray(), pdf_setrgbcolor_fill(), pdf_setrgbcolor().
The pdf_fill_stroke() function fills the interior of the current path with the current fill color and draws current path.
See also pdf_closepath(), pdf_stroke(), pdf_fill(), pdf_setgray_fill(), pdf_setgray(), pdf_setrgbcolor_fill(), pdf_setrgbcolor().
The pdf_closepath_fill_stroke() function closes, fills the interior of the current path with the current fill color and draws current path.
See also pdf_closepath(), pdf_stroke(), pdf_fill(), pdf_setgray_fill(), pdf_setgray(), pdf_setrgbcolor_fill(), pdf_setrgbcolor().
The pdf_endpath() function ends the current path but does not close it.
See also pdf_closepath().
The pdf_setgray_fill() function sets the current gray value to fill a path.
See also pdf_setrgbcolor_fill().
The pdf_setgray_stroke() function sets the current drawing color to the given gray value.
See also pdf_setrgbcolor_stroke().
The pdf_setgray() function sets the current drawing and filling color to the given gray value.
See also pdf_setrgbcolor_stroke(), pdf_setrgbcolor_fill().
void pdf_setrgbcolor_fill (int pdf document, double red value, double green value, double blue value)
The pdf_setrgbcolor_fill() function sets the current rgb color value to fill a path.
See also pdf_setrgbcolor_fill().
void pdf_setrgbcolor_stroke (int pdf document, double red value, double green value, double blue value)
The pdf_setrgbcolor_stroke() function sets the current drawing color to the given rgb color value.
See also pdf_setrgbcolor_stroke().
The pdf_setrgbcolor_stroke() function sets the current drawing and filling color to the given rgb color value.
See also pdf_setrgbcolor_stroke(), pdf_setrgbcolor_fill().
The pdf_add_outline() function adds a bookmark with text text that points to the current page. The bookmark is inserted as a child of parent and is by default open if open is not 0. The return value is an identifier for the bookmark which can be used as a parent for other bookmarks. Therefore you can build up hierarchies of bookmarks.
Unfortunately pdflib does not make a copy of the string, which forces PHP to allocate the memory. Currently this piece of memory is not been freed by any PDF function but it will be taken care of by the PHP memory manager.
The pdf_set_transition() function set the transition between following pages. The value of transition can be
| 0 for none, |
| 1 for two lines sweeping across the screen reveal the page, |
| 2 for multiple lines sweeping across the screen reveal the page, |
| 3 for a box reveals the page, |
| 4 for a single line sweeping across the screen reveals the page, |
| 5 for the old page dissolves to reveal the page, |
| 6 for the dissolve effect moves from one screen edge to another, |
| 7 for the old page is simply replaced by the new page (default) |
See also pdf_set_duration().
The pdf_set_duration() function set the duration between following pages in seconds.
See also pdf_set_transition().
The pdf_open_gif() function opens an image stored in the file with the name filename. The format of the image has to be gif. The function returns a pdf image identifier.
Note: This function shouldn't be used anymore. Please use the function pdf_open_image_file() instead.
See also pdf_close_image(), pdf_open_jpeg(), pdf_open_memory_image(), pdf_execute_image(), pdf_place_image(), pdf_put_image().
The pdf_open_png() function opens an image stored in the file with the name filename. The format of the image has to be png. The function returns a pdf image identifier.
Note: This function shouldn't be used anymore. Please use the function pdf_open_image_file() instead.
See also pdf_close_image(), pdf_open_jpeg(), pdf_open_gif(), pdf_open_memory_image(), pdf_execute_image(), pdf_place_image(), pdf_put_image().
The function pdf_open_image_file() reads an image of format format from the file filename. Possible formats are 'png', 'tiff', 'jpeg' and 'gif'. The function returns a pdf image identifier.
See also pdf_close_image(), pdf_open_jpeg(), pdf_open_gif(), pdf_open_tiff(), pdf_open_png(), pdf_execute_image(), pdf_place_image(), pdf_put_image().
(PHP 3>= 3.0.10, PHP 4 >= 4.0b2)
pdf_open_memory_image -- Opens an image created with PHP's image functionsThe pdf_open_memory_image() function takes an image created with the PHP's image functions and makes it available for the pdf document. The function returns a pdf image identifier.
See also pdf_close_image(), pdf_open_jpeg(), pdf_open_gif(), pdf_open_png() pdf_execute_image(), pdf_place_image(), pdf_put_image().
The pdf_open_jpeg() function opens an image stored in the file with the name filename. The format of the image has to be jpeg. The function returns a pdf image identifier.
Note: This function shouldn't be used anymore. Please use the function pdf_open_image_file() instead.
See also pdf_close_image(), pdf_open_gif(), pdf_open_png(), pdf_open_memory_image(), pdf_execute_image(), pdf_place_image(), pdf_put_image().
The pdf_open_tiff() function opens an image stored in the file with the name filename. The format of the image has to be tiff. The function returns a pdf image identifier.
Note: This function shouldn't be used anymore. Please use the function pdf_open_image_file() instead.
See also pdf_close_image(), pdf_open_gif(), pdf_open_jpeg(), pdf_open_png(), pdf_open_memory_image(), pdf_execute_image(), pdf_place_image(), pdf_put_image().
The pdf_close_image() function closes an image which has been opened with any of the pdf_open_xxx() functions.
See also pdf_open_jpeg(), pdf_open_gif(), pdf_open_memory_image().
The pdf_place_image() function places an image on the page at postion (x-coor, x-coor). The image can be scaled at the same time.
See also pdf_put_image().
The pdf_put_image() function places an image in the PDF file without showing it. The stored image can be displayed with the pdf_execute_image() function as many times as needed. This is useful when using the same image multiple times in order to keep the file size small. Using pdf_put_image() and pdf_execute_image() is highly recommended for larger images (several kb) if they show up more than once in the document.
Note: This function has become meaningless with version 2.01 of pdflib. It will just output a warning.
See also pdf_put_image(), pdf_place_image(), pdf_execute_image().
The pdf_execute_image() function displays an image that has been put in the PDF file with the pdf_put_image() function on the current page at the given coordinates.
The image can be scaled while displaying it. A scale of 1.0 will show the image in the original size.
Note: This function has become meaningless with version 2.01 of pdflib. It will just output a warning.
Example 1. Multiple show of an image
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void pdf_add_annotation (int pdf document, double llx, double lly, double urx, double ury, string title, string content)
The pdf_add_annotation() adds a note with the lower left corner at (llx, lly) and the upper right corner at (urx, ury).
(PHP 3>= 3.0.12, PHP 4 >= 4.0b2)
pdf_set_border_style -- Sets style of border around links and annotationsThe pdf_set_border_style() function sets the style and width of the suroundig box of links and annotations. The parameter style can be 'solid' or 'dashed'.
See also pdf_set_border_color(), pdf_set_border_dash().
(PHP 3>= 3.0.12, PHP 4 >= 4.0b2)
pdf_set_border_color -- Sets color of border around links and annotationsThe pdf_set_border_color() function sets the color of the suroundig box of links and annotations. The three color components have to have a value between 0.0 and 1.0.
See also pdf_set_border_style(), pdf_set_border_dash().
The pdf_set_border_dash() function sets the lenght of black and white areas of a dashed line of the suroundig box of links and annotations.
See also pdf_set_border_style(), pdf_set_border_color().
This extension allows you to process credit cards and other financial transactions using Verisign Payment Services, formerly known as Signio (http://www.verisign.com/payment/).
These functions are only available if PHP has been compiled with the --with-pfpro[=DIR] option. You will require the appropriate SDK for your platform, which may be downloaded from within the manager interface once you have registered.
Once you have downloaded the SDK you should copy the files from the lib directory of the distribution. Copy the header file pfpro.h to /usr/local/include and the library file libpfpro.so to /usr/local/lib.
When using these functions, you may omit calls to pfpro_init() and pfpro_cleanup() as this extension will do so automatically if required. However the functions are still available in case you are processing a number of transactions and require fine control over the library. You may perform any number of transactions using pfpro_process() between the two.
These functions have been added in PHP 4.0.2.
Note: These functions only provide a link to Verisign Payment Services. Be sure to read the Payflow Pro Developers Guide for full details of the required parameters.
pfpro_init() is used to initialise the Payflow Pro library. You may omit this call, in which case this extension will automatically call pfpro_init() before the first transaction.
See also pfpro_cleanup().
pfpro_cleanup() is used to shutdown the Payflow Pro library cleanly. It should be called after you have processed any transactions and before the end of your script. However you may omit this call, in which case this extension will automatically call pfpro_cleanup() after your script terminates.
See also pfpro_init().
array pfpro_process (array parameters [, string
address [, int
port [, int
timeout [, string
proxy address [, int
proxy port [, string
proxy logon [, string
proxy password]]]]]]])
Returns: An associative array containing the response
pfpro_process() processes a transaction with Payflow Pro. The first parameter is an associative array containing keys and values that will be encoded and passed to the processor.
The second parameter is optional and specifies the host to connect to. By default this is "test.signio.com", so you will certainly want to change this to "connect.signio.com" in order to process live transactions.
The third parameter specifies the port to connect on. It defaults to 443, the standard SSL port.
The fourth parameter specifies the timeout to be used, in seconds. This defaults to 30 seconds. Note that this timeout appears to only begin once a link to the processor has been established and so your script could potentially continue for a very long time in the event of DNS or network problems.
The fifth parameter, if required, specifies the hostname of your SSL proxy. The sixth parameter specifies the port to use.
The seventh and eighth parameters specify the logon identity and password to use on the proxy.
The function returns an associative array of the keys and values in the response.
Note: Be sure to read the Payflow Pro Developers Guide for full details of the required parameters.
Example 1. Payflow Pro example
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string pfpro_process_raw (string parameters [, string
address [, int
port [, int
timeout [, string
proxy address [, int
proxy port [, string
proxy logon [, string
proxy password]]]]]]])
Returns: A string containing the response.
pfpro_process_raw() processes a raw transaction string with Payflow Pro. You should really use pfpro_process() instead, as the encoding rules of these transactions are non-standard.
The first parameter in this case is a string containing the raw transaction request. All other parameters are the same as with pfpro_process(). The return value is a string containing the raw response.
Note: Be sure to read the Payflow Pro Developers Guide for full details of the required parameters and encoding rules. You would be well advised to use pfpro_process() instead.
Example 1. Payflow Pro raw example
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assert() will check the given assertion and take appropriate action if its result is false.
If the assertion is given as a string it will be evaluated as PHP code by assert(). The advantages of a string assertion are less overhead when assertion checking is off and messages containing the assertion expression when an assertion failes.
Assertion should be used as a debugging feature only. You may use them for sanity-checks that test for conditions that should always be true and that indicate some programming errors if not or to check for the presence of certain features like extension functions or certain system limits and features.
Assertions should not be used for normal runtime operations like input parameter checks. As a rule of thumb your code should always be able to work correct if assertion checking is not activated.
The behavior of assert() may be configured by assert_options() or by .ini-settings described in that functions manual page.
Using assert_options() you may set the various assert() control options or just query their current settings.
Table 1. assert options
| option | ini-parameter | default | description |
|---|---|---|---|
| ASSERT_ACTIVE | assert.active | 1 | enable assert() evaluation |
| ASSERT_WARNING | assert.warning | 1 | issue a PHP warning for each failed assertion |
| ASSERT_BAIL | assert.bail | 0 | terminate execution on failed assertions |
| ASSERT_QUIET_EVAL | assert.quiet_eval | 0 | disable error_reporting during assertion expression evaluation |
| ASSERT_CALLBACK | assert_callback | (null) | user function to call on failed assertions |
assert_options() will return the original setting of any option or false on errors.
Returns true if the extension identified by name is loaded. You can see the names of various extensions by using phpinfo().
See also phpinfo().
Note: This function was added in 3.0.10.
Loads the PHP extension defined in library. See also the extension_dir configuration directive.
Returns the value of the environment variable varname, or false on an error.
You can see a list of all the environmental variables by using phpinfo(). You can find out what many of them mean by taking a look at the CGI specification, specifically the page on environmental variables.
Note: This function does not work in ISAPI mode.
Returns the current value of the PHP configuration variable specified by varname, or false if an error occurs.
It will not return configuration information set when the PHP was compiled, or read from an Apache configuration file (using the php3_configuration_option directives).
To check whether the system is using a configuration file, try retrieving the value of the cfg_file_path configuration setting. If this is available, a configuration file is being used.
Returns the name of the owner of the current PHP script.
See also getmyuid(), getmypid(), getmyinode(), and getlastmod().
(PHP 3>= 3.0.6, PHP 4 )
get_magic_quotes_gpc -- Get the current active configuration setting of magic quotes gpc.Returns the current active configuration setting of magic_quotes_gpc. (0 for off, 1 for on).
See also get_magic_quotes_runtime(), set_magic_quotes_runtime().
(PHP 3>= 3.0.6, PHP 4 )
get_magic_quotes_runtime -- Get the current active configuration setting of magic_quotes_runtime.Returns the current active configuration setting of magic_quotes_runtime. (0 for off, 1 for on).
See also get_magic_quotes_gpc(), set_magic_quotes_runtime().
Returns the time of the last modification of the current page. The value returned is a Unix timestamp, suitable for feeding to date(). Returns false on error.
See alse date(), getmyuid(), get_current_user(), getmyinode(), and getmypid().
Returns the current script's inode, or false on error.
See also getmyuid(), get_current_user(), getmypid(), and getlastmod().
Note: This function is not supported on Windows systems.
Returns the current PHP process ID, or false on error.
| Warning |
Process IDs are not unique, thus they are a weak entropy source. We recommend against relying on pids in security-dependent contexts. |
See also getmyuid(), get_current_user(), getmyinode(), and getlastmod().
Returns the user ID of the current script, or false on error.
See also getmypid(), get_current_user(), getmyinode(), and getlastmod().
This is an interface to getrusage(2). It returns an associative array containing the data returned from the system call. If who is 1, getrusage will be called with RUSAGE_CHILDREN.
All entries are accessible by using their documented field names.
Changes the value of a configuration option, returns false on failure, and the previous value of the configuration option on success.
Note: This is an alias of ini_set()
See also ini_get(), ini_restore(), ini_set()
Returns the value of the configuration option on success, false on failure.
See also ini_alter(), ini_restore(), ini_set()
Restores a given configuration option to its original value.
See also ini_alter(), ini_get(), ini_set()
Sets the value of the given configuration option. Returns the old value on success, false on failure.
See also ini_alter(), ini_get(), ini_restore()
This function prints out the credits listing the PHP developers, modules, etc. It generates the appropriate HTML codes to insert the information in a page. A parameter indicating what will be printed (a pre-defined constant flag, see table below) needs to be passed. For example to print the general credits, you will use somewhere in your code:
And if you want to print the core developers and the documentation group, in a page of its own, you will use: And if you feel like embedding all the credits in your page, then code like the one below will do it:<html>
<head>
<title>My credits page</title>
</head>
<body>
<?php
// some code of your own
phpcredits(CREDITS_ALL + CREDITS_FULLPAGE);
// some more code
?>
</body>
</html>
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Table 1. Pre-defined phpcredits() flags
| name | description |
|---|---|
| CREDITS_ALL | All the credits, equivalent to using: CREDITS_DOCS + CREDITS_GENERAL + CREDITS_GROUP + CREDITS_MODULES + CREDITS_FULLPAGE. It generates a complete stand-alone HTML page with the appropriate tags. |
| CREDITS_DOCS | The credits for the documentation team |
| CREDITS_FULLPAGE | Usually used in combination with the other flags. Indicates that the a complete stand-alone HTML page needs to be printed including the information indicated by the other flags. |
| CREDITS_GENERAL | General credits: Language design and concept, PHP 4.0 authors and SAPI module. |
| CREDITS_GROUP | A list of the core developers |
| CREDITS_MODULES | A list of the extension modules for PHP, and their authors |
| CREDITS_SAPI | A list of the server API modules for PHP, and their authors |
See also phpinfo(), phpversion(), php_logo_guid().
Outputs a large amount of information about the current state of PHP. This includes information about PHP compilation options and extensions, the PHP version, server information and environment (if compiled as a module), the PHP environment, OS version information, paths, master and local values of configuration options, HTTP headers, and the PHP License.
The output may be customized by passing one or more of the following values ored together in the optional parameter what.
INFO_GENERAL
INFO_CREDITS
INFO_CONFIGURATION
INFO_MODULES
INFO_ENVIRONMENT
INFO_VARIABLES
INFO_LICENSE
INFO_ALL
See also phpversion(), phpcredits(), php_logo_guid()
Returns a string containing the version of the currently running PHP parser.
See also phpinfo(), phpcredits(), php_logo_guid()
Note: This funcionality was added in PHP 4 Beta 4.
See also phpinfo(). phpversion(), phpcredits()
Php_sapi_name() returns a lowercase string which describes the type of interface between web server and PHP (Server API, SAPI). In CGI PHP, this string is "cgi", in mod_php for Apache, this string is "apache" and so on.
php_uname() returns a string with a description of the operating system PHP is built on.
(PHP 3>= 3.0.6, PHP 4 )
set_magic_quotes_runtime -- Set the current active configuration setting of magic_quotes_runtime.Set the current active configuration setting of magic_quotes_runtime. (0 for off, 1 for on)
See also get_magic_quotes_gpc(), get_magic_quotes_runtime().
Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the configuration file. If seconds is set to zero, no time limit is imposed.
When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.
Note that set_time_limit() has no effect when PHP is running in safe mode. There is no workaround other than turning off safe mode or changing the time limit in the configuration file.
(PHP 4 >= 4.0b4)
get_loaded_extensions -- Returns an array with the names of all modules compiled and loadedThis function returns the names of all the modules compiled and loaded in the PHP interpreter.
For example the line below
will print a list like:Array
(
[0] => xml
[1] => wddx
[2] => standard
[3] => session
[4] => posix
[5] => pgsql
[6] => pcre
[7] => gd
[8] => ftp
[9] => db
[10] => Calendar
[11] => bcmath
)
|
See also: get_extension_funcs().
This function returns the names of all the functions defined in the module indicated by module_name.
For example the lines below
will print a list of the functions in the modules xml and gd respectively.See also: get_loaded_extensions()
(PHP 4 >= 4.0RC2)
get_required_files -- Returns an array with the names of the files require_once()'d in a scriptThis function returns an associtative array of the names of all the files that have been loaded into a script using require_once(). The indexes of the array are the file names as used in the require_once() without the ".php" extension.
The example below
Required_once files
Array
(
[local] => local.php
[../inc/global] => /full/path/to/inc/global.php
)
Included_once files
Array
(
[util1] => util1.php
[util2] => util2.php
[util3] => util3.php
[util4] => util4.php
)
|
Note: As of PHP 4.0.1pl2 this function assumes that the required_once files end in the extension ".php", other extensions do not work.
See also: require_once(), include_once(), get_included_files()
(PHP 4 >= 4.0RC1)
get_included_files -- Returns an array with the names of the files include_once()'d in a scriptThis function returns an associtative array of the names of all the files that have been loaded into a script using include_once(). The indexes of the array are the file names as used in the include_once() without the ".php" extension.
Note: As of PHP 4.0.1pl2 this function assumes that the include_once files end in the extension ".php", other extensions do not work.
See also: require_once(), include_once(), get_required_files()
This module contains an interface to those functions defined in the IEEE 1003.1 (POSIX.1) standards document which are not accessible through other means. POSIX.1 for example defined the open(), read(), write() and close() functions, too, which traditionally have been part of PHP 3 for a long time. Some more system specific functions have not been available before, though, and this module tries to remedy this by providing easy access to these functions.
Send the signal sig to the process with the process identifier pid. Returns FALSE, if unable to send the signal, TRUE otherwise.
See also the kill(2) manual page of your POSIX system, which contains additional information about negative process identifiers, the special pid 0, the special pid -1, and the signal number 0.
Return the numeric real user ID of the current process. See also posix_getpwuid() for information on how to convert this into a useable username.
(PHP 3>= 3.0.10, PHP 4 >= 4.0b4)
posix_geteuid -- Return the effective user ID of the current processReturn the numeric effective user ID of the current process. See also posix_getpwuid() for information on how to convert this into a useable username.
Return the numeric real group ID of the current process. See also posix_getgrgid() for information on how to convert this into a useable group name.
(PHP 3>= 3.0.10, PHP 4 >= 4.0b4)
posix_getegid -- Return the effective group ID of the current processReturn the numeric effective group ID of the current process. See also posix_getgrgid() for information on how to convert this into a useable group name.
Set the real user ID of the current process. This is a privileged function and you need appropriate privileges (usually root) on your system to be able to perform this function.
Returns TRUE on success, FALSE otherwise. See also posix_setgid().
Set the real group ID of the current process. This is a privileged function and you need appropriate privileges (usually root) on your system to be able to perform this function. The appropriate order of function calls is posix_setgid() first, posix_setuid() last.
Returns TRUE on success, FALSE otherwise.
Returns an array of integers containing the numeric group ids of the group set of the current process. See also posix_getgrgid() for information on how to convert this into useable group names.
Returns the login name of the user owning the current process. See posix_getpwnam() for information how to get more information about this user.
Return the process group identifier of the current process. See POSIX.1 and the getpgrp(2) manual page on your POSIX system for more information on process groups.
Make the current process a session leader. See POSIX.1 and the setsid(2) manual page on your POSIX system for more informations on process groups and job control. Returns the session id.
Let the process pid join the process group pgid. See POSIX.1 and the setsid(2) manual page on your POSIX system for more informations on process groups and job control. Returns TRUE on success, FALSE otherwise.
Returns the process group identifier of the process pid.
This is not a POSIX function, but is common on BSD and System V systems. If your system does not support this function at system level, this PHP function will always return FALSE.
Return the sid of the process pid. If pid is 0, the sid of the current process is returned.
This is not a POSIX function, but is common on System V systems. If your system does not support this function at system level, this PHP function will always return FALSE.
Returns a hash of strings with information about the system. The indices of the hash are
sysname - operating system name (e.g. Linux)
nodename - system name (e.g. valiant)
release - operating system release (e.g. 2.2.10)
version - operating system version (e.g. #4 Tue Jul 20 17:01:36 MEST 1999)
machine - system architecture (e.g. i586)
domainname - DNS domainname (e.g. php.net)
domainname is a GNU extension and not part of POSIX.1, so this field is only available on GNU systems or when using the GNU libc.
Posix requires that you must not make any assumptions about the format of the values, e.g. you cannot rely on three digit version numbers or anything else returned by this function.
Returns a hash of strings with information about the current process CPU usage. The indices of the hash are
ticks - the number of clock ticks that have elapsed since reboot.
utime - user time used by the current process.
stime - system time used by the current process.
cutime - user time used by current process and children.
cstime - system time used by current process and children.
(PHP 3>= 3.0.13, PHP 4 >= 4.0b4)
posix_isatty -- Determine if a file descriptor is an interactive terminalReturns an associative array containing information about a user referenced by an alphanumeric username, passed in the username parameter.
The array elements returned are:
Table 1. The user information array
| Element | Description |
|---|---|
| name | The name element contains the username of the user. This is a short, usually less than 16 character "handle" of the user, not her real, full name. This should be the same as the username parameter used when calling the function, and hence redundant. |
| passwd | The passwd element contains the user's password in an encrypted format. Often, for example on a system employing "shadow" passwords, an asterisk is returned instead. |
| uid | User ID of the user in numeric form. |
| gid | The group ID of the user. Use the function posix_getgrgid() to resolve the group name and a list of its members. |
| gecos | GECOS is an obsolete term that refers to the finger information field on a Honeywell batch processing system. The field, however, lives on, and its contents have been formalized by POSIX. The field contains a comma separated list containing the user's full name, office phone, office number, and home phone number. On most systems, only the user's full name is available. |
| dir | This element contains the absolute path to the home directory of the user. |
| shell | The shell element contains the absolute path to the executable of the user's default shell. |
Returns an associative array containing information about a user referenced by a numeric user ID, passed in the uid parameter.
The array elements returned are:
Table 1. The user information array
| Element | Description |
|---|---|
| name | The name element contains the username of the user. This is a short, usually less than 16 character "handle" of the user, not her real, full name. |
| passwd | The passwd element contains the user's password in an encrypted format. Often, for example on a system employing "shadow" passwords, an asterisk is returned instead. |
| uid | User ID, should be the same as the uid parameter used when calling the function, and hence redundant. |
| gid | The group ID of the user. Use the function posix_getgrgid() to resolve the group name and a list of its members. |
| gecos | GECOS is an obsolete term that refers to the finger information field on a Honeywell batch processing system. The field, however, lives on, and its contents have been formalized by POSIX. The field contains a comma separated list containing the user's full name, office phone, office number, and home phone number. On most systems, only the user's full name is available. |
| dir | This element contains the absolute path to the home directory of the user. |
| shell | The shell element contains the absolute path to the executable of the user's default shell. |
Postgres, developed originally in the UC Berkeley Computer Science Department, pioneered many of the object-relational concepts now becoming available in some commercial databases. It provides SQL92/SQL3 language support, transaction integrity, and type extensibility. PostgreSQL is an open source descendant of this original Berkeley code.
PostgreSQL is available without cost. The current version is available at www.PostgreSQL.org.
Since version 6.3 (03/02/1998) PostgreSQL uses unix domain sockets. A table is shown below describing these new connection possibilities. This socket will be found in /tmp/.s.PGSQL.5432. This option can be enabled with the '-i' flag to postmaster and it's meaning is: "listen on TCP/IP sockets as well as Unix domain sockets".
Table 1. Postmaster and PHP
| Postmaster | PHP | Status |
|---|---|---|
| postmaster & | pg_connect("dbname=MyDbName"); | OK |
| postmaster -i & | pg_connect("dbname=MyDbName"); | OK |
| postmaster & | pg_connect("host=localhost dbname=MyDbName"); | Unable to connect to PostgreSQL server: connectDB() failed: Is the postmaster running and accepting TCP/IP (with -i) connection at 'localhost' on port '5432'? in /path/to/file.php3 on line 20. |
| postmaster -i & | pg_connect("host=localhost dbname=MyDbName"); | OK |
One can establish a connection with the following value pairs set in the command string: $conn = pg_Connect("host=myHost port=myPort tty=myTTY options=myOptions user=myUser password=myPassword dbname=myDB");
The previous syntax of: $conn = pg_connect ("host", "port", "options", "tty", "dbname") has been deprecated.
To use the large object (lo) interface, it is necessary to enclose it within a transaction block. A transaction block starts with a begin and if the transaction was valid ends with commit or end. If the transaction fails the transaction should be closed with rollback or abort.
Example 1. Using Large Objects
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Returns false if connection is not a valid connection index, true otherwise. Closes down the connection to a PostgreSQL database associated with the given connection index.
Note: This isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
pg_close() will not close persistent links generated by pg_pconnect().
Pg_cmdtuples() returns the number of tuples (instances) affected by INSERT, UPDATE, and DELETE queries. If no tuple is affected the function will return 0.
Returns a connection index on success, or false if the connection could not be made. Opens a connection to a PostgreSQL database. The arguments should be within a quoted string.
Example 1. Using pg_connect arguments
|
This function returns a connection index that is needed by other PostgreSQL functions. You can have multiple connections open at once.
The previous syntax of: $conn = pg_connect ("host", "port", "options", "tty", "dbname") has been deprecated.
See also pg_pconnect().
Returns the name of the database that the given PostgreSQL connection index is connected to, or false if connection is not a valid connection index.
pg_end_copy() syncs PostgreSQL frontend with the backend after doing a copy operation. It must be issued or the backend may get "out of sync" with the frontend. Returns TRUE if successfull, FALSE otherwise.
For further details and an example, see also pg_put_line().
Returns a string containing the error message, false on failure. Details about the error probably cannot be retrieved using the pg_errormessage() function if an error occured on the last database action for which a valid connection exists, this function will return a string containing the error message generated by the backend server.
Returns a result index if query could be executed, false on failure or if connection is not a valid connection index. Details about the error can be retrieved using the pg_ErrorMessage() function if connection is valid. Sends an SQL statement to the PostgreSQL database specified by the connection index. The connection must be a valid index that was returned by pg_Connect(). The return value of this function is an index to be used to access the results from other PostgreSQL functions.
Note: PHP/FI returned 1 if the query was not expected to return data (inserts or updates, for example) and greater than 1 even on selects that did not return anything. No such assumption can be made in PHP.
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
Pg_fetch_array() is an extended version of pg_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
The third optional argument result_type in pg_fetch_array() is a constant and can take the following values: PGSQL_ASSOC, PGSQL_NUM, and PGSQL_BOTH.
Note: Result_type was added in PHP 4.0.
An important thing to note is that using pg_fetch_array() is NOT significantly slower than using pg_fetch_row(), while it provides a significant added value.
For further details, see also pg_fetch_row()
Example 1. PostgreSQL fetch array
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Returns: An object with properties that correspond to the fetched row, or false if there are no more rows.
Pg_fetch_object() is similar to pg_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
The third optional argument result_type in pg_fetch_object() is a constant and can take the following values: PGSQL_ASSOC, PGSQL_NUM, and PGSQL_BOTH.
Note: Result_type was added in PHP 4.0.
Speed-wise, the function is identical to pg_fetch_array(), and almost as quick as pg_fetch_row() (the difference is insignificant).
See also: pg_fetch_array() and pg_fetch_row().
Example 1. Postgres fetch object
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Returns: An array that corresponds to the fetched row, or false if there are no more rows.
Pg_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.
See also: pg_fetch_array(), pg_fetch_object(), pg_result().
Example 1. Postgres fetch row
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Test if a field is NULL or not. Returns 0 if the field in the given row is not NULL. Returns 1 if the field in the given row is NULL. Field can be specified as number or fieldname. Row numbering starts at 0.
Pg_fieldname() will return the name of the field occupying the given column number in the given PostgreSQL result identifier. Field numbering starts from 0.
Pg_fieldnum() will return the number of the column slot that corresponds to the named field in the given PosgreSQL result identifier. Field numbering starts at 0. This function will return -1 on error.
Pg_fieldprtlen() will return the actual printed length (number of characters) of a specific value in a PostgreSQL result. Row numbering starts at 0. This function will return -1 on an error.
Pg_fieldsize() will return the internal storage size (in bytes) of the field number in the given PostgreSQL result. Field numbering starts at 0. A field size of -1 indicates a variable length field. This function will return false on error.
Pg_fieldtype() will return a string containing the type name of the given field in the given PostgreSQL result identifier. Field numbering starts at 0.
Pg_freeresult() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script is finished. But, if you are sure you are not going to need the result data anymore in a script, you may call pg_freeresult() with the result identifier as an argument and the associated result memory will be freed.
Pg_getlastoid() can be used to retrieve the oid assigned to an inserted tuple if the result identifier is used from the last command sent via pg_exec() and was an SQL INSERT. This function will return a positive integer if there was a valid oid. It will return -1 if an error occured or the last command sent via pg_exec() was not an INSERT.
Pg_host() will return the host name of the given PostgreSQL connection identifier is connected to.
Pg_loclose() closes an Inversion Large Object. Fd is a file descriptor for the large object from pg_loopen().
Pg_locreate() creates an Inversion Large Object and returns the oid of the large object. conn specifies a valid database connection. PostgreSQL access modes INV_READ, INV_WRITE, and INV_ARCHIVE are not supported, the object is created always with both read and write access. INV_ARCHIVE has been removed from PostgreSQL itself (version 6.3 and above).
The oid argument specifies the object id of the large object to export and the filename argument specifies the pathname of the file. Returns FALSE if an error occurred, TRUE otherwise. Remember that handling large objects in PostgreSQL must happen inside a transaction.
The filename argument specifies the pathname of the file to be imported as a large object. Returns FALSE if an error occurred, object id of the just created large object otherwise. Remember that handling large objects in PostgreSQL must happen inside a transaction.
Pg_loopen() open an Inversion Large Object and returns file descriptor of the large object. The file descriptor encapsulates information about the connection. Do not close the connection before closing the large object file descriptor. objoid specifies a valid large object oid and mode can be either "r", "w", or "rw".
pg_loread() reads at most len bytes from a large object and returns it as a string. fd specifies a valid large object file descriptor andlen specifies the maximum allowable size of the large object segment.
Pg_loreadall() reads a large object and passes it straight through to the browser after sending all pending headers. Mainly intended for sending binary data like images or sound.
Pg_lowrite() writes at most to a large object from a variable buf and returns the number of bytes actually written, or false in the case of an error. fd is a file descriptor for the large object from pg_loopen().
Pg_numfields() will return the number of fields (columns) in a PostgreSQL result. The argument is a valid result identifier returned by pg_exec(). This function will return -1 on error.
Pg_numrows() will return the number of rows in a PostgreSQL result. The argument is a valid result identifier returned by pg_exec(). This function will return -1 on error.
Pg_options() will return a string containing the options specified on the given PostgreSQL connection identifier.
Returns a connection index on success, or false if the connection could not be made. Opens a connection to a PostgreSQL database. The arguments should be within a quoted string. The arguments available include dbname port, host, tty, options, user, and password
This function returns a connection index that is needed by other PostgreSQL functions. You can have multiple connections open at once.
The previous syntax of: $conn = pg_pconnect ("host", "port", "options", "tty", "dbname") has been deprecated.
See also pg_connect().
Pg_port() will return the port number that the given PostgreSQL connection identifier is connected to.
pg_put_line() sends a NULL-terminated string to the PostgreSQL backend server. This is useful for example for very high-speed inserting of data into a table, initiated by starting a PostgreSQL copy-operation. That final NULL-character is added automatically. Returns TRUE if successfull, FALSE otherwise.
Note: Note the application must explicitly send the two characters "\." on a final line to indicate to the backend that it has finished sending its data.
See also pg_end_copy().
Example 1. High-speed insertion of data into a table
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Pg_result() will return values from a result identifier produced by pg_Exec(). The row_number and fieldname sepcify what cell in the table of results to return. Row numbering starts from 0. Instead of naming the field, you may use the field index as an unquoted number. Field indices start from 0.
PostgreSQL has many built in types and only the basic ones are directly supported here. All forms of integer, boolean and oid types are returned as integer values. All forms of float, and real types are returned as double values. All other types, including arrays are returned as strings formatted in the same default PostgreSQL manner that you would see in the psql program.
The function set the client encoding and return 0 if success or -1 if error.
encoding is the client encoding and can be either : SQL_ASCII, EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE, MULE_INTERNAL, LATINX (X=1...9), KOI8, WIN, ALT, SJIS, BIG5, WIN1250.
Note: This function requires PHP-4.0.2 or higher and PostgreSQL-7.0 or higher.
The function used to be called pg_setclientencoding().
See also pg_client_encoding().
The functions returns the client encoding as the string. The returned string should be either : SQL_ASCII, EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE, MULE_INTERNAL, LATINX (X=1...9), KOI8, WIN, ALT, SJIS, BIG5, WIN1250.
Note: This function requires PHP-4.0.2 or higher and PostgreSQL-7.0 or higher.
The function used to be called pg_clientencoding().
See also pg_set_client_encoding().
Enables tracing of the PostgreSQL frontend/backend communication to a debugging file. To fully understand the results one needs to be familiar with the internals of PostgreSQL communication protocol. For those who are not, it can still be useful for tracing errors in queries sent to the server, you could do for example grep '^To backend' trace.log and see what query actually were sent to the PostgreSQL server.
Filename and mode are the same as in fopen() (mode defaults to 'w'), connection specifies the connection to trace and defaults to the last one opened.
Returns TRUE if filename could be opened for logging, FALSE otherwise.
See also fopen() and pg_untrace().
Pg_tty() will return the tty name that server side debugging output is sent to on the given PostgreSQL connection identifier.
Stop tracing started by pg_trace(). connection specifies the connection that was traced and defaults to the last one opened.
Returns always TRUE.
See also pg_trace().
EscapeShellArg() adds single quotes around a string and quotes/escapes any existing single quotes allowing you to pass a string directly to a shell function and having it be treated as a single safe argument. This function should be used to escape individual arguments to shell functions coming from user input. The shell functions include exec(), system() and the backtick operator. A standard use would be:
See also exec(), popen(), system(), and the backtick operator.
EscapeShellCmd() escapes any characters in a string that might be used to trick a shell command into executing arbitrary commands. This function should be used to make sure that any data coming from user input is escaped before this data is passed to the exec() or system() functions, or to the backtick operator. A standard use would be:
$e = EscapeShellCmd($userinput);
system("echo $e"); // here we don't care if $e has spaces
$f = EscapeShellCmd($filename);
system("touch \"/tmp/$f\"; ls -l \"/tmp/$f\""); // and here we do, so we use quotes
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See also escapeshellarg(), exec(), popen(), system(), and the backtick operator.
exec() executes the given command, however it does not output anything. It simply returns the last line from the result of the command. If you need to execute a command and have all the data from the command passed directly back without any interference, use the PassThru() function.
If the array argument is present, then the specified array will be filled with every line of output from the command. Note that if the array already contains some elements, exec() will append to the end of the array. If you do not want the function to append elements, call unset() on the array before passing it to exec().
If the return_var argument is present along with the array argument, then the return status of the executed command will be written to this variable.
Note that if you are going to allow data coming from user input to be passed to this function, then you should be using EscapeShellCmd() to make sure that users cannot trick the system into executing arbitrary commands.
Note also that if you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.
See also system(), PassThru(), popen(), EscapeShellCmd(), and the backtick operator.
The passthru() function is similar to the Exec() function in that it executes a command. If the return_var argument is present, the return status of the Unix command will be placed here. This function should be used in place of Exec() or System() when the output from the Unix command is binary data which needs to be passed directly back to the browser. A common use for this is to execute something like the pbmplus utilities that can output an image stream directly. By setting the content-type to image/gif and then calling a pbmplus program to output a gif, you can create PHP scripts that output images directly.
Note that if you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.
See also exec(), system(), popen(), EscapeShellCmd(), and the backtick operator.
System() is just like the C version of the function in that it executes the given command and outputs the result. If a variable is provided as the second argument, then the return status code of the executed command will be written to this variable.
Note, that if you are going to allow data coming from user input to be passed to this function, then you should be using the EscapeShellCmd() function to make sure that users cannot trick the system into executing arbitrary commands.
Note also that if you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.
The System() call also tries to automatically flush the web server's output buffer after each line of output if PHP is running as a server module.
Returns the last line of the command output on success, and false on failure.
If you need to execute a command and have all the data from the command passed directly back without any interference, use the PassThru() function.
See also exec(), PassThru(), popen(), EscapeShellCmd(), and the backtick operator.
These functions allow you to check the spelling of a word and offer suggestions.
You need the aspell and pspell libraries, available from http://aspell.sourceforge.net/ and http://pspell.sourceforge.net/ respectively, and add the --with-pspell[=dir] option when compiling php.
Pspell_add_to_personal() adds a word to the personal wordlist. If you used pspell_new_config() with pspell_config_personal() to open the dictionary, you can save the wordlist later with pspell_save_wordlist(). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
Pspell_add_to_session() adds a word to the wordlist associated with the current session. It is very similar to pspell_add_to_personal()
Pspell_check() checks the spelling of a word and returns true if the spelling is correct, false if not.
Pspell_clear_session() clears the current session. The current wordlist becomes blank, and, for example, if you try to save it with pspell_save_wordlist(), nothing happens.
Example 1. Pspell_add_to_personal()
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int pspell_config_create (string language [, string
spelling [, string
jargon [, string
encoding]]])
Pspell_config_create() has a very similar syntax to pspell_new(). In fact, using pspell_config_create() immediatelly followed by pspell_new_config() will produce the exact same result. However, after creating a new config, you can also use pspell_config_*() functions before calling pspell_new_config() to take advantage of some advanced functionality.
The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.
The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.
The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.
The encoding parameter is the encoding that words are expected to be in. Valid values are 'utf-8', 'iso8859-*', 'koi8-r', 'viscii', 'cp1252', 'machine unsigned 16', 'machine unsigned 32'. This parameter is largely untested, so be careful when using.
The mode parameter is the mode in which spellchecker will work. There are several modes available:
PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
For more information and examples, check out inline manual pspell website:http://pspell.sourceforge.net/.
Pspell_config_ignore() should be used on a config before calling pspell_new_config(). This function allows short words to be skipped by the spellchecker. Words less then n characters will be skipped.
Pspell_config_mode() should be used on a config before calling pspell_new_config(). This function determines how many suggestions will be returned by pspell_suggest().
The mode parameter is the mode in which spellchecker will work. There are several modes available:
PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
Pspell_config_personal() should be used on a config before calling pspell_new_config(). The personal wordlist will be loaded and used in addition to the standard one after you call pspell_new_config(). If the file does not exist, it will be created. The file is also the file where pspell_save_wordlist() will save personal wordlist to. The file should be writable by whoever php runs as (e.g. nobody). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
Pspell_config_repl() should be used on a config before calling pspell_new_config(). The replacement pairs improve the quality of the spellchecker. When a word is misspelled, and a proper suggestion was not found in the list, pspell_store_replacement() can be used to store a replacement pair and then pspell_save_wordlist() to save the wordlist along with the replacement pairs. The file should be writable by whoever php runs as (e.g. nobody). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
Example 1. Pspell_config_repl()
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Pspell_config_runtogether() should be used on a config before calling pspell_new_config(). This function determines whether run-together words will be treated as legal compounds. That is, "thecat" will be a legal compound, athough there should be a space between the two words. Changing this setting only affects the results returned by pspell_check(); pspell_suggest() will still return suggestions.
(PHP 4 >= 4.0.2)
pspell_config_save_repl -- Determine whether to save a replacement pairs list along with the wordlist.Pspell_config_save_repl() should be used on a config before calling pspell_new_config(). It determines whether pspell_save_wordlist() will save the replacement pairs along with the wordlist. Usually there is no need to use this function because if pspell_config_repl() is used, the replacement pairs will be saved by pspell_save_wordlist() anyway, and if it is not, the replacement pairs will not be saved. Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
int pspell_new (string language [, string
spelling [, string
jargon [, string
encoding [, int
mode]]]])
Pspell_new() opens up a new dictionary and returns the dictionary link identifier for use in other pspell functions.
The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.
The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.
The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.
The encoding parameter is the encoding that words are expected to be in. Valid values are 'utf-8', 'iso8859-*', 'koi8-r', 'viscii', 'cp1252', 'machine unsigned 16', 'machine unsigned 32'. This parameter is largely untested, so be careful when using.
The mode parameter is the mode in which spellchecker will work. There are several modes available:
PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
PSPELL_RUN_TOGETHER - Consider run-together words as legal compounds. That is, "thecat" will be a legal compound, athough there should be a space between the two words. Changing this setting only affects the results returned by pspell_check(); pspell_suggest() will still return suggestions.
For more information and examples, check out inline manual pspell website:http://pspell.sourceforge.net/.
Pspell_new_config() opens up a new dictionary with settings specified in a config, created with with pspell_config_create() and modified with pspell_config_*() functions. This method provides you with the most flexibility and has all the functionality provided by pspell_new() and pspell_new_personal().
The config parameter is the one returned by pspell_config_create() when the config was created.
int pspell_new_personal (string personal, string language [, string
spelling [, string
jargon [, string
encoding [, int
mode]]]])
Pspell_new_personal() opens up a new dictionary with a personal wordlist and returns the dictionary link identifier for use in other pspell functions. The wordlist can be modified and saved with pspell_save_wordlist(), if desired. However, the replacement pairs are not saved. In order to save replacement pairs, you should create a config using pspell_config_create(), set the personal wordlist file with pspell_config_personal (), set the file for replacement pairs with pspell_config_repl(), and open a new dictionary with pspell_new_config().
The personal parameter specifies the file where words added to the personal list will be stored. It should be an absolute filename beginning with '/' because otherwise it will be relative to $HOME, which is "/root" for most systems, and is probably not what you want.
The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.
The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.
The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.
The encoding parameter is the encoding that words are expected to be in. Valid values are 'utf-8', 'iso8859-*', 'koi8-r', 'viscii', 'cp1252', 'machine unsigned 16', 'machine unsigned 32'. This parameter is largely untested, so be careful when using.
The mode parameter is the mode in which spellchecker will work. There are several modes available:
PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
PSPELL_RUN_TOGETHER - Consider run-together words as legal compounds. That is, "thecat" will be a legal compound, athough there should be a space between the two words. Changing this setting only affects the results returned by pspell_check(); pspell_suggest() will still return suggestions.
For more information and examples, check out inline manual pspell website:http://pspell.sourceforge.net/.
Pspell_save_wordlist() saves the personal wordlist from the current session. The dictionary has to be open with pspell_new_personal(), and the location of files to be saved specified with pspell_config_personal() and (optionally) pspell_config_repl(). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
Pspell_store_replacement() stores a replacement pair for a word, so that replacement can be returned by pspell_suggest() later. In order to be able to take advantage of this function, you have to use pspell_new_personal() to open the dictionary. In order to permanently save the replacement pair, you have to use pspell_config_personal() and pspell_config_repl() to set the path where to save your custom wordlists, and then use pspell_save_wordlist() for the changes to be written to disk. Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.
Example 1. Pspell_store_replacement()
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The readline() functions implement an interface to the GNU Readline library. These are functions that provide editable command lines. An example being the way Bash allows you to use the arrow keys to insert characters or scroll through command history. Because of the interactive nature of this library, it will be of little use for writing Web applications, but may be useful when writing scripts meant to be run from a shell.
The home page of the GNU Readline project is http://cnswww.cns.cwru.edu/~chet/readline/rltop.html. It's maintained by Chet Ramey, who's also the author of Bash.
This function returns a single string from the user. You may specify a string with which to prompt the user. The line returned has the ending newline removed. You must add this line to the history yourself using readline_add_history().
This function registers a completion function. You must supply the name of an existing function which accepts a partial command line and returns an array of possible matches. This is the same kind of functionality you'd get if you hit your tab key while using Bash.
If called with no parameters, this function returns an array of values for all the setting readline uses. The elements will will be indexed by the following values: done, end, erase_empty_line, library_version, line_buffer, mark, pending_input, point, prompt, readline_name, and terminal_name.
If called with one parameter, the value of that setting is returned. If called with two parameters, the setting will be changed to the given value.
This function returns an array of the entire command line history. The elements are indexed by integers starting at zero.
This module contains an interface to the GNU Recode library, version 3.5. To be able to use the functions defined in this module you must compile you PHP interpreter using the --with-recode option. In order to do so, you must have GNU Recode 3.5 or higher installed on your system.
The GNU Recode library converts files between various coded character sets and surface encodings. When this cannot be achieved exactly, it may get rid of the offending characters or fall back on approximations. The library recognises or produces nearly 150 different character sets and is able to convert files between almost any pair. Most RFC 1345 character sets are supported.
Recode the string string according to the recode request request. Returns the recoded string or FALSE, if unable to perform the recode request.
A simple recode request may be "lat1..iso646-de". See also the GNU Recode documentation of your installation for detailed instructions about recode requests.
(PHP 3>= 3.0.13, PHP 4 >= 4.0RC1)
recode_file -- Recode from file to file according to recode requestRecode the file referenced by file handle input into the file referenced by file handle output according to the recode request. Returns FALSE, if unable to comply, TRUE otherwise.
This function does not currently process filehandles referencing remote files (URLs). Both filehandles must refer to local files.
The syntax for patterns used in these functions closely resembles Perl. The expression should be enclosed in the delimiters, a forward slash (/), for example. Any character can be used for delimiter as long as it's not alphanumeric or backslash (\). If the delimiter character has to be used in the expression itself, it needs to be escaped by backslash.
The ending delimiter may be followed by various modifiers that affect the matching. See Pattern Modifiers.
Note: The Perl-compatible regular expression functions are available in PHP 4 and in PHP 3.0.9 and up.
Searches subject for a match to the regular expression given in pattern.
If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that match the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.
Returns true if a match for pattern was found in the subject string, or false if not match was found or an error occurred.
Example 2. find the word "web"
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Example 3. Getting the domain name out of a URL
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domain name is: php.net
|
Searches subject for all matches to the regular expression given in pattern and puts them in matches in the order specified by order.
After the first match is found, the subsequent searches are continued on from end of the last match.
order can be one of two things:
Orders results so that $matches[0] is an array of full pattern matches, $matches[1] is an array of strings matched by the first parenthesized subpattern, and so on.
This example will produce: So, $out[0] contains array of strings that matched full pattern, and $out[1] contains array of strings enclosed by tags.Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on.
This example will produce: In this case, $matches[0] is the first set of matches, and $matches[0][0] has text matched by full pattern, $matches[0][1] has text matched by first subpattern and so on. Similarly, $matches[1] is the second set of matches, etc.If order is not specified, it is assumed to be PREG_PATTERN_ORDER.
Returns the number of full pattern matches, or false if no match is found or an error occurred.
Example 2. Find matching HTML tags (greedy)
|
matched: <b>bold text</b>
part 1: <b>
part 2: bold text
part 3: </b>
matched: <a href=howdy.html>click me</a>
part 1: <a href=howdy.html>
part 2: click me
part 3: </a>
|
See also preg_match(), preg_replace(), and preg_split().
Searches subject for matches to pattern and replaces them with replacement . If limit is specified, then only limit matches will be replaced; if limit is omitted or is -1, then all matches are replaced.
Replacement may contain references of the form \\n or (since PHP 4.0.4) $n, with the latter form being the preferred one. Every such reference will be replaced by the text captured by the n'th parenthesized pattern. n can be from 0 to 99, and \\0 or $0 refers to the text matched by the whole pattern. Opening parentheses are counted from left to right (starting from 1) to obtain the number of the capturing subpattern.
If no matches are found in subject, then it will be returned unchanged.
Every parameter to preg_replace() can be an array.
If subject is an array, then the search and replace is performed on every entry of subject, and the return value is an array as well.
If pattern and replacement are arrays, then preg_replace() takes a value from each array and uses them to do search and replace on subject. If replacement has fewer values than pattern, then empty string is used for the rest of replacement values. If pattern is an array and replacement is a string; then this replacement string is used for every value of pattern. The converse would not make sense, though.
/e modifier makes preg_replace() treat the replacement parameter as PHP code after the appropriate references substitution is done. Tip: make sure that replacement constitutes a valid PHP code string, otherwise PHP will complain about a parse error at the line containing preg_replace().
$startDate = 5/27/1999
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Example 3. Convert HTML to text
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Note: Parameter limit was added after PHP 4.0.1pl2.
See also preg_match(), preg_match_all(), and preg_split().
Note: Parameter flags was added in PHP 4 Beta 3.
Returns an array containing substrings of subject split along boundaries matched by pattern.
If limit is specified, then only substrings up to limit are returned.
If flags is PREG_SPLIT_NO_EMPTY then only non-empty pieces will be returned by preg_split().
Example 1. preg_split() example Get the parts of a search string.
Splitting a string into component characters.
|
See also preg_match(), preg_match_all(), and preg_replace().
preg_quote() takes str and puts a backslash in front of every character that is part of the regular expression syntax. This is useful if you have a run-time string that you need to match in some text and the string may contain special regex characters.
If the optional delimiter is specified, it will also be escaped. This is useful for escaping the delimeter that is required by the PCRE functions. The / is the most commonly used delimiter.
The special regular expression characters are:
. \\ + * ? [ ^ ] $ ( ) { } = ! < > | : |
Example 2. Italicizing a word within some text
|
preg_grep() returns the array consisting of the elements of the input array that match the given pattern.
The current possible PCRE modifiers are listed below. The names in parentheses refer to internal PCRE names for these modifiers.
- i (PCRE_CASELESS)
If this modifier is set, letters in the pattern match both upper and lower case letters.
- m (PCRE_MULTILINE)
By default, PCRE treats the subject string as consisting of a single "line" of characters (even if it actually contains several newlines). The "start of line" metacharacter (^) matches only at the start of the string, while the "end of line" metacharacter ($) matches only at the end of the string, or before a terminating newline (unless E modifier is set). This is the same as Perl.
When this modifier is set, the "start of line" and "end of line" constructs match immediately following or immediately before any newline in the subject string, respectively, as well as at the very start and end. This is equivalent to Perl's /m modifier. If there are no "\n" characters in a subject string, or no occurrences of ^ or $ in a pattern, setting this modifier has no effect.
- s (PCRE_DOTALL)
If this modifier is set, a dot metacharater in the pattern matches all characters, including newlines. Without it, newlines are excluded. This modifier is equivalent to Perl's /s modifier. A negative class such as [^a] always matches a newline character, independent of the setting of this modifier.
- x (PCRE_EXTENDED)
If this modifier is set, whitespace data characters in the pattern are totally ignored except when escaped or inside a character class, and characters between an unescaped # outside a character class and the next newline character, inclusive, are also ignored. This is equivalent to Perl's /x modifier, and makes it possible to include comments inside complicated patterns. Note, however, that this applies only to data characters. Whitespace characters may never appear within special character sequences in a pattern, for example within the sequence (?( which introduces a conditional subpattern.
- e
If this modifier is set, preg_replace() does normal substitution of backreferences in the replacement string, evaluates it as PHP code, and uses the result for replacing the search string.
Only preg_replace() uses this modifier; it is ignored by other PCRE functions.
- A (PCRE_ANCHORED)
If this modifier is set, the pattern is forced to be "anchored", that is, it is constrained to match only at the start of the string which is being searched (the "subject string"). This effect can also be achieved by appropriate constructs in the pattern itself, which is the only way to do it in Perl.
- D (PCRE_DOLLAR_ENDONLY)
If this modifier is set, a dollar metacharacter in the pattern matches only at the end of the subject string. Without this modifier, a dollar also matches immediately before the final character if it is a newline (but not before any other newlines). This modifier is ignored if m modifier is set. There is no equivalent to this modifier in Perl.
- S
When a pattern is going to be used several times, it is worth spending more time analyzing it in order to speed up the time taken for matching. If this modifier is set, then this extra analysis is performed. At present, studying a pattern is useful only for non-anchored patterns that do not have a single fixed starting character.
- U (PCRE_UNGREEDY)
This modifier inverts the "greediness" of the quantifiers so that they are not greedy by default, but become greedy if followed by "?". It is not compatible with Perl. It can also be set by a (?U) modifier setting within the pattern.
- X (PCRE_EXTRA)
This modifier turns on additional functionality of PCRE that is incompatible with Perl. Any backslash in a pattern that is followed by a letter that has no special meaning causes an error, thus reserving these combinations for future expansion. By default, as in Perl, a backslash followed by a letter with no special meaning is treated as a literal. There are at present no other features controlled by this modifier.
The PCRE library is a set of functions that implement regular
expression pattern matching using the same syntax and semantics
as Perl 5, with just a few differences (see below). The current
implementation corresponds to Perl 5.005.
The differences described here are with respect to Perl
5.005.
1. By default, a whitespace character is any character that
the C library function isspace() recognizes, though it is
possible to compile PCRE with alternative character type
tables. Normally isspace() matches space, formfeed, newline,
carriage return, horizontal tab, and vertical tab. Perl 5 no
longer includes vertical tab in its set of whitespace char-
acters. The \v escape that was in the Perl documentation for
a long time was never in fact recognized. However, the char-
acter itself was treated as whitespace at least up to 5.002.
In 5.004 and 5.005 it does not match \s.
2. PCRE does not allow repeat quantifiers on lookahead
assertions. Perl permits them, but they do not mean what you
might think. For example, (?!a){3} does not assert that the
next three characters are not "a". It just asserts that the
next character is not "a" three times.
3. Capturing subpatterns that occur inside negative looka-
head assertions are counted, but their entries in the
offsets vector are never set. Perl sets its numerical vari-
ables from any such patterns that are matched before the
assertion fails to match something (thereby succeeding), but
only if the negative lookahead assertion contains just one
branch.
4. Though binary zero characters are supported in the sub-
ject string, they are not allowed in a pattern string
because it is passed as a normal C string, terminated by
zero. The escape sequence "\0" can be used in the pattern to
represent a binary zero.
5. The following Perl escape sequences are not supported:
\l, \u, \L, \U, \E, \Q. In fact these are implemented by
Perl's general string-handling and are not part of its pat-
tern matching engine.
6. The Perl \G assertion is not supported as it is not
relevant to single pattern matches.
7. Fairly obviously, PCRE does not support the (?{code})
construction.
8. There are at the time of writing some oddities in Perl
5.005_02 concerned with the settings of captured strings
when part of a pattern is repeated. For example, matching
"aba" against the pattern /^(a(b)?)+$/ sets $2 to the value
"b", but matching "aabbaa" against /^(aa(bb)?)+$/ leaves $2
unset. However, if the pattern is changed to
/^(aa(b(b))?)+$/ then $2 (and $3) get set.
In Perl 5.004 $2 is set in both cases, and that is also true
of PCRE. If in the future Perl changes to a consistent state
that is different, PCRE may change to follow.
9. Another as yet unresolved discrepancy is that in Perl
5.005_02 the pattern /^(a)?(?(1)a|b)+$/ matches the string
"a", whereas in PCRE it does not. However, in both Perl and
PCRE /^(a)?a/ matched against "a" leaves $1 unset.
10. PCRE provides some extensions to the Perl regular
expression facilities:
(a) Although lookbehind assertions must match fixed length
strings, each alternative branch of a lookbehind assertion
can match a different length of string. Perl 5.005 requires
them all to have the same length.
(b) If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not
set, the $ meta- character matches only at the very end of
the string.
(c) If PCRE_EXTRA is set, a backslash followed by a letter
with no special meaning is faulted.
(d) If PCRE_UNGREEDY is set, the greediness of the repeti-
tion quantifiers is inverted, that is, by default they are
not greedy, but if followed by a question mark they are.
The syntax and semantics of the regular expressions sup-
ported by PCRE are described below. Regular expressions are
also described in the Perl documentation and in a number of
other books, some of which have copious examples. Jeffrey
Friedl's "Mastering Regular Expressions", published by
O'Reilly (ISBN 1-56592-257-3), covers them in great detail.
The description here is intended as reference documentation.
A regular expression is a pattern that is matched against a
subject string from left to right. Most characters stand for
themselves in a pattern, and match the corresponding charac-
ters in the subject. As a trivial example, the pattern
The quick brown fox
matches a portion of a subject string that is identical to
itself. The power of regular expressions comes from the
ability to include alternatives and repetitions in the pat-
tern. These are encoded in the pattern by the use of meta-
characters, which do not stand for themselves but instead
are interpreted in some special way.
There are two different sets of meta-characters: those that
are recognized anywhere in the pattern except within square
brackets, and those that are recognized in square brackets.
Outside square brackets, the meta-characters are as follows:
\ general escape character with several uses
^ assert start of subject (or line, in multiline
mode)
$ assert end of subject (or line, in multiline mode)
. match any character except newline (by default)
[ start character class definition
| start of alternative branch
( start subpattern
) end subpattern
? extends the meaning of (
also 0 or 1 quantifier
also quantifier minimizer
* 0 or more quantifier
+ 1 or more quantifier
{ start min/max quantifier
Part of a pattern that is in square brackets is called a
"character class". In a character class the only meta-
characters are:
\ general escape character
^ negate the class, but only if the first character
- indicates character range
] terminates the character class
The following sections describe the use of each of the
meta-characters.
BACKSLASH
The backslash character has several uses. Firstly, if it is
followed by a non-alphameric character, it takes away any
special meaning that character may have. This use of
backslash as an escape character applies both inside and
outside character classes.
For example, if you want to match a "*" character, you write
"\*" in the pattern. This applies whether or not the follow-
ing character would otherwise be interpreted as a meta-
character, so it is always safe to precede a non-alphameric
with "\" to specify that it stands for itself. In particu-
lar, if you want to match a backslash, you write "\\".
If a pattern is compiled with the PCRE_EXTENDED option, whi-
tespace in the pattern (other than in a character class) and
characters between a "#" outside a character class and the
next newline character are ignored. An escaping backslash
can be used to include a whitespace or "#" character as part
of the pattern.
A second use of backslash provides a way of encoding non-
printing characters in patterns in a visible manner. There
is no restriction on the appearance of non-printing charac-
ters, apart from the binary zero that terminates a pattern,
but when a pattern is being prepared by text editing, it is
usually easier to use one of the following escape sequences
than the binary character it represents:
\a alarm, that is, the BEL character (hex 07)
\cx "control-x", where x is any character
\e escape (hex 1B)
\f formfeed (hex 0C)
\n newline (hex 0A)
\r carriage return (hex 0D)
\t tab (hex 09)
\xhh character with hex code hh
\ddd character with octal code ddd, or backreference
The precise effect of "\cx" is as follows: if "x" is a lower
case letter, it is converted to upper case. Then bit 6 of
the character (hex 40) is inverted. Thus "\cz" becomes hex
1A, but "\c{" becomes hex 3B, while "\c;" becomes hex 7B.
After "\x", up to two hexadecimal digits are read (letters
can be in upper or lower case).
After "\0" up to two further octal digits are read. In both
cases, if there are fewer than two digits, just those that
are present are used. Thus the sequence "\0\x\07" specifies
two binary zeros followed by a BEL character. Make sure you
supply two digits after the initial zero if the character
that follows is itself an octal digit.
The handling of a backslash followed by a digit other than 0
is complicated. Outside a character class, PCRE reads it
and any following digits as a decimal number. If the number
is less than 10, or if there have been at least that many
previous capturing left parentheses in the expression, the
entire sequence is taken as a back reference. A description
of how this works is given later, following the discussion
of parenthesized subpatterns.
Inside a character class, or if the decimal number is
greater than 9 and there have not been that many capturing
subpatterns, PCRE re-reads up to three octal digits follow-
ing the backslash, and generates a single byte from the
least significant 8 bits of the value. Any subsequent digits
stand for themselves. For example:
\040 is another way of writing a space
\40 is the same, provided there are fewer than 40
previous capturing subpatterns
\7 is always a back reference
\11 might be a back reference, or another way of
writing a tab
\011 is always a tab
\0113 is a tab followed by the character "3"
\113 is the character with octal code 113 (since there
can be no more than 99 back references)
\377 is a byte consisting entirely of 1 bits
\81 is either a back reference, or a binary zero
followed by the two characters "8" and "1"
Note that octal values of 100 or greater must not be intro-
duced by a leading zero, because no more than three octal
digits are ever read.
All the sequences that define a single byte value can be
used both inside and outside character classes. In addition,
inside a character class, the sequence "\b" is interpreted
as the backspace character (hex 08). Outside a character
class it has a different meaning (see below).
The third use of backslash is for specifying generic charac-
ter types:
\d any decimal digit
\D any character that is not a decimal digit
\s any whitespace character
\S any character that is not a whitespace character
\w any "word" character
\W any "non-word" character
Each pair of escape sequences partitions the complete set of
characters into two disjoint sets. Any given character
matches one, and only one, of each pair.
A "word" character is any letter or digit or the underscore
character, that is, any character which can be part of a
Perl "word". The definition of letters and digits is con-
trolled by PCRE's character tables, and may vary if locale-
specific matching is taking place (see "Locale support"
above). For example, in the "fr" (French) locale, some char-
acter codes greater than 128 are used for accented letters,
and these are matched by \w.
These character type sequences can appear both inside and
outside character classes. They each match one character of
the appropriate type. If the current matching point is at
the end of the subject string, all of them fail, since there
is no character to match.
The fourth use of backslash is for certain simple asser-
tions. An assertion specifies a condition that has to be met
at a particular point in a match, without consuming any
characters from the subject string. The use of subpatterns
for more complicated assertions is described below. The
backslashed assertions are
\b word boundary
\B not a word boundary
\A start of subject (independent of multiline mode)
\Z end of subject or newline at end (independent of
multiline mode)
\z end of subject (independent of multiline mode)
These assertions may not appear in character classes (but
note that "\b" has a different meaning, namely the backspace
character, inside a character class).
A word boundary is a position in the subject string where
the current character and the previous character do not both
match \w or \W (i.e. one matches \w and the other matches
\W), or the start or end of the string if the first or last
character matches \w, respectively.
The \A, \Z, and \z assertions differ from the traditional
circumflex and dollar (described below) in that they only
ever match at the very start and end of the subject string,
whatever options are set. They are not affected by the
PCRE_NOTBOL or PCRE_NOTEOL options. The difference between
\Z and \z is that \Z matches before a newline that is the
last character of the string as well as at the end of the
string, whereas \z matches only at the end.
CIRCUMFLEX AND DOLLAR
Outside a character class, in the default matching mode, the
circumflex character is an assertion which is true only if
the current matching point is at the start of the subject
string. Inside a character class, circumflex has an entirely
different meaning (see below).
Circumflex need not be the first character of the pattern if
a number of alternatives are involved, but it should be the
first thing in each alternative in which it appears if the
pattern is ever to match that branch. If all possible alter-
natives start with a circumflex, that is, if the pattern is
constrained to match only at the start of the subject, it is
said to be an "anchored" pattern. (There are also other con-
structs that can cause a pattern to be anchored.)
A dollar character is an assertion which is true only if the
current matching point is at the end of the subject string,
or immediately before a newline character that is the last
character in the string (by default). Dollar need not be the
last character of the pattern if a number of alternatives
are involved, but it should be the last item in any branch
in which it appears. Dollar has no special meaning in a
character class.
The meaning of dollar can be changed so that it matches only
at the very end of the string, by setting the
PCRE_DOLLAR_ENDONLY option at compile or matching time. This
does not affect the \Z assertion.
The meanings of the circumflex and dollar characters are
changed if the PCRE_MULTILINE option is set. When this is
the case, they match immediately after and immediately
before an internal "\n" character, respectively, in addition
to matching at the start and end of the subject string. For
example, the pattern /^abc$/ matches the subject string
"def\nabc" in multiline mode, but not otherwise. Conse-
quently, patterns that are anchored in single line mode
because all branches start with "^" are not anchored in mul-
tiline mode. The PCRE_DOLLAR_ENDONLY option is ignored if
PCRE_MULTILINE is set.
Note that the sequences \A, \Z, and \z can be used to match
the start and end of the subject in both modes, and if all
branches of a pattern start with \A is it always anchored,
whether PCRE_MULTILINE is set or not.
FULL STOP (PERIOD, DOT)
Outside a character class, a dot in the pattern matches any
one character in the subject, including a non-printing
character, but not (by default) newline. If the PCRE_DOTALL
option is set, then dots match newlines as well. The han-
dling of dot is entirely independent of the handling of cir-
cumflex and dollar, the only relationship being that they
both involve newline characters. Dot has no special meaning
in a character class.
SQUARE BRACKETS
An opening square bracket introduces a character class, ter-
minated by a closing square bracket. A closing square
bracket on its own is not special. If a closing square
bracket is required as a member of the class, it should be
the first data character in the class (after an initial cir-
cumflex, if present) or escaped with a backslash.
A character class matches a single character in the subject;
the character must be in the set of characters defined by
the class, unless the first character in the class is a cir-
cumflex, in which case the subject character must not be in
the set defined by the class. If a circumflex is actually
required as a member of the class, ensure it is not the
first character, or escape it with a backslash.
For example, the character class [aeiou] matches any lower
case vowel, while [^aeiou] matches any character that is not
a lower case vowel. Note that a circumflex is just a con-
venient notation for specifying the characters which are in
the class by enumerating those that are not. It is not an
assertion: it still consumes a character from the subject
string, and fails if the current pointer is at the end of
the string.
When caseless matching is set, any letters in a class
represent both their upper case and lower case versions, so
for example, a caseless [aeiou] matches "A" as well as "a",
and a caseless [^aeiou] does not match "A", whereas a case-
ful version would.
The newline character is never treated in any special way in
character classes, whatever the setting of the PCRE_DOTALL
or PCRE_MULTILINE options is. A class such as [^a] will
always match a newline.
The minus (hyphen) character can be used to specify a range
of characters in a character class. For example, [d-m]
matches any letter between d and m, inclusive. If a minus
character is required in a class, it must be escaped with a
backslash or appear in a position where it cannot be inter-
preted as indicating a range, typically as the first or last
character in the class.
It is not possible to have the literal character "]" as the
end character of a range. A pattern such as [W-]46] is
interpreted as a class of two characters ("W" and "-") fol-
lowed by a literal string "46]", so it would match "W46]" or
"-46]". However, if the "]" is escaped with a backslash it
is interpreted as the end of range, so [W-\]46] is inter-
preted as a single class containing a range followed by two
separate characters. The octal or hexadecimal representation
of "]" can also be used to end a range.
Ranges operate in ASCII collating sequence. They can also be
used for characters specified numerically, for example
[\000-\037]. If a range that includes letters is used when
caseless matching is set, it matches the letters in either
case. For example, [W-c] is equivalent to [][\^_`wxyzabc],
matched caselessly, and if character tables for the "fr"
locale are in use, [\xc8-\xcb] matches accented E characters
in both cases.
The character types \d, \D, \s, \S, \w, and \W may also
appear in a character class, and add the characters that
they match to the class. For example, [\dABCDEF] matches any
hexadecimal digit. A circumflex can conveniently be used
with the upper case character types to specify a more res-
tricted set of characters than the matching lower case type.
For example, the class [^\W_] matches any letter or digit,
but not underscore.
All non-alphameric characters other than \, -, ^ (at the
start) and the terminating ] are non-special in character
classes, but it does no harm if they are escaped.
VERTICAL BAR
Vertical bar characters are used to separate alternative
patterns. For example, the pattern
gilbert|sullivan
matches either "gilbert" or "sullivan". Any number of alter-
natives may appear, and an empty alternative is permitted
(matching the empty string). The matching process tries
each alternative in turn, from left to right, and the first
one that succeeds is used. If the alternatives are within a
subpattern (defined below), "succeeds" means matching the
rest of the main pattern as well as the alternative in the
subpattern.
INTERNAL OPTION SETTING
The settings of PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL,
and PCRE_EXTENDED can be changed from within the pattern by
a sequence of Perl option letters enclosed between "(?" and
")". The option letters are
i for PCRE_CASELESS
m for PCRE_MULTILINE
s for PCRE_DOTALL
x for PCRE_EXTENDED
For example, (?im) sets caseless, multiline matching. It is
also possible to unset these options by preceding the letter
with a hyphen, and a combined setting and unsetting such as
(?im-sx), which sets PCRE_CASELESS and PCRE_MULTILINE while
unsetting PCRE_DOTALL and PCRE_EXTENDED, is also permitted.
If a letter appears both before and after the hyphen, the
option is unset.
The scope of these option changes depends on where in the
pattern the setting occurs. For settings that are outside
any subpattern (defined below), the effect is the same as if
the options were set or unset at the start of matching. The
following patterns all behave in exactly the same way:
(?i)abc
a(?i)bc
ab(?i)c
abc(?i)
which in turn is the same as compiling the pattern abc with
PCRE_CASELESS set. In other words, such "top level" set-
tings apply to the whole pattern (unless there are other
changes inside subpatterns). If there is more than one set-
ting of the same option at top level, the rightmost setting
is used.
If an option change occurs inside a subpattern, the effect
is different. This is a change of behaviour in Perl 5.005.
An option change inside a subpattern affects only that part
of the subpattern that follows it, so
(a(?i)b)c
matches abc and aBc and no other strings (assuming
PCRE_CASELESS is not used). By this means, options can be
made to have different settings in different parts of the
pattern. Any changes made in one alternative do carry on
into subsequent branches within the same subpattern. For
example,
(a(?i)b|c)
matches "ab", "aB", "c", and "C", even though when matching
"C" the first branch is abandoned before the option setting.
This is because the effects of option settings happen at
compile time. There would be some very weird behaviour oth-
erwise.
The PCRE-specific options PCRE_UNGREEDY and PCRE_EXTRA can
be changed in the same way as the Perl-compatible options by
using the characters U and X respectively. The (?X) flag
setting is special in that it must always occur earlier in
the pattern than any of the additional features it turns on,
even when it is at top level. It is best put at the start.
SUBPATTERNS
Subpatterns are delimited by parentheses (round brackets),
which can be nested. Marking part of a pattern as a subpat-
tern does two things:
1. It localizes a set of alternatives. For example, the pat-
tern
cat(aract|erpillar|)
matches one of the words "cat", "cataract", or "caterpil-
lar". Without the parentheses, it would match "cataract",
"erpillar" or the empty string.
2. It sets up the subpattern as a capturing subpattern (as
defined above). When the whole pattern matches, that por-
tion of the subject string that matched the subpattern is
passed back to the caller via the ovector argument of
pcre_exec(). Opening parentheses are counted from left to
right (starting from 1) to obtain the numbers of the captur-
ing subpatterns.
For example, if the string "the red king" is matched against
the pattern
the ((red|white) (king|queen))
the captured substrings are "red king", "red", and "king",
and are numbered 1, 2, and 3.
The fact that plain parentheses fulfil two functions is not
always helpful. There are often times when a grouping sub-
pattern is required without a capturing requirement. If an
opening parenthesis is followed by "?:", the subpattern does
not do any capturing, and is not counted when computing the
number of any subsequent capturing subpatterns. For example,
if the string "the white queen" is matched against the
pattern
the ((?:red|white) (king|queen))
the captured substrings are "white queen" and "queen", and
are numbered 1 and 2. The maximum number of captured sub-
strings is 99, and the maximum number of all subpatterns,
both capturing and non-capturing, is 200.
As a convenient shorthand, if any option settings are
required at the start of a non-capturing subpattern, the
option letters may appear between the "?" and the ":". Thus
the two patterns
(?i:saturday|sunday)
(?:(?i)saturday|sunday)
match exactly the same set of strings. Because alternative
branches are tried from left to right, and options are not
reset until the end of the subpattern is reached, an option
setting in one branch does affect subsequent branches, so
the above patterns match "SUNDAY" as well as "Saturday".
REPETITION
Repetition is specified by quantifiers, which can follow any
of the following items:
a single character, possibly escaped
the . metacharacter
a character class
a back reference (see next section)
a parenthesized subpattern (unless it is an assertion -
see below)
The general repetition quantifier specifies a minimum and
maximum number of permitted matches, by giving the two
numbers in curly brackets (braces), separated by a comma.
The numbers must be less than 65536, and the first must be
less than or equal to the second. For example:
z{2,4}
matches "zz", "zzz", or "zzzz". A closing brace on its own
is not a special character. If the second number is omitted,
but the comma is present, there is no upper limit; if the
second number and the comma are both omitted, the quantifier
specifies an exact number of required matches. Thus
[aeiou]{3,}
matches at least 3 successive vowels, but may match many
more, while
\d{8}
matches exactly 8 digits. An opening curly bracket that
appears in a position where a quantifier is not allowed, or
one that does not match the syntax of a quantifier, is taken
as a literal character. For example, {,6} is not a quantif-
ier, but a literal string of four characters.
The quantifier {0} is permitted, causing the expression to
behave as if the previous item and the quantifier were not
present.
For convenience (and historical compatibility) the three
most common quantifiers have single-character abbreviations:
* is equivalent to {0,}
+ is equivalent to {1,}
? is equivalent to {0,1}
It is possible to construct infinite loops by following a
subpattern that can match no characters with a quantifier
that has no upper limit, for example:
(a?)*
Earlier versions of Perl and PCRE used to give an error at
compile time for such patterns. However, because there are
cases where this can be useful, such patterns are now
accepted, but if any repetition of the subpattern does in
fact match no characters, the loop is forcibly broken.
By default, the quantifiers are "greedy", that is, they
match as much as possible (up to the maximum number of per-
mitted times), without causing the rest of the pattern to
fail. The classic example of where this gives problems is in
trying to match comments in C programs. These appear between
the sequences /* and */ and within the sequence, individual
* and / characters may appear. An attempt to match C com-
ments by applying the pattern
/\*.*\*/
to the string
/* first command */ not comment /* second comment */
fails, because it matches the entire string due to the
greediness of the .* item.
However, if a quantifier is followed by a question mark,
then it ceases to be greedy, and instead matches the minimum
number of times possible, so the pattern
/\*.*?\*/
does the right thing with the C comments. The meaning of the
various quantifiers is not otherwise changed, just the pre-
ferred number of matches. Do not confuse this use of ques-
tion mark with its use as a quantifier in its own right.
Because it has two uses, it can sometimes appear doubled, as
in
\d??\d
which matches one digit by preference, but can match two if
that is the only way the rest of the pattern matches.
If the PCRE_UNGREEDY option is set (an option which is not
available in Perl) then the quantifiers are not greedy by
default, but individual ones can be made greedy by following
them with a question mark. In other words, it inverts the
default behaviour.
When a parenthesized subpattern is quantified with a minimum
repeat count that is greater than 1 or with a limited max-
imum, more store is required for the compiled pattern, in
proportion to the size of the minimum or maximum.
If a pattern starts with .* or .{0,} and the PCRE_DOTALL
option (equivalent to Perl's /s) is set, thus allowing the .
to match newlines, then the pattern is implicitly anchored,
because whatever follows will be tried against every charac-
ter position in the subject string, so there is no point in
retrying the overall match at any position after the first.
PCRE treats such a pattern as though it were preceded by \A.
In cases where it is known that the subject string contains
no newlines, it is worth setting PCRE_DOTALL when the pat-
tern begins with .* in order to obtain this optimization, or
alternatively using ^ to indicate anchoring explicitly.
When a capturing subpattern is repeated, the value captured
is the substring that matched the final iteration. For exam-
ple, after
(tweedle[dume]{3}\s*)+
has matched "tweedledum tweedledee" the value of the cap-
tured substring is "tweedledee". However, if there are
nested capturing subpatterns, the corresponding captured
values may have been set in previous iterations. For exam-
ple, after
/(a|(b))+/
matches "aba" the value of the second captured substring is
"b".
BACK REFERENCES
Outside a character class, a backslash followed by a digit
greater than 0 (and possibly further digits) is a back
reference to a capturing subpattern earlier (i.e. to its
left) in the pattern, provided there have been that many
previous capturing left parentheses.
However, if the decimal number following the backslash is
less than 10, it is always taken as a back reference, and
causes an error only if there are not that many capturing
left parentheses in the entire pattern. In other words, the
parentheses that are referenced need not be to the left of
the reference for numbers less than 10. See the section
entitled "Backslash" above for further details of the han-
dling of digits following a backslash.
A back reference matches whatever actually matched the cap-
turing subpattern in the current subject string, rather than
anything matching the subpattern itself. So the pattern
(sens|respons)e and \1ibility
matches "sense and sensibility" and "response and responsi-
bility", but not "sense and responsibility". If caseful
matching is in force at the time of the back reference, then
the case of letters is relevant. For example,
((?i)rah)\s+\1
matches "rah rah" and "RAH RAH", but not "RAH rah", even
though the original capturing subpattern is matched case-
lessly.
There may be more than one back reference to the same sub-
pattern. If a subpattern has not actually been used in a
particular match, then any back references to it always
fail. For example, the pattern
(a|(bc))\2
always fails if it starts to match "a" rather than "bc".
Because there may be up to 99 back references, all digits
following the backslash are taken as part of a potential
back reference number. If the pattern continues with a digit
character, then some delimiter must be used to terminate the
back reference. If the PCRE_EXTENDED option is set, this can
be whitespace. Otherwise an empty comment can be used.
A back reference that occurs inside the parentheses to which
it refers fails when the subpattern is first used, so, for
example, (a\1) never matches. However, such references can
be useful inside repeated subpatterns. For example, the pat-
tern
(a|b\1)+
matches any number of "a"s and also "aba", "ababaa" etc. At
each iteration of the subpattern, the back reference matches
the character string corresponding to the previous itera-
tion. In order for this to work, the pattern must be such
that the first iteration does not need to match the back
reference. This can be done using alternation, as in the
example above, or by a quantifier with a minimum of zero.
ASSERTIONS
An assertion is a test on the characters following or
preceding the current matching point that does not actually
consume any characters. The simple assertions coded as \b,
\B, \A, \Z, \z, ^ and $ are described above. More compli-
cated assertions are coded as subpatterns. There are two
kinds: those that look ahead of the current position in the
subject string, and those that look behind it.
An assertion subpattern is matched in the normal way, except
that it does not cause the current matching position to be
changed. Lookahead assertions start with (?= for positive
assertions and (?! for negative assertions. For example,
\w+(?=;)
matches a word followed by a semicolon, but does not include
the semicolon in the match, and
foo(?!bar)
matches any occurrence of "foo" that is not followed by
"bar". Note that the apparently similar pattern
(?!foo)bar
does not find an occurrence of "bar" that is preceded by
something other than "foo"; it finds any occurrence of "bar"
whatsoever, because the assertion (?!foo) is always true
when the next three characters are "bar". A lookbehind
assertion is needed to achieve this effect.
Lookbehind assertions start with (?<= for positive asser-
tions and (?<! for negative assertions. For example,
(?<!foo)bar
does find an occurrence of "bar" that is not preceded by
"foo". The contents of a lookbehind assertion are restricted
such that all the strings it matches must have a fixed
length. However, if there are several alternatives, they do
not all have to have the same fixed length. Thus
(?<=bullock|donkey)
is permitted, but
(?<!dogs?|cats?)
causes an error at compile time. Branches that match dif-
ferent length strings are permitted only at the top level of
a lookbehind assertion. This is an extension compared with
Perl 5.005, which requires all branches to match the same
length of string. An assertion such as
(?<=ab(c|de))
is not permitted, because its single top-level branch can
match two different lengths, but it is acceptable if rewrit-
ten to use two top-level branches:
(?<=abc|abde)
The implementation of lookbehind assertions is, for each
alternative, to temporarily move the current position back
by the fixed width and then try to match. If there are
insufficient characters before the current position, the
match is deemed to fail. Lookbehinds in conjunction with
once-only subpatterns can be particularly useful for match-
ing at the ends of strings; an example is given at the end
of the section on once-only subpatterns.
Several assertions (of any sort) may occur in succession.
For example,
(?<=\d{3})(?<!999)foo
matches "foo" preceded by three digits that are not "999".
Furthermore, assertions can be nested in any combination.
For example,
(?<=(?<!foo)bar)baz
matches an occurrence of "baz" that is preceded by "bar"
which in turn is not preceded by "foo".
Assertion subpatterns are not capturing subpatterns, and may
not be repeated, because it makes no sense to assert the
same thing several times. If an assertion contains capturing
subpatterns within it, these are always counted for the pur-
poses of numbering the capturing subpatterns in the whole
pattern. Substring capturing is carried out for positive
assertions, but it does not make sense for negative asser-
tions.
Assertions count towards the maximum of 200 parenthesized
subpatterns.
ONCE-ONLY SUBPATTERNS
With both maximizing and minimizing repetition, failure of
what follows normally causes the repeated item to be re-
evaluated to see if a different number of repeats allows the
rest of the pattern to match. Sometimes it is useful to
prevent this, either to change the nature of the match, or
to cause it fail earlier than it otherwise might, when the
author of the pattern knows there is no point in carrying
on.
Consider, for example, the pattern \d+foo when applied to
the subject line
123456bar
After matching all 6 digits and then failing to match "foo",
the normal action of the matcher is to try again with only 5
digits matching the \d+ item, and then with 4, and so on,
before ultimately failing. Once-only subpatterns provide the
means for specifying that once a portion of the pattern has
matched, it is not to be re-evaluated in this way, so the
matcher would give up immediately on failing to match "foo"
the first time. The notation is another kind of special
parenthesis, starting with (?> as in this example:
(?>\d+)bar
This kind of parenthesis "locks up" the part of the pattern
it contains once it has matched, and a failure further into
the pattern is prevented from backtracking into it. Back-
tracking past it to previous items, however, works as nor-
mal.
An alternative description is that a subpattern of this type
matches the string of characters that an identical stan-
dalone pattern would match, if anchored at the current point
in the subject string.
Once-only subpatterns are not capturing subpatterns. Simple
cases such as the above example can be thought of as a max-
imizing repeat that must swallow everything it can. So,
while both \d+ and \d+? are prepared to adjust the number of
digits they match in order to make the rest of the pattern
match, (?>\d+) can only match an entire sequence of digits.
This construction can of course contain arbitrarily compli-
cated subpatterns, and it can be nested.
Once-only subpatterns can be used in conjunction with look-
behind assertions to specify efficient matching at the end
of the subject string. Consider a simple pattern such as
abcd$
when applied to a long string which does not match it.
Because matching proceeds from left to right, PCRE will look
for each "a" in the subject and then see if what follows
matches the rest of the pattern. If the pattern is specified
as
^.*abcd$
then the initial .* matches the entire string at first, but
when this fails, it backtracks to match all but the last
character, then all but the last two characters, and so on.
Once again the search for "a" covers the entire string, from
right to left, so we are no better off. However, if the pat-
tern is written as
^(?>.*)(?<=abcd)
then there can be no backtracking for the .* item; it can
match only the entire string. The subsequent lookbehind
assertion does a single test on the last four characters. If
it fails, the match fails immediately. For long strings,
this approach makes a significant difference to the process-
ing time.
CONDITIONAL SUBPATTERNS
It is possible to cause the matching process to obey a sub-
pattern conditionally or to choose between two alternative
subpatterns, depending on the result of an assertion, or
whether a previous capturing subpattern matched or not. The
two possible forms of conditional subpattern are
(?(condition)yes-pattern)
(?(condition)yes-pattern|no-pattern)
If the condition is satisfied, the yes-pattern is used; oth-
erwise the no-pattern (if present) is used. If there are
more than two alternatives in the subpattern, a compile-time
error occurs.
There are two kinds of condition. If the text between the
parentheses consists of a sequence of digits, then the con-
dition is satisfied if the capturing subpattern of that
number has previously matched. Consider the following pat-
tern, which contains non-significant white space to make it
more readable (assume the PCRE_EXTENDED option) and to
divide it into three parts for ease of discussion:
( \( )? [^()]+ (?(1) \) )
The first part matches an optional opening parenthesis, and
if that character is present, sets it as the first captured
substring. The second part matches one or more characters
that are not parentheses. The third part is a conditional
subpattern that tests whether the first set of parentheses
matched or not. If they did, that is, if subject started
with an opening parenthesis, the condition is true, and so
the yes-pattern is executed and a closing parenthesis is
required. Otherwise, since no-pattern is not present, the
subpattern matches nothing. In other words, this pattern
matches a sequence of non-parentheses, optionally enclosed
in parentheses.
If the condition is not a sequence of digits, it must be an
assertion. This may be a positive or negative lookahead or
lookbehind assertion. Consider this pattern, again contain-
ing non-significant white space, and with the two alterna-
tives on the second line:
(?(?=[^a-z]*[a-z])
\d{2}[a-z]{3}-\d{2} | \d{2}-\d{2}-\d{2} )
The condition is a positive lookahead assertion that matches
an optional sequence of non-letters followed by a letter. In
other words, it tests for the presence of at least one
letter in the subject. If a letter is found, the subject is
matched against the first alternative; otherwise it is
matched against the second. This pattern matches strings in
one of the two forms dd-aaa-dd or dd-dd-dd, where aaa are
letters and dd are digits.
COMMENTS
The sequence (?# marks the start of a comment which
continues up to the next closing parenthesis. Nested
parentheses are not permitted. The characters that make up a
comment play no part in the pattern matching at all.
If the PCRE_EXTENDED option is set, an unescaped # character
outside a character class introduces a comment that contin-
ues up to the next newline character in the pattern.
PERFORMANCE
Certain items that may appear in patterns are more efficient
than others. It is more efficient to use a character class
like [aeiou] than a set of alternatives such as (a|e|i|o|u).
In general, the simplest construction that provides the
required behaviour is usually the most efficient. Jeffrey
Friedl's book contains a lot of discussion about optimizing
regular expressions for efficient performance.
When a pattern begins with .* and the PCRE_DOTALL option is
set, the pattern is implicitly anchored by PCRE, since it
can match only at the start of a subject string. However, if
PCRE_DOTALL is not set, PCRE cannot make this optimization,
because the . metacharacter does not then match a newline,
and if the subject string contains newlines, the pattern may
match from the character immediately following one of them
instead of from the very start. For example, the pattern
(.*) second
matches the subject "first\nand second" (where \n stands for
a newline character) with the first captured substring being
"and". In order to do this, PCRE has to retry the match
starting after every newline in the subject.
If you are using such a pattern with subject strings that do
not contain newlines, the best performance is obtained by
setting PCRE_DOTALL, or starting the pattern with ^.* to
indicate explicit anchoring. That saves PCRE from having to
scan along the subject looking for a newline to restart at.
Regular expressions are used for complex string manipulation in PHP. The functions that support regular expressions are:
These functions all take a regular expression string as their first argument. PHP uses the POSIX extended regular expressions as defined by POSIX 1003.2. For a full description of POSIX regular expressions see the regex man pages included in the regex directory in the PHP distribution. It's in manpage format, so you'll want to do something along the lines of man /usr/local/src/regex/regex.7 in order to read it.
Example 1. Regular Expression Examples
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Searches a string for matches to the regular expression given in pattern.
If matches are found for parenthesized substrings of pattern and the function is called with the third argument regs, the matches will be stored in the elements of the array regs. $regs[1] will contain the substring which starts at the first left parenthesis; $regs[2] will contain the substring starting at the second, and so on. $regs[0] will contain a copy of string.
If ereg() finds any matches at all, $regs will be filled with exactly ten elements, even though more or fewer than ten parenthesized substrings may actually have matched. This has no effect on ereg()'s ability to match more substrings. If no matches are found, $regs will not be altered by ereg().
Searching is case sensitive.
Returns true if a match for pattern was found in string, or false if no matches were found or an error occurred.
The following code snippet takes a date in ISO format (YYYY-MM-DD) and prints it in DD.MM.YYYY format:
See also eregi(), ereg_replace(), and eregi_replace().
This function scans string for matches to pattern, then replaces the matched text with replacement.
The modified string is returned. (Which may mean that the original string is returned if there are no matches to be replaced.)
If pattern contains parenthesized substrings, replacement may contain substrings of the form \\digit, which will be replaced by the text matching the digit'th parenthesized substring; \\0 will produce the entire contents of string. Up to nine substrings may be used. Parentheses may be nested, in which case they are counted by the opening parenthesis.
If no matches are found in string, then string will be returned unchanged.
For example, the following code snippet prints "This was a test" three times:
One thing to take note of is that if you use an integer value as the replacement parameter, you may not get the results you expect. This is because ereg_replace() will interpret the number as the ordinal value of a character, and apply that. For instance:
Example 2. ereg_replace() Example
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See also ereg(), eregi(), and eregi_replace().
This function is identical to ereg() except that this ignores case distinction when matching alphabetic characters.
See also ereg(), ereg_replace(), and eregi_replace().
This function is identical to ereg_replace() except that this ignores case distinction when matching alphabetic characters.
See also ereg(), eregi(), and ereg_replace().
Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the regular expression pattern. If limit is set, the returned array will contain a maximum of limit elements with the last element containing the whole rest of string. If an error occurs, split() returns false.
To split off the first four fields from a line from /etc/passwd:
To parse a date which may be delimited with slashes, dots, or hyphens:
Note that pattern is case-sensitive.
Note that if you don't require the power of regular expressions, it is faster to use explode(), which doesn't incur the overhead of the regular expression engine.
For users looking for a way to emulate perl's $chars = split('', $str) behaviour, please see the examples for preg_split().
Please note that pattern is a regular expression. If you want to split on any of the characters which are considered special by regular expressions, you'll need to escape them first. If you think split() (or any other regex function, for that matter) is doing something weird, please read the file regex.7, included in the regex/ subdirectory of the PHP distribution. It's in manpage format, so you'll want to do something along the lines of man /usr/local/src/regex/regex.7 in order to read it.
This function is identical to split() except that this ignores case distinction when matching alphabetic characters.
Returns a valid regular expression which will match string, ignoring case. This expression is string with each character converted to a bracket expression; this bracket expression contains that character's uppercase and lowercase form if applicable, otherwise it contains the original character twice.
[Ff][Oo][Oo][ ][Bb][Aa][Rr] |
This can be used to achieve case insensitive pattern matching in products which support only case sensitive regular expressions.
The Satellite extension is used for accessing CORBA objects. You will need to set the idl_directory= entry in php.ini to a path where you store all IDL files you use.
This class provides access to a CORBA object. The ior parameter should be a string containing the IOR (Interoperable Object Reference) that identifies the remote object.
This class represents the enumeration identified with the id parameter. The id can be either the name of the enumeration (e.g "MyEnum"), or the full repository id (e.g. "IDL:MyEnum:1.0").
This class represents the structure identified with the id parameter. The id can be either the name of the struct (e.g "MyStruct"), or the full repository id (e.g. "IDL:MyStruct:1.0").
Example 2. PHP code for accessing MyStruct
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(PHP 4 >= 4.0.3)
satellite_caught_exception -- See if an exception was caught from the previous functionReturn a repository id string. (E.g. "IDL:MyException:1.0".) For example usage see satellite_caught_exception().
This module provides semaphore functions using System V semaphores. Semaphores may be used to provide exclusive access to resources on the current machine, or to limit the number of processes that may simultaneously use a resource.
This module provides also shared memory functions using System V shared memory. Shared memory may be used to provide access to global variables. Different httpd-daemons and even other programs (such as Perl, C, ...) are able to access this data to provide a global data-exchange. Remember, that shared memory is NOT safe against simultaneous access. Use semaphores for synchronization.
Table 1. Limits of Shared Memory by the Unix OS
| SHMMAX | max size of shared memory, normally 131072 bytes |
| SHMMIN | minimum size of shared memory, normally 1 byte |
| SHMMNI | max amount of shared memory segments on a system, normally 100 |
| SHMSEG | max amount of shared memory segments per process, normally 6 |
Note: These functions do not work on Windows systems.
Returns: A positive semaphore identifier on success, or false on error.
Sem_get() returns an id that can be used to access the System V semaphore with the given key. The semaphore is created if necessary using the permission bits specified in perm (defaults to 0666). The number of processes that can acquire the semaphore simultaneously is set to max_acquire (defaults to 1). Actually this value is set only if the process finds it is the only process currently attached to the semaphore.
A second call to sem_get() for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore.
See also: sem_acquire() and sem_release().
Note: This function does not work on Windows systems
Returns: true on success, false on error.
Sem_acquire() blocks (if necessary) until the semaphore can be acquired. A process attempting to acquire a semaphore which it has already acquired will block forever if acquiring the semaphore would cause its max_acquire value to be exceeded.
After processing a request, any semaphores acquired by the process but not explicitly released will be released automatically and a warning will be generated.
See also: sem_get() and sem_release().
Returns: true on success, false on error.
Sem_release() releases the semaphore if it is currently acquired by the calling process, otherwise a warning is generated.
After releasing the semaphore, sem_acquire() may be called to re-acquire it.
See also: sem_get() and sem_acquire().
Note: This function does not work on Windows systems
Shm_attach() returns an id that that can be used to access the System V shared memory with the given key, the first call creates the shared memory segment with mem_size (default: sysvshm.init_mem in the configuration file, otherwise 10000 bytes) and the optional perm-bits (default: 0666).
A second call to shm_attach() for the same key will return a different shared memory identifier, but both identifiers access the same underlying shared memory. Memsize and perm will be ignored.
Note: This function does not work on Windows systems
Shm_detach() disconnects from the shared memory given by the shm_identifier created by shm_attach(). Remember, that shared memory still exist in the Unix system and the data is still present.
Removes shared memory from Unix systems. All data will be destroyed.
Note: This function does not work on Windows systems
Inserts or updates a variable with a given variable_key. All variable-types (double, int, string, array) are supported.
Note: This function does not work on Windows systems
Shm_get_var() returns the variable with a given variable_key. The variable is still present in the shared memory.
Note: This function does not work on Windows systems
SESAM/SQL-Server is a mainframe database system, developed by Fujitsu Siemens Computers, Germany. It runs on high-end mainframe servers using the operating system BS2000/OSD.
In numerous productive BS2000 installations, SESAM/SQL-Server has proven ...
the ease of use of Java-, Web- and client/server connectivity,
the capability to work with an availability of more than 99.99%,
the ability to manage tens and even hundreds of thousands of users.
Now there is a PHP3 SESAM interface available which allows database operations via PHP-scripts.
Configuration notes: There is no standalone support for the PHP SESAM interface, it works only as an integrated Apache module. In the Apache PHP module, this SESAM interface is configured using Apache directives.
Table 1. SESAM Configuration directives
Directive Meaning php3_sesam_oml Name of BS2000 PLAM library containing the loadable SESAM driver modules. Required for using SESAM functions. Example:
php3_sesam_configfile Name of SESAM application configuration file. Required for using SESAM functions. Example:
It will usually contain a configuration like (see SESAM reference manual):php3_sesam_messagecatalog Name of SESAM message catalog file. In most cases, this directive is not neccessary. Only if the SESAM message file is not installed in the system's BS2000 message file table, it can be set with this directive. Example:
In addition to the configuration of the PHP/SESAM interface, you have to configure the SESAM-Database server itself on your mainframe as usual. That means:
starting the SESAM database handler (DBH), and
connecting the databases with the SESAM database handler
To get a connection between a PHP script and the database handler, the CNF and NAM parameters of the selected SESAM configuration file must match the id of the started database handler.
In case of distributed databases you have to start a SESAM/SQL-DCN agent with the distribution table including the host and database names.
The communication between PHP (running in the POSIX subsystem) and the database handler (running outside the POSIX subsystem) is realized by a special driver module called SQLSCI and SESAM connection modules using common memory. Because of the common memory access, and because PHP is a static part of the web server, database accesses are very fast, as they do not require remote accesses via ODBC, JDBC or UTM.
Only a small stub loader (SESMOD) is linked with PHP, and the SESAM connection modules are pulled in from SESAM's OML PLAM library. In the configuration, you must tell PHP the name of this PLAM library, and the file link to use for the SESAM configuration file (As of SESAM V3.0, SQLSCI is available in the SESAM Tool Library, which is part of the standard distribution).
Because the SQL command quoting for single quotes uses duplicated single quotes (as opposed to a single quote preceded by a backslash, used in some other databases), it is advisable to set the PHP configuration directives php3_magic_quotes_gpc and php3_magic_quotes_sybase to On for all PHP scripts using the SESAM interface.
Runtime considerations: Because of limitations of the BS2000 process model, the driver can be loaded only after the Apache server has forked off its server child processes. This will slightly slow down the initial SESAM request of each child, but subsequent accesses will respond at full speed.
When explicitly defining a Message Catalog for SESAM, that catalog will be loaded each time the driver is loaded (i.e., at the initial SESAM request). The BS2000 operating system prints a message after successful load of the message catalog, which will be sent to Apache's error_log file. BS2000 currently does not allow suppression of this message, it will slowly fill up the log.
Make sure that the SESAM OML PLAM library and SESAM configuration file are readable by the user id running the web server. Otherwise, the server will be unable to load the driver, and will not allow to call any SESAM functions. Also, access to the database must be granted to the user id under which the Apache server is running. Otherwise, connections to the SESAM database handler will fail.
Cursor Types: The result cursors which are allocated for SQL "select type" queries can be either "sequential" or "scrollable". Because of the larger memory overhead needed by "scrollable" cursors, the default is "sequential".
When using "scrollable" cursors, the cursor can be freely positioned on the result set. For each "scrollable" query, there are global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT) and the scrolling offset which can either be set once by sesam_seek_row() or each time when fetching a row using sesam_fetch_row(). When fetching a row using a "scrollable" cursor, the following post-processing is done for the global default values for the scrolling type and scrolling offset:
Table 2. Scrolled Cursor Post-Processing
Scroll Type Action SESAM_SEEK_NEXT none SESAM_SEEK_PRIOR none SESAM_SEEK_FIRST set scroll type to SESAM_SEEK_NEXT SESAM_SEEK_LAST set scroll type to SESAM_SEEK_PRIOR SESAM_SEEK_ABSOLUTE Auto-Increment internal offset value SESAM_SEEK_RELATIVE none. (maintain global default offset value, which allows for, e.g., fetching each 10th row backwards)
Porting note: Because in the PHP world it is natural to start indexes at zero (rather than 1), some adaptions have been made to the SESAM interface: whenever an indexed array is starting with index 1 in the native SESAM interface, the PHP interface uses index 0 as a starting point. E.g., when retrieving columns with sesam_fetch_row(), the first column has the index 0, and the subsequent columns have indexes up to (but not including) the column count ($array["count"]). When porting SESAM applications from other high level languages to PHP, be aware of this changed interface. Where appropriate, the description of the respective php sesam functions include a note that the index is zero based.
Security concerns: When allowing access to the SESAM databases, the web server user should only have as little privileges as possible. For most databases, only read access privilege should be granted. Depending on your usage scenario, add more access rights as you see fit. Never allow full control to any database for any user from the 'net! Restrict access to php scripts which must administer the database by using password control and/or SSL security.
Migration from other SQL databases: No two SQL dialects are ever 100% compatible. When porting SQL applications from other database interfaces to SESAM, some adaption may be required. The following typical differences should be noted:
Vendor specific data types
Some vendor specific data types may have to be replaced by standard SQL data types (e.g., TEXT could be replaced by VARCHAR(max. size)).
Keywords as SQL identifiers
In SESAM (as in standard SQL), such identifiers must be enclosed in double quotes (or renamed).
Display length in data types
SESAM data types have a precision, not a display length. Instead of int(4) (intended use: integers up to '9999'), SESAM requires simply int for an implied size of 31 bits. Also, the only datetime data types available in SESAM are: DATE, TIME(3) and TIMESTAMP(3).
SQL types with vendor-specific unsigned, zerofill, or auto_increment attributes
Unsigned and zerofill are not supported. Auto_increment is automatic (use "INSERT ... VALUES(*, ...)" instead of "... VALUES(0, ...)" to take advantage of SESAM-implied auto-increment.
int ... DEFAULT '0000'
Numeric variables must not be initialized with string constants. Use DEFAULT 0 instead. To initialize variables of the datetime SQL data types, the initialization string must be prefixed with the respective type keyword, as in: CREATE TABLE exmpl ( xtime timestamp(3) DEFAULT TIMESTAMP '1970-01-01 00:00:00.000' NOT NULL );
$count = xxxx_num_rows();
Some databases promise to guess/estimate the number of the rows in a query result, even though the returned value is grossly incorrect. SESAM does not know the number of rows in a query result before actually fetching them. If you REALLY need the count, try SELECT COUNT(...) WHERE ..., it will tell you the number of hits. A second query will (hopefully) return the results.
DROP TABLE thename;
In SESAM, in the DROP TABLE command, the table name must be either followed by the keyword RESTRICT or CASCADE. When specifying RESTRICT, an error is returned if there are dependent objects (e.g., VIEWs), while with CASCADE, dependent objects will be deleted along with the specified table.
Notes on the use of various SQL types: SESAM does not currently support the BLOB type. A future version of SESAM will have support for BLOB.
At the PHP interface, the following type conversions are automatically applied when retrieving SQL fields:
When retrieving a complete row, the result is returned as an array. Empty fields are not filled in, so you will have to check for the existence of the individual fields yourself (use isset() or empty() to test for empty fields). That allows more user control over the appearance of empty fields (than in the case of an empty string as the representation of an empty field).Table 3. SQL to PHP Type Conversions
SQL Type PHP Type SMALLINT, INTEGER "integer" NUMERIC, DECIMAL, FLOAT, REAL, DOUBLE "double" DATE, TIME, TIMESTAMP "string" VARCHAR, CHARACTER "string"
Support of SESAM's "multiple fields" feature: The special "multiple fields" feature of SESAM allows a column to consist of an array of fields. Such a "multiple field" column can be created like this:
and can be filled in using:
Note that (like in this case) leading empty sub-fields are ignored, and the filled-in values are collapsed, so that in the above example the result will appear as multi(1..2) instead of multi(2..3).
When retrieving a result row, "multiple columns" are accessed like "inlined" additional columns. In the example above, "pkey" will have the index 0, and the three "multi(1..3)" columns will be accessible as indices 1 through 3.
For specific SESAM details, please refer to the SESAM/SQL-Server documentation (english) or the SESAM/SQL-Server documentation (german), both available online, or use the respective manuals.
Returns TRUE if a connection to the SESAM database was made, or FALSE on error.
sesam_connect() establishes a connection to an SESAM database handler task. The connection is always "persistant" in the sense that only the very first invocation will actually load the driver from the configured SESAM OML PLAM library. Subsequent calls will reuse the driver and will immediately use the given catalog, schema, and user.
When creating a database, the "catalog" name is specified in the SESAM configuration directive //ADD-SQL-DATABASE-CATALOG-LIST ENTRY-1 = *CATALOG(CATALOG-NAME = catalogname,...)
The "schema" references the desired database schema (see SESAM handbook).
The "user" argument references one of the users which are allowed to access this "catalog" / "schema" combination. Note that "user" is completely independent from both the system's user id's and from HTTP user/password protection. It appears in the SESAM configuration only.
See also sesam_disconnect().
Returns: always TRUE.
sesam_disconnect() closes the logical link to a SESAM database (without actually disconnecting and unloading the driver).
Note that this isn't usually necessary, as the open connection is automatically closed at the end of the script's execution. Uncommitted data will be discarded, because an implicit sesam_rollback() is executed.
sesam_disconnect() will not close the persistent link, it will only invalidate the currently defined "catalog", "schema" and "user" triple, so that any sesam function called after sesam_disconnect() will fail.
See also: sesam_connect().
Returns: TRUE if the values are valid, and the settransaction() operation was successful, FALSE otherwise.
sesam_settransaction() overrides the default values for the "isolation level" and "read-only" transaction parameters (which are set in the SESAM configuration file), in order to optimize subsequent queries and guarantee database consistency. The overridden values are used for the next transaction only.
sesam_settransaction() can only be called before starting a transaction, not after the transaction has been started already.
To simplify the use in php scripts, the following constants have been predefined in php (see SESAM handbook for detailed explanation of the semantics):
Table 1. Valid values for "Isolation_Level" parameter
| Value | Constant | Meaning |
|---|---|---|
| 1 | SESAM_TXISOL_READ_UNCOMMITTED | Read Uncommitted |
| 2 | SESAM_TXISOL_READ_COMMITTED | Read Committed |
| 3 | SESAM_TXISOL_REPEATABLE_READ | Repeatable Read |
| 4 | SESAM_TXISOL_SERIALIZABLE | Serializable |
Table 2. Valid values for "Read_Only" parameter
| Value | Constant | Meaning |
|---|---|---|
| 0 | SESAM_TXREAD_READWRITE | Read/Write |
| 1 | SESAM_TXREAD_READONLY | Read-Only |
The values set by sesam_settransaction() will override the default setting specified in the SESAM configuration file.
Returns: TRUE on success, FALSE on errors
sesam_commit() commits any pending updates to the database.
Note that there is no "auto-commit" feature as in other databases, as it could lead to accidental data loss. Uncommitted data at the end of the current script (or when calling sesam_disconnect()) will be discarded by an implied sesam_rollback() call.
See also: sesam_rollback().
Returns: TRUE on success, FALSE on errors
sesam_rollback() discards any pending updates to the database. Also affected are result cursors and result descriptors.
At the end of each script, and as part of the sesam_disconnect() function, an implied sesam_rollback() is executed, discarding any pending changes to the database.
See also: sesam_commit().
Example 1. Discarding an update to the SESAM database
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Returns: A SESAM "result identifier" on success, or FALSE on error.
sesam_execimm() executes an "immediate" statement (i.e., a statement like UPDATE, INSERT or DELETE which returns no result, and has no INPUT or OUTPUT variables). "select type" queries can not be used with sesam_execimm(). Sets the affected_rows value for retrieval by the sesam_affected_rows() function.
Note that sesam_query() can handle both "immediate" and "select-type" queries. Use sesam_execimm() only if you know beforehand what type of statement will be executed. An attempt to use SELECT type queries with sesam_execimm() will return $err["sqlstate"] == "42SBW".
The returned "result identifier" can not be used for retrieving anything but the sesam_affected_rows(); it is only returned for symmetry with the sesam_query() function.
$stmt = "INSERT INTO mytable VALUES ('one', 'two')";
$result = sesam_execimm ($stmt);
$err = sesam_diagnostic();
print ("sqlstate = ".$err["sqlstate"]."\n".
"Affected rows = ".$err["rowcount"]." == ".
sesam_affected_rows($result)."\n");
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Returns: A SESAM "result identifier" on success, or FALSE on error.
A "result_id" resource is used by other functions to retrieve the query results.
sesam_query() sends a query to the currently active database on the server. It can execute both "immediate" SQL statements and "select type" queries. If an "immediate" statement is executed, then no cursor is allocated, and any subsequent sesam_fetch_row() or sesam_fetch_result() call will return an empty result (zero columns, indicating end-of-result). For "select type" statements, a result descriptor and a (scrollable or sequential, depending on the optional boolean scrollable parameter) cursor will be allocated. If scrollable is omitted, the cursor will be sequential.
When using "scrollable" cursors, the cursor can be freely positioned on the result set. For each "scrollable" query, there are global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT) and the scrolling offset which can either be set once by sesam_seek_row() or each time when fetching a row using sesam_fetch_row().
For "immediate" statements, the number of affected rows is saved for retrieval by the sesam_affected_rows() function.
See also: sesam_fetch_row() and sesam_fetch_result().
Example 1. Show all rows of the "phone" table as a html table
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After calling sesam_query() with a "select type" query, this function gives you the number of columns in the result. Returns an integer describing the total number of columns (aka. fields) in the current result_id result set or FALSE on error.
For "immediate" statements, the value zero is returned. The SESAM "multiple field" columns count as their respective dimension, i.e., a three-column "multiple field" counts as three columns.
See also: sesam_query() and sesam_field_array() for a way to distinguish between "multiple field" columns and regular columns.
Returns the name of a field (i.e., the column name) in the result set, or FALSE on error.
For "immediate" queries, or for dynamic columns, an empty string is returned.
Note: The column index is zero-based, not one-based as in SESAM.
See also: sesam_field_array(). It provides an easier interface to access the column names and types, and allows for detection of "multiple fields".
Returns an associative array of status and return codes for the last SQL query/statement/command. Elements of the array are:
Table 1. Status information returned by sesam_diagnostic()
| Element | Contents |
|---|---|
| $array["sqlstate"] | 5 digit SQL return code (see the SESAM manual for the description of the possible values of SQLSTATE) |
| $array["rowcount"] | number of affected rows in last update/insert/delete (set after "immediate" statements only) |
| $array["errmsg"] | "human readable" error message string (set after errors only) |
| $array["errcol"] | error column number of previous error (0-based; or -1 if undefined. Set after errors only) |
| $array["errlin"] | error line number of previous error (0-based; or -1 if undefined. Set after errors only) |
In the following example, a syntax error (E SEW42AE ILLEGAL CHARACTER) is displayed by including the offending SQL statement and pointing to the error location:
Example 1. Displaying SESAM error messages with error position
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See also: sesam_errormsg() for simple access to the error string only
Returns a mixed array with the query result entries, optionally limited to a maximum of max_rows rows. Note that both row and column indexes are zero-based.
Table 1. Mixed result set returned by sesam_fetch_result()
| Array Element | Contents |
|---|---|
| int $arr["count"] | number of columns in result set (or zero if this was an "immediate" query) |
| int $arr["rows"] | number of rows in result set (between zero and max_rows) |
| boolean $arr["truncated"] | TRUE if the number of rows was at least max_rows, FALSE otherwise. Note that even when this is TRUE, the next sesam_fetch_result() call may return zero rows because there are no more result entries. |
| mixed $arr[col][row] | result data for all the fields at row(row) and column(col), (where the integer index row is between 0 and $arr["rows"]-1, and col is between 0 and $arr["count"]-1). Fields may be empty, so you must check for the existence of a field by using the php isset() function. The type of the returned fields depend on the respective SQL type declared for its column (see SESAM overview for the conversions applied). SESAM "multiple fields" are "inlined" and treated like a sequence of columns. |
See also: sesam_fetch_row(), and sesam_field_array() to check for "multiple fields". See the description of the sesam_query() function for a complete example using sesam_fetch_result().
result_id is a valid result id returned by sesam_query().
Returns the number of rows affected by a query associated with result_id.
The sesam_affected_rows() function can only return useful values when used in combination with "immediate" SQL statements (updating operations like INSERT, UPDATE and DELETE) because SESAM does not deliver any "affected rows" information for "select type" queries. The number returned is the number of affected rows.
See also: sesam_query() and sesam_execimm()
Returns the SESAM error message associated with the most recent SESAM error.
See also: sesam_diagnostic() for the full set of SESAM SQL status information
result_id is a valid result id returned by sesam_query().
Returns a mixed associative/indexed array with meta information (column name, type, precision, ...) about individual columns of the result after the query associated with result_id.
Table 1. Mixed result set returned by sesam_field_array()
| Array Element | Contents |
|---|---|
| int $arr["count"] | Total number of columns in result set (or zero if this was an "immediate" query). SESAM "multiple fields" are "inlined" and treated like the respective number of columns. |
| string $arr[col]["name"] | column name for column(col), where col is between 0 and $arr["count"]-1. The returned value can be the empty string (for dynamically computed columns). SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same column name. |
| string $arr[col]["count"] | The "count" attribute describes the repetition factor when the column has been declared as a "multiple field". Usually, the "count" attribute is 1. The first column of a "multiple field" column however contains the number of repetitions (the second and following column of the "multiple field" contain a "count" attribute of 1). This can be used to detect "multiple fields" in the result set. See the example shown in the sesam_query() description for a sample use of the "count" attribute. |
| string $arr[col]["type"] |
php variable type of the data for
column(col), where col
is between 0 and $arr["count"]-1. The
returned value can be one of
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| string $arr[col]["sqltype"] |
SQL variable type of the column data for
column(col), where col is
between 0 and $arr["count"]-1. The returned
value can be one of
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| string $arr[col]["length"] | The SQL "length" attribute of the SQL variable in column(col), where col is between 0 and $arr["count"]-1. The "length" attribute is used with "CHARACTER" and "VARCHAR" SQL types to specify the (maximum) length of the string variable. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same length attribute. |
| string $arr[col]["precision"] | The "precision" attribute of the SQL variable in column(col), where col is between 0 and $arr["count"]-1. The "precision" attribute is used with numeric and time data types. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same precision attribute. |
| string $arr[col]["scale"] | The "scale" attribute of the SQL variable in column(col), where col is between 0 and $arr["count"]-1. The "scale" attribute is used with numeric data types. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same scale attribute. |
See the sesam_query() function for an example of the sesam_field_array() use.
Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.
The number of columns in the result set is returned in an associative array element $array["count"]. Because some of the result columns may be empty, the count() function can not be used on the result row returned by sesam_fetch_row().
result_id is a valid result id returned by sesam_query() (select type queries only!).
whence is an optional parameter for a fetch operation on "scrollable" cursors, which can be set to the following predefined constants:
Table 1. Valid values for "whence" parameter
| Value | Constant | Meaning |
|---|---|---|
| 0 | SESAM_SEEK_NEXT | read sequentially (after fetch, the internal default is set to SESAM_SEEK_NEXT) |
| 1 | SESAM_SEEK_PRIOR | read sequentially backwards (after fetch, the internal default is set to SESAM_SEEK_PRIOR) |
| 2 | SESAM_SEEK_FIRST | rewind to first row (after fetch, the default is set to SESAM_SEEK_NEXT) |
| 3 | SESAM_SEEK_LAST | seek to last row (after fetch, the default is set to SESAM_SEEK_PRIOR) |
| 4 | SESAM_SEEK_ABSOLUTE | seek to absolute row number given as offset (Zero-based. After fetch, the internal default is set to SESAM_SEEK_ABSOLUTE, and the internal offset value is auto-incremented) |
| 5 | SESAM_SEEK_RELATIVE | seek relative to current scroll position, where offset can be a positive or negative offset value. |
When using "scrollable" cursors, the cursor can be freely positioned on the result set. If the whence parameter is omitted, the global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT, and settable by sesam_seek_row()) are used. If whence is supplied, its value replaces the global default.
offset is an optional parameter which is only evaluated (and required) if whence is either SESAM_SEEK_RELATIVE or SESAM_SEEK_ABSOLUTE. This parameter is only valid for "scrollable" cursors.
sesam_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array (indexed by values between 0 and $array["count"]-1). Fields may be empty, so you must check for the existence of a field by using the php isset() function. The type of the returned fields depend on the respective SQL type declared for its column (see SESAM overview for the conversions applied). SESAM "multiple fields" are "inlined" and treated like a sequence of columns.
Subsequent calls to sesam_fetch_row() would return the next (or prior, or n'th next/prior, depending on the scroll attributes) row in the result set, or FALSE if there are no more rows.
Example 1. SESAM fetch rows
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See also: sesam_fetch_array() which returns an associative array, and sesam_fetch_result() which returns many rows per invocation.
Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.
sesam_fetch_array() is an alternative version of sesam_fetch_row(). Instead of storing the data in the numeric indices of the result array, it stores the data in associative indices, using the field names as keys.
result_id is a valid result id returned by sesam_query() (select type queries only!).
For the valid values of the optional whenceand offset parameters, see the sesam_fetch_row() function for details.
sesam_fetch_array() fetches one row of data from the result associated with the specified result identifier. The row is returned as an associative array. Each result column is stored with an associative index equal to its column (aka. field) name. The column names are converted to lower case.
Columns without a field name (e.g., results of arithmetic operations) and empty fields are not stored in the array. Also, if two or more columns of the result have the same column names, the later column will take precedence. In this situation, either call sesam_fetch_row() or make an alias for the column.
A special handling allows fetching "multiple field" columns (which would otherwise all have the same column names). For each column of a "multiple field", the index name is constructed by appending the string "(n)" where n is the sub-index of the multiple field column, ranging from 1 to its declared repetition factor. The indices are NOT zero based, in order to match the nomenclature used in the respective query syntax. For a column declared as:
the associative indices used for the individual "multiple field" columns would be "multi(1)", "multi(2)", and "multi(3)" respectively.Subsequent calls to sesam_fetch_array() would return the next (or prior, or n'th next/prior, depending on the scroll attributes) row in the result set, or FALSE if there are no more rows.
Example 1. SESAM fetch array
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See also: sesam_fetch_row() which returns an indexed array.
result_id is a valid result id (select type queries only, and only if a "scrollable" cursor was requested when calling sesam_query()).
whence sets the global default value for the scrolling type, it specifies the scroll type to use in subsequent fetch operations on "scrollable" cursors, which can be set to the following predefined constants:
Table 1. Valid values for "whence" parameter
| Value | Constant | Meaning |
|---|---|---|
| 0 | SESAM_SEEK_NEXT | read sequentially |
| 1 | SESAM_SEEK_PRIOR | read sequentially backwards |
| 2 | SESAM_SEEK_FIRST | fetch first row (after fetch, the default is set to SESAM_SEEK_NEXT) |
| 3 | SESAM_SEEK_LAST | fetch last row (after fetch, the default is set to SESAM_SEEK_PRIOR) |
| 4 | SESAM_SEEK_ABSOLUTE | fetch absolute row number given as offset (Zero-based. After fetch, the default is set to SESAM_SEEK_ABSOLUTE, and the offset value is auto-incremented) |
| 5 | SESAM_SEEK_RELATIVE | fetch relative to current scroll position, where offset can be a positive or negative offset value (this also sets the default "offset" value for subsequent fetches). |
offset is an optional parameter which is only evaluated (and required) if whence is either SESAM_SEEK_RELATIVE or SESAM_SEEK_ABSOLUTE.
Session support in PHP consists of a way to preserve certain data across subsequent accesses. This enables you to build more customized applications and increase the appeal of your web site.
If you are familiar with the session management of PHPLIB, you will notice that some concepts are similar to PHP's session support.
A visitor accessing your web site is assigned an unique id, the so-called session id. This is either stored in a cookie on the user side or is propagated in the URL.
The session support allows you to register arbitrary numbers of variables to be preserved across requests. When a visitor accesses your site, PHP will check automatically (if session.auto_start is set to 1) or on your request (explicitly through session_start() or implicitly through session_register()) whether a specific session id has been sent with the request. If this is the case, the prior saved environment is recreated.
All registered variables are serialized after the request finishes. Registered variables which are undefined are marked as being not defined. On subsequent accesses, these are not defined by the session module unless the user defines them later.
The track_vars and register_globals configuration settings influence how the session variables get stored and restored.
Note: As of PHP 4.0.3, track_vars is always turned on.
If track_vars is enabled and register_globals is disabled, only members of the global associative array $HTTP_SESSION_VARS can be registered as session variables. The restored session variables will only be available in the array $HTTP_SESSION_VARS.
Example 1. Registering a variable with track_vars enabled
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If register_globals is enabled, then all global variables can be registered as session variables and the session variables will be restored to corresponding global variables.
Example 2. Registering a variable with register_globals enabled
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If both track_vars and register_globals are enabled, then the globals variables and the $HTTP_SESSION_VARS entries will reference the same value.
There are two methods to propagate a session id:
Cookies
URL parameter
The session module supports both methods. Cookies are optimal, but since they are not reliable (clients are not bound to accept them), we cannot rely on them. The second method embeds the session id directly into URLs.
PHP is capable of doing this transparently when compiled with --enable-trans-sid. If you enable this option, relative URIs will be changed to contain the session id automatically. Alternatively, you can use the constant SID which is defined, if the client did not send the appropriate cookie. SID is either of the form session_name=session_id or is an empty string.
The following example demonstrates how to register a variable, and how to link correctly to another page using SID.
Example 3. Counting the number of hits of a single user
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The <?=SID?> is not necessary, if --enable-trans-sid was used to compile PHP.
To implement database storage, or any other storage method, you will need to use session_set_save_handler() to create a set of user-level storage functions.
The session management system supports a number of configuration options which you can place in your php.ini file. We will give a short overview.
session.save_handler defines the name of the handler which is used for storing and retrieving data associated with a session. Defaults to files.
session.save_path defines the argument which is passed to the save handler. If you choose the default files handler, this is the path where the files are created. Defaults to /tmp.
session.name specifies the name of the session which is used as cookie name. It should only contain alphanumeric characters. Defaults to PHPSESSID.
session.auto_start specifies whether the session module starts a session automatically on request startup. Defaults to 0 (disabled).
session.cookie_lifetime specifies the lifetime of the cookie in seconds which is sent to the browser. The value 0 means "until the browser is closed." Defaults to 0.
session.serialize_handler defines the name of the handler which is used to serialize/deserialize data. Currently, a PHP internal format (name php) and WDDX is supported (name wddx). WDDX is only available, if PHP is compiled with WDDX support. Defaults to php.
session.gc_probability specifies the probability that the gc (garbage collection) routine is started on each request in percent. Defaults to 1.
session.gc_maxlifetime specifies the number of seconds after which data will be seen as 'garbage' and cleaned up.
session.referer_check contains the substring you want to check each HTTP Referer for. If the Referer was sent by the client and the substring was not found, the embedded session id will be marked as invalid. Defaults to the empty string.
session.entropy_file gives a path to an external resource (file) which will be used as an additional entropy source in the session id creation process. Examples are /dev/random or /dev/urandom which are available on many Unix systems.
session.entropy_length specifies the number of bytes which will be read from the file specified above. Defaults to 0 (disabled).
session.use_cookies specifies whether the module will use cookies to store the session id on the client side. Defaults to 1 (enabled).
session.cookie_path specifies path to set in session_cookie. Defaults to /.
session.cookie_domain specifies domain to set in session_cookie. Default is none at all.
session.cache_limiter specifies cache control method to use for session pages (nocache/private/public). Defaults to nocache.
session.cache_expire specifies time-to-live for cached session pages in minutes, this has no effect for nocache limiter. Defaults to 180.
Note: Session handling was added in PHP 4.0.
session_start() creates a session (or resumes the current one based on the session id being passed via a GET variable or a cookie).
This function always returns true.
Note: This function was added in PHP 4.0.
session_destroy() destroys all of the data associated with the current session.
This function returns true on success and false on failure to destroy the session data.
session_name() returns the name of the current session. If name is specified, the name of the current session is changed to its value.
The session name references the session id in cookies and URLs. It should contain only alphanumeric characters; it should be short and descriptive (i.e. for users with enabled cookie warnings). The session name is reset to the default value stored in session.name at request startup time. Thus, you need to call session_name() for every request (and before session_start() or session_register() are called).
Note: This function was added in PHP 4.0.
session_module_name() returns the name of the current session module. If module is specified, that module will be used instead.
Note: This function was added in PHP 4.0.
session_save_path() returns the path of the current directory used to save session data. If path is specified, the path to which data is saved will be changed.
Note: On some operating systems, you may want to specify a path on a filesystem that handles lots of small files efficiently. For example, on Linux, reiserfs may provide better performance than ext2fs.
Note: This function was added in PHP 4.0.
session_id() returns the session id for the current session. If id is specified, it will replace the current session id.
The constant SID can also be used to retrieve the current name and session id as a string suitable for adding to URLs.
session_register() variable number of arguments, any of which can be either a string holding the variable name or an array consisting of such variable names or other arrays. For each encountered variable name, session_register() registers the global variable named by it with the current session.
This function returns true when the variable is successfully registered with the session.
Note: This function was added in PHP 4.0.
session_unregister() unregisters (forgets) the global variable named name from the current session.
This function returns true when the variable is successfully unregistered from the session.
Note: This function was added in PHP 4.0.
session_is_registered() returns true if there is a variable with the name name registered in the current session.
Note: This function was added in PHP 4.0.
The session_get_cookie_params() function returns an array with the current session cookie information, the array contains the following items:
"lifetime" - The lifetime of the cookie.
"path" - The path where information is stored.
"domain" - The domain of the cookie.
Set cookie parameters defined in the php.ini file. The effect of this function only lasts for the duration of the script.
session_decode() decodes the session data in data, setting variables stored in the session.
Note: This function was added in PHP 4.0.
session_encode() returns a string with the contents of the current session encoded within.
Note: This function was added in PHP 4.0.
void
session_set_save_handler
(string
open, string
close, string
read, string
write, string
destroy, string
gc)
session_set_save_handler() sets the user-level session storage functions which are used for storing and retrieving data associated with a session. This is most useful when a storage method other than those supplied by PHP sessions is preferred. i.e. Storing the session data in a local database.
Note: You must set the configuration option session.save_handler to user in your php.ini file for session_set_save_handler() to take effect.
The following example provides file based session storage similar to the PHP sessions default save handler files. This example could easily be extended to cover database storage using your favorite PHP supported database engine.
Example 1. session_set_save_handler() example
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session_cache_limiter() returns the name of the current cache limiter. If cache_limiter is specified, the name of the current cache limiter is changed to the new value.
The cache limiter controls the cache control HTTP headers sent to the client. These headers determine the rules by which the page content may be cached. Setting the cache limiter to nocache, for example, would disallow any client-side caching. A value of public, however, would permit caching. It can also be set to private, which is slightly more restrictive than public.
The cache limiter is reset to the default value stored in session.cache_limiter at request startup time. Thus, you need to call session_cache_limiter() for every request (and before session_start() is called).
Note: This function was added in PHP 4.0.3.
Shmop is an easy to use set of functions that allows php to read, write, create and delete UNIX shared memory segments. The functions will not work on windows, as it does not support shared memory. To use shmop you will need to compile php with the --enable-shmop parameter in your configure line.
Note: The functions explained in the chapter begin all with shm_() in PHP 4.0.3, but in PHP 4.0.4 and later versions these names are changed to begin with shmop_().
Example 1. Shared Memory Operations Overview
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shmop_open() can create or open a shared memory block.
shmop_open() takes 4 parameters: key, which is the system's id for the shared memory block, this parameter can be passed as a decimal or hex. The second parameter are the flags that you can use:
"a" for access (sets IPC_EXCL) use this flag when you need to open an existing shared memory segment
"c" for create (sets IPC_CREATE) use this flag when you need to create a new shared memory segment.
Note: Note: the 3rd and 4th should be entered as 0 if you are opening an existing memory segment. On success shmop_open() will return an id that you can use to access the shared memory segment you've created.
This example opened a shared memory block with a system id of 0x0fff.
shmop_read() will read a string from shared memory block.
shmop_read() takes 3 parameters: shmid, which is the shared memory block identifier created by shmop_open(), offset from which to start reading and count on the number of bytes to read.
This example will read 50 bytes from shared memory block and place the data inside $shm_data.
shmop_write() will write a string into shared memory block.
shmop_write() takes 3 parameters: shmid, which is the shared memory block identifier created by shmop_open(), data, a string that you want to write into shared memory block and offset, which specifies where to start writing data inside the shared memory segment.
This example will write data inside $my_string into shared memory block, $shm_bytes_written will contain the number of bytes written.
shmop_size() is used to get the size, in bytes of the shared memory block.
shmop_size() takes the shmid, which is the shared memory block identifier created by shmop_open(), the function will return and int, which represents the number of bytes the shared memory block occupies.
This example will put the size of shared memory block identified by $shm_id into $shm_size.
shmop_delete() is used to delete a shared memory block.
shmop_delete() takes the shmid, which is the shared memory block identifier created by shmop_open(). On success 1 is returned, on failure 0 is returned.
This example will delete shared memory block identified by $shm_id.
PHP offers the ability to create Shockwave Flash files via Paul Haeberli's libswf module. You can download libswf at http://reality.sgi.com/grafica/flash/. Once you have libswf all you need to do is to configure --with-swf[=DIR] where DIR is a location containing the directories include and lib. The include directory has to contain the swf.h file and the lib directory has to contain the libswf.a file. If you unpack the libswf distribution the two files will be in one directory. Consequently you will have to copy the files to the proper location manually.
Once you've successfully installed PHP with Shockwave Flash support you can then go about creating Shockwave files from PHP. You would be surprised at what you can do, take the following code:
Example 1. SWF example
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Note: SWF support was added in PHP 4 RC2.
The libswf does not have support for Windows. The development of that library has been stopped, and the source is not available to port it to another systems.
void
swf_openfile
(string
filename, float
width, float
height, float
framerate, float
r, float
g, float
b)
The swf_openfile() function opens a new file named filename with a width of width and a height of height a frame rate of framerate and background with a red color of r a green color of g and a blue color of b.
The swf_openfile() must be the first function you call, otherwise your script will cause a segfault. If you want to send your output to the screen make the filename: "php://stdout" (support for this is in 4.0.1 and up).
Close a file that was opened by the swf_openfile() function. If the return_file parameter is set then the contents of the SWF file are returned from the function.
Example 1. Creating a simple flash file based on user input and outputting it and saving it in a database
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The swf_mulcolor() function sets the global multiply color to the rgba color specified. This color is then used (implicitly) by the swf_placeobject(), swf_modifyobject() and the swf_addbuttonrecord() functions. The color of the object will be multiplied by the rgba values when the object is written to the screen.
Note: The rgba values can be either positive or negative.
The swf_addcolor() function sets the global add color to the rgba color specified. This color is then used (implicitly) by the swf_placeobject(), swf_modifyobject() and the swf_addbuttonrecord() functions. The color of the object will be add by the rgba values when the object is written to the screen.
Note: The rgba values can be either positive or negative.
Places the object specified by objid in the current frame at a depth of depth. The objid parameter and the depth must be between 1 and 65535.
This uses the current mulcolor (specified by swf_mulcolor()) and the current addcolor (specified by swf_addcolor()) to color the object and it uses the current matrix to position the object.
Note: Full RGBA colors are supported.
Updates the position and/or color of the object at the specified depth, depth. The parameter how determines what is updated. how can either be the constant MOD_MATRIX or MOD_COLOR or it can be a combination of both (MOD_MATRIX|MOD_COLOR).
MOD_COLOR uses the current mulcolor (specified by the function swf_mulcolor()) and addcolor (specified by the function swf_addcolor()) to color the object. MOD_MATRIX uses the current matrix to position the object.
The swf_startdoaction() function starts the description of an action list for the current frame. This must be called before actions are defined for the current frame.
The swf_actionGotoFrame() function will go to the frame specified by framenumber, play it, and then stop.
The swf_actionGetUrl() function gets the URL specified by the parameter url with the target target.
The swf_actionWaitForFrame() function will check to see if the frame, specified by the framenumber parameter has been loaded, if not it will skip the number of actions specified by the skipcount parameter. This can be useful for "Loading..." type animations.
The swf_actionSetTarget() function sets the context for all actions. You can use this to control other flash movies that are currently playing.
The swf_actionGotoLabel() function displays the frame with the label given by the label parameter and then stops.
The swf_defineline() defines a line starting from the x coordinate given by x1 and the y coordinate given by y1 parameter. Up to the x coordinate given by the x2 parameter and the y coordinate given by the y2 parameter. It will have a width defined by the width parameter.
The swf_definerect() defines a rectangle with an upper left hand coordinate given by the x, x1, and the y, y1. And a lower right hand coordinate given by the x coordinate, x2, and the y coordinate, y2 . Width of the rectangles border is given by the width parameter, if the width is 0.0 then the rectangle is filled.
The swf_definepoly() function defines a polygon given an array of x, y coordinates (the coordinates are defined in the parameter coords). The parameter npoints is the number of overall points that are contained in the array given by coords. The width is the width of the polygon's border, if set to 0.0 the polygon is filled.
The swf_startshape() function starts a complex shape, with an object id given by the objid parameter.
The swf_shapeLineSolid() function sets the current line style to the color of the rgba parameters and width to the width parameter. If 0.0 is given as a width then no lines are drawn.
The swf_shapeFillSolid() function sets the current fill style to solid, and then sets the fill color to the values of the rgba parameters.
Sets the fill to bitmap clipped, empty spaces will be filled by the bitmap given by the bitmapid parameter.
Sets the fill to bitmap tile, empty spaces will be filled by the bitmap given by the bitmapid parameter (tiled).
The swf_shapeMoveTo() function moves the current position to the x coordinate given by the x parameter and the y position given by the y parameter.
The swf_shapeLineTo() draws a line to the x,y coordinates given by the x parameter & the y parameter. The current position is then set to the x,y parameters.
The swf_shapecurveto() function draws a quadratic bezier curve from the x coordinate given by x1 and the y coordinate given by y1 to the x coordinate given by x2 and the y coordinate given by y2. The current position is then set to the x,y coordinates given by the x2 and y2 parameters
Draw a cubic bezier curve using the x,y coordinate pairs x1, y1 and x2,y2 as off curve control points and the x,y coordinate x3, y3 as an endpoint. The current position is then set to the x,y coordinate pair given by x3,y3.
The swf_shapeArc() function draws a circular arc from angle A given by the ang1 parameter to angle B given by the ang2 parameter. The center of the circle has an x coordinate given by the x parameter and a y coordinate given by the y, the radius of the circle is given by the r parameter.
The swf_definefont() function defines a font given by the fontname parameter and gives it the id specified by the fontid parameter. It then sets the font given by fontname to the current font.
The swf_fontsize() function changes the font size to the value given by the size parameter.
Set the current font slant to the angle indicated by the slant parameter. Positive values create a foward slant, negative values create a negative slant.
Set the font tracking to the value specified by the tracking parameter. This function is used to increase the spacing between letters and text, positive values increase the space and negative values decrease the space between letters.
The swf_getfontinfo() function returns an associative array with the following parameters:
Aheight - The height in pixels of a capital A.
xheight - The height in pixels of a lowercase x.
Define a text string (the str parameter) using the current font and font size. The docenter is where the word is centered, if docenter is 1, then the word is centered in x.
The swf_textwidth() function gives the width of the string, str, in pixels, using the current font and font size.
The swf_definebitmap() function defines a bitmap given a GIF, JPEG, RGB or FI image. The image will be converted into a Flash JPEG or Flash color map format.
The swf_getbitmapinfo() function returns an array of information about a bitmap given by the bitmapid parameter. The returned array has the following elements:
"size" - The size in bytes of the bitmap.
"width" - The width in pixels of the bitmap.
"height" - The height in pixels of the bitmap.
Define an object id as a symbol. Symbols are tiny flash movies that can be played simultaneously. The objid parameter is the object id you want to define as a symbol.
The swf_endsymbol() function ends the definition of a symbol that was started by the swf_startsymbol() function.
The swf_startbutton() function starts off the definition of a button. The type parameter can either be TYPE_MENUBUTTON or TYPE_PUSHBUTTON. The TYPE_MENUBUTTON constant allows the focus to travel from the button when the mouse is down, TYPE_PUSHBUTTON does not allow the focus to travel when the mouse is down.
(PHP 4 >= 4.0RC2)
swf_addbuttonrecord -- Controls location, appearance and active area of the current buttonThe swf_addbuttonrecord() function allows you to define the specifics of using a button. The first parameter, states, defines what states the button can have, these can be any or all of the following constants: BSHitTest, BSDown, BSOver or BSUp. The second parameter, the shapeid is the look of the button, this is usually the object id of the shape of the button. The depth parameter is the placement of the button in the current frame.
Example 1. Swf_addbuttonrecord() function example
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The swf_onCondition() function describes a transition that will trigger an action list. There are several types of possible transitions, the following are for buttons defined as TYPE_MENUBUTTON:
IdletoOverUp
OverUptoIdle
OverUptoOverDown
OverDowntoOverUp
IdletoOverDown
OutDowntoIdle
MenuEnter (IdletoOverUp|IdletoOverDown)
MenuExit (OverUptoIdle|OverDowntoIdle)
IdletoOverUp
OverUptoIdle
OverUptoOverDown
OverDowntoOverUp
OverDowntoOutDown
OutDowntoOverDown
OutDowntoIdle
ButtonEnter (IdletoOverUp|OutDowntoOverDown)
ButtonExit (OverUptoIdle|OverDowntoOutDown)
The swf_viewport() function selects an area for future drawing for xmin to xmax and ymin to ymax, if this function is not called the area defaults to the size of the screen.
(PHP 4 >= 4.0.1)
swf_ortho -- Defines an orthographic mapping of user coordinates onto the current viewportThe swf_ortho() funcion defines a orthographic mapping of user coordinates onto the current viewport.
(PHP 4 >= 4.0RC2)
swf_ortho2 -- Defines 2D orthographic mapping of user coordinates onto the current viewportThe swf_ortho2() function defines a two dimensional orthographic mapping of user coordinates onto the current viewport, this defaults to one to one mapping of the area of the Flash movie. If a perspective transformation is desired, the swf_perspective () function can be used.
The swf_perspective() function defines a perspective projection transformation. The fovy parameter is field-of-view angle in the y direction. The aspect parameter should be set to the aspect ratio of the viewport that is being drawn onto. The near parameter is the near clipping plane and the far parameter is the far clipping plane.
Note: Various distortion artifacts may appear when performing a perspective projection, this is because Flash players only have a two dimensional matrix. Some are not to pretty.
The swf_polarview() function defines the viewer's position in polar coordinates. The dist parameter gives the distance between the viewpoint to the world space origin. The azimuth parameter defines the azimuthal angle in the x,y coordinate plane, measured in distance from the y axis. The incidence parameter defines the angle of incidence in the y,z plane, measured in distance from the z axis. The incidence angle is defined as the angle of the viewport relative to the z axis. Finally the twist specifies the amount that the viewpoint is to be rotated about the line of sight using the right hand rule.
void
swf_lookat
(double
view_x, double
view_y, double
view_z, double
reference_x, double
reference_y, double
reference_z, double
twist)
The swf_lookat() function defines a viewing transformation by giving the viewing position (the parameters view_x, view_y, and view_z) and the coordinates of a reference point in the scene, the reference point is defined by the reference_x, reference_y , and reference_z parameters. The twist controls the rotation along with viewer's z axis.
The swf_pushmatrix() function pushes the current transformation matrix back onto the stack.
The swf_popmatrix() function pushes the current transformation matrix back onto the stack.
The swf_scale() scales the x coordinate of the curve by the value of the x parameter, the y coordinate of the curve by the value of the y parameter, and the z coordinate of the curve by the value of the z parameter.
The swf_translate() function translates the current transformation by the x, y, and z values given.
The swf_rotate() rotates the current transformation by the angle given by the angle parameter around the axis given by the axis parameter. Valid values for the axis are 'x' (the x axis), 'y' (the y axis) or 'z' (the z axis).
(PHP 4 >= 4.0RC2)
swf_posround -- Enables or Disables the rounding of the translation when objects are placed or movedThe swf_posround() function enables or disables the rounding of the translation when objects are placed or moved, there are times when text becomes more readable because rounding has been enabled. The round is whether to enable rounding or not, if set to the value of 1, then rounding is enabled, if set to 0 then rounding is disabled.
In order to use the SNMP functions on Unix you need to install the UCD SNMP package. On Windows these functions are only available on NT and not on Win95/98.
Important: In order to use the UCD SNMP package, you need to define NO_ZEROLENGTH_COMMUNITY to 1 before compiling it. After configuring UCD SNMP, edit config.h and search for NO_ZEROLENGTH_COMMUNITY. Uncomment the #define line. It should look like this afterwards:
#define NO_ZEROLENGTH_COMMUNITY 1
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If you see strange segmentation faults in combination with SNMP commands, you did not follow the above instructions. If you do not want to recompile UCD SNMP, you can compile PHP with the --enable-ucd-snmp-hack switch which will work around the misfeature.
string snmpget (string hostname, string community, string object_id [, int timeout [, int retries]])
Returns SNMP object value on success and false on error.
The snmpget() function is used to read the value of an SNMP object specified by the object_id. SNMP agent is specified by the hostname and the read community is specified by the community parameter.
bool snmpset (string hostname, string community, string object_id, string type, mixed value [, int timeout [, int retries]])
Sets the specified SNMP object value, returning true on success and false on error.
The snmpset() function is used to set the value of an SNMP object specified by the object_id. SNMP agent is specified by the hostname and the read community is specified by the community parameter.
array snmpwalk (string hostname, string community, string object_id [, int timeout [, int retries]])
Returns an array of SNMP object values starting from the object_id() as root and false on error.
snmpwalk() function is used to read all the values from an SNMP agent specified by the hostname. Community specifies the read community for that agent. A null object_id is taken as the root of the SNMP objects tree and all objects under that tree are returned as an array. If object_id is specified, all the SNMP objects below that object_id are returned.
Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop
(PHP 3>= 3.0.8, PHP 4 >= 4.0b2)
snmpwalkoid -- Query for a tree of information about a network entityarray snmpwalkoid (string hostname, string community, string object_id [, int timeout [, int retries]])
Returns an associative array with object ids and their respective object value starting from the object_id as root and false on error.
snmpwalkoid() function is used to read all object ids and their respective values from an SNMP agent specified by the hostname. Community specifies the read community for that agent. A null object_id is taken as the root of the SNMP objects tree and all objects under that tree are returned as an array. If object_id is specified, all the SNMP objects below that object_id are returned.
The existence of snmpwalkoid() and snmpwalk() has historical reasons. Both functions are provided for backward compatibility.
Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop
(PHP 3>= 3.0.8, PHP 4 >= 4.0b2)
snmp_get_quick_print -- Fetch the current value of the UCD library's quick_print settingReturns the current value stored in the UCD Library for quick_print. quick_print is off by default.
Above function call would return false if quick_print is on, and true if quick_print is on.
snmp_get_quick_print() is only available when using the UCD SNMP library. This function is not available when using the Windows SNMP library.
See: snmp_set_quick_print() for a full description of what quick_print does.
(PHP 3>= 3.0.8, PHP 4 >= 4.0b2)
snmp_set_quick_print -- Set the value of quick_print within the UCD SNMP library.Sets the value of quick_print within the UCD SNMP library. When this is set (1), the SNMP library will return 'quick printed' values. This means that just the value will be printed. When quick_print is not enabled (default) the UCD SNMP library prints extra information including the type of the value (i.e. IpAddress or OID). Additionally, if quick_print is not enabled, the library prints additional hex values for all strings of three characters or less.
Setting quick_print is often used when using the information returned rather then displaying it.
snmp_set_quick_print(0);
$a = snmpget("127.0.0.1", "public", ".1.3.6.1.2.1.2.2.1.9.1");
echo "$a<BR>\n";
snmp_set_quick_print(1);
$a = snmpget("127.0.0.1", "public", ".1.3.6.1.2.1.2.2.1.9.1");
echo "$a<BR>\n";
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The first value printed might be: 'Timeticks: (0) 0:00:00.00', whereas with quick_print enabled, just '0:00:00.00' would be printed.
By default the UCD SNMP library returns verbose values, quick_print is used to return only the value.
Currently strings are still returned with extra quotes, this will be corrected in a later release.
snmp_set_quick_print() is only available when using the UCD SNMP library. This function is not available when using the Windows SNMP library.
The socket extension implements a low-level interface to the socket communication functions, providing the possibility to act as a socket server as well as a client.
The socket functions described here are part of an extension to PHP which must be enabled at compile time by giving the --enable-sockets option to configure.
For a more generic client-side socket interface, see fsockopen() and pfsockopen().
When using these functions, it is important to remember that while many of them have identical names to their C counterparts, they often have different declarations. Please be sure to read the descriptions to avoid confusion.
That said, those unfamiliar with socket programming can still find a lot of useful material in the appropriate Unix man pages, and there is a great deal of tutorial information on socket programming in C on the web, much of which can be applied, with slight modifications, to socket programming in PHP.
Example 1. Socket example: Simple TCP/IP server This example shows a simple talkback server. Change the address and port variables to suit your setup and execute. You may then connect to the server with a command similar to: telnet 192.168.1.53 10000 (where the address and port match your setup). Anything you type will then be output on the server side, and echoed back to you. To disconnect, enter 'quit'.
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Example 2. Socket example: Simple TCP/IP client This example shows a simple, one-shot HTTP client. It simply connects to a page, submits a HEAD request, echoes the reply, and exits.
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After the socket socket has been created using socket(), bound to a name with bind(), and told to listen for connections with listen(), this function will accept incoming connections on that socket. Once a successful connection is made, a new socket descriptor is returned, which may be used for communication. If there are multiple connections queued on the socket, the first will be used. If there are no pending connections, accept_connect() will block until a connection becomes present. If socket has been made non-blocking using socket_set_blocking() or set_nonblock(), an error code will be returned.
The socket descriptor returned by accept_connect() may not be used to accept new connections. The original listening socket socket, however, remains open and may be reused.
Returns a new socket descriptor on success, or a negative error code on failure. This code may be passed to strerror() to get a textual explanation of the error.
See also bind(), connect(), listen(), socket(), socket_get_status(), and strerror().
bind() binds the name given in address to the socket described by socket, which must be a valid socket descriptor created with socket().
The address parameter is either an IP address in dotted-quad notation (e.g. 127.0.0.1), if the socket is of the AF_INET family; or the pathname of a Unix-domain socket, if the socket family is AF_UNIX.
The port parameter is only used when connecting to an AF_INET socket, and designates the port on the remote host to which a connection should be made.
Returns zero on success, or a negative error code on failure. This code may be passed to strerror() to get a textual explanation of the error.
See also accept_connect(), connect(), listen(), socket(), socket_get_status(), and strerror().
close() closes the file (or socket) descriptor given by socket.
Note that close() should not be used on PHP file descriptors created with fopen(), popen(), fsockopen(), or psockopen(); it is meant for sockets created with socket() or accept_connect().
Returns true on success, or false if an error occurs (i.e., socket is invalid).
See also bind(), listen(), socket(), socket_get_status(), and strerror().
Initiates a connection using the socket descriptor socket, which must be a valid socket descriptor created with socket().
The address parameter is either an IP address in dotted-quad notation (e.g. 127.0.0.1), if the socket is of the AF_INET family; or the pathname of a Unix-domain socket, if the socket family is AF_UNIX.
The port parameter is only used when connecting to an AF_INET socket, and designates the port on the remote host to which a connection should be made.
Returns zero on success, or a negative error code on failure. This code may be passed to strerror() to get a textual explanation of the error.
See also bind(), listen(), socket(), socket_get_status(), and strerror().
After the socket socket has been created using socket() and bound to a name with bind(), it may be told to listen for incoming connections on socket. A maximum of backlog incoming connections will be queued for processing.
listen() is applicable only to sockets with type SOCK_STREAM or SOCK_SEQPACKET.
Returns zero on success, or a negative error code on failure. This code may be passed to strerror() to get a textual explanation of the error.
See also accept_connect(), bind(), connect(), socket(), socket_get_status(), and strerror().
The function read() reads from socket socket_descreated by the accept_connect() function into &buffer the number of bytes set by length. Otherwise you can use \n, \t or \0 to end reading. Returns number of bytes that have been read.
See also accept_connect(), bind(), connect(), listen(), strerror(), socket_get_status(). and write().
Creates a communication endpoint (a socket), and returns a descriptor to the socket.
The domain parameter sets the domain. Currently, AF_INET and AF_UNIX are understood.
The type parameter selects the socket type. This is one of SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET, SOCK_RAW, SOCK_RDM, or SOCK_PACKET.
protocol sets the protocol.
Returns a valid socket descriptor on success, or a negative error code on failure. This code may be passed to strerror() to get a textual explanation of the error.
For more information on the usage of socket(), as well as on the meanings of the various parameters, see the Unix man page socket (2).
See also accept_connect(), bind(), connect(), listen(), strerror(), and socket_get_status().
strerror() takes as its errno parameter the return value of one of the socket functions, and returns the corresponding explanatory text. This makes it a bit more pleasant to figure out why something didn't work; for instance, instead of having to track down a system include file to find out what '-111' means, you just pass it to strerror(), and it tells you what happened.
Example 1. strerror() example
The expected output from the above example (assuming the script is not run with root privileges):
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See also accept_connect(), bind(), connect(), listen(), socket(), and socket_get_status().
The function write() writes to the socket socket_des from &buffer the number of bytes set by length.
See also accept_connect(), bind(), connect(), listen(), read(), strerror(), and socket_get_status().
These functions all manipulate strings in various ways. Some more specialized sections can be found in the regular expression and URL handling sections.
For information on how strings behave, especially with regard to usage of single quotes, double quotes, and escape sequences, see the Strings entry in the Types section of the manual.
Returns a string with backslashes before characters that are listed in charlist parameter. It escapes \n, \r etc. in C-like style, characters with ASCII code lower than 32 and higher than 126 are converted to octal representation. Be carefull when escaping alphanumeric characters. You can specify a range in charlist like "\0..\37", which would escape all characters with ASCII code between 0 and 31.
Note: Added in PHP4b3-dev.
See also stripcslashes(), stripslashes(), htmlspecialchars(), htmlspecialchars(), and quotemeta().
Returns a string with backslashes before characters that need to be quoted in database queries etc. These characters are single quote ('), double quote ("), backslash (\) and NUL (the null byte).
See also stripslashes(), htmlspecialchars(), and quotemeta().
Returns an ASCII string containing the hexadecimal representation of str. The conversion is done byte-wise with the high-nibble first.
Returns the argument string without trailing whitespace, including newlines.
Note: chop() is different than the Perl chop() function, which removes the last character in the string.
Returns a one-character string containing the character specified by ascii.
Can be used to split a string into smaller chunks which is useful for e.g. converting base64_encode output to match RFC 2045 semantics. It inserts every chunklen (defaults to 76) chars the string end (defaults to "\r\n"). It returns the new string leaving the original string untouched.
Note: This function was added in 3.0.6.
This function converts the given string from one Cyrillic character set to another. The from and to arguments are single characters that represent the source and target Cyrillic character sets. The supported types are:
k - koi8-r
w - windows-1251
i - iso8859-5
a - x-cp866
d - x-cp866
m - x-mac-cyrillic
Counts the number of occurances of every byte-value (0..255) in string and returns it in various ways. The optional parameter Mode default to 0. Depending on mode count_chars() returns one of the following:
0 - an array with the byte-value as key and the freqency of every byte as value.
1 - same as 0 but only byte-values with a frequency greater than zero are listed.
2 - same as 0 but only byte-values with a frequency equal to zero are listed.
3 - a string containing all used byte-values is returned.
4 - a string containing all not used byte-values is returned.
Note: This function was added in PHP 4.0.
Generates the cyclic redundancy checksum polynomial of 32-bit lengths of the str. This is usually used to validate the integrity of data being trasmited.
See also: md5()
crypt() will encrypt a string using the standard Unix DES encryption method. Arguments are a string to be encrypted and an optional two-character salt string to base the encryption on. See the Unix man page for your crypt function for more information.
If the salt argument is not provided, one will be randomly generated by PHP.
Some operating systems support more than one type of encryption. In fact, sometimes the standard DES encryption is replaced by an MD5 based encryption algorithm. The encryption type is triggered by the salt argument. At install time, PHP determines the capabilities of the crypt function and will accept salts for other encryption types. If no salt is provided, PHP will auto-generate a standard 2-character DES salt by default, unless the default encryption type on the system is MD5, in which case a random MD5-compatible salt is generated. PHP sets a constant named CRYPT_SALT_LENGTH which tells you whether a regular 2-character salt applies to your system or the longer 12-char MD5 salt is applicable.
If you are using the supplied salt, you should be aware that the salt is generated once. If you are calling this function recursively, this may impact both appearance and, to a certain extent, security.
The standard DES encryption crypt() contains the salt as the first two characters of the output.
On systems where the crypt() function supports multiple encryption types, the following constants are set to 0 or 1 depending on whether the given type is available:
CRYPT_STD_DES - Standard DES encryption with a 2-char SALT
CRYPT_EXT_DES - Extended DES encryption with a 9-char SALT
CRYPT_MD5 - MD5 encryption with a 12-char SALT starting with $1$
CRYPT_BLOWFISH - Extended DES encryption with a 16-char SALT starting with $2$
There is no decrypt function, since crypt() uses a one-way algorithm.
See also: md5().
Outputs all parameters.
Echo() is not actually a function (it is a language construct) so you are not required to use parantheses with it.
Note: In fact, if you want to pass more than one parameter to echo, you must not enclose the parameters within parentheses.
Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the string delim. If limit is set, the returned array will contaion a maximum of limit elements with the last element containing the whole rest of string.
Note: Although implode() can for historical reasons accept its parameters in either order, explode() cannot. You must ensure that the separator argument comes before the string argument.
(PHP 4 >= 4.0b4)
get_html_translation_table -- Returns the translation table used by htmlspecialchars() and htmlentities()get_html_translation_table() will return the translation table that is used internally for htmlspecialchars() and htmlentities(). There are two new defines (HTML_ENTITIES, HTML_SPECIALCHARS) that allow you to specify the table you want. And as in the htmlspecialchars() and htmlentities() functions you can optionally specify the quote_style you are working with. The default is ENT_COMPAT mode. See the description of these modes in htmlspecialchars().
The cool thing is using array_flip() to change the direction of the translation.
The content of $original would be: "Hallo & <Frau> & KrΣmer".Note: This function was added in PHP 4.0.
See also: htmlspecialchars(), htmlentities(), strtr(), and array_flip().
(PHP 3>= 3.0.4, PHP 4 )
get_meta_tags -- Extracts all meta tag content attributes from a file and returns an arrayOpens filename and parses it line by line for <meta> tags of the form
The value of the name property becomes the key, the value of the content property becomes the value of the returned array, so you can easily use standard array functions to traverse it or access single values. Special characters in the value of the name property are substituted with '_', the rest is converted to lower case.
Setting use_include_path to 1 will result in PHP trying to open the file along the standard include path.
The optional parameter max_chars_per_line indicates maximum number of characters per line will be output. The function tries to avoid breaking words.
See also hebrevc()
This function is similar to hebrev() with the difference that it converts newlines (\n) to "<br>\n". The optional parameter max_chars_per_line indicates maximum number of characters per line will be output. The function tries to avoid breaking words.
See also hebrev()
This function is identical to htmlspecialchars() in all ways, except that all characters which have HTML character entity equivalents are translated into these entities. Like htmlspecialchars(), it takes an optional second argument which indicates what should be done with single and double quotes. ENT_COMPAT (the default) will only convert double-quotes and leave single-quotes alone. ENT_QUOTES will convert both double and single quotes, and ENT_NOQUOTES will leave both double and single quotes unconverted.
At present, the ISO-8859-1 character set is used. Note that the optional second argument was added in PHP 3.0.17 and PHP 4.0.3.
See also htmlspecialchars() and nl2br().
Certain characters have special significance in HTML, and should be represented by HTML entities if they are to preserve their meanings. This function returns a string with some of these conversions made; the translations made are those most useful for everyday web programming. If you require all HTML character entities to be translated, use htmlentities() instead.
This function is useful in preventing user-supplied text from containing HTML markup, such as in a message board or guest book application. The optional second argument, quote_style, tells the function what to do with single and double quote characters. The default mode, ENT_COMPAT, is the backwards compatible mode which only translates the double-quote character and leaves the single-quote untranslated. If ENT_QUOTES is set, both single and double quotes are translated and if ENT_NOQUOTES is set neither single nor double quotes are translated.
The translations performed are:
'&' (ampersand) becomes '&'
'"' (double quote) becomes '"' when ENT_NOQUOTES is not set.
''' (single quote) becomes ''' only when ENT_QUOTES is set.
'<' (less than) becomes '<'
'>' (greater than) becomes '>'
Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities(). Also note that the optional second argument was added in PHP 3.0.17 and PHP 4.0.3.
See also htmlentities() and nl2br().
Returns a string containing a string representation of all the array elements in the same order, with the glue string between each element.
Note: implode() can, for historical reasons, accept its parameters in either order. For consistency with explode(), however, it may be less confusing to use the documented order of arguments.
int levenshtein (string str1, string str2)
int levenshtein (string str1, string str2, int cost_ins, int cost_rep, int cost_del)
int levenshtein (string str1, string str2, function cost)
This function returns the Levenshtein-Distance between the two argument strings or -1, if one of the argument strings is longer than the limit of 255 characters (255 should be more than enough for name or dictionary comparison, and nobody serious would be doing genetic analysis with PHP).
The Levenshtein distance is defined as the minimal number of characters you have to replace, insert or delete to transform str1 into str2. The complexity of the algorithm is O(m*n), where n and m are the length of str1 and str2 (rather good when compared to similar_text(), which is O(max(n,m)**3), but still expensive).
In its simpelest form the function will take only the two strings as parameter and will calculate just the number of insert, replace and delete operations needed to transform str1 into str2.
A second variant will take three additional parameters that define the cost of insert, replace and delete operations. This is more general and adaptive than variant one, but not as efficient.
The third variant (which is not implemented yet) will be the most general and adaptive, but also the slowest alternative. It will call a user-supplied function that will determine the cost for every possible operation.
The user-supplied function will be called with the following arguments:
operation to apply: 'I', 'R' or 'D'
actual character in string 1
actual character in string 2
position in string 1
position in string 2
remaining characters in string 1
remaining characters in string 2
The user-supplied function approach offers the possibility to take into account the relevance of and/or difference between certain symbols (characters) or even the context those symbols appear in to determine the cost of insert, replace and delete operations, but at the cost of loosing all optimizations done regarding cpu register utilization and cache misses that have been worked into the other two variants.
See also soundex(), similar_text() and metaphone().
This function strips whitespace from the start of a string and returns the stripped string. The whitespace characters it currently strips are: "\n", "\r", "\t", "\v", "\0", and a plain space.
Calculates the MD5 hash of str using the RSA Data Security, Inc. MD5 Message-Digest Algorithm.
See also: crc32()
Calculates the metaphone key of str.
Similar to soundex() metaphone creates the same key for similar sounding words. It's more accurate than soundex() as it knows the basic rules of English pronunciation. The metaphone generated keys are of variable length.
Metaphone was developed by Lawrence Philips <lphilips@verity.com>. It is described in ["Practical Algorithms for Programmers", Binstock & Rex, Addison Wesley, 1995].
Note: This function was added in PHP 4.0.
Returns string with '<BR>' inserted before all newlines.
See also htmlspecialchars(), htmlentities() and wordwrap().
Returns the ASCII value of the first character of string. This function complements chr().
See also chr().
Parses str as if it were the query string passed via an URL and sets variables in the current scope. If the second parameter arr is present, variables are stored in this variable as an array elements instead.
Produces output according to format, which is described in the documentation for sprintf().
See also: print(), sprintf(), sscanf(), fscanf(), and flush().
(PHP 3>= 3.0.6, PHP 4 )
quoted_printable_decode -- Convert a quoted-printable string to an 8 bit stringThis function returns an 8-bit binary string corresponding to the decoded quoted printable string. This function is similar to imap_qprint(), except this one does not require the IMAP module to work.
Returns a version of str with a backslash character (\) before every character that is among these:
. \\ + * ? [ ^ ] ( $ ) |
See also addslashes(), htmlentities(), htmlspecialchars(), nl2br(), and stripslashes().
Returns the argument string without trailing whitespace, including newlines. This is an alias for chop().
The function sscanf() is the input analog of printf(). Sscanf() reads from the string str and interprets it according to the specified format. If only two parameters were passed to this function, the values parsed will be returned as an array.
Category is a string specifying the category of the functions affected by the locale setting:
LC_ALL for all of the below
LC_COLLATE for string comparison - not currently implemented in PHP
LC_CTYPE for character classification and conversion, for example strtoupper()
LC_MONETARY for localeconv() - not currently implemented in PHP
LC_NUMERIC for decimal separator
LC_TIME for date and time formatting with strftime()
If locale is the empty string "", the locale names will be set from the values of environment variables with the same names as the above categories, or from "LANG".
If locale is zero or "0", the locale setting is not affected, only the current setting is returned.
Setlocale returns the new current locale, or false if the locale functionality is not implemented in the plattform, the specified locale does not exist or the category name is invalid. An invalid category name also causes a warning message.
This calculates the similarity between two strings as described in Oliver [1993]. Note that this implementation does not use a stack as in Oliver's pseudo code, but recursive calls which may or may not speed up the whole process. Note also that the complexity of this algorithm is O(N**3) where N is the length of the longest string.
By passing a reference as third argument, similar_text() will calculate the similarity in percent for you. It returns the number of matching chars in both strings.
Calculates the soundex key of str.
Soundex keys have the property that words pronounced similarly produce the same soundex key, and can thus be used to simplify searches in databases where you know the pronunciation but not the spelling. This soundex function returns a string 4 characters long, starting with a letter.
This particular soundex function is one described by Donald Knuth in "The Art Of Computer Programming, vol. 3: Sorting And Searching", Addison-Wesley (1973), pp. 391-392.
Example 1. Soundex Examples
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Returns a string produced according to the formatting string format.
The format string is composed of zero or more directives: ordinary characters (excluding %) that are copied directly to the result, and conversion specifications, each of which results in fetching its own parameter. This applies to both sprintf() and printf().
Each conversion specification consists of a percent sign (%), followed by one or more of these elements, in order:
An optional padding specifier that says what character will be used for padding the results to the right string size. This may be a space character or a 0 (zero character). The default is to pad with spaces. An alternate padding character can be specified by prefixing it with a single quote ('). See the examples below.
An optional alignment specifier that says if the result should be left-justified or right-justified. The default is right-justified; a - character here will make it left-justified.
An optional number, a width specifier that says how many characters (minimum) this conversion should result in.
An optional precision specifier that says how many decimal digits should be displayed for floating-point numbers. This option has no effect for other types than double. (Another function useful for formatting numbers is number_format().)
A type specifier that says what type the argument data should be treated as. Possible types:
| % - a literal percent character. No argument is required. |
| b - the argument is treated as an integer, and presented as a binary number. |
| c - the argument is treated as an integer, and presented as the character with that ASCII value. |
| d - the argument is treated as an integer, and presented as a decimal number. |
| f - the argument is treated as a double, and presented as a floating-point number. |
| o - the argument is treated as an integer, and presented as an octal number. |
| s - the argument is treated as and presented as a string. |
| x - the argument is treated as an integer and presented as a hexadecimal number (with lowercase letters). |
| X - the argument is treated as an integer and presented as a hexadecimal number (with uppercase letters). |
See also: printf(), sscanf(), fscanf(), and number_format().
(PHP 4 >= 4.0.2)
strncasecmp -- Binary safe case-insensitive string comparison of the first n charactersThis function is similar to strcasecmp(), with the difference that you can specify the (upper limit of the) number of characters (len) from each string to be used in the comparison. If any of the strings is shorter than len, then the length of that string will be used for the comparison.
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
See also ereg(), strcasecmp(), strcmp(), substr(), stristr(), and strstr().
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
See also ereg(), strcmp(), substr(), stristr(), strncasecmp(), and strstr().
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
Note that this comparison is case sensitive.
See also ereg(), strcasecmp(), substr(), stristr(), strncasecmp(), strncmp(), and strstr().
Returns the length of the initial segment of str1 which does not contain any of the characters in str2.
See also strspn().
This function tries to strip all HTML and PHP tags from the given string. It errors on the side of caution in case of incomplete or bogus tags. It uses the same tag stripping state machine as the fgetss() function.
You can use the optional second parameter to specify tags which should not be stripped.
Note: Allowable_tags was added in PHP 3.0.13, PHP4B3.
Returns a string with backslashes stripped off. Recognizes C-like \n, \r ..., octal and hexadecimal representation.
Note: Added in PHP4b3-dev.
See also addcslashes().
Returns a string with backslashes stripped off. (\' becomes ' and so on.) Double backslashes are made into a single backslash.
See also addslashes().
Returns all of haystack from the first occurrence of needle to the end. needle and haystack are examined in a case-insensitive manner.
If needle is not found, returns false.
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would, this is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in strcmp()) can be seen below:
$arr1 = $arr2 = array ("img12.png","img10.png","img2.png","img1.png");
echo "Standard string comparison\n";
usort($arr1,"strcmp");
print_r($arr1);
echo "\nNatural order string comparison\n";
usort($arr2,"strnatcmp");
print_r($arr2);
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Standard string comparison
Array
(
[0] => img1.png
[1] => img10.png
[2] => img12.png
[3] => img2.png
)
Natural order string comparison
Array
(
[0] => img1.png
[1] => img2.png
[2] => img10.png
[3] => img12.png
)
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Similar to other string comparison functions, this one returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
Note that this comparison is case sensitive.
See also ereg(), strcasecmp(), substr(), stristr(), strcmp(), strncmp(), strncasecmp(), strnatcasecmp(), strstr(), natsort() and natcasesort().
(PHP 4 >= 4.0RC2)
strnatcasecmp -- Case insensitive string comparisons using a "natural order" algorithmThis function implements a comparison algorithm that orders alphanumeric strings in the way a human being would. The behavior of this function is similar to strnatcmp(), except that the comparison is not case sensitive. For more infomation see: Martin Pool's Natural Order String Comparison page.
Similar to other string comparison functions, this one returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
See also ereg(), strcasecmp(), substr(), stristr(), strcmp(), strncmp(), strncasecmp(), strnatcmp(), and strstr().
This function is similar to strcmp(), with the difference that you can specify the (upper limit of the) number of characters (len) from each string to be used in the comparison. If any of the strings is shorter than len, then the length of that string will be used for the comparison.
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.
Note that this comparison is case sensitive.
See also ereg(), strncasecmp(), strcasecmp(), substr(), stristr(), strcmp(), and strstr().
This functions pads the input string on the left, the right, or both sides to the specifed padding length. If the optional argument pad_string is not supplied, the input is padded with spaces, otherwise it is padded with characters from pad_string up to the limit.
Optional argument pad_type can be STR_PAD_RIGHT, STR_PAD_LEFT, or STR_PAD_BOTH. If pad_type is not specified it is assumed to be STR_PAD_RIGHT.
If the value of pad_length is negative or less than the length of the input string, no padding takes place.
Returns the numeric position of the first occurrence of needle in the haystack string. Unlike the strrpos(), this function can take a full string as the needle parameter and the entire string will be used.
If needle is not found, returns false.
Note: It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
The optional offset parameter allows you to specify which character in haystack to start searching. The position returned is still relative to the the beginning of haystack.
See also strrpos(), strrchr(), substr(), stristr(), and strstr().
This function returns the portion of haystack which starts at the last occurrence of needle and goes until the end of haystack.
Returns false if needle is not found.
If needle contains more than one character, the first is used.
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
Returns input_str repeated multiplier times. multiplier has to be greater than 0.
This will output "-=-=-=-=-=-=-=-=-=-=".
Note: This function was added in PHP 4.0.
Returns the numeric position of the last occurrence of needle in the haystack string. Note that the needle in this case can only be a single character. If a string is passed as the needle, then only the first character of that string will be used.
If needle is not found, returns false.
Note: It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
See also strpos(), strrchr(), substr(), stristr(), and strstr().
Returns the length of the initial segment of str1 which consists entirely of characters in str2.
See also strcspn().
Returns all of haystack from the first occurrence of needle to the end.
If needle is not found, returns false.
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
Note: Note that this function is case-sensitive. For case-insensitive searches, use stristr().
strtok() is used to tokenize a string. That is, if you have a string like "This is an example string" you could tokenize this string into its individual words by using the space character as the token.
Note that only the first call to strtok uses the string argument. Every subsequent call to strtok only needs the token to use, as it keeps track of where it is in the current string. To start over, or to tokenize a new string you simply call strtok with the string argument again to initialize it. Note that you may put multiple tokens in the token parameter. The string will be tokenized when any one of the characters in the argument are found.
Also be careful that your tokens may be equal to "0". This evaluates to false in conditional expressions.
Returns string with all alphabetic characters converted to lowercase.
Note that 'alphabetic' is determined by the current locale. This means that in i.e. the default "C" locale, characters such as umlaut-A (─) will not be converted.
See also strtoupper() and ucfirst().
Returns string with all alphabetic characters converted to uppercase.
Note that 'alphabetic' is determined by the current locale. For instance, in the default "C" locale characters such as umlaut-a (Σ) will not be converted.
See also strtolower() and ucfirst().
This function replaces all occurences of needle in haystack with the given str. If you don't need fancy replacing rules, you should always use this function instead of ereg_replace().
This function is binary safe.
Note: Str_replace() was added in PHP 3.0.6, but was buggy up until PHP 3.0.8.
See also ereg_replace() and strtr().
This function operates on str, translating all occurrences of each character in from to the corresponding character in to and returning the result.
If from and to are different lengths, the extra characters in the longer of the two are ignored.
strtr() can be called with only two arguments. If called with two arguments it behaves in a new way: from then has to be an array that contains string -> string pairs that will be replaced in the source string. strtr() will always look for the longest possible match first and will *NOT* try to replace stuff that it has already worked on.
Examples:
$trans = array ("hello" => "hi", "hi" => "hello");
echo strtr("hi all, I said hello", $trans) . "\n";
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Note: This feature (two arguments) was added in PHP 4.0.
See also ereg_replace().
Substr returns the portion of string specified by the start and length parameters.
If start is positive, the returned string will start at the start'th position in string, counting from zero. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth.
Examples:
If start is negative, the returned string will start at the start'th character from the end of string.
Examples:
$rest = substr ("abcdef", -1); // returns "f"
$rest = substr ("abcdef", -2); // returns "ef"
$rest = substr ("abcdef", -3, 1); // returns "d"
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If length is given and is positive, the string returned will end length characters from start. If this would result in a string with negative length (because the start is past the end of the string), then the returned string will contain the single character at start.
If length is given and is negative, the string returned will end length characters from the end of string. If this would result in a string with negative length, then the returned string will contain the single character at start.
Examples:
substr_count() returns the number of times the needle substring occurs in the haystack string.
substr_replace() replaces the part of string delimited by the start and (optionally) length parameters with the string given in replacement. The result is returned.
If start is positive, the replacing will begin at the start'th offset into string.
If start is negative, the replacing will begin at the start'th character from the end of string.
If length is given and is positive, it represents the length of the portion of string which is to be replaced. If it is negative, it represents the number of characters from the end of string at which to stop replacing. If it is not given, then it will default to strlen( string ); i.e. end the replacing at the end of string.
Example 1. Substr_replace() example
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See also str_replace() and substr().
Note: Substr_replace() was added in PHP 4.0.
This function strips whitespace from the start and the end of a string and returns the stripped string. The whitespace characters it currently strips are: "\n", "\r", "\t", "\v", "\0", and a plain space.
Capitalizes the first character of str if that character is alphabetic.
Note that 'alphabetic' is determined by the current locale. For instance, in the default "C" locale characters such as umlaut-a (Σ) will not be converted.
See also strtoupper() and strtolower().
Capitalizes the first character of each word in str if that character is alphabetic.
Note: The definition of a word is any string of characters that is immediately after a whitespace (These are: space, form-feed, newline, carriage return, horizontal tab, and vertical tab).
See also strtoupper(), strtolower() and ucfirst().
(PHP 4 >= 4.0.2)
wordwrap -- Wraps a string to a given number of characters using a string break character.Wraps the string str at the column number specified by the (optional) width parameter. The line is broken using the (optional) break parameter.
wordwrap() will automatically wrap at column 75 and break using '\n' (newline) if width or break are not given.
If the cut is set to 1, the string is always wrapped at the specified width. So if you have a word that is larger than the given width, it is broken appart. (See second example).
Note: The cut parameter was added in PHP 4.0.3.
This example would display:
This example would display:
See also nl2br().
Returns: The number of affected rows by the last query.
sybase_affected_rows() returns the number of rows affected by the last INSERT, UPDATE or DELETE query on the server associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
This command is not effective for SELECT statements, only on statements which modify records. To retrieve the number of rows returned from a SELECT, use sybase_num_rows().
Note: This function is only available using the CT library interface to Sybase, and not the DB library.
Returns: true on success, false on error
sybase_close() closes the link to a Sybase database that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.
Note that this isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.
sybase_close() will not close persistent links generated by sybase_pconnect().
See also: sybase_connect(), sybase_pconnect().
Returns: A positive Sybase link identifier on success, or false on error.
sybase_connect() establishes a connection to a Sybase server. The servername argument has to be a valid servername that is defined in the 'interfaces' file.
In case a second call is made to sybase_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.
The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling sybase_close().
See also sybase_pconnect(), sybase_close().
Returns: true on success, false on failure
sybase_data_seek() moves the internal row pointer of the Sybase result associated with the specified result identifier to pointer to the specifyed row number. The next call to sybase_fetch_row() would return that row.
See also: sybase_data_seek().
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
sybase_fetch_array() is an extended version of sybase_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.
An important thing to note is that using sybase_fetch_array() is NOT significantly slower than using sybase_fetch_row(), while it provides a significant added value.
For further details, also see sybase_fetch_row()
Returns an object containing field information.
sybase_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retreived by sybase_fetch_field() is retreived.
The properties of the object are:
name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric
type - datatype of the column
See also sybase_field_seek()
Returns: An object with properties that correspond to the fetched row, or false if there are no more rows.
sybase_fetch_object() is similar to sybase_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).
Speed-wise, the function is identical to sybase_fetch_array(), and almost as quick as sybase_fetch_row() (the difference is insignificant).
See also: sybase_fetch-array() and sybase_fetch-row().
Returns: An array that corresponds to the fetched row, or false if there are no more rows.
sybase_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.
Subsequent call to sybase_fetch_rows() would return the next row in the result set, or false if there are no more rows.
See also: sybase_fetch_array(), sybase_fetch_object(), sybase_data_seek(), sybase_fetch_lengths(), and sybase_result().
Seeks to the specified field offset. If the next call to sybase_fetch_field() won't include a field offset, this field would be returned.
See also: sybase_fetch_field().
sybase_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script ends. You may call sybase_free_result() with the result identifier as an argument and the associated result memory will be freed.
sybase_min_client_severity() sets the minimum client severity level.
Note: This function is only available using the CT library interface to Sybase, and not the DB library.
See also: sybase_min_server_severity().
sybase_min_error_severity() sets the minimum error severity level.
See also: sybase_min_message_severity().
sybase_min_message_severity() sets the minimum message severity level.
See also: sybase_min_error_severity().
sybase_min_server_severity() sets the minimum server severity level.
Note: This function is only available using the CT library interface to Sybase, and not the DB library.
See also: sybase_min_client_severity().
sybase_num_fields() returns the number of fields in a result set.
See also: sybase_db_query(), sybase_query(), sybase_fetch_field(), sybase_num_rows().
sybase_num_rows() returns the number of rows in a result set.
See also: sybase_db_query(), sybase_query() and, sybase_fetch_row().
Returns: A positive Sybase persistent link identifier on success, or false on error
sybase_pconnect() acts very much like sybase_connect() with two major differences.
First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.
Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (sybase_close() will not close links established by sybase_pconnect()()).
This type of links is therefore called 'persistent'.
Returns: A positive Sybase result identifier on success, or false on error.
sybase_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if sybase_connect() was called, and use it.
See also: sybase_db_query(), sybase_select_db(), and sybase_connect().
Returns: The contents of the cell at the row and offset in the specified Sybase result set.
sybase_result() returns the contents of one cell from a Sybase result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (tablename.fieldname). If the column name has been aliased ('select foo as bar from...'), use the alias instead of the column name.
When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than sybase_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.
Recommended high-performance alternatives: sybase_fetch_row(), sybase_fetch_array(), and sybase_fetch_object().
Returns: true on success, false on error
sybase_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if sybase_connect() was called, and use it.
Every subsequent call to sybase_query() will be made on the active database.
See also: sybase_connect(), sybase_pconnect(), and sybase_query()
Base64_decode() decodes encoded_data and returns the original data. The returned data may be binary.
See also: base64_encode(), RFC-2045 section 6.8.
Base64_encode() returns data encoded with base64. This encoding is designed to make binary data survive transport through transport layers that are not 8-bit clean, such as mail bodies.
Base64-encoded data takes about 33% more space than the original data.
See also: base64_decode(), chunk_split(), RFC-2045 section 6.8.
This function returns an associative array returning any of the various components of the URL that are present. This includes the "scheme", "host", "port", "user", "pass", "path", "query", and "fragment".
Returns a string in which the sequences with percent (%) signs followed by two hex digits have been replaced with literal characters. For example, the string
foo%20bar%40baz |
foo
bar@baz |
See also rawurlencode(), urldecode(), urlencode().
Returns a string in which all non-alphanumeric characters except
-_. |
See also rawurldecode(), urldecode(), urlencode().
Decodes any %## encoding in the given string. The decoded string is returned.
See also urlencode(), rawurlencode(), rawurldecode().
Returns a string in which all non-alphanumeric characters except -_. have been replaced with a percent (%) sign followed by two hex digits and spaces encoded as plus (+) signs. It is encoded the same way that the posted data from a WWW form is encoded, that is the same way as in application/x-www-form-urlencoded media type. This differs from the RFC1738 encoding (see rawurlencode()) in that for historical reasons, spaces are encoded as plus (+) signs. This function is convenient when encoding a string to be used in a query part of an URL, as a convenient way to pass variables to the next page:
Note: Be careful about variables that may match HTML entities. Things like &, © and £ are parsed by the browser and the actual entity is used instead of the desired variable name. This is an obvious hassle that the W3C has been telling people about for years. The reference is here: http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.2 PHP supports changing the argument separator to the W3C-suggested semi-colon through the arg_separator .ini directive. Unfortunately most user agents do not send form data in this semi-colon separated format. A more portable way around this is to use & instead of & as the separator. You don't need to change PHP's arg_separator for this. Leave it as &, but simply encode your URLs using htmlentities()(urlencode($data)).
See also urldecode(), htmlentities(), rawurldecode(), rawurlencode().
Returns the double (floating point) value of var.
Var may be any scalar type. You cannot use doubleval() on arrays or objects.
$var = '122.34343The';
$double_value_of_var = doubleval ($var);
print $double_value_of_var; // prints 122.34343
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See also intval(), strval(), settype() and Type juggling.
Returns false if var is set and has a non-empty or non-zero value; true otherwise.
$var = 0;
if (empty($var)) { // evaluates true
echo '$var is either 0 or not set at all';
}
if (!isset($var)) { // evaluates false
echo '$var is not set at all';
}
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Note that this is meaningless when used on anything which isn't a variable; i.e. empty (addslashes ($name)) has no meaning since it would be checking whether something which isn't a variable is a variable with a false value.
Returns the type of the PHP variable var.
Possibles values for the returned string are:
"boolean"
"integer"
"double"
"string"
"array"
"object"
"resource"
"user function" (PHP 3 only, deprecated)
"unknown type"
For PHP 4, you should use function_exists() and method_exists() to replace the prior usage of gettype() on a function.
See also settype().
Returns the integer value of var, using the specified base for the conversion (the default is base 10).
Var may be any scalar type. You cannot use intval() on arrays or objects.
See also doubleval(), strval(), settype() and Type juggling.
Returns true if var is an array, false otherwise.
See also is_double(), is_float(), is_int(), is_integer(), is_real(), is_string(), is_long(), and is_object().
Returns true if the var parameter is a boolean.
See also is_array(), is_double(), is_float(), is_int(), is_integer(), is_real(), is_string(), is_long(), and is_object().
Returns true if var is a double, false otherwise.
See also is_array(), is_bool(), is_float(), is_int(), is_integer(), is_real(), is_string(), is_long(), and is_object().
This function is an alias for is_double().
See also is_double(), is_bool(), is_real(), is_int(), is_integer(), is_string(), is_object(), is_array(), and is_long().
This function is an alias for is_long().
See also is_bool(), is_double(), is_float(), is_integer(), is_string(), is_real(), is_object(), is_array(), and is_long().
This function is an alias for is_long().
See also is_bool(), is_double(), is_float(), is_int(), is_string(), is_real(), is_object(), is_array(), and is_long().
Returns true if var is an integer (long), false otherwise.
See also is_bool(), is_double(), is_float(), is_int(), is_real(), is_string(), is_object(), is_array(), and is_integer().
Returns true if var is a number or a numeric string, false otherwise.
See also is_bool(), is_double(), is_float(), is_int(), is_real(), is_string(), is_object(), is_array(), and is_integer().
Returns true if var is an object, false otherwise.
See also is_bool(), is_long(), is_int(), is_integer(), is_float(), is_double(), is_real(), is_string(), and is_array().
This function is an alias for is_double().
See also is_bool(), is_long(), is_int(), is_integer(), is_float(), is_double(), is_object(), is_string(), and is_array().
is_resource() returns true if the variable given by the var parameter is a resource, otherwise it returns false.
Resources are things like file or database result handles that are allocated and freed by internal PHP functions and that may need some cleanup when they are no longer in use but haven't been freed by user code.
Returns true if var is a string, false otherwise.
See also is_bool(), is_long(), is_int(), is_integer(), is_float(), is_double(), is_real(), is_object(), and is_array().
Returns true if var exists; false otherwise.
If a variable has been unset with unset(), it will no longer be isset().
This function displays information about the values of variables in a way that's readable by humans. If given a string, integer or double, the value itself will be printed. If given an array, values will be presented in a format that shows keys and elements. Similar notation is used for objects.
Compare print_r() to var_dump().
| Warning |
This function will continue forever if given an array or object that contains a direct or indirect reference to itself or that contains an array or object on a deeper level that does so. This is especially true for print_r($GLOBALS), as $GLOBALS is itself a global variable and contains a reference to itself as such. |
Serialize() returns a string containing a byte-stream representation of value that can be stored anywhere.
This is useful for storing or passing PHP values around without losing their type and structure.
To make the serialized string into a PHP value again, use unserialize(). Serialize() handles the types integer, double, string, array (multidimensional) and object (object properties will be serialized, but methods are lost).
Example 1. Serialize() example
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Set the type of variable var to type.
Possibles values of type are:
"integer"
"double"
"string"
"array"
"object"
Returns true if successful; otherwise returns false.
See also gettype().
Returns the string value of var.
var may be any scalar type. You cannot use strval() on arrays or objects.
See also doubleval(), intval(), settype() and Type juggling.
unserialize() takes a single serialized variable (see serialize()) and converts it back into a PHP value. The converted value is returned, and can be an integer, double, string, array or object. If an object was serialized, its methods are not preserved in the returned value.
Example 1. Unserialize() example
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unset() destroys the specified variables and returns true.
The behavior of unset() inside of a function can vary depending on what type of variable you are attempting to destroy.
If a globalized variable is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.
The above example would output:If a variable that is PASSED BY REFERENCE is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.
function foo(&$bar) {
unset($bar);
$bar = "blah";
}
$bar = 'something';
echo "$bar\n";
foo($bar);
echo "$bar\n";
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If a static variable is unset() inside of a function, unset() unsets the reference to the static variable, rather than the static variable itself.
The above example would output:If you would like to unset() a global variable inside of a function, you can use the $GLOBALS array to do so:
This function returns structured information about an expression that includes its type and value. Arrays are explored recursively with values indented to show structure.
Compare var_dump() to print_r().
These functions are intended for work with WDDX.
Note that all the functions that serialize variables use the first element of an array to determine whether the array is to be serialized into an array or structure. If the first element has string key, then it is serialized into a structure, otherwise, into an array.
This example will produce:
<wddxPacket version='1.0'><header comment='PHP packet'/><data>
<string>PHP to WDDX packet example</string></data></wddxPacket>
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Example 2. Using incremental packets
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This example will produce:
wddx_serialize_value() is used to create a WDDX packet from a single given value. It takes the value contained in var, and an optional comment string that appears in the packet header, and returns the WDDX packet.
wddx_serialize_vars() is used to create a WDDX packet with a structure that contains the serialized representation of the passed variables.
wddx_serialize_vars() takes a variable number of arguments, each of which can be either a string naming a variable or an array containing strings naming the variables or another array, etc.
The above example will produce:
<wddxPacket version='1.0'><header/><data><struct><var name='a'><number>1</number></var>
<var name='b'><number>5.5</number></var><var name='c'><array length='3'>
<string>blue</string><string>orange</string><string>violet</string></array></var>
<var name='d'><string>colors</string></var></struct></data></wddxPacket>
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(PHP 3>= 3.0.7, PHP 4 >= 4.0b2)
wddx_packet_start -- Starts a new WDDX packet with structure inside itUse wddx_packet_start() to start a new WDDX packet for incremental addition of variables. It takes an optional comment string and returns a packet ID for use in later functions. It automatically creates a structure definition inside the packet to contain the variables.
wddx_packet_end() ends the WDDX packet specified by the packet_id and returns the string with the packet.
wddx_add_vars() is used to serialize passed variables and add the result to the packet specified by the packet_id. The variables to be serialized are specified in exactly the same way as wddx_serialize_vars().
XML (eXtensible Markup Language) is a data format for structured document interchange on the Web. It is a standard defined by The World Wide Web consortium (W3C). Information about XML and related technologies can be found at http://www.w3.org/XML/.
This extension uses expat, which can be found at http://www.jclark.com/xml/. The Makefile that comes with expat does not build a library by default, you can use this make rule for that:
libexpat.a: $(OBJS)
ar -rc $@ $(OBJS)
ranlib $@
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Note that if you are using Apache-1.3.7 or later, you already have the required expat library. Simply configure PHP using --with-xml (without any additional path) and it will automatically use the expat library built into Apache.
On UNIX, run configure with the --with-xml option. The expat library should be installed somewhere your compiler can find it. If you compile PHP as a module for Apache 1.3.9 or later, PHP will automatically use the bundled expat library from Apache. You may need to set CPPFLAGS and LDFLAGS in your environment before running configure if you have installed expat somewhere exotic.
Build PHP. Tada! That should be it.
This PHP extension implements support for James Clark's expat in PHP. This toolkit lets you parse, but not validate, XML documents. It supports three source character encodings also provided by PHP: US-ASCII, ISO-8859-1 and UTF-8. UTF-16 is not supported.
This extension lets you create XML parsers and then define handlers for different XML events. Each XML parser also has a few parameters you can adjust.
The XML event handlers defined are:
Table 1. Supported XML handlers
| PHP function to set handler | Event description |
|---|---|
| xml_set_element_handler() | Element events are issued whenever the XML parser encounters start or end tags. There are separate handlers for start tags and end tags. |
| xml_set_character_data_handler() | Character data is roughly all the non-markup contents of XML documents, including whitespace between tags. Note that the XML parser does not add or remove any whitespace, it is up to the application (you) to decide whether whitespace is significant. |
| xml_set_processing_instruction_handler() | PHP programmers should be familiar with processing instructions (PIs) already. <?php ?> is a processing instruction, where php is called the "PI target". The handling of these are application-specific, except that all PI targets starting with "XML" are reserved. |
| xml_set_default_handler() | What goes not to another handler goes to the default handler. You will get things like the XML and document type declarations in the default handler. |
| xml_set_unparsed_entity_decl_handler() | This handler will be called for declaration of an unparsed (NDATA) entity. |
| xml_set_notation_decl_handler() | This handler is called for declaration of a notation. |
| xml_set_external_entity_ref_handler() | This handler is called when the XML parser finds a reference to an external parsed general entity. This can be a reference to a file or URL, for example. See the external entity example for a demonstration. |
The element handler functions may get their element names case-folded. Case-folding is defined by the XML standard as "a process applied to a sequence of characters, in which those identified as non-uppercase are replaced by their uppercase equivalents". In other words, when it comes to XML, case-folding simply means uppercasing.
By default, all the element names that are passed to the handler functions are case-folded. This behaviour can be queried and controlled per XML parser with the xml_parser_get_option() and xml_parser_set_option() functions, respectively.
The following constants are defined for XML error codes (as returned by xml_parse()):
| XML_ERROR_NONE |
| XML_ERROR_NO_MEMORY |
| XML_ERROR_SYNTAX |
| XML_ERROR_NO_ELEMENTS |
| XML_ERROR_INVALID_TOKEN |
| XML_ERROR_UNCLOSED_TOKEN |
| XML_ERROR_PARTIAL_CHAR |
| XML_ERROR_TAG_MISMATCH |
| XML_ERROR_DUPLICATE_ATTRIBUTE |
| XML_ERROR_JUNK_AFTER_DOC_ELEMENT |
| XML_ERROR_PARAM_ENTITY_REF |
| XML_ERROR_UNDEFINED_ENTITY |
| XML_ERROR_RECURSIVE_ENTITY_REF |
| XML_ERROR_ASYNC_ENTITY |
| XML_ERROR_BAD_CHAR_REF |
| XML_ERROR_BINARY_ENTITY_REF |
| XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF |
| XML_ERROR_MISPLACED_XML_PI |
| XML_ERROR_UNKNOWN_ENCODING |
| XML_ERROR_INCORRECT_ENCODING |
| XML_ERROR_UNCLOSED_CDATA_SECTION |
| XML_ERROR_EXTERNAL_ENTITY_HANDLING |
PHP's XML extension supports the Unicode character set through different character encodings. There are two types of character encodings, source encoding and target encoding. PHP's internal representation of the document is always encoded with UTF-8.
Source encoding is done when an XML document is parsed. Upon creating an XML parser, a source encoding can be specified (this encoding can not be changed later in the XML parser's lifetime). The supported source encodings are ISO-8859-1, US-ASCII and UTF-8. The former two are single-byte encodings, which means that each character is represented by a single byte. UTF-8 can encode characters composed by a variable number of bits (up to 21) in one to four bytes. The default source encoding used by PHP is ISO-8859-1.
Target encoding is done when PHP passes data to XML handler functions. When an XML parser is created, the target encoding is set to the same as the source encoding, but this may be changed at any point. The target encoding will affect character data as well as tag names and processing instruction targets.
If the XML parser encounters characters outside the range that its source encoding is capable of representing, it will return an error.
If PHP encounters characters in the parsed XML document that can not be represented in the chosen target encoding, the problem characters will be "demoted". Currently, this means that such characters are replaced by a question mark.
Here are some example PHP scripts parsing XML documents.
This first example displays the stucture of the start elements in a document with indentation.
Example 1. Show XML Element Structure
|
Example 2. Map XML to HTML This example maps tags in an XML document directly to HTML tags. Elements not found in the "map array" are ignored. Of course, this example will only work with a specific XML document type.
|
This example highlights XML code. It illustrates how to use an external entity reference handler to include and parse other documents, as well as how PIs can be processed, and a way of determining "trust" for PIs containing code.
XML documents that can be used for this example are found below the example (xmltest.xml and xmltest2.xml.)
Example 3. External Entity Example
|
Example 4. xmltest.xml
|
This file is included from xmltest.xml:
Which character encoding the parser should use. The following character encodings are supported:
| ISO-8859-1 (default) |
| US-ASCII |
| UTF-8 |
This function allows to use parser inside object. All callback functions could be set with xml_set_element_handler() etc and assumed to be methods of object.
<?php
class xml {
var $parser;
function xml() {
$this->parser = xml_parser_create();
xml_set_object($this->parser,&$this);
xml_set_element_handler($this->parser,"tag_open","tag_close");
xml_set_character_data_handler($this->parser,"cdata");
}
function parse($data) {
xml_parse($this->parser,$data);
}
function tag_open($parser,$tag,$attributes) {
var_dump($parser,$tag,$attributes);
}
function cdata($parser,$cdata) {
var_dump($parser,$cdata);
}
function tag_close($parser,$tag) {
var_dump($parser,$tag);
}
} // end of class xml
$xml_parser = new xml();
$xml_parser->parse("<A ID=\"hallo\">PHP</A>");
?>
|
Sets the element handler functions for the XML parser parser. startElementHandler and endElementHandler are strings containing the names of functions that must exist when xml_parse() is called for parser.
The function named by startElementHandler must accept three parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, name, contains the name of the element for which this handler is called. If case-folding is in effect for this parser, the element name will be in uppercase letters.
The third parameter, attribs, contains an associative array with the element's attributes (if any). The keys of this array are the attribute names, the values are the attribute values. Attribute names are case-folded on the same criteria as element names. Attribute values are not case-folded.
The original order of the attributes can be retrieved by walking through attribs the normal way, using each(). The first key in the array was the first attribute, and so on.
The function named by endElementHandler must accept two parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, name, contains the name of the element for which this handler is called. If case-folding is in effect for this parser, the element name will be in uppercase letters.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handlers are set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
Sets the character data handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
The function named by handler must accept two parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, data, contains the character data as a string.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
(PHP 3>= 3.0.6, PHP 4 )
xml_set_processing_instruction_handler -- Set up processing instruction (PI) handlerSets the processing instruction (PI) handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
A processing instruction has the following format:
You can put PHP code into such a tag, but be aware of one limitation: in an XML PI, the PI end tag (?>) can not be quoted, so this character sequence should not appear in the PHP code you embed with PIs in XML documents. If it does, the rest of the PHP code, as well as the "real" PI end tag, will be treated as character data.The function named by handler must accept three parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, target, contains the PI target.
The third parameter, data, contains the PI data.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
Sets the default handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
The function named by handler must accept two parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, data, contains the character data. This may be the XML declaration, document type declaration, entities or other data for which no other handler exists.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
(PHP 3>= 3.0.6, PHP 4 )
xml_set_unparsed_entity_decl_handler -- Set up unparsed entity declaration handlerSets the unparsed entity declaration handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
This handler will be called if the XML parser encounters an external entity declaration with an NDATA declaration, like the following:
<!ENTITY name {publicId | systemId}
NDATA notationName>
|
See section 4.2.2 of the XML 1.0 spec for the definition of notation declared external entities.
The function named by handler must accept six parameters:
handler (int parser, string entityName, string base, string systemId, string publicId, string notationName)
The first parameter, parser, is a reference to the XML parser calling the handler.
The name of the entity that is about to be defined.
This is the base for resolving the system identifier (systemId) of the external entity. Currently this parameter will always be set to an empty string.
System identifier for the external entity.
Public identifier for the external entity.
Name of the notation of this entity (see xml_set_notation_decl_handler()).
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
Sets the notation declaration handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
A notation declaration is part of the document's DTD and has the following format:
<!NOTATION
name {systemId |
publicId}> |
The function named by handler must accept five parameters:
The first parameter, parser, is a reference to the XML parser calling the handler.
This is the notation's name, as per the notation format described above.
This is the base for resolving the system identifier (systemId) of the notation declaration. Currently this parameter will always be set to an empty string.
System identifier of the external notation declaration.
Public identifier of the external notation declaration.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
(PHP 3>= 3.0.6, PHP 4 )
xml_set_external_entity_ref_handler -- set up external entity reference handlerSets the notation declaration handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.
The function named by handler must accept five parameters, and should return an integer value. If the value returned from the handler is false (which it will be if no value is returned), the XML parser will stop parsing and xml_get_error_code() will return XML_ERROR_EXTERNAL_ENTITY_HANDLING.
The first parameter, parser, is a reference to the XML parser calling the handler.
The second parameter, openEntityNames, is a space-separated list of the names of the entities that are open for the parse of this entity (including the name of the referenced entity).
This is the base for resolving the system identifier (systemid) of the external entity. Currently this parameter will always be set to an empty string.
The fourth parameter, systemId, is the system identifier as specified in the entity declaration.
The fifth parameter, publicId, is the public identifier as specified in the entity declaration, or an empty string if none was specified; the whitespace in the public identifier will have been normalized as required by the XML spec.
If a handler function is set to an empty string, or false, the handler in question is disabled.
True is returned if the handler is set up, false if parser is not a parser.
There is currently no support for object/method handlers. See xml_set_object() for using the XML parser within an object.
A reference to the XML parser to use.
Chunk of data to parse. A document may be parsed piece-wise by calling xml_parse() several times with new data, as long as the isFinal parameter is set and true when the last data is parsed.
If set and true, data is the last piece of data sent in this parse.
When the XML document is parsed, the handlers for the configured events are called as many times as necessary, after which this function returns true or false.
True is returned if the parse was successful, false if it was not successful, or if parser does not refer to a valid parser. For unsuccessful parses, error information can be retrieved with xml_get_error_code(), xml_error_string(), xml_get_current_line_number(), xml_get_current_column_number() and xml_get_current_byte_index().
A reference to the XML parser to get error code from.
This function returns false if parser does not refer to a valid parser, or else it returns one of the error codes listed in the error codes section.
An error code from xml_get_error_code().
Returns a string with a textual description of the error code code, or false if no description was found.
A reference to the XML parser to get line number from.
This function returns false if parser does not refer to a valid parser, or else it returns which line the parser is currently at in its data buffer.
A reference to the XML parser to get column number from.
This function returns false if parser does not refer to a valid parser, or else it returns which column on the current line (as given by xml_get_current_line_number()) the parser is currently at.
A reference to the XML parser to get byte index from.
This function returns false if parser does not refer to a valid parser, or else it returns which byte index the parser is currently at in its data buffer (starting at 0).
This function parses an XML file into 2 parallel array structures, one (index) containing pointers to the location of the appropriate values in the values array. These last two parameters must be passed by reference.
Below is an example that illustrates the internal structure of the arrays being generated by the function. We use a simple note tag embeded inside a para tag, and then we parse this an print out the structures generated:
$simple = "<para><note>simple note</note></para>";
$p = xml_parser_create();
xml_parse_into_struct($p,$simple,&$vals,&$index);
xml_parser_free($p);
echo "Index array\n";
print_r($index);
echo "\nVals array\n";
print_r($vals);
|
Index array
Array
(
[PARA] => Array
(
[0] => 0
[1] => 2
)
[NOTE] => Array
(
[0] => 1
)
)
Vals array
Array
(
[0] => Array
(
[tag] => PARA
[type] => open
[level] => 1
)
[1] => Array
(
[tag] => NOTE
[type] => complete
[level] => 2
[value] => simple note
)
[2] => Array
(
[tag] => PARA
[type] => close
[level] => 1
)
)
|
Event-driven parsing (based on the expat library) can get complicated when you have an XML document that is complex. This function does not produce a DOM style object, but it generates structures amenable of being transversed in a tree fashion. Thus, we can create objects representing the data in the XML file easily. Let's consider the following XML file representing a small database of aminoacids information:
Example 1. moldb.xml - small database of molecular information
|
Example 2. parsemoldb.php - parses moldb.xml into and array of molecular objects
|
A reference to the XML parser to free.
This function returns false if parser does not refer to a valid parser, or else it frees the parser and returns true.
A reference to the XML parser to set an option in.
Which option to set. See below.
The option's new value.
This function returns false if parser does not refer to a valid parser, or if the option could not be set. Else the option is set and true is returned.
The following options are available:
Table 1. XML parser options
| Option constant | Data type | Description |
|---|---|---|
| XML_OPTION_CASE_FOLDING | integer | Controls whether case-folding is enabled for this XML parser. Enabled by default. |
| XML_OPTION_TARGET_ENCODING | string | Sets which target encoding to use in this XML parser. By default, it is set to the same as the source encoding used by xml_parser_create(). Supported target encodings are ISO-8859-1, US-ASCII and UTF-8. |
A reference to the XML parser to get an option from.
Which option to fetch. See xml_parser_set_option() for a list of options.
This function returns false if parser does not refer to a valid parser, or if the option could not be set. Else the option's value is returned.
See xml_parser_set_option() for the list of options.
(PHP 3>= 3.0.6, PHP 4 )
utf8_decode -- Converts a string with ISO-8859-1 characters encoded with UTF-8 to single-byte ISO-8859-1.This function decodes data, assumed to be UTF-8 encoded, to ISO-8859-1.
See utf8_encode() for an explaination of UTF-8 encoding.
This function encodes the string data to UTF-8, and returns the encoded version. UTF-8 is a standard mechanism used by Unicodefor encoding wide character values into a byte stream. UTF-8 is transparent to plain ASCII characters, is self-synchronized (meaning it is possible for a program to figure out where in the bytestream characters start) and can be used with normal string comparison functions for sorting and such. PHP encodes UTF-8 characters in up to four bytes, like this:
Each b represents a bit that can be used to store character data.XSLT (Extensible Stylesheet Language (XSL) Transformations) is a language for transforming XML documents into other XML documents. It is a standard defined by The World Wide Web consortium (W3C). Information about XSLT and related technologies can be found at http://www.w3.org/TR/xslt.
This extension uses Sabloton and expat, which can both be found at http://www.gingerall.com/. Binaries are provided as well as source.
On UNIX, run configure with the --with-sablot. The Sablotron library should be installed somewhere your compiler can find it.
This PHP extension implements support Sablotron from Ginger Alliance in PHP. This toolkit lets you transform XML documents into other documents, including new XML documents, but also into HTML or other target formats. It basically provides a standardized and portable template mechanism, separating content and design of a website.
A reference to the XSLT parser.
This function returns false if parser does not refer to a valid parser, or if the closing of the logfile fails. Otherwise it returns true.
This function returns a handle for a new XSL processor. This handle is needed in all subsequent calls to XSL functions.
Return the current error number of the given XSL processor. If no handle is given, the last error number that occured anywhere is returned.
Return the current error string of the given XSL processor. If no handle is given, the last error string that occured anywhere is returned.
Fetch a result buffer from the XSLT processor identified by the given handle. If no result name is given, the buffer named "/_result" is fetched.
This function will begin the output transformation on your data. From the point you call xslt_output_begintransform() till the point you call xslt_output_endtransform() all output will be transformed through the xslt stylesheet given by the first argument.
Example 1. Transforming output through an XSLT stylesheet, using the DOM-XML functions for xml generation
|
(PHP 4 >= 4.0.3)
xslt_output_endtransform -- End an output transformation started with xslt_output_begintransformThe xslt_output_endtransform() ends the output transformation started by the xslt_output_begintransform() function. You must call this function in order to see the results of the output transformation.
The xslt_process() takes a string containing the XSLT stylesheet as its first argument, it takes a second string containing the XML data you want to transform and then a third string containing the results of the transformation. xslt_process() will return true on success and false on failure, to get the error number and error string if an error occurs use the xslt_errno() and xslt_error() functions.
Example 1. Using the xslt_process() to transform three strings
|
bool xslt_run ([resource xh
string xslt_file
string xml_data_file
string result
array xslt_params
array xslt_args]]])
Process the xml_data_file by applying the xslt_file stylesheet to it. The stylesheet has access to xslt_params and the processor is started with xslt_args. The result of the XSLT transformation is placed in the named buffer (default is "/_result").
This extension offers a PHP interface to the YAZ toolkit that implements the Z39.50 protocol for information retrieval. With this extension you can easily implement a Z39.50 origin (client) that searches Z39.50 targets (servers) in parallel.
YAZ is available at http://www.indexdata.dk/yaz/. You can find news information, example scripts, etc. for this extension at http://www.indexdata.dk/phpyaz/.
The module hides most of the complexity of Z39.50 so it should be fairly easy to use. It supports persistent stateless connections very similar to those offered by the various SQL APIs that are available for PHP. This means that sessions are stateless but shared amongst users, thus saving the connect and initialize phase steps in most cases.
Compile YAZ and install it. Build PHP with your favourite modules and add option --with-yaz. Your task is roughly the following:
PHP/YAZ keeps track of connections with targets (Z-Associations). A positive integer represents the ID of a particular association.
The script below demonstrates the parallel searching feature of the API. When invoked with no arguments it prints a query form; else (arguments are supplied) it searches the targets as given in in array host.
Example 1. YAZ()
|
Returns additional error message for target (last request). An empty string is returned if last operation was a success or if no additional information was provided by the target.
Closes a connection to a target. The application can no longer refer to the target with the given ID.
Yaz_connect() prepares for a connection to a Z39.50 target. The zurl argument takes the form host[:port][/database]. If port is omitted 210 is used. If database is omitted Default is used. This function is non-blocking and doesn't attempt to establish a socket - it merely prepares a connect to be performed later when yaz_wait() is called.
Returns error for target (last request). A positive value is returned if the target returned a diagnostic code; a value of zero is returned if no errors occurred (success); negative value is returned for other errors targets didn't indicate the error in question.
Yaz_errno() should be called after network activity for each target - (after yaz_wait() returns) to determine the success or failure of the last operation (e.g. search).
Returns error message for target (last request). An empty string is returned if last operation was a success.
Yaz_error() returns a english message corresponding to the last error number as returned by yaz_errno().
This function is used in conjunction with yaz_search() to specify the maximum number of records to retrieve (number) and the first record position (start). If this function is not invoked (only yaz_search()) start is set to 1 and number is set to 10.
Returns true on success; false on error.
Returns record at position or empty string if no record exists at given position.
The yaz_record() function inspects a record in the current result set at the position specified. If no database record exists at the given position an empty string is returned. The argument, type, specifies the form of the returned record. If type is "string" the record is returned in a string representation suitable for printing (for XML and SUTRS). If type is "array" the record is returned as an array representation (for structured records).
yaz_search() prepares for a search on the target with given id. The type represents the query type - only "rpn" is supported now in which case the third argument specifies a Type-1 query (RPN). Like yaz_connect() this function is non-blocking and only prepares for a search to be executed later when yaz_wait() is called.
The RPN query is a textual represenation of the Type-1 query as defined by the Z39.50 standard. However, in the text representation as used by YAZ a prefix notation is used, that is the operater precedes the operands. The query string is a sequence of tokens where white space is ignored is ignored unless surrounded by double quotes. Tokens beginning with an at-character (@) are considered operators, otherwise they are treated as search terms.
Table 1. RPN Operators
| Syntax | Description |
|---|---|
| @and query1 query2 | intersection of query1 and query2 |
| @or query1 query2 | union of query1 and query2 |
| @not query1 query2 | query1 and not query2 |
| @set name | result set reference |
| @attrset set query | specifies attribute-set for query. This construction is only allowed once - in the beginning of the whole query |
| @attr set type=value query | applies attribute to query. The type and value are integers specifying the attribute-type and attribute-value respectively. The set, if given, specifies the attribute-set. |
The following illustrates valid query constructions:
Matches documents where "computer" occur. No attributes are specified.Matches documents where "donald knuth" occur.
Attribute type is 1 (Bib-1 use), attribute value is 4 Title), so this should match documents where "art" occur in the title.
The query as a whole uses the GILS attributeset. The query matches documents where "art" occur in the title and in which "donald knuth" occur in the author.
(PHP 4 >= 4.0.1)
yaz_syntax -- Specifies the object identifier (OID) for the preferred record syntax for retrieval.The syntax may be specified in a raw dot-notation (like 1.2.840.10003.5.10) or as one of the known record syntaxes (sutrs, usmarc, grs1, xml, etc.). This function is used in conjunction with yaz_search() to specify the preferred record syntax for retrieval.
This function carries out networked (blocked) activity for outstanding requests which have been prepared by the functions yaz_connect(), yaz_search(). yaz_wait() returns when all targets have either completed all requests or otherwise completed (in case of errors).
NIS (formerly called Yellow Pages) allows network management of important administrative files (e.g. the password file). For more information refer to the NIS manpage and Introduction to YP/NIS. There is also a book called Managing NFS and NIS by Hal Stern.
To get these functions to work, you have to configure PHP with --with-yp(PHP 3) or --enable-yp(PHP 4).
Yp_get_default_domain() returns the default domain of the node or FALSE. Can be used as the domain parameter for successive NIS calls.
A NIS domain can be described a group of NIS maps. Every host that needs to look up information binds itself to a certain domain. Refer to the documents mentioned at the beginning for more detailed information.
Yp_order() returns the order number for a map or FALSE.
See also yp-get-default-domain().
Yp_master() returns the machine name of the master NIS server for a map.
See also yp-get-default-domain().
Yp_match() returns the value associated with the passed key out of the specified map or FALSE. This key must be exact.
In this case this could be: joe:##joe:11111:100:Joe User:/home/j/joe:/usr/local/bin/bash
See also yp-get-default-domain()
Yp_first() returns the first key-value pair from the named map in the named domain, otherwise FALSE.
See also yp-get-default-domain()
Yp_next() returns the next key-value pair in the named map after the specified key or FALSE.
See also yp-get-default-domain().
This module uses the functions of zlib by Jean-loup Gailly and Mark Adler to transparently read and write gzip (.gz) compressed files. You have to use a zlib version >= 1.0.9 with this module.
This module contains versions of most of the filesystem functions which work with gzip-compressed files (and uncompressed files, too, but not with sockets).
Note: The current CVS version 4.0.4-dev introduces a fopen-wrapper for .gz-files, so that you can use a special 'zlib:' URL to access compressed files transparently using the normal f*() file access functions if you prepend the filename or path with a 'zlib:' prefix when calling fopen().
This feature requires a C runtime library that provides the fopencookie() function. To my current knowledge the GNU libc is the only library that provides this feature.
Opens a temporary file and writes a test string to it, then it prints out the content of this file twice.
Example 1. Small Zlib Example
|
The gz-file pointed to by zp is closed.
Returns true on success and false on failure.
The gz-file pointer must be valid, and must point to a file successfully opened by gzopen().
Returns true if the gz-file pointer is at EOF or an error occurs; otherwise returns false.
The gz-file pointer must be valid, and must point to a file successfully opened by gzopen().
Identical to readgzfile(), except that gzfile() returns the file in an array.
You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.
See also readgzfile(), and gzopen().
Returns a string containing a single (uncompressed) character read from the file pointed to by zp. Returns FALSE on EOF (as does gzeof()).
The gz-file pointer must be valid, and must point to a file successfully opened by gzopen().
Returns a (uncompressed) string of up to length - 1 bytes read from the file pointed to by fp. Reading ends when length - 1 bytes have been read, on a newline, or on EOF (whichever comes first).
If an error occurs, returns false.
The file pointer must be valid, and must point to a file successfully opened by gzopen().
Identical to gzgets(), except that gzgetss() attempts to strip any HTML and PHP tags from the text it reads.
You can use the optional third parameter to specify tags which should not be stripped.
Note: Allowable_tags was added in PHP 3.0.13, PHP4B3.
See also gzgets(), gzopen(), and strip_tags().
Opens a gzip (.gz) file for reading or writing. The mode parameter is as in fopen() ("rb" or "wb") but can also include a compression level ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman only compression as in "wb1h". (See the description of deflateInit2 in zlib.h for more information about the strategy parameter.)
Gzopen() can be used to read a file which is not in gzip format; in this case gzread() will directly read from the file without decompression.
Gzopen() returns a file pointer to the file opened, after that, everything you read from this file descriptor will be transparently decompressed and what you write gets compressed.
If the open fails, the function returns false.
You can use the optional third parameter and set it to "1", if you want to search for the file in the include_path, too.
See also gzclose().
Reads to EOF on the given gz-file pointer and writes the (uncompressed) results to standard output.
If an error occurs, returns false.
The file pointer must be valid, and must point to a file successfully opened by gzopen().
The gz-file is closed when gzpassthru() is done reading it (leaving zp useless).
gzread() reads up to length bytes from the gz-file pointer referenced by zp. Reading stops when length (uncompressed) bytes have been read or EOF is reached, whichever comes first.
// get contents of a gz-file into a string
$filename = "/usr/local/something.txt.gz";
$zd = gzopen ($filename, "r");
$contents = gzread ($zd, 10000);
gzclose ($zd);
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See also gzwrite(), gzopen(), gzgets(), gzgetss(), gzfile(), and gzpassthru().
Sets the file position indicator for zp to the beginning of the file stream.
If an error occurs, returns 0.
The file pointer must be valid, and must point to a file successfully opened by gzopen().
Sets the file position indicator for the file referenced by zp to offset bytes into the file stream. Equivalent to calling (in C) gzseek( zp, offset, SEEK_SET ).
If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; gzseek then compresses a sequence of zeroes up to the new starting position.
Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.
See also gztell() and gzrewind().
Returns the position of the file pointer referenced by zp; i.e., its offset into the file stream.
If an error occurs, returns false.
The file pointer must be valid, and must point to a file successfully opened by gzopen().
See also gzopen(), gzseek() and gzrewind().
Gzwrite() writes the contents of string to the gz-file stream pointed to by zp. If the length argument is given, writing will stop after length (uncompressed) bytes have been written or the end of string is reached, whichever comes first.
Note that if the length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from string.
Reads a file, decompresses it and writes it to standard output.
Readgzfile() can be used to read a file which is not in gzip format; in this case readgzfile() will directly read from the file without decompression.
Returns the number of (uncompressed) bytes read from the file. If an error occurs, false is returned and unless the function was called as @readgzfile, an error message is printed.
The file filename will be opened from the filesystem and its contents written to standard output.
You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.
See also gzpassthru(), gzfile(), and gzopen().
This function returns a gzip-compressed version of the input data or false on errors. The optional parameter level can be given as 0 for no compression up to 9 for maximum compression.
See also gzuncompress().
This function takes data compressed by gzcompress() and returns the orignial uncompressed data or false on error. The function will return an error if the uncompressed data is more than 256 times the lenght of the compressed input data or more than the optional parameter length.
See also gzcompress().
PHP 3.0 is rewritten from the ground up. It has a proper parser that is much more robust and consistent than 2.0's. 3.0 is also significantly faster, and uses less memory. However, some of these improvements have not been possible without compatibility changes, both in syntax and functionality.
In addition, PHP's developers have tried to clean up both PHP's syntax and semantics in version 3.0, and this has also caused some incompatibilities. In the long run, we believe that these changes are for the better.
This chapter will try to guide you through the incompatibilities you might run into when going from PHP/FI 2.0 to PHP 3.0 and help you resolve them. New features are not mentioned here unless necessary.
A conversion program that can automatically convert your old PHP/FI 2.0 scripts exists. It can be found in the convertor subdirectory of the PHP 3.0 distribution. This program only catches the syntax changes though, so you should read this chapter carefully anyway.
The first thing you probably will notice is that PHP's start and end tags have changed. The old <? > form has been replaced by three new possible forms:
The `alternative' way to write if/elseif/else statements, using if(); elseif(); else; endif; cannot be efficiently implemented without adding a large amount of complexity to the 3.0 parser. Because of this, the syntax has been changed:
Just like with if..endif, the syntax of while..endwhile has changed as well:
| Warning |
If you use the old while..endwhile syntax in PHP 3.0, you will get a never-ending loop. |
PHP/FI 2.0 used the left side of expressions to determine what type the result should be. PHP 3.0 takes both sides into account when determining result types, and this may cause 2.0 scripts to behave unexpectedly in 3.0.
Consider this example:
In PHP/FI 2.0, this would display both of $a's indices. In PHP 3.0, it wouldn't display anything. The reason is that in PHP 2.0, because the left argument's type was string, a string comparison was made, and indeed "" does not equal "0", and the loop went through. In PHP 3.0, when a string is compared with an integer, an integer comparison is made (the string is converted to an integer). This results in comparing atoi("") which is 0, and variablelist which is also 0, and since 0==0, the loop doesn't go through even once.The fix for this is simple. Replace the while statement with:
PHP 3.0's error messages are usually more accurate than 2.0's were, but you no longer get to see the code fragment causing the error. You will be supplied with a file name and a line number for the error, though.
In PHP 3.0 boolean evaluation is short-circuited. This means that in an expression like (1 || test_me()), the function test_me() would not be executed since nothing can change the result of the expression after the 1.
This is a minor compatibility issue, but may cause unexpected side-effects.
Most internal functions have been rewritten so they return TRUE when successful and FALSE when failing, as opposed to 0 and -1 in PHP/FI 2.0, respectively. The new behaviour allows for more logical code, like $fp = fopen("/your/file") or fail("darn!");. Because PHP/FI 2.0 had no clear rules for what functions should return when they failed, most such scripts will probably have to be checked manually after using the 2.0 to 3.0 convertor.
The PHP 3.0 Apache module no longer supports Apache versions prior to 1.2. Apache 1.2 or later is required.
echo() no longer supports a format string. Use the printf() function instead.
In PHP/FI 2.0, an implementation side-effect caused $foo[0] to have the same effect as $foo. This is not true for PHP 3.0.
Reading arrays with $array[] is no longer supported
That is, you cannot traverse an array by having a loop that does $data = $array[]. Use current() and next() instead.
Also, $array1[] = $array2 does not append the values of $array2 to $array1, but appends $array2 as the last entry of $array1. See also multidimensional array support.
"+" is no longer overloaded as a concatenation operator for strings, instead it converts it's arguments to numbers and performs numeric addition. Use "." instead.
All functions look like this:
void php3_foo(INTERNAL_FUNCTION_PARAMETERS) {
}
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Arguments are always of type pval. This type contains a union which has the actual type of the argument. So, if your function takes two arguments, you would do something like the following at the top of your function:
When you change any of the passed parameters, whether they are sent by reference or by value, you can either start over with the parameter by calling pval_destructor on it, or if it's an ARRAY you want to add to, you can use functions similar to the ones in internal_functions.h which manipulate return_value as an ARRAY.
Also if you change a parameter to IS_STRING make sure you first assign the new estrdup()'ed string and the string length, and only later change the type to IS_STRING. If you change the string of a parameter which already IS_STRING or IS_ARRAY you should run pval_destructor on it first.
A function can take a variable number of arguments. If your function can take either 2 or 3 arguments, use the following:
The type of each argument is stored in the pval type field. This type can be any of the following:
Table B-1. PHP Internal Types
| IS_STRING | String |
| IS_DOUBLE | Double-precision floating point |
| IS_LONG | Long integer |
| IS_ARRAY | Array |
| IS_EMPTY | None |
| IS_USER_FUNCTION | ?? |
| IS_INTERNAL_FUNCTION | ?? (if some of these cannot be passed to a function - delete) |
| IS_CLASS | ?? |
| IS_OBJECT | ?? |
If you get an argument of one type and would like to use it as another, or if you just want to force the argument to be of a certain type, you can use one of the following conversion functions:
convert_to_long(arg1);
convert_to_double(arg1);
convert_to_string(arg1);
convert_to_boolean_long(arg1); /* If the string is "" or "0" it becomes 0, 1 otherwise */
convert_string_to_number(arg1); /* Converts string to either LONG or DOUBLE depending on string */
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These function all do in-place conversion. They do not return anything.
The actual argument is stored in a union; the members are:
IS_STRING: arg1->value.str.val
IS_LONG: arg1->value.lval
IS_DOUBLE: arg1->value.dval
Any memory needed by a function should be allocated with either emalloc() or estrdup(). These are memory handling abstraction functions that look and smell like the normal malloc() and strdup() functions. Memory should be freed with efree().
There are two kinds of memory in this program: memory which is returned to the parser in a variable, and memory which you need for temporary storage in your internal function. When you assign a string to a variable which is returned to the parser you need to make sure you first allocate the memory with either emalloc() or estrdup(). This memory should NEVER be freed by you, unless you later in the same function overwrite your original assignment (this kind of programming practice is not good though).
For any temporary/permanent memory you need in your functions/library you should use the three emalloc(), estrdup(), and efree() functions. They behave EXACTLY like their counterpart functions. Anything you emalloc() or estrdup() you have to efree() at some point or another, unless it's supposed to stick around until the end of the program; otherwise, there will be a memory leak. The meaning of "the functions behave exactly like their counterparts" is: if you efree() something which was not emalloc()'ed nor estrdup()'ed you might get a segmentation fault. So please take care and free all of your wasted memory.
If you compile with "-DDEBUG", PHP 3 will print out a list of all memory that was allocated using emalloc() and estrdup() but never freed with efree() when it is done running the specified script.
A number of macros are available which make it easier to set a variable in the symbol table:
SET_VAR_STRING(name,value) [1]
SET_VAR_DOUBLE(name,value)
SET_VAR_LONG(name,value)
Symbol tables in PHP 3.0 are implemented as hash tables. At any given time, &symbol_table is a pointer to the 'main' symbol table, and active_symbol_table points to the currently active symbol table (these may be identical like in startup, or different, if you're inside a function).
The following examples use 'active_symbol_table'. You should replace it with &symbol_table if you specifically want to work with the 'main' symbol table. Also, the same functions may be applied to arrays, as explained below.
If you want to define a new array in a symbol table, you should do the following.
First, you may want to check whether it exists and abort appropiately, using hash_exists() or hash_find().
Next, initialize the array:
Here's how to add new entries to it:
Example B-6. Adding entries to a new array
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hash_next_index_insert() uses more or less the same logic as "$foo[] = bar;" in PHP 2.0.
If you are building an array to return from a function, you can initialize the array just like above by doing:
if (array_init(return_value) == FAILURE) { failed...; }
|
...and then adding values with the helper functions:
add_next_index_long(return_value,long_value); add_next_index_double(return_value,double_value); add_next_index_string(return_value,estrdup(string_value)); |
Of course, if the adding isn't done right after the array initialization, you'd probably have to look for the array first:
pval *arr;
if (hash_find(active_symbol_table,"foo",sizeof("foo"),(void **)&arr)==FAILURE) { can't find... }
else { use arr->value.ht... }
|
Note that hash_find receives a pointer to a pval pointer, and not a pval pointer.
Just about any hash function returns SUCCESS or FAILURE (except for hash_exists(), which returns a boolean truth value).
A number of macros are available to make returning values from a function easier.
The RETURN_* macros all set the return value and return from the function:
RETURN
RETURN_FALSE
RETURN_TRUE
RETURN_LONG(l)
RETURN_STRING(s,dup) If dup is true, duplicates the string
RETURN_STRINGL(s,l,dup) Return string (s) specifying length (l).
RETURN_DOUBLE(d)
The RETVAL_* macros set the return value, but do not return.
RETVAL_FALSE
RETVAL_TRUE
RETVAL_LONG(l)
RETVAL_STRING(s,dup) If dup is true, duplicates the string
RETVAL_STRINGL(s,l,dup) Return string (s) specifying length (l).
RETVAL_DOUBLE(d)
The string macros above will all estrdup() the passed 's' argument, so you can safely free the argument after calling the macro, or alternatively use statically allocated memory.
If your function returns boolean success/error responses, always use RETURN_TRUE and RETURN_FALSE respectively.
Your function can also return a complex data type such as an object or an array.
Returning an object:
Call object_init(return_value).
Fill it up with values. The functions available for this purpose are listed below.
Possibly, register functions for this object. In order to obtain values from the object, the function would have to fetch "this" from the active_symbol_table. Its type should be IS_OBJECT, and it's basically a regular hash table (i.e., you can use regular hash functions on .value.ht). The actual registration of the function can be done using:
add_method( return_value, function_name, function_ptr );
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The functions used to populate an object are:
add_property_long( return_value, property_name, l ) - Add a property named 'property_name', of type long, equal to 'l'
add_property_double( return_value, property_name, d ) - Same, only adds a double
add_property_string( return_value, property_name, str ) - Same, only adds a string
add_property_stringl( return_value, property_name, str, l ) - Same, only adds a string of length 'l'
Returning an array:
Call array_init(return_value).
Fill it up with values. The functions available for this purpose are listed below.
The functions used to populate an array are:
add_assoc_long(return_value,key,l) - add associative entry with key 'key' and long value 'l'
add_assoc_double(return_value,key,d)
add_assoc_string(return_value,key,str,duplicate)
add_assoc_stringl(return_value,key,str,length,duplicate) specify the string length
add_index_long(return_value,index,l) - add entry in index 'index' with long value 'l'
add_index_double(return_value,index,d)
add_index_string(return_value,index,str)
add_index_stringl(return_value,index,str,length) - specify the string length
add_next_index_long(return_value,l) - add an array entry in the next free offset with long value 'l'
add_next_index_double(return_value,d)
add_next_index_string(return_value,str)
add_next_index_stringl(return_value,str,length) - specify the string length
PHP 3.0 has a standard way of dealing with various types of resources. This replaces all of the local linked lists in PHP 2.0.
Available functions:
php3_list_insert(ptr, type) - returns the 'id' of the newly inserted resource
php3_list_delete(id) - delete the resource with the specified id
php3_list_find(id,*type) - returns the pointer of the resource with the specified id, updates 'type' to the resource's type
Typical list code would look like this:
Example B-8. Using an existing resource
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PHP 3.0 has a standard way of storing persistent resources (i.e., resources that are kept in between hits). The first module to use this feature was the MySQL module, and mSQL followed it, so one can get the general impression of how a persistent resource should be used by reading mysql.c. The functions you should look at are:
| php3_mysql_do_connect |
| php3_mysql_connect() |
| php3_mysql_pconnect() |
The general idea of persistence modules is this:
Code all of your module to work with the regular resource list mentioned in section (9).
Code extra connect functions that check if the resource already exists in the persistent resource list. If it does, register it as in the regular resource list as a pointer to the persistent resource list (because of 1., the rest of the code should work immediately). If it doesn't, then create it, add it to the persistent resource list AND add a pointer to it from the regular resource list, so all of the code would work since it's in the regular resource list, but on the next connect, the resource would be found in the persistent resource list and be used without having to recreate it. You should register these resources with a different type (e.g. LE_MYSQL_LINK for non-persistent link and LE_MYSQL_PLINK for a persistent link).
If you read mysql.c, you'll notice that except for the more complex connect function, nothing in the rest of the module has to be changed.
The very same interface exists for the regular resource list and the persistent resource list, only 'list' is replaced with 'plist':
php3_plist_insert(ptr, type) - returns the 'id' of the newly inserted resource
php3_plist_delete(id) - delete the resource with the specified id
php3_plist_find(id,*type) - returns the pointer of the resource with the specified id, updates 'type' to the resource's type
However, it's more than likely that these functions would prove to be useless for you when trying to implement a persistent module. Typically, one would want to use the fact that the persistent resource list is really a hash table. For instance, in the MySQL/mSQL modules, when there's a pconnect() call (persistent connect), the function builds a string out of the host/user/passwd that were passed to the function, and hashes the SQL link with this string as a key. The next time someone calls a pconnect() with the same host/user/passwd, the same key would be generated, and the function would find the SQL link in the persistent list.
Until further documented, you should look at mysql.c or msql.c to see how one should use the plist's hash table abilities.
One important thing to note: resources going into the persistent resource list must *NOT* be allocated with PHP's memory manager, i.e., they should NOT be created with emalloc(), estrdup(), etc. Rather, one should use the regular malloc(), strdup(), etc. The reason for this is simple - at the end of the request (end of the hit), every memory chunk that was allocated using PHP's memory manager is deleted. Since the persistent list isn't supposed to be erased at the end of a request, one mustn't use PHP's memory manager for allocating resources that go to it.
When you register a resource that's going to be in the persistent list, you should add destructors to it both in the non-persistent list and in the persistent list. The destructor in the non-persistent list destructor shouldn't do anything. The one in the persistent list destructor should properly free any resources obtained by that type (e.g. memory, SQL links, etc). Just like with the non-persistent resources, you *MUST* add destructors for every resource, even it requires no destructotion and the destructor would be empty. Remember, since emalloc() and friends aren't to be used in conjunction with the persistent list, you mustn't use efree() here either.
Many of the features of PHP 3 can be configured at runtime. These configuration directives can appear in either the designated php3.ini file, or in the case of the Apache module version in the Apache .conf files. The advantage of having them in the Apache .conf files is that they can be configured on a per-directory basis. This means that one directory may have a certain safemodeexecdir for example, while another directory may have another. This configuration granularity is especially handy when a server supports multiple virtual hosts.
The steps required to add a new directive:
Add directive to php3_ini_structure struct in mod_php3.h.
In main.c, edit the php3_module_startup function and add the appropriate cfg_get_string() or cfg_get_long() call.
Add the directive, restrictions and a comment to the php3_commands structure in mod_php3.c. Note the restrictions part. RSRC_CONF are directives that can only be present in the actual Apache .conf files. Any OR_OPTIONS directives can be present anywhere, include normal .htaccess files.
In either php3take1handler() or php3flaghandler() add the appropriate entry for your directive.
In the configuration section of the _php3_info() function in functions/info.c you need to add your new directive.
And last, you of course have to use your new directive somewhere. It will be addressable as php3_ini.directive.
To call user functions from an internal function, you should use the call_user_function() function.
call_user_function() returns SUCCESS on success, and FAILURE in case the function cannot be found. You should check that return value! If it returns SUCCESS, you are responsible for destroying the retval pval yourself (or return it as the return value of your function). If it returns FAILURE, the value of retval is undefined, and you mustn't touch it.
All internal functions that call user functions must be reentrant. Among other things, this means they must not use globals or static variables.
call_user_function() takes six arguments:
This is a pointer to an object on which the function is invoked. This should be NULL if a global function is called. If it's not NULL (i.e. it points to an object), the function_table argument is ignored, and instead taken from the object's hash. The object *may* be modified by the function that is invoked on it (that function will have access to it via $this). If for some reason you don't want that to happen, send a copy of the object instead.
The name of the function to call. Must be a pval of type IS_STRING with function_name.str.val and function_name.str.len set to the appropriate values. The function_name is modified by call_user_function() - it's converted to lowercase. If you need to preserve the case, send a copy of the function name instead.
A pointer to a pval structure, into which the return value of the invoked function is saved. The structure must be previously allocated - call_user_function() does NOT allocate it by itself.
An array of pointers to values that will be passed as arguments to the function, the first argument being in offset 0, the second in offset 1, etc. The array is an array of pointers to pval's; The pointers are sent as-is to the function, which means if the function modifies its arguments, the original values are changed (passing by reference). If you don't want that behavior, pass a copy instead.
To report errors from an internal function, you should call the php3_error() function. This takes at least two parameters -- the first is the level of the error, the second is the format string for the error message (as in a standard printf() call), and any following arguments are the parameters for the format string. The error levels are:
Notices are not printed by default, and indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script. For example, trying to access the value of a variable which has not been set, or calling stat() on a file that doesn't exist.
Warnings are printed by default, but do not interrupt script execution. These indicate a problem that should have been trapped by the script before the call was made. For example, calling ereg() with an invalid regular expression.
Errors are also printed by default, and execution of the script is halted after the function returns. These indicate errors that can not be recovered from, such as a memory allocation problem.
Parse errors should only be generated by the parser. The code is listed here only for the sake of completeness.
This is like an E_ERROR, except it is generated by the core of PHP. Functions should not generate this type of error.
This is like an E_WARNING, except it is generated by the core of PHP. Functions should not generate this type of error.
This is like an E_ERROR, except it is generated by the Zend Scripting Engine. Functions should not generate this type of error.
This is like an E_WARNING, except it is generated by the Zend Scripting Engine. Functions should not generate this type of error.
This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error(). Functions should not generate this type of error.
This is like an E_WARNING, except it is generated by using the PHP function trigger_error(). Functions should not generate this type of error.
This is like an E_NOTICE, except it is generated by using the PHP function trigger_error(). Functions should not generate this type of error.
PHP's internal debugger is useful for tracking down evasive bugs. The debugger works by connecting to a TCP port for every time PHP starts up. All error messages from that request will be sent to this TCP connection. This information is intended for "debugging server" that can run inside an IDE or programmable editor (such as Emacs).
How to set up the debugger:
Set up a TCP port for the debugger in the configuration file (debugger.port) and enable it (debugger.enabled).
Set up a TCP listener on that port somewhere (for example socket -l -s 1400 on UNIX).
In your code, run "debugger_on(host)", where host is the IP number or name of the host running the TCP listener.
Note: The code for the debugger has not been ported to PHP 4, at the present time only PHP 3 supports the debugger code.
The debugger protocol is line-based. Each line has a type, and several lines compose a message. Each message starts with a line of the type start and terminates with a line of the type end. PHP may send lines for different messages simultaneously.
A line has this format:
Date in ISO 8601 format (yyyy-mm-dd)
Time including microseconds: hh:mm:uuuuuu
DNS name or IP address of the host where the script error was generated.
PID (process id) on host of the process with the PHP script that generated this error.
Type of line. Tells the receiving program about what it should treat the following data as:
Table C-1. Debugger Line Types
| Name | Meaning |
|---|---|
| start | Tells the receiving program that a debugger message starts here. The contents of data will be the type of error message, listed below. |
| message | The PHP error message. |
| location | File name and line number where the error occured. The first location line will always contain the top-level location. data will contain file:line. There will always be a location line after message and after every function. |
| frames | Number of frames in the following stack dump. If there are four frames, expect information about four levels of called functions. If no "frames" line is given, the depth should be assumed to be 0 (the error occured at top-level). |
| function | Name of function where the error occured. Will be repeated once for every level in the function call stack. |
| end | Tells the receiving program that a debugger message ends here. |
Line data.
Table C-2. Debugger Error Types
| Debugger | PHP Internal |
|---|---|
| warning | E_WARNING |
| error | E_ERROR |
| parse | E_PARSE |
| notice | E_NOTICE |
| core-error | E_CORE_ERROR |
| core-warning | E_CORE_WARNING |
| unknown | (any other) |
Example C-1. Example Debugger Message
|
| [1] | Be careful here. The value part must be malloc'ed manually because the memory management code will try to free this pointer later. Do not pass statically allocated memory into a SET_VAR_STRING. |