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Info file gdb.info, produced by Makeinfo, -*- Text -*- from input file gdb-all.texi. This file documents the GNU debugger GDB. Copyright (C) 1988, 1989, 1990, 1991 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the section entitled "GNU General Public License" is included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the section entitled "GNU General Public License" may be included in a translation approved by the Free Software Foundation instead of in the original English. File: gdb.info, Node: Emacs, Next: GDB Bugs, Prev: Sequences, Up: Top Using GDB under GNU Emacs ************************* A special interface allows you to use GNU Emacs to view (and edit) the source files for the program you are debugging with GDB. To use this interface, use the command `M-x gdb' in Emacs. Give the executable file you want to debug as an argument. This command starts GDB as a subprocess of Emacs, with input and output through a newly created Emacs buffer. Using GDB under Emacs is just like using GDB normally except for two things: * All "terminal" input and output goes through the Emacs buffer. This applies both to GDB commands and their output, and to the input and output done by the program you are debugging. This is useful because it means that you can copy the text of previous commands and input them again; you can even use parts of the output in this way. All the facilities of Emacs' Shell mode are available for interacting with your program. In particular, you can send signals the usual way--for example, `C-c C-c' for an interrupt, `C-c C-z' for a stop. * GDB displays source code through Emacs. Each time GDB displays a stack frame, Emacs automatically finds the source file for that frame and puts an arrow (`=>') at the left margin of the current line. Emacs uses a separate buffer for source display, and splits the window to show both your GDB session and the source. Explicit GDB `list' or search commands still produce output as usual, but you probably will have no reason to use them. *Warning:* If the directory where your program resides is not your current directory, it can be easy to confuse Emacs about the location of the source files, in which case the auxiliary display buffer will not appear to show your source. GDB can find programs by searching your environment's `PATH' variable, so the GDB input and output session will proceed normally; but Emacs doesn't get enough information back from GDB to locate the source files in this situation. To avoid this problem, either start GDB mode from the directory where your program resides, or specify a full path name when prompted for the `M-x gdb' argument. A similar confusion can result if you use the GDB `file' command to switch to debugging a program in some other location, from an existing GDB buffer in Emacs. By default, `M-x gdb' calls the program called `gdb'. If you need to call GDB by a different name (for example, if you keep several configurations around, with different names) you can set the Emacs variable `gdb-command-name'; for example, (setq gdb-command-name "mygdb") (preceded by `ESC ESC', or typed in the `*scratch*' buffer, or in your `.emacs' file) will make Emacs call the program named "`mygdb'" instead. In the GDB I/O buffer, you can use these special Emacs commands in addition to the standard Shell mode commands: `C-h m' Describe the features of Emacs' GDB Mode. `M-s' Execute to another source line, like the GDB `step' command; also update the display window to show the current file and location. `M-n' Execute to next source line in this function, skipping all function calls, like the GDB `next' command. Then update the display window to show the current file and location. `M-i' Execute one instruction, like the GDB `stepi' command; update display window accordingly. `M-x gdb-nexti' Execute to next instruction, using the GDB `nexti' command; update display window accordingly. `C-c C-f' Execute until exit from the selected stack frame, like the GDB `finish' command. `M-c' Continue execution of the program, like the GDB `continue' command. *Warning:* In Emacs v19, this command is `C-c C-p'. `M-u' Go up the number of frames indicated by the numeric argument (*note Numeric Arguments: (emacs)Arguments.), like the GDB `up' command. *Warning:* In Emacs v19, this command is `C-c C-u'. `M-d' Go down the number of frames indicated by the numeric argument, like the GDB `down' command. *Warning:* In Emacs v19, this command is `C-c C-d'. `C-x &' Read the number where the cursor is positioned, and insert it at the end of the GDB I/O buffer. For example, if you wish to disassemble code around an address that was displayed earlier, type `disassemble'; then move the cursor to the address display, and pick up the argument for `disassemble' by typing `C-x &'. You can customize this further on the fly by defining elements of the list `gdb-print-command'; once it is defined, you can format or otherwise process numbers picked up by `C-x &' before they are inserted. A numeric argument to `C-x &' will both indicate that you wish special formatting, and act as an index to pick an element of the list. If the list element is a string, the number to be inserted is formatted using the Emacs function `format'; otherwise the number is passed as an argument to the corresponding list element. In any source file, the Emacs command `C-x SPC' (`gdb-break') tells GDB to set a breakpoint on the source line point is on. If you accidentally delete the source-display buffer, an easy way to get it back is to type the command `f' in the GDB buffer, to request a frame display; when you run under Emacs, this will recreate the source buffer if necessary to show you the context of the current frame. The source files displayed in Emacs are in ordinary Emacs buffers which are visiting the source files in the usual way. You can edit the files with these buffers if you wish; but keep in mind that GDB communicates with Emacs in terms of line numbers. If you add or delete lines from the text, the line numbers that GDB knows will cease to correspond properly to the code. File: gdb.info, Node: GDB Bugs, Next: Renamed Commands, Prev: Emacs, Up: Top Reporting Bugs in GDB ********************* Your bug reports play an essential role in making GDB reliable. Reporting a bug may help you by bringing a solution to your problem, or it may not. But in any case the principal function of a bug report is to help the entire community by making the next version of GDB work better. Bug reports are your contribution to the maintenance of GDB. In order for a bug report to serve its purpose, you must include the information that enables us to fix the bug. * Menu: * Bug Criteria:: Have You Found a Bug? * Bug Reporting:: How to Report Bugs File: gdb.info, Node: Bug Criteria, Next: Bug Reporting, Prev: GDB Bugs, Up: GDB Bugs Have You Found a Bug? ===================== If you are not sure whether you have found a bug, here are some guidelines: * If the debugger gets a fatal signal, for any input whatever, that is a GDB bug. Reliable debuggers never crash. * If GDB produces an error message for valid input, that is a bug. * If GDB does not produce an error message for invalid input, that is a bug. However, you should note that your idea of "invalid input" might be our idea of "an extension" or "support for traditional practice". * If you are an experienced user of debugging tools, your suggestions for improvement of GDB are welcome in any case. File: gdb.info, Node: Bug Reporting, Prev: Bug Criteria, Up: GDB Bugs How to Report Bugs ================== A number of companies and individuals offer support for GNU products. If you obtained GDB from a support organization, we recommend you contact that organization first. Contact information for many support companies and individuals is available in the file `etc/SERVICE' in the GNU Emacs distribution. In any event, we also recommend that you send bug reports for GDB to one of these addresses: bug-gdb@prep.ai.mit.edu {ucbvax|mit-eddie|uunet}!prep.ai.mit.edu!bug-gdb *Do not send bug reports to `info-gdb', or to `help-gdb', or to any newsgroups.* Most users of GDB do not want to receive bug reports. Those that do, have arranged to receive `bug-gdb'. The mailing list `bug-gdb' has a newsgroup `gnu.gdb.bug' which serves as a repeater. The mailing list and the newsgroup carry exactly the same messages. Often people think of posting bug reports to the newsgroup instead of mailing them. This appears to work, but it has one problem which can be crucial: a newsgroup posting often lacks a mail path back to the sender. Thus, if we need to ask for more information, we may be unable to reach you. For this reason, it is better to send bug reports to the mailing list. As a last resort, send bug reports on paper to: GNU Debugger Bugs Free Software Foundation 545 Tech Square Cambridge, MA 02139 The fundamental principle of reporting bugs usefully is this: *report all the facts*. If you are not sure whether to state a fact or leave it out, state it! Often people omit facts because they think they know what causes the problem and assume that some details don't matter. Thus, you might assume that the name of the variable you use in an example does not matter. Well, probably it doesn't, but one cannot be sure. Perhaps the bug is a stray memory reference which happens to fetch from the location where that name is stored in memory; perhaps, if the name were different, the contents of that location would fool the debugger into doing the right thing despite the bug. Play it safe and give a specific, complete example. That is the easiest thing for you to do, and the most helpful. Keep in mind that the purpose of a bug report is to enable us to fix the bug if it is new to us. It isn't as important what happens if the bug is already known. Therefore, always write your bug reports on the assumption that the bug has not been reported previously. Sometimes people give a few sketchy facts and ask, "Does this ring a bell?" Those bug reports are useless, and we urge everyone to *refuse to respond to them* except to chide the sender to report bugs properly. To enable us to fix the bug, you should include all these things: * The version of GDB. GDB announces it if you start with no arguments; you can also print it at any time using `show version'. Without this, we won't know whether there is any point in looking for the bug in the current version of GDB. * A complete input script, and all necessary source files, that will reproduce the bug. * What compiler (and its version) was used to compile GDB--e.g. "gcc-1.37.1". * The command arguments you gave the compiler to compile your example and observe the bug. For example, did you use `-O'? To guarantee you won't omit something important, list them all. If we were to try to guess the arguments, we would probably guess wrong and then we might not encounter the bug. * The type of machine you are using, and the operating system name and version number. * A description of what behavior you observe that you believe is incorrect. For example, "It gets a fatal signal." Of course, if the bug is that GDB gets a fatal signal, then we will certainly notice it. But if the bug is incorrect output, we might not notice unless it is glaringly wrong. We are human, after all. You might as well not give us a chance to make a mistake. Even if the problem you experience is a fatal signal, you should still say so explicitly. Suppose something strange is going on, such as, your copy of GDB is out of synch, or you have encountered a bug in the C library on your system. (This has happened!) Your copy might crash and ours would not. If you told us to expect a crash, then when ours fails to crash, we would know that the bug was not happening for us. If you had not told us to expect a crash, then we would not be able to draw any conclusion from our observations. * If you wish to suggest changes to the GDB source, send us context diffs. If you even discuss something in the GDB source, refer to it by context, not by line number. The line numbers in our development sources won't match those in your sources. Your line numbers would convey no useful information to us. Here are some things that are not necessary: * A description of the envelope of the bug. Often people who encounter a bug spend a lot of time investigating which changes to the input file will make the bug go away and which changes will not affect it. This is often time consuming and not very useful, because the way we will find the bug is by running a single example under the debugger with breakpoints, not by pure deduction from a series of examples. We recommend that you save your time for something else. Of course, if you can find a simpler example to report *instead* of the original one, that is a convenience for us. Errors in the output will be easier to spot, running under the debugger will take less time, etc. However, simplification is not vital; if you don't want to do this, report the bug anyway and send us the entire test case you used. * A patch for the bug. A patch for the bug does help us if it is a good one. But don't omit the necessary information, such as the test case, on the assumption that a patch is all we need. We might see problems with your patch and decide to fix the problem another way, or we might not understand it at all. Sometimes with a program as complicated as GDB it is very hard to construct an example that will make the program follow a certain path through the code. If you don't send us the example, we won't be able to construct one, so we won't be able to verify that the bug is fixed. And if we can't understand what bug you are trying to fix, or why your patch should be an improvement, we won't install it. A test case will help us to understand. * A guess about what the bug is or what it depends on. Such guesses are usually wrong. Even we can't guess right about such things without first using the debugger to find the facts. File: gdb.info, Node: Renamed Commands, Next: Installing GDB, Prev: GDB Bugs, Up: Top Renamed Commands **************** The following commands were renamed in GDB 4.0, in order to make the command set as a whole more consistent and easier to use and remember: OLD COMMAND NEW COMMAND --------------- ------------------------------- add-syms add-symbol-file delete environment unset environment info convenience show convenience info copying show copying info directories show directories info editing show commands info history show values info targets help target info values show values info version show version info warranty show warranty set/show addressprint set/show print address set/show array-max set/show print elements set/show arrayprint set/show print array set/show asm-demangle set/show print asm-demangle set/show caution set/show confirm set/show demangle set/show print demangle set/show history write set/show history save set/show prettyprint set/show print pretty set/show screen-height set/show height set/show screen-width set/show width set/show sevenbit-strings set/show print sevenbit-strings set/show unionprint set/show print union set/show vtblprint set/show print vtbl unset [No longer an alias for delete] File: gdb.info, Node: Installing GDB, Next: Copying, Prev: Renamed Commands, Up: Top Installing GDB ************** GDB comes with a `configure' script that automates the process of preparing GDB for installation; you can then use `make' to build the `gdb' program. The gdb distribution includes all the source code you need for gdb in a single directory `gdb-4.2'. That directory in turn contains: `gdb-4.2/configure (and supporting files)' script for configuring GDB and all its supporting libraries. `gdb-4.2/gdb' the source specific to GDB itself `gdb-4.2/bfd' source for the Binary File Descriptor Library `gdb-4.2/include' GNU include files `gdb-4.2/libiberty' source for the `-liberty' free software library `gdb-4.2/readline' source for the GNU command-line interface It is most convenient to run `configure' from the `gdb-4.2' directory. The simplest way to configure and build GDB is the following: cd gdb-4.2 ./configure HOST make where HOST is something like `sun4' or `decstation', that identifies the platform where GDB will run. This builds the three libraries `bfd', `readline', and `libiberty', then `gdb' itself. The configured source files, and the binaries, are left in the corresponding source directories. `configure' is a Bourne-shell (`/bin/sh') script; if your system doesn't recognize this automatically when you run a different shell, you may need to run `sh' on it explicitly: `sh configure HOST'. You can *run* the `configure' script from any of the subordinate directories in the GDB distribution (if you only want to configure that subdirectory); but be sure to specify a path to it. For example, to configure only the `bfd' subdirectory, cd gdb-4.2/bfd ../configure HOST You can install `gdb' anywhere; it has no hardwired paths. However, you should make sure that the shell on your path (named by the `SHELL' environment variable) is publicly readable; some systems refuse to let GDB debug child processes whose programs are not readable, and GDB uses the shell to start your program. * Menu: * Subdirectories:: Configuration subdirectories * Config Names:: Specifying names for hosts and targets * configure Options:: Summary of options for configure * Formatting Documentation:: How to format and print GDB documentation File: gdb.info, Node: Subdirectories, Next: Config Names, Prev: Installing GDB, Up: Installing GDB Configuration Subdirectories ============================ If you want to run GDB versions for several host or target machines, you'll need a different gdb compiled for each combination of host and target. `configure' is designed to make this easy by allowing you to generate each configuration in a separate subdirectory. If your `make' program handles the `VPATH' feature (GNU `make' does), running `make' in each of these directories then builds the gdb program specified there. `configure' creates these subdirectories for you when you simultaneously specify several configurations; but it's a good habit even for a single configuration. You can specify the use of subdirectories using the `+subdirs' option (abbreviated `+sub'). For example, you can build GDB this way on a Sun 4 as follows: cd gdb-4.2 ./configure +sub sun4 cd H-sun4/T-sun4 make When `configure' uses subdirectories to build programs or libraries, it creates nested directories `H-HOST/T-TARGET'. `configure' uses these two directory levels because GDB can be configured for cross-compiling: GDB can run on one machine (the host) while debugging programs that run on another machine (the target). You specify cross-debugging targets by giving the `+target=TARGET' option to `configure'. Specifying only hosts still gives you two levels of subdirectory for each host, with the same configuration suffix on both; that is, if you give any number of hosts but no targets, GDB will be configured for native debugging on each host. On the other hand, whenever you specify both hosts and targets on the same command line, `configure' creates all combinations of the hosts and targets you list. If you run `configure' from a directory (notably, `gdb-4.2') that contains source directories for multiple libraries or programs, `configure' creates the `H-HOST/T-TARGET' subdirectories in each library or program's source directory. For example, typing: cd gdb-4.2 configure sun4 +target=vxworks960 creates the following directories: gdb-4.2/H-sun4/T-vxworks960 gdb-4.2/bfd/H-sun4/T-vxworks960 gdb-4.2/gdb/H-sun4/T-vxworks960 gdb-4.2/libiberty/H-sun4/T-vxworks960 gdb-4.2/readline/H-sun4/T-vxworks960 When you run `make' to build a program or library, you must run it in a configured directory. If you made a single configuration, without subdirectories, run `make' in the source directory. If you have `H-HOST/T-TARGET' subdirectories, run `make' in those subdirectories. The `Makefile' generated by `configure' for each source directory runs recursively, so that typing `make' in `gdb-4.2' (or in a `gdb-4.2/H-HOST/T-TARGET' subdirectory) builds all the required libraries, then GDB. When you have multiple hosts or targets configured, you can run `make' on them in parallel (for example, if they are NFS-mounted on each of the hosts); they will not interfere with each other. You can also use the `+objdir=ALTROOT' option to have the configured files placed in a parallel directory structure rather than alongside the source files; *note configure Options::.. File: gdb.info, Node: Config Names, Next: configure Options, Prev: Subdirectories, Up: Installing GDB Specifying Names for Hosts and Targets ====================================== The specifications used for hosts and targets in the `configure' script are based on a three-part naming scheme, but some short predefined aliases are also supported. The full naming scheme encodes three pieces of information in the following pattern: ARCHITECTURE-VENDOR-OS For example, you can use the alias `sun4' as a HOST argument or in a `+target=TARGET' option, but the equivalent full name is `sparc-sun-sunos4'. The following table shows all the architectures, hosts, and OS prefixes that `configure' recognizes in GDB 4.2. Entries in the "OS prefix" column ending in a `*' may be followed by a release number. ARCHITECTURE VENDOR OS prefix ------------+------------+------------- | | 580 | altos | aix* a29k | amd | amigados alliant | amdahl | aout arm | aout | bout c1 | apollo | bsd* c2 | att | coff cray2 | bcs | ctix* h8300 | bout | dgux* i386 | bull | dynix* i860 | cbm | ebmon i960 | coff | esix* m68000 | convergent | hds m68k | convex | hpux* m88k | cray | irix* mips | dec | isc* ns32k | encore | kern pyramid | gould | mach* romp | hitachi | msdos* rs6000 | hp | newsos* sparc | ibm | nindy* tahoe | intel | osf* tron | isi | sco* vax | little | sunos* xmp | mips | svr4 ymp | motorola | sym* | ncr | sysv* | next | ultrix* | nyu | unicos* | sco | unos* | sequent | uts | sgi | v88r* | sony | vms* | sun | vxworks* | unicom | | utek | | wrs | *Warning:* Many combinations of architecture, vendor, and OS are untested. The `configure' script accompanying GDB 4.2 does not provide any query facility to list all supported host and target names or aliases. `configure' calls the Bourne shell script `config.sub' to map abbreviations to full names; you can read the script, if you wish, or you can use it to test your guesses on abbreviations--for example: % sh config.sub sun4 sparc-sun-sunos4 % sh config.sub sun3 m68k-sun-sunos4 % sh config.sub decstation mips-dec-ultrix % sh config.sub hp300bsd m68k-hp-bsd % sh config.sub i386v i386-none-sysv % sh config.sub i486v *** Configuration "i486v" not recognized `config.sub' is also distributed in the directory `gdb-4.2'. File: gdb.info, Node: configure Options, Next: Formatting Documentation, Prev: Config Names, Up: Installing GDB `configure' Options =================== Here is a summary of all the `configure' options and arguments that you might use for building GDB: configure [+destdir=DIR] [+subdirs] [+objdir=ALTROOT] [+norecursion] [+rm] [+target=TARGET...] HOST... You may introduce options with the character `-' rather than `+' if you prefer; but you may abbreviate option names if you use `+'. `+destdir=DIR' DIR is an installation directory *path prefix*. After you configure with this option, `make install' will install GDB as `DIR/bin/gdb', and the libraries in `DIR/lib'. If you specify `+destdir=/usr/local', for example, `make install' creates `/usr/local/bin/gdb'. `+subdirs' Write configuration specific files in subdirectories of the form H-HOST/T-TARGET (and configure the `Makefile' to generate object code in subdirectories of this form as well). Without this option, if you specify only one configuration for GDB, `configure' will use the same directory for source, configured files, and binaries. This option is used automatically if you specify more than one HOST or more than one `+target=TARGET' option on the `configure' command line. `+norecursion' Configure only the directory where `configure' is executed; do not propagate configuration to subdirectories. `+objdir=ALTROOT' ALTROOT is an alternative directory used as the root for configured files. `configure' will create directories under ALTROOT in parallel to the source directories. If you use `+objdir=ALTROOT' with `+subdirs', `configure' also builds the `H-HOST/T-TARGET' subdirectories in the directory tree rooted in ALTROOT. `+rm' Remove the configuration that the other arguments specify. `+target=TARGET ...' Configure GDB for cross-debugging programs running on each specified TARGET. You may specify as many `+target' options as you wish. Without this option, GDB is configured to debug programs that run on the same machine (HOST) as GDB itself. There is no convenient way to generate a list of all available targets. `HOST ...' Configure GDB to run on each specified HOST. You may specify as many host names as you wish. There is no convenient way to generate a list of all available hosts. `configure' accepts other options, for compatibility with configuring other GNU tools recursively; but these are the only options that affect GDB or its supporting libraries. File: gdb.info, Node: Formatting Documentation, Prev: configure Options, Up: Installing GDB Formatting the Documentation ============================ The GDB 4.2 release includes an already-formatted reference card, ready for printing on a PostScript printer, as `gdb-4.2/gdb/refcard.ps'. It uses the most common PostScript fonts: the Times family, Courier, and Symbol. If you have a PostScript printer, you can print the reference card by just sending `refcard.ps' to the printer. The release also includes the online Info version of this manual already formatted: the main Info file is `gdb-4.2/gdb/gdb.info', and it refers to subordinate files matching `gdb.info*' in the same directory. If you want to make these Info files yourself from the GDB manual's source, you need the GNU `makeinfo' program. Once you have it, you can type cd gdb-4.2/gdb make gdb.info to make the Info file. If you want to format and print copies of the manual, you need several things: * TeX, the public domain typesetting program written by Donald Knuth, must be installed on your system and available through your execution path. * `gdb-4.2/texinfo': TeX macros defining the GNU Documentation Format. * *A DVI output program.* TeX doesn't actually make marks on paper; it produces output files called DVI files. If your system has TeX installed, chances are it has a program for printing out these files; one popular example is `dvips', which can print DVI files on PostScript printers. Once you have these things, you can type cd gdb-4.2/gdb make gdb.dvi to format the text of this manual, and print it with the usual output method for TeX DVI files at your site. If you want to print the reference card, but don't have a PostScript printer, or you want to use Computer Modern fonts instead, you can still print it if you have TeX. Format the reference card by typing cd gdb-4.2/gdb make refcard.dvi The GDB reference card is designed to print in landscape mode on US "letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches high. You will need to specify this form of printing as an option to your DVI output program. File: gdb.info, Node: Copying, Next: Index, Prev: Installing GDB, Up: Top GNU GENERAL PUBLIC LICENSE ************************** Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble ======== The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it. For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software. Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations. Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all. The precise terms and conditions for copying, distribution and modification follow. TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 1. This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you". Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. 2. You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program. You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee. 3. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions: a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License. c) If the modified program normally reads commands interactively when run, you must cause it, when started running for such interactive use in the most ordinary way, to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty) and that users may redistribute the program under these conditions, and telling the user how to view a copy of this License. (Exception: if the Program itself is interactive but does not normally print such an announcement, your work based on the Program is not required to print an announcement.) These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License. 4. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.) The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. 5. You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. 6. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it. 7. Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein. You are not responsible for enforcing compliance by third parties to this License. 8. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. 9. If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 10. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. 11. If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. NO WARRANTY 12. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 13. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS Applying These Terms to Your New Programs ========================================= If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES. Copyright (C) 19YY NAME OF AUTHOR This program is free software; you can redistribute it and/or modify it 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. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. SIGNATURE OF TY COON, 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License.