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[1]The Columbia Crown The Kermit Project | Columbia University
612 West 115th Street, New York NY 10025 USA o [2]kermit@columbia.edu
...since 1981
[3]Home [4]Kermit 95 [5]C-Kermit [6]Scripts [7]Current [8]New [9]FAQ
[10]Support
[11]CLICK HERE to read about some of these items.
[12]Table of platforms [13]Book: Using C-Kermit [14]Download
C-Kermit 9.0
C-Kermit 9.0 Update Notes
* [15]Large Files
* [16]How to Test Large-File Transfer
* [17]Arithmetic with Large Integers
* [18]FORCE-3 Packet Protocol
* [19]Variable Evaluation
* [20]The RENAME Command You Always Wanted
* [21]Other New Features
* [22]Incompatibilities
* [23]What's Not In C-Kermit 9.0
* [24]And a Loose End
* [25]Demonstration: Secure POP mail fetcher
* [26]Demonstration: HP Switch Configuration Backup
* [27]Demonstration: HP iLO Blade Configuration
* [28]Demonstration: IBM/Rolm/Siemens CBX Management
* [29]Demonstration: CSV and TSV Files
* [30]Demonstration Scripts for Webmasters
This is the third supplement to [31]Using C-Kermit, Second Edition. I
apologize for the scattered nature of the information and I hope I can
organize it and gather it all into one place for easy and definitive
reference some day. It's a big job so it depends on the demand. For the
time being the definitive reference and introduction is the book (which
is now available also in a [32]Kindle Edition), plus the [33]C-Kermit
7.0 update, [34]C-Kermit 8.0 update, and now this one. Plus tons of
other web pages on this site, sample script programs, and so on.
In version 6.0, C-Kermit was a pretty powerful and flexible
communication program with scripting capabilities. By version 9.0, I'd
like to think of it more as a scripting language with built-in
communications. You can get an idea of the kinds of programs you can
write in Kermit language [35]here. You can develop programs quickly
because it's an interactive program, not a compiler. The scripting
language is the command language. Kind of like the Unix shell but
"somewhat" less cryptic, including concepts not only from C but from
PL/I, Snobol, LISP, and Smalltalk. The language itself is built upon
the command language of the much-loved [36]DECSYSTEM-20 from the 1970s
and 80s, the Clipper Ship of the Text Era. (Text is not a bad word.
Those of us who can touch-type and who are proficient in text-based
computing environments like Unix shell or VMS DCL are likely to be
orders of magnitude more productive than users of GUIs.)
Thanks to (at least) Jeff Altman, William Bader, Ian Beckwith, Nelson
Beebe, Gerry Belanger, Joop Boonen, Rob Brown, Christian Corti, John
Dunlap, Peter Eichhorn, Carl Friedberg, Terry Kennedy, Gⁿnter Knauf,
Jason Lehr, Arthur Marsh, Lewis McCarthy, Gary Mills, Jonathan Reams,
Mike Rechtman, Mark Sapiro, Steven Schweda (SMS), Kinjal Shah, Michael
Sokolov, Andy Tanenbaum, Seth Theriault, Zach A. Thomas, Martin
VorlΣnder, and Eric Weaver for assistance, and to Hewlett-Packard
Company for support.
- Frank da Cruz [37]fdc@columbia.edu, 30 June 2011
P.S. It occurred to me just before the end of the day that maybe I
should back up the Kermit website on DVD, just in case. Using
[38]Kermit 95 on the desktop over an SSH connection to the Unix file
system where the website resides, I made a fresh directory on the PC,
CD'd to it, and on Unix cd'd to the Website directory, and told
C-Kermit 9.0 to:
C-Kermit> send /recursive /dotfiles /nobackup *
and it re-created the website directory tree in the PC directory, text
files correctly converted to Windows format and binary files correctly
left as-is. The /dotfiles switch means to include files such as
.htaccesss whose names start with a dot (period), and the /nobackup
switch means to skip backup files created by EMACs (such as
index.html.~243~). And then I did the same with the FTP sites, about
8GB in all. Watching the file-transfer display was kind of like having
30 years of my life flash before my eyes in a few minutes. Then I
copied the two directories to DVD (the FTP site had to split over 2
DVDs). The whole operation took under half an hour. The directory tree
on the CD is directly usable in Windows, Unix, or any other operating
system (unlike if I had made, say, a gzipped tar archive or a zip
archive). I believe that, to this day, Kermit is the only software that
can do this. If someday I have to upload from these DVDs to Unix, VMS,
or any other operating system, it can be done exactly the same way,
with any necessary conversions on text files done automatically, and
binary files left intact.
What's New in General
Very briefly, the major items:
* [39]Open Source license.
* [40]64-bit file accesss and transfer and 64-bit integer arithmetic
on most common platforms.
* Support for recent releases of Linux, Mac OS X, *BSD, etc ([41]see
table).
* Support for newer OpenSSL releases up to and including 1.0.0d
([42]see table).
* [43]Strengthened error checking for file transfer under extremely
harsh conditions.
* [44]Simplified semantics for variables used in scripts.
* Super-handy [45]extensions to the RENAME command.
* Other scripting improvements including support for reading and
writing [46]CSV and TSV files.
* [47]MIME character-set names are now recognized.
* Improved logging and debugging (see demo [48]here).
* Lots more described or listed below, and [49]here.
Open Source License
C-Kermit 9.0 has the [50]Revised 3-Clause BSD License, an open source
license approved by OSI, the [51]Open Source Initiative.
Large Files
Kermit is, first and foremost, a file-transfer program. One might
expect it to be able to transfer any kind of file, but that has been
decreasingly the case as file sizes began to cross the 2 gigabyte
threshold.
The biggest change since C-Kermit 8.0.211 is support for large files on
platforms that support them. A "large file" is one whose size is
greater than 2^31-1 (2,147,483,647) bytes (2GB-1); that is, one whose
size requires more than 31 bits to represent. Before now, Kermit was
able to accesss such files only on 100% 64-bit platforms such as
Digital Unix, later known as Tru64 Unix. In the new release, Kermit
takes advantage of the X/Open Single UNIX Specification Version 2 (UNIX
98) Large File Support (LFS) specification, which allows 32-bit
platforms to create, accesss, and manage files larger than 2GB.
Accommodating large files required code changes in many modules,
affecting not only file transfer, but also file management functions
from directory listings to local file manipulation, plus the user
interface itself to allow entry and display of large numbers. All this
had to be done in a way that would not affect pure 32-bit builds on
platforms that do not support large files. Large file support is
summarized in the [52]Table of Platforms; entries in Yellow (32-bit
builds that support 64-bit integers) and Green (64-bit builds) support
large files.
Note that VMS C-Kermit and Kermit 95 for Windows have always been able
to transfer large files. However their user interface used 32-bit
integers for statistics and the file transfer display. In C-Kermit 9.0
Alpha.03, VMS C-Kermit on 64-bit platforms (Alpha and Itanium) should
now give correct statistics and progress displays. (We'll see about
Kermit 95 later.)
How to Test Large-File Transfer
Several methods are available for testing large-file transfers:
* By transferring a real file that is more than 2147483648 bytes long
(a file whose length requires more than 31 bits to express); or to
be totally sure, that is longer than 4294967296 bytes (32 bits or
more). Or to be double super sure, longer than 8589934592 (33
bits).
* If you don't have such a file or there is not sufficient disk space
for such a file, you can create a special kind of file that takes
up one block on the disk but appears to be 4.3GB long by compiling
and running [53]THIS C PROGRAM on Linux, Solaris, HP-UX, or other
Unix platform that supports large files. Kermit or FTP or any other
file transfer program will transfer the result (BIGFILE) in such a
way as to actually put 4.3GB (or other desired size; see source) on
the wire.
* You can use Kermit's CALIBRATE feature to transfer a large file
that doesn't exist. At the receiver, use RECEIVE /CALIBRATE. At the
sender, use SEND /CALIBRATE:length, e.g.:
(At remote kermit...)
$ kermit -Y
C-Kermit> receive /calibrate
(Return to local kermit...)
Ctrl-\c
C-Kermit> send /calibrate:4300000000
This sends a simulated file 4.3GB in length, that does not exist on
the sender and will not take up any disk space on the receiver.
SEND /CALIBRATE: accepts big numbers only in Kermit versions that
support them (this does not include Kermit 95 on Windows). This
method tests only Kermit's ability to express and understand large
file sizes, but does not test Kermit's file-system interface, since
no files are involved.
Arithmetic with Large Integers
Because large file support requires the availability of a 64-bit signed
integer data type, other aspects of C-Kermit were adapted to use it
too, most notably Kermit's algebraic expression evaluator and its
[54]S-Expression interpreter, on all platforms that support large files
(those listed as 64 or 32/64 in the Word column of the [55]table). In
fact, every Kermit command that parses a number in any field can now
parse a large number on those platforms.
S-Expressions can now be forced to operate with integers only, without
floating-point conversion or having to explicitly truncate each result;
as an example. see the revised [56]Easter date calculation script.
FORCE-3 Packet Protocol
The Kermit protocol has proven itself over the past 30 years to be
robust in terms of surviving harsh transmission environments and
delivering the data correctly and completely. In these times of
Internet everywhere and error-correcting modems in the few places where
the Internet isn't, few people even recall the kinds of difficult
conditions that were common when the Kermit protocol was first
developed: noisy telephone lines, serial interfaces that drop
characters, lack of transparency to control or 8-bit characters,
absence of flow control, "bare" modems without error correction.
But the Internet is not everywhere, and not all modems are
error-correcting. Perhaps the most difficult trial so far for Kermit or
any other protocol is the [57]EM-APEX project, in which floats are
dropped into the ocean from an aircraft into the path of a hurricane;
these floats dive into the water measuring current, temperature, and
salinity at different depths and then surface to phone home, sending
the data to land stations using Kermit protocol over
non-error-correcting 300bps [58]Iridium satellite modems, with high
seas and winds battering the floats and heavy ([59]sometimes
electrical) storms between the modem and the satellite.
Because of the transmission speed and long distances involved, the
transfers were very slow. The Kermit software in the floats is
[60]Embedded Kermit, which did not implement sliding windows, which
would have sped up the flow considerably. John Dunlap, engineer at the
University of Washington's Applied Physics Laboratory, undertook the
task of adding sliding windows to E-Kermit. For testing, he rigged up a
[61]simulator in which Kermit transfers take place over a connection
with different amounts of noise and delay. He found that occasionally,
a transfer would appear to succeed, but the received file would be
corrupt.
According to the Kermit protocol definition, the first packet always
has block-check type 1, a 6-bit checksum, which is the only block check
type that all Kermit implementations are required to support; thus any
Kermit partner can process this packet. This packet itself can
negotiate a higher level of checking, such that subsequent packets have
(say) block-check type 3, a 16-bit cyclic redundancy check (CRC)
encoded as three printable 7-bit ASCII characters. The 16-bit CRC can
catch all errors of certain kinds (single-bit, double-bit, bursts of 16
bits or less), and more than 99.9984741210937% of all other possible
errors.
John's simulations revealed that file corruption could occur undetected
when the initial packet was corrupted in such a way that a parameter or
capability byte was changed and the checksum also changed to make the
packet appear to be correct, thus allowing the transfer to proceed with
the two Kermit partners out of sync as to packet encoding and
interpretation (the chances of two such errors producing a seemingly
valid packet are about 1 in 6000 when using the 6-bit checksum). For
example, the compression technique might be misnegotiated and then the
receiver might store incoming data without decompressing it.
The solution is a new option, selected by:
BLOCK-CHECK TYPE 5
to require a type 3 block check (16-bit CRC) on every packet, including
the initial ones, thus reducing the probability of a misnegotiation by
many orders of magnitude. THIS PARAMETER CAN NOT BE NEGOTIATED. Each
Kermit program must be given the "set block 5" command prior to
transfer. That's because normally every Kermit program expects the
first packet to have a 6-bit checksum, and if the first packet has a
3-byte, 16-bit CRC, the packet receiver will think it is corrupted.
In practice, however, it is possible to code the packet receiver
"cheat" by reading the packet data before verifying the block check.
Thus when the receiver is C-Kermit 9.0 Beta.01 or later or E-Kermit 1.7
or later, it is only necessary to give the "set block 5" command to the
file sender, and the receiver will check for a FORCE-3 first packet. If
the receiver does not support this feature, however, the the initial
packet will be be rejected (after several retries) and the file
transfer will not take place. There is no attempt to "back off" to
normal behavior.
CAPTION: Table 4. Kermit Protocol Packet Block Check Types
Type Command Bytes Status Explanation
1 SET BLOCK 1 1 Required in all Kermit implementations. Negotiated.
6-bit checksum, suitable for good connections.
2 SET BLOCK 2 2 Optional, negotiated. 12-bit checksum. 64 times
stronger than type 1.
3 SET BLOCK 3 3 Optional, negotiated. 16-bit CRC.
BLANK-FREE-2 SET BLOCK 4 2 Optional, negotiated. 12-bit checksum, two
nonblank bytes.
FORCE-3 SET BLOCK 5 3 Optional, not negotiated. 16-bit CRC forced all
packets.
BLANK-FREE-2 is for environments where Kermit packets are treated as
lines of text, and in which trailing blanks can be stripped; for
example, when transferring files with an IBM mainframe through a 3270
protocol converter.
[62]E-Kermit 1.7
Variable Evaluation
Does the strange behavior of Kermit's \%x variables puzzle or annoy
you?
Kermit software development has been a collaborative project over the
years, with contributions coming in from almost every country and every
sector of the economy - academic, corporate, government. Thus not all
versions, and not all features of a given version, are a product of
systematic design.
One example was the introduction of variables for text substitution,
first in a version of MS-DOS Kermit that was sent in by someone
somewhere (I could look it up, but no time...) Although the design of
the notation for variable names (table below) is mine, the underlying
code was contributed. In that code there was only one kind of variable,
and if I recall correctly the variable name was a backslash followed by
a single letter, for example \a, \b, etc. The contributed code
evaluated these variables recursively, meaning if the definition of a
variable contained variable references, then these were resolved when
derefencing the variable, and the process would continue as deep down
as necessary to resolve the thing fully.
This was sometimes handy, but it had one severe drawback: There was no
way to use variables in a straightforward way to represent strings that
contained literal backslashes; for example, DOS or Windows pathnames.
This gave rise to all kinds of quoting rules and conventions (e.g.
doubling backslashes or forcing single-level evaluation with
\\fcontents()), and also to the introduction of other kinds of
variables that were evaluated one level deep, rather than recursively.
To accommodate coexistence of different kinds of variables as well as
"escape sequences" for representing control and 8-bit characters, the
syntax for variable names was extended to include three elements: the
leading backslash, then a single character indicating the type of
variable, and then the name of the variable in a format corresponding
to the type designator, as shown in this somewhat simplified table:
CAPTION: Table 1. Variable-name Syntax in Kermit
Notation Meaning
\000 - \255 8-bit character constant (decimal)
\d000 - \d255 Alternative notation for 8-bit character (byte) constant
(decimal)
\o000 - \o377 8-bit character constant (octal)
\x00 - \xff 8-bit character constant (hexadecimal)
\%a - \%z Scalar variable, evaluated recursively.
\%0 - \%9 Macro argument, scalar, evaluated recursively.
\&a - \%& Array name
\&a[x] Array reference, evaluated recursively (x is any constant or
variable)
\v(name) Built-in scalar variable, evaluated one level deep.
\m(name) User-defined scalar variable, evaluated one level deep.
\$(name) An environment variable, evaluated one level deep.
\s(name[n:m]) Compact substring notation, evaluated one level deep.
\fname(args...)) Built-in function with zero or more arguments.
\\ Literal backslash
\N OUTPUT command only: NUL, ASCII 0
\B OUTPUT command only: BREAK (250ms, for serial connections)
\L OUTPUT command only: Long BREAK (1.5sec, ditto)
Variable names in Kermit are case-independent. The simplifications in
the table are that the notation for decimal and octal bytes can have
from one to three digits, and can include braces to separate them from
text digits, e.g. \7, \{123}, \o{50}. Hex bytes too, except they must
always have exactly two hex digits, 0-9a-f. Array indices must be, or
must evaluate to, numbers (floating point numbers are truncated).
Associative arrays are also available (dynamic arrays with arbitrary
text as subscript), but they are really just a variation on \m()
variables (read about associative arrays [63]here). Also, there are
some alternative notations for compact substring notation.
We didn't want to have lots of "distinguished" characters, as the UNIX
shell does; one is enough, clarity over brevity. Although the notation
can be a bit cumbersome, we can use the \m(name) form to circumvent the
overevaluation in most contexts. But macro arguments are always
assigned to the \%0-9 variables, and thus always evaluated recursively,
making it difficult and confusing to pass (e.g.) Windows pathnames as
arguments to macros. The same is true for array elements, especially in
contexts where they are used to return results from built-in functions
(for example, \fsplit() used to return the elements of a
[64]comma-separated value list if any of the values contained
backslashes). An even worse scenario is when macro arguments are passed
from one macro to another; for some graphic illustrations see
[65]Taming the Wild Backslash - Part Deux from the [66]C-Kermit 7.0
Update Notes.
We can't just change how variables are evaluated because that would
break existing scripts. But we can always add Yet Another SET Command:
SET COMMAND VARIABLE-EVALUATION { RECURSIVE, SIMPLE }
This applies only to \%a-z and \%0-9 variables and to \&a-z[] arrays
(since all other kinds of variables are evaluated only one level deep).
The default, of course, for backwards compatibility, is RECURSIVE.
SIMPLE forces the evaluation of these variables to return their literal
contents, without further evaluation:
* An exception is made in the case of array subscripts, because
changing how they are evaluated could break a lot of scripts, and
anyway there should never be any harm in evaluating them
recursively because their final value is always (or should be)
numeric, not some string that might contain backslashes.
* The VARIABLE-EVALUTION setting is on the command stack. Thus you
can give this command in a macro, command file, or user-defined
function without affecting the calling environment.
* The new \frecurse() function forces recursive evaluation of its
argument regardless of the VARIABLE-EVALUATION setting. The
argument can be any string (or nothing at all); all the variables
in the string, even \m() ones, are evaluated recursively:
def \%a 1 \%b 3
def \%b 2
def xx easy as \%a
show mac xx
echo \frecurse(\m(xx))
easy as 1 2 3
echo \frecurse(it's as easy as \m(xx))
it's as easy as easy as 1 2 3
* The new \v(vareval) built-in variable contains the current setting
(recursive or simple) at the current command-stack level.
Here's a short script for illustration:
define path c:\users\fdc\somefile.txt
define test1 { # Normal recursive argument evaluation
echo \%0: arg=\%1
}
define test2 { # Simple argument evaluation
set var simple
echo \%0: arg=\%1
}
test1 \m(path)
test2 \m(path)
exit
And here's the result:
?<ERROR:NO_SUCH_FUNCTION:\fdc\somefile.txt()>
test2: arg=c:\users\fdc\somefile.txt
The first line might seem surprising, but under the normal rules (see
table above) \f indicates a function call, with the letters following
the 'f' being the name of the function. But there is no function by
that name... and if there were, you probably didn't intend to call it!
SET COMMAND VARIABLE-EVALUATION SIMPLE has no effect on constants, only
on variables. Note how \m(path) is defined. The DEFINE command assigns
the literal value of its argument to the named variable (see Table 3
below), thus in this case no special syntax is needed. But in other
contexts, you must double the backslashes or use the \fliteral()
function to use literal backslashes in data:
test2 c:\\users\\fdc\\somefile.txt
test2 \fliteral(c:\users\fdc\somefile.txt)
C-Kermit 9.0 adds a new notation for \fliteral() which also has certain
advantages over it: \q(string)
:
test2 \q(c:\users\fdc\somefile.txt)
Since \fliteral() is a function, its argument list (the text within
parentheses) has special syntax of its own, in which commas and braces
are treated specially and introduce another set of quoting problems.
\q(string) doesn't have these problems. The only consideration is that
parentheses must be balanced or else quoted (preceded by backslash), or
represented as numeric character entities (left paren = \40, (right
paren = \41).
Or else hold the value in a simple variable as we did with \\m(path)
above.
SET COMMAND VARIABLE-EVALUATION SIMPLE is a big change and might have
repercussions that didn't show up in the initial tests; a lot more
testing is needed.
On the topic of variables, let's summarize in one place the ways in
which values can be explicitly assigned to variables. There is nothing
new here except the table itself:
CAPTION: Table 2. Variable Assignment in Kermit
Command Shorthand Explanation
DEFINE name value .name = value The literal value becomes the contents
of the named variable; variables names in the value are copied without
evaluation. This command is for defining macros that take parameters,
as well as for defining simple variables, especially if the values
contain backslashes.
_DEFINE name value Like DEFINE but the name is evaluated before use.
ASSIGN name value .name := value The value is evaluated and the result
becomes the contents of the named variable.
_ASSIGN name value Like ASSIGN but the name is evaluated before use.
EVALUATE name expression .name ::= value The expression (in regular
algebraic notation) is evaluated arithmetically and the result becomes
the contents of the named variable. If the expression contains any
variables they are evaluated first.
_EVALUATE name expression Like EVALUATE but the name is evaluated
before use.
INCREMENT name expression Evaluates the variables in the expression,
then evaluates the expression arithmetically, and then adds the value
to the contents of the named variable, which must be a number or an
algebraic expression. If the expression is empty, a value of 1 is used.
_INCREMENT name expression Like INCREMENT but the name is evaluated
before use.
DECREMENT name expression Evaluates the variables in the expression,
then evaluates the expression arithmetically, and then subtracts the
value from the contents of the named variable, which must be a number
or an algebraic expression. If the expression is empty, a value of 1 is
used.
_DECREMENT name expression Like DECREMENT but the name is evaluated
before use.
DECLARE name = list An array declaration can include an initializer
list; items in the list are evaluated before assignment. This can be
defeated by doubling any backslashes or enclosing individual arguments
in \fliteral().
DO name arguments name arguments When invoking a macro with a DO
command (or an implied one), the arguments are evaluated, then assigned
to \%1, \%2, etc, and the macro's name to \%0.
(SETQ name value) Kermit also includes a mini-[67]LISP interpreter
Variables are evaluated automatically in Kermit commands simply by
referencing them, according to rules given in Table 1. The following
functions can be used to change how a a particular variable is
evaluated:
CAPTION: Table 3. Kermit Functions for Evaluating Variables
Function Argument Description
\fcontents() \%x or \&x[y] Evaluates the variable or array element
(which normally would be evaluated recursively) one level deep.
\fdefinition() name If the argument is a \%x variable or an array
element, it is evaluated to get the name; otherwise the argument is the
name. Its definition is returned with no recursion.
\m() name Equivalent to \fdefinition().
\frecurse() \m(name) Forces recursive evaluation of a macro definition
(a.k.a. long variable name). NOTE: \frecurse() can operate on any kind
of variable as well as on any string containing any mixture of
variables.
C-Kermit's RENAME Command
C-Kermit's RENAME command, which is used for changing the names of
local files or for moving files locally, has two basic forms:
RENAME [ optional-switches ] oldfilename newfilename
This form lets you change the name of a single file from
oldfilename to newfilename. Example:
rename thismonth.log lastmonth.log
RENAME [ optional-switches ] filespec directoryname
This form lets you move (without renaming) one or more files
(all the files that match the filespec, which may contain
wildcard characters such as "*") to the given directory.
Example:
rename *.txt ~/textfiles/
Traditionally, the optional switches have been:
RENAME /LIST oldname newname
Display the old and new name for each file while renaming.
Synonyms: /LOG, /VERBOSE. Example:
rename /list *.txt ~/textfiles/
RENAME /NOLIST oldname newname
Don't display the old and new name for each file while renaming.
This is the default behavior. Synonyms: /NOLOG, /QUIET. Example:
rename /nolist *.txt ~/textfiles/
Reminder: Every switch starts with a slash (/) and must be preceded by
a space.
New RENAME Features for C-Kermit 9.0
A series of new options (switches) have been added to let you change
the names of multiple files at once by case conversion, string
substitution, or character-set conversion, and optionally also move
them to a different directory:
/LOWER: Convert the filename to lowercase
/UPPER: Convert the filename to uppercase
/CONVERT: Change the filename's character encoding
/REPLACE: Do string substitutions on the filename
If the source-file specification includes a path or directory, any
changes are applied to the filenames only, not to the directory or path
specification.
Since name changes, when applied to many files at once, can have
consequences that are not easily undone, there are also some new
controls, safeguards, and conveniences:
RENAME /SIMULATE
This switch tells Kermit to show you what the RENAME command
would do without actually doing it. /SIMULATE implies /LIST.
RENAME /COLLISION:{FAIL,SKIP,OVERWRITE}
This switch governs Kermit's behavior when renaming multiple
files, and any of the names would collide with the name of a
file that already exists. The default, for compatibility with
earlier releases of C-Kermit, is OVERWRITE, i.e. write over the
existing file. The other two protect existing files. SKIP means
to skip (not rename) the file that would cause the collision,
and proceed to the next file, if any. FAIL means that no files
will be renamed if there would be any collisions; for this
Kermit makes two passes, checking each new name it constructs
for existence before starting the second pass (however, there is
no guarantee that in the second pass, it won't create the same
new name for more than one file; in that case, it will stop
before executing the second rename). Example:
rename /simulate /collision:proceed * ~/tmp/
Reminder: In switches such as /COLLISION that take arguments
(operands), the switch name and its argument(s) are separated by a
colon (:) with no intervening spaces. Also remember that Kermit
keywords can always be abbreviated by leaving off characters from the
right, as long as the result is still unique in its context. Thus "ren
/col:f" would be equivalent to "rename /collision:fail".
You can change the following preferences for the RENAME command with
the new SET RENAME command:
SET RENAME LIST { ON, OFF }
Tells the RENAME command whether to list its actions if you
don't include a /LIST or /NOLIST or equivalent switch.
SET RENAME COLLISION { FAIL, OVERWRITE, SKIP }
Tells the RENAME command how to handle filename collisions in
the absence of a /COLLISION switch. That is, it replaces the
default action of OVERWRITE with action of your choosing, which
is then used in any RENAME command that does not include an
explicit /COLLISION switch.
SHOW RENAME
Displays the current SET RENAME settings.
Changing the Case of Filenames
RENAME /UPPER:{ALL,LOWER} filespec [ directory ]
RENAME /LOWER:{ALL,UPPER} filespec [ directory ]
These switches let you change the alphabetic case of letters in
all the files whose names match the filespec. If a directory
name is given after the filespec, then the files are also moved
to the given directory.
By default, all files that match the given filespec have their names
changed (if necessary). This is what the ALL argument means, e.g.:
RENAME /LOWER:ALL *
RENAME /LOWER *
You can use either form: RENAME /LOWER is equivalent to RENAME
/LOWER:ALL. The other argument (/LOWER:UPPER or /UPPER:LOWER) means to
leave mixed-case filenames alone, and rename only those files whose
names contain letters of only the given case. Examples:
RENAME /UPPER:ALL foo.bar
Changes the filename to FOO.BAR.
RENAME /UPPER foo.bar
Same as "rename /upper:all foo.bar".
RENAME /UPPER foo.bar ~/old/
Renames foo.bar to FOO.BAR and moves it to the user's old
directory (Unix).
RENAME /LOWER *
Changes the names of all files to have only lowercase letters.
RENAME /LOWER:UPPER *
Changes the names of only those files whose names contain no
lowercase letters to have only lowercase letters. For example,
FOO.BAR would be changed, Foo.Bar would not be changed. foo.bar
would not be changed either because it's already all lowercase.
RENAME /LOWER:UPPER * ~/new/
Same as the previous example, but also moves each file to the
user's new directory (whether it was renamed or not).
Case conversion works reliably for ASCII characters only. Kermit uses
the C library for this, which on any given platform might or might not
handle non-ASCII letters, and if it does, then how it works would
normally depend on your locale definitions (the LC_CTYPE and/or LANG
environment variable in Unix). When non-ASCII letters are not handled
by the C library, the RENAME command does change their case. For
example, Olga_Ta±≤n.txt might become OLGA_TA±≤N.TXT.
String Replacement in Filenames
The RENAME command also lets you change filenames by string
substitution.
RENAME /FIXSPACES[:String] filespec [ directory ]
Replaces all spaces in each matching filename by the given
string, if any, or if none is given, by underscore. Examples:
RENAME /FIX *
RENAME /FIXSPACES:_ *
RENAME /FIXSPACES:"" *
RENAME /FIXSPACES:<040> *
The first two are equivalent, replacing each space with
underscore; a file called "My Favorite Photo.jpg" becomes
"My_Favorite_Photo.jpg". The third example removes all spaces
("MyFavoritePhoto.jpg"). The fourth replaces each space with the
string "<040>" ("My<040>Favorite<040>Photo.jpg").
RENAME /REPLACE:{{String1}{String2}} filespec [ directory ]
Renames each matching file by changing occurrences of String1 in
its name to String2. If a directory specification is included,
the file is also moved to the given directory (even if the name
was not changed). Note that in this case, the curly braces are
part of the command. Example:
RENAME /REPLACE:{{.jpeg}{.jpg}} *
changes all *.jpeg files to *.jpg.
By default, RENAME /REPLACE changes all occurrences of String1 in each
filename to String2 so, for example, if you had a file called
abcjpegxyz.jpeg, the command just shown would change its name to
abcjpgxyz.jpg.
For greater control and flexibility, the /REPLACE: switch argument can
take several distinct forms:
RENAME /REPLACE:String1 filespec [ directory ]
This means to remove all occurrences of String1 from the given
filenames name. It is equivalent to /REPLACE:{{String1}{}}. A
handy use for this option is to remove spaces from filenames.
RENAME /REPLACE:{{String1}{String2}} filespec [ directory ]
As already noted, this replaces every occurrence of String1 with
String2 in each filename. Alphabetic case in string matching is
done according to the current SET CASE setting.
RENAME /REPLACE:{{ }{_}} filespec [ directory ]
This replaces all spaces in the given filenames with underscore,
equivalent to RENAME /FIXSPACES.
RENAME /REPLACE:{{String1}{String2}{Options}} filespec [ directory ]
Options can be included that add more control to the process.
The option string is a sequence of characters; each character in
the string is an option. The choices are:
A String matching is to be case-sensitive, regardless of SET CASE.
a String matching is to be case-independent, regardless of SET CASE.
^ String replacement will occur only at the beginning of the filename.
$ String replacement will occur only at the end of the filename.
1 Only the first occurrence of the string will be replaced.
2 Only the second occurrence of the string will be replaced.
3 4 5 6 7 8 ...
9 Only the ninth occurrence of the string will be replaced.
- (hyphen, minus sign) Before a digit: occurrences will be counted from
the right.
~ (tilde) Before digit or minus sign: all occurrences but the given one
will be replaced.
The tilde modifier works only with single-byte character sets such as
ASCII, CP437, ISO 8859-1, etc, but not with multibyte character sets
such as UCS2, UTF8, or any of the Japanese Kanji sets.
Here are some examples showing how to use the /REPLACE options:
RENAME /REPLACE:{{foo}{bar}{^}} *
For all files whose names start with "foo", replaces the "foo"
at the beginning with "bar".
RENAME /REPLACE:{{}{New-}{^}} *
Prepends "New-" to the name of each file.
RENAME /REPLACE:{{.jpeg}{.jpg}{$}} *
Replaces ".jpeg" at the end of each filename with ".jpg".
RENAME /REPLACE:{{}{-Old}{$}} *
Appends "-Old" to the name of each file.
RENAME /REPLACE:{{foo}{bar}{a}} *
Replaces "foo", "FOO", "Foo", "fOO", etc, with "bar" in each
filename.
RENAME /REPLACE:{{foo}{bar}{A}} *
Replaces only (lowercase) "foo" in filenames with "bar".
RENAME /REPLACE:{{a}{XX}} *
Changes every "a" to "XX". For example a file called "a.a.a.a"
would become "XX.XX.XX.XX".
RENAME /REPLACE:{{a}{X}{2}}
Changes only the second "a" to "X". For example a file called
"a.a.a.a" would become "a.X.a.a".
RENAME /REPLACE:{{a}{X}{-1}}
Changes only the final "a" in the filename (it doesn't have to
be at the end) to "X". For example a file called "a.b.a.c.a.d"
would become "a.b.a.c.X.d".
RENAME /REPLACE:{{foo}{NOTFOO}{-2}}
Changes the second-to-last "foo" (if any) in the filename to
"NOTFOO".
RENAME /REPLACE:{{foo}{}{-2}}
Deletes the second-to-last "foo" (if any) from the filename.
RENAME /REPLACE:{{.}{_}{~1}}
Changes all but the first period to an underscore; for example,
"a.b.c.d.e" would become "a.b_c_d_e".
RENAME /REPLACE:{{.}{_}{~-1}}
Changes all but the final period to an underscore; for example,
"a.b.c.d.e" would become "a_b_c_d.e".
In the Options field, digits (and their modifiers), ^, and $ are
mutually exclusive. If you include more than one of these in the option
string, only the last one is used. Similarly for 'a' and 'A':
RENAME /REPLACE:{{foo}{bar}{Aa2$^}} *
This replaces "foo" with "bar" no matter what combination of
upper and lower case letters are used in "foo" ('a' overrides
'A' in the option string), but only if "foo" is at the beginning
of the filename ('^' overrides '$' and '2').
If you give an /UPPER or /LOWER switch and a /REPLACE switch in the
same RENAME command, the /REPLACE action occurs first, then the case
conversion:
RENAME /REPLACE:{{foo}{bar}} /UPPER * /tmp
For each file: changes all occurrences of "foo" in the name to
"bar", then converts the result to uppercase, and then moves the
file to the /tmp directory. So (for example) "foot.txt" would
become "/tmp/BART.TXT".
Changing the Character Encoding of Filenames
As you know, text is represented on the computer as a series of
numbers, with a given number corresponding to a given character
according to some convention or standard. Filenames are represented the
same way. The trouble is, different computers, or even different
applications on the same computer, might use different standards or
conventions ("character sets") for representing the same characters.
Usually ASCII is safe, but anything beyond that -- non-ASCII characters
such as accented or non-Roman letters -- is likely to vary. Sometimes
you have text that's in the "wrong" character set and you need to
convert it to something you can can use. Kermit has always been able to
handle this as part of file transfer and terminal emulation, as well as
being able to convert text files locally with its TRANSLATE command.
Now there's a way to convert filenames too, for example after copying
files from a CD that uses a different encoding:
RENAME /CONVERT:charset1:charset2 filespec [ directory ]
Converts filenames from the first character set to the second
one. The two character sets can be chosen from the SET FILE
CHARACTER-SET list; for complete details see [68]this page. For
example suppose you have a file called "Olga_Ta±≤n.txt" on a
computer where ISO 8859-1 Latin Alphabet 1 is used, and you have
transported it (e.g. on CDROM) to another computer where the
text encoding is UTF8. Maybe you also have a lot of other files
with similar names in the same directory. You can convert the
filenames to UTF8 like this:
RENAME /CONVERT:latin1:utf8 *
/CONVERT can not be combined with /UPPER, /LOWER, or /REPLACE.
You should NOT use UCS2 for filenames since this encoding is not
compatible with C strings used in Unix and elsewhere.
RENAME /CONVERT affects only the filename, not the file's contents. You
can use the TRANSLATE command to convert the encoding of the contents
of a text file.
Other New Features
See the [69]C-Kermit Daily Builds page for details. Very briefly:
* Perhaps most important, modernized makefile targets for the major
Unix platforms: Linux, Mac OS X, AIX, Solaris, etc. These are
somewhat automated; not autoconf exactly, but they cut down
significantly on redundant targets. For example, one single "linux"
target works on many (hopefully all) different Linux
configurations, where before different targets were required for
different combinations of (e.g.) curses / ncurses / no curses;
32-bit / 64-bit; different feature sets and library locations.
(Separate targets are still required for Kerberos and/or SSL
builds, but they are "subroutinized".)
* Bigger buffers, more storage for commands, macros, scripts,
strings, and filename expansion in 64-bit versions and in 32-bit
versions that support large files.
* User-settable FTP timeout, works on both the data and control
connection.
* FTP accesss to ports higher than 16383.
* Built-in FTP client for VMS. This is the [70]same FTP client Unix
C-Kermit has had since version 8.0, minimally adapted to VMS by
SMS, supporting binary and Stream_LF file transfer only (in other
words, nothing to handle RMS files), but otherwise fully functional
(and scriptable) and theoretically capable of making connections
secured by SSL (at least it compiles and links OK with SSL - HP SSL
1.3 in this case).
* Large file support in VMS, also by SMS. Alpha and Itanium only (not
VAX). VMS C-Kermit was already able to transfer large files, but
the file-transfer display (numbers and progress bar) and statistics
were wrong because they used ints. In the present Alpha test
release, this is an optional feature requested by including the "f"
option in P1.
* New PUTENV command that allows Kermit to pass environment variables
to subprocesses (Unix only, "help putenv").
* New TOUCH command, many file selection options ("help touch").
* New DIRECTORY command options and switches (/TOP, /COUNT;
HDIRECTORY, WDIRECTORY...). To see the ten biggest files in the
current directory: "dir /top:10 /sort:size /reverse *" or
equivalently, "hdir /top:10 *". WDIR lists files in reverse
chronological order, shorthand for "dir /sort:date /reverse".
* New command FSEEK /FIND:string-or-pattern, seeks to the first line
in an FOPEN'd file that contains the given string or matches the
given pattern. Example: Suppose you have a file of lines like this:
quantity description...
in which the first "word" is a number, followed by a description
(for example, the name of an item). Here is how to use FSEEK to
quickly get the total quantity of any given item, which is passed
as a parameter (either a literal string or a pattern) on the
command line:
#!/usr/local/bin/kermit +
if not def \%1 exit 1 Usage: \fbasename(\%0) string-or-pattern
.filename = /usr/local/data/items.log # Substitute the actual filename
set case off # Searches are case-independent
fopen /read \%c \m(filename) # Open the file
if fail exit 1 "\m(filename): \v(errstring)" # Fail: exit with error message
.total = 0 # OK: Initialize the total
echo Searching "\%1"...
while true {
fseek /line /relative /find:\%1 \%c 0 # Get next line that has target
if fail break # Failure indicates EOF
fread /line \%c line # Read it
if fail break # (shouldn't happen)
increment total \fword(\m(line),1) # Increment the total
}
fclose \%c # Close the file
echo Total for "\%1" : \m(total) # Print the result
exit 0
The syntax of the FSEEK command in this example indicates that each
search should start relative to the current file line. Since Kermit
is an interpretive language, FSEEK is a lot faster than FREAD'ing
each line and checking it for the target, especially for big files.
An especially handy use for FSEEK is for use with potentially huge
sequentially timestamped logs, to seek directly to the date-time
where you want to start processing. Some other improvements for the
FOPEN/FREAD/FWRITE/FCLOSE family of commands are included also
(performance, bug fixes, convenience features), listed in the
[71]change log. (Prior to 9.0.299 Alpha.02, the FSEEK /FIND:
command always started from the top.)
* MIME synonyms for character-set names: A new equivalence between
MIME names and Kermit names for character sets, with a new table
showing the supported sets [72]HERE (this feature is also
illustrated in the [73]Weblog script).
* Unix C-Kermit SET TERMINAL TYPE now passes its arguments to
subprocesses as an environment variable.
* SET SESSION-LOG TEXT now strips out ANSI escape sequences from the
session log.
* For interacting with POP servers over clear-text or SSL-secured
connections:
+ New SSL and TLS "raw" connections (no Telnet protocol).
+ New INPUT command options for reading and capturing (perhaps
while scanning) continuous incoming text, such as INPUT
/NOWRAP (explained [74]HERE).
+ New \femailaddress() command to extract the e-mail address
from an Internet mail message To: or From: line, used in
fetching mail from POP servers.
+ Improved date parsing commands and functions for parsing the
different date formats that can appear in e-mail.
+ Production scripts for fetching mail from a secure POP server,
available [75]HERE.
* Various features added to make Kermit more useful for writing CGI
scripts such as INPUT /COUNT:n to INPUT exactly n characters
(useful for reading form data).
* New \fpictureinfo() function for getting orientation and dimensions
of JPG and GIF images, described [76]HERE.
* New \fgetpidinfo() function for testing whether a given process
exists.
* \fkwdvalue() function fixed to allow multiword values.
* New function \fcount(s1,s2) to tell the number of occurrences of s1
in s2.
* New \flopx() function returns rightmost field from string (such as
a file's extension).
* New function \ffunction(s1) to tell whether a built-in s1 function
exists.
* New \fsqueeze(s1) function removes leading and trailing whitespace
from string s1, changes tabs to spaces, squeezing each run of
repeated whitespace characters to a single space.
* Compact substring notation: \s(somestring[12:18]) is the same as
\fsubstring(\m(somestring),12,18), i.e. the substring starting at
position 12, 18 characters long. \s(somestring[12_18]) means
characters 12 through 18 of the string (7 characters). Also,
\s(somestring[17.]) returns character number 17 of somestring.
* The string indexing functions now accept an optional trailing
argument specifying the occurrence number of the target string.
Likewise, \fword() can fetch words from the right as well as the
left.
* The COPY command in Unix C-Kermit has a new /PRESERVE switch,
equivalent to Unix "cp -p".
* ASKQ /ECHO:c can be used to make the characters the user types echo
as the character c, e.g. asterisk when typing a password.
* IF LINK filename to test if the filename is a symlink.
* Ctrl-K, when typed at the command parser, replaces itself with most
recently entered file specification.
* In Unix, the ability to log a terminal session to a serial port,
for use with speaking devices or serial printers; described
[77]HERE. Also for the same purpose, SET SESSION-LOG
NULL-PADDED-LINES for a speech synthesizer than needed this.
* Adaptation to OpenSSL 0.9.8 and 1.0.0.
* Lifted the restriction on having a remote Kermit program send
REMOTE commands to the local. A very big ex-client needed to be
able to do this (branches would connect to headquarters and upload
files; HQ would then download patches, a REMOTE HOST command was
necessary to allow the remote headquarters machines to install the
patches on the local client; of course the client first has to
ENABLE HOST because this is a risky scenario). The reason for the
restriction was that the server, upon receiving any REMOTE command
would send the results (output) back to the client as a file
transfer with "destination screen", but of course the remote has no
screen.
* Added XMESSAGE, which is to [78]MESSAGE as XECHO is ECHO: it
outputs a string with no line terminator DEBUG MESSAGE is ON.
* Fixed \frecurse() to not dump core when invoked with no arguments.
* Improved text for HELP FUNCTION SPLIT and HELP FUNCTION WORD.
* Patches for Debian 6.0 "Squeeze" from Ian Beckwith.
* \fcontents(\&a[3]) got an error if the array was declared but its
dimension was less than 3. Now it simply returns and empty string.
* \fsplit(), when parsing lines from CSV and TSV files, was treating
backslash in the data the same way it treats backslash in Kermit
commands. This was fixed to treat backslash like any other
character.
* Builds for Solaris 9 and later now use streams ptys rather then the
old BSD-style ptys. Thanks to Gary Mills for this one, who noticed
that he couldn't have more than 48 C-Kermit SSH sessions going at
once and figured out why.
* As noted [79]below DES encryption is being retired from many
platforms and libraries that once used it. I changed the Solaris
and Linux OpenSSL builds to account for this by testing for it. I
probably should also add a OMITDES option to omit DES even if it is
installed, but "KFLAGS=-UCK_DES" seems to do the job for now.
* I changed the Linux build to test for the OpenSSL version (like the
Solaris version already did), rather than assuming OpenSSL 0.9.7.
* A couple minor changes for Tru64 Unix 5.1B from Steven Schweda but
we still have some trouble on that platform. As a workaround "make
osf1" can be used there.
* Unix makefile and man page are now included in the Zip
distribution.
* \fjoin(), which is the inverse function of fsplit() now accepts CSV
and TSV as a second argument, to transform an array into a
comma-separated or tab-separated value list, as described [80]HERE.
* Even in 2010, Unix distributions continue to change their UUCP
lockfile conventions. C-Kermit 9.0 contains support from Joop
Boonen for OpenSuSE >= 11.3 and recent Debian, which no longer have
baudboy.h, which first appeared in Red Hat 7.2 in 2003.
* From Lewis McCarthy:
Based on code inspection, C-Kermit appears to have an SSL-related
security vulnerability analogous to that identified as CVE-2009-3767
(see e.g.
[81]http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3767).
I'm attaching a patch for this issue relative to the revision of
ck_ssl.c obtained from a copy of
[82]http://www.columbia.edu/kermit/ftp/test/tar/x.zip downloaded on
2010/07/30, which I believe is the latest.
When this flaw was first widely publicized at last year's Black Hat
conference, it was claimed that some public certificate authorities
had indeed issued certificates that could be used to exploit this
class of vulnerability. As far as I know they have not revealed
specifically which public CA(s) had been found issuing such
certificates. Some references:
+ [83]http://www.mseclab.com/?p=180
+ [84]http://www.theregister.co.uk/2009/07/30/universal_ssl_cert
ificate/
* Peter Eichhorn reported that "RENAME ../x ." didn't work; fixed
now.
* If only one file is FOPEN'd, FCLOSE given with no arguments would
close it; this was a "convenience feature" that turned out to be
dangerous. For safety FCLOSE has to require a specific channel
number or the word ALL.
* Added \fstrcmp(s1,s2,case,start,length), which has the advantage
over IF EQU,LGT,LLT that case sensitivity can be specified as a
function arg, and also substrings can be specified.
* New built-in functions:
\fcvtcsets(string,cs1,cs2)
Function to convert a string from one character set to
another.
\fdecodehex(string[,prefix])
Function to decode a string containing hex escapes.
\fstringtype(string)
Function to tell whether a string is 7-bit, 8-bit, or
UTF-8.
For the motivation for these features and an application that uses
them to analyze web logs, see the Weblog script below.
*
Lazy IF Conditions: Third, now you can do this:
define foo some number
if foo command
instead of this:
define foo some number
if \m(foo) command
Of course the old way still works too. But watch out because if the
variable name is the same as a symbolic IF condition (for example
COUNT), it won't do what you expected. (IF COUNT was used for loop
control in early versions of MS-DOS Kermit, before it got true FOR
and WHILE loops; it was added to C-Kermit for compatibility, and it
can't be removed because it could break existing scripts).
* Escape sequences are now stripped from text-mode session logs not
only in CONNECT sessions but also in whatever is logged by the
INPUT command; described in the [85]next section.
* New commands for selectively issuing progress or debugging messages
from scripts, also described in the next section.
* Fix from [86]John Dunlap to prevent the fixed packet-timeout
interval from going to an unexpected value.
* Alpha.04 fixes a problem with FTP connections made from 64-bit Unix
platforms. All the other changes in this section were to Alpha.03.
* Relaunching a closed SSH connection with the CONNECT command is now
possible, as it always has been with Telnet and other connection
types; suggested by Peter Eichhorn (needs testing).
* A symbol conflict fixed that prevented successful build on
[87]FreeBSD 8.0.
* Fixes from Christian Corti for building on SunOS 4.1.
* New aixg target for building on AIX with gcc.
* New aix+ibmssl target. This is nice because the IBM-supplied SSL
libraries and header files are in a known location; no need to
[88]set environment variables giving their locations.
* "Large File Support" is now included by default on Alpha and IA64
hardware on VMS 7.3 and later, and it should work much better than
before.
* Kermit's internal FTP client is now included by default in any
build that also includes TCP/IP networking. At present, the FTP
client seems to work well for binary-mode transfers; text (ASCII)
mode transfers still need some work. In builds that also include
Secure Sockets Layer (SSL) security (next item) the FTP client
should be able to make securely authenticated and encrypted
connections.
* In network builds that request OpenSSL support, e.g.:
$ @ckvker "" "" "CK_SSL"
the OpenSSL version is detected automatically and the appropriate
compile-time options are emitted (such as
OPENSSL_DISABLE_OLD_DES_SUPPORT).
* Preliminary / limited support for the ODS-5 file system on VMS 7.2
and later, Alpha and Itanium only (needs testing): Filenames can be
mixed case and can be longer.
* Support for older and older VMS versions.
* In the VMS build procedure, CKVKER.COM, the "i" option in P1 now
means don't include the internal FTP client, and the "f" option
means do not include "Large File" support. Large File support in
VMS really only applies to the file-transfer display and
statistics, which would go out of whack as soon as the byte count
overflowed 31 bits because this is C-Kermit, built with the C
compiler and the C library (runtime system), which did not support
long integers until VMS 7.3.
* The [89]LISP Operator ROUND now takes an optional second argument
that specifies the number of places to round to, e.g.
(ROUND dollars 2) rounds dollars to 2 decimal places.
* Improved pattern matching in many commands for both strings and
filenames.
* Various minor new features, plus numerous bug fixes and speedups.
Incompatibilities
A top priority for new Kermit software releases has always been
backwards compatibility. A script written for a previous Kermit release
should run the same way in the new release.
There's one exception this time. The [90]\fsplit() function is
incredibly handy, it can do almost anything, up to and including
parsing a LISP program (the underlying code is the basis of the
[91]S-Expression interpreter). But did you ever try to use it to parse
(say) a Tab-Separated-List (TSV file) or Comma-Separated-List (CSV)? It
works as expected as long as the data contains only 7-bit characters.
But if your data contains (say) Spanish or German or Russian text
written in an 8-bit character set such as ISO 8859-1, every 8-bit
character (any value 128-255) is treated as a break character. This is
fixed in C-Kermit 9.0 by treating all 8-bit bytes as "include"
characters rather than break characters, a total reversal of past
behavior. I don't think it will affect anyone though, because if this
had happened to anyone, I would have heard about it!
Since most standard 8-bit character sets have control characters in
positions 128-160, it might have made sense to keep 128-160 in the
break set, but with the proliferation of Microsoft Windows code pages,
there is no telling which 8-bit character is likely to be some kind of
text, e.g. "smart quotes" or East European or Turkish accented letters.
What's Not In C-Kermit 9.0
Some large projects that were contemplated have not been done,
including:
* IPv6. Honestly, there has been zero demand for this, and it would
be a lot of work and disruption to the code base. Volunteers
welcome, I guess. It could be a CS project.
* A database interface - MySQL or ODBC. For this one, there is some
demand but I haven't had a chance to even look into it.
* There's a looming issue with DES encryption; major vendors are
removing it from their platforms, starting with Apple in Mac OS X
10.6, with Microsoft to follow suit. A secure version of Kermit can
be built without DES, but in limited testing successful connections
were spotty (e.g. with Kerberos 5).
* Cleaning up the Unix makefile. It has 25 years' worth of targets in
it. It is very likely safe to remove most of them, since (a) most
old platforms have gone away by now, or have been upgraded, due to
hacking vulnerabilities; (b) the market has consolidated
considerably; and (c) most of the new features of C-Kermit 9.0,
such as large files, won't be of any use on older platforms and
previous C-Kermit versions will remain available.
* Packages. Everybody wants an install package custom made for their
own computer, Linux RPMs being the prime example but far from the
only one. These will come, I suppose (especially with some Linux
sites having a policy against installing any application that does
not come as an RPM). In the meantime, here's a page that describes
some Kermit-specific issues in package construction:
[92]ckpackages.html.
And a Loose End...
Using External File-Transfer Protocols on Secure Connections
After C-Kermit 8.0.212 Dev.27 (2006/12/22), I spent a big chunk of time
trying to solve a particular problem that some of you have complained
about and others might be familiar with: If you use C-Kermit to make a
secure Telnet connection to another host (e.g. with Telnet SSL/TLS,
Kerberos, or SRP) and then attempt to transfer a file using an external
protocol such as Zmodem, it doesn't work.
That's because as coded (through 8.0.211), C-Kermit simply starts the
external protocol in a fork with its standard i/o redirected to the
connection. This completely bypasses the encryption and decryption that
is done by C-Kermit itself, and of course it doesn't work. The same
thing occurs if you use the REDIRECT command. The routine that handles
this is ttruncmd() in ckutio.c.
In order to allow (say) Zmodem transfers on secure connections, it is
necessary for C-Kermit to interpose itself between the external Zmodem
program and the connection, decrypting the incoming stream before
feeding it to Zmodem and encrypting Zmodem's output before sending out
the connection.
In principal, this is simple enough. We open a pseudoterminal pair
("master" and "slave") for Zmodem's i/o and we create a fork and start
Zmodem in it; we read from the fork pty's standard output, encrypt, and
send to the net; we read from the net, decrypt, and write to the fork
pty's standard input.
In practice, it's not so simple. First of all, pseudoterminals (ptys)
don't seem to interface correctly with certain crucial APIs, at least
not in the OS's I have tried (Mac OS X, Linux, NetBSD, etc), such as
select(). And i/o with the pty often - perhaps always - fails to
indicate errors when they occur; for example, when the fork has exited.
But, even after coding around the apparent uselessness of select() for
multiplexing pty and net, and using various tricks to detect when the
external protocol exits and what its exit status is, I'm still left
with a show-stopping problem: I just simply can not download (receive)
a file with Zmodem, which is the main thing that people would probably
want to do. I can send files just fine, but not receive. The incoming
stream is delivered to Zmodem (to the pty slave) but upon arrival at
the Zmodem process itself, pieces are always missing and/or corrupt.
Yet I can receive files just fine if I use Kermit itself (C-Kermit or
G-Kermit) as the external protocol, rather than Zmodem.
I can think of two reasons why this might be the case:
1. Zmodem sends all 8-bit bytes and control codes in the clear, and
maybe the pty is choking on them because it thinks it is a real
terminal.
But Zmodem puts its controlling terminal into raw mode. And C-Kermit
puts the pty into raw mode too, just for good measure. If any 0xFF
codes are in the Zmodem data stream, and it's a Telnet session, Kermit
does any needed byte stuffing/unstuffing automatically. Anyway, if I
tell Zmodem to prefix everything, it makes no difference.
2. Zmodem is a streaming protocol and perhaps the pty driver can't
keep up with a sustained stream of input at network speeds. What
would be the method of flow control?
I can vary the size of the i/o buffers used for writing to the pty, and
get different effects, but I am not able to get a clean download, no
matter what buffer size I use. write()'ing to the pty does not return
an error, and I can't see the errors because they happen on the master
side. It's as if the path between the pty slave and master lacks flow
control; I deliver a valid data stream to the pty slave and the master
gets bits and pieces. This impression is bolstered somewhat by the
"[93]man 7 pty" page in HP-UX, which talks about some special modes for
ptys that turn off all termio processing and guarantee a
flow-controlled reliable stream of bytes in both directions - a feature
that seems to be specific to HP-UX, and exactly the one we need
everywhere.
Well, in Pass One I used C-Kermit's existing pty routines from
ckupty.[ch], which are well-proven in terms of portability and of
actually working. They are currently used by SET HOST /PTY for making
terminal connections to external processes. But these routines are
written on the assumption that the pty is to be accesssed
interactively, and maybe they are setting the fork/pty arrangement up
in such a way that that's not suitable for file transfer. The Pass One
routine is called xttptycmd() in ckutio.c.
So in Pass Two I made a second copy of the routine, yttptycmd(), that
manages the pty and fork itself, so all the code is in one place and
it's simple and understandable. But it still doesn't work for Zmodem
downloads. In this routine, I use openpty() to get the pty pair, which
is not portable, so I can have accesss to both the master and slave pty
file descriptors. This version can be used only a platforms that have
openpty(): Linux, Mac OS X, NetBSD, etc.
In Pass Three, zttptycmd(), I tried using pipes instead of ptys, in
case ptys are simply not up to this task (but that can't be true
because if I make a Telnet or SSH connection into a host, I can send
files to it with Zmodem, and the remote Zmodem receiver is, indeed,
running on a pty). But pipes didn't work either.
In Pass Four, I extracted the relevant routines into a standalone
program based on yttptycmd() (the openpty() version, for simplicity),
which I tested on Mac OS X, the idea being to rule out any
"environmental" effects of running inside the C-Kermit process. There
was no difference -- Kermit transfers (with C-Kermit itself as the
external protocol) worked; Zmodem transfers (neither sz or lsz) did
not.
Well, it's a much longer story. As the external protocol, I've tried
rzsz, crzsz, and lrzsz. We know that some of these have quirks
regarding standard i/o, etc, which is one of the reasons for using ptys
in the first place, and i/o does work - just not reliably. Anyway, the
1100 lines or so of [94]ckc299.txt, starting just below where it says
"--- Dev.27 ---" tell the full story. At this point I have to give up
and move on; it might be more productive to let somebody else who has
more experience with ptys take a look at it - if indeed anyone still
cares about being able to do Zmodem transfers over secure Telnet
connections.
C-Kermit 9.0 contains the three new routines (and some auxiliary ones),
but they are not compiled or called unless you build it specially:
make targetname KFLAGS=-DXTTPTYCMD (builds with xttptycmd())
make targetname KFLAGS=-DYTTPTYCMD (builds with yttptycmd())
make targetname KFLAGS=-DZTTPTYCMD (builds with zttptycmd())
These are all in [95]ckutio.c. As noted, the second one works only for
Linux, FreeBSD, NetBSD, and Mac OS X, because it uses non-POSIX,
non-portable openpty(). If you want to try it on some other platform
that has openpty(), you can build it like this:
make targetname "KFLAGS=-DYTTPTYCMD -DHAVE_OPENPTY"
(and let me know, so I can have HAVE_OPENPTY predefined for that
platform too). The best strategy to get this working, I think, would be
to concentrate on yttptycmd(), which is the simpler of the two
pty-based routines. If it can be made to work, then we'll see if we can
retrofit it to use the ckupty.c routines so it will be portable to
non-BSD platforms.
By the way, if you build with any of [XYZ]TTPTYCMD defined, then the
selected routine will always be used in place of ttruncmd(). This is to
allow testing on all kinds of connections, not just secure ones, in
both local and remote mode. Once the thing works, if it ever does, I'll
add the appropriate tests and/or commands.
By default, in the initial test release, C-Kermit 9.0 uses ttruncmd()
on serial connections and ttyptycmd() on network connections. Even when
a network connection is not encrypted, Kermit still needs to handle the
network protocol, e.g. the quoting of 0xff bytes on Telnet connections.
Demonstration: Fetch Mail from POP Server Secured by SSL
[96]pop.ksc is a fully elaborated production script for fetching one's
mail from a POP3 server over a connection secured by SSL. For
explanation and documentation, [97]CLICK HERE. [98]mailcheck is a
wrapper for the pop.ksc script, which collects your password one time,
and then checks for new mail every 5 minutes (or other selected
interval) and calls pop.ksc to fetch it if there is any.
Demonstration: HP Switch Configuration Backup
A common use for Kermit software is to make automated backups of the
configuration of network switches and routers, such as those made by
Cisco or Hewlett-Packard (although [99]tftp can be used for this, it is
not available in all such devices; Kermit, however, works with those
that have tftp as well as those that don't).
Typically a backup can be done by making a Telnet, SSH, or serial
connection to the device with Kermit and giving a command such as "show
config" at the command-line prompt of the device with Kermit's session
log activated. The result is a list of the commands that were used to
establish the current configuration, suitable for feeding back to the
device's console (e.g. with C-Kermit's TRANSMIT command) to reestablish
the same configuration or to duplicate it on another device.
At an HP installation it was noted, however, that while the HP switches
(various ProCurve models) produced the desired list of commands, they
were interspersed with escape sequences for special effects, thus
rendering the recorded sessions unsuitable for feeding back into the
switches.
C-Kermit 9.0 introduces a new feature to strip the offending sequences
out of a session log, leaving just the text. The command SET
SESSION-LOG TEXT activates this feature. In C-Kermit 9.0 Alpha.02 and
earlier, escape sequence stripping occurred only while logging
interactive (CONNECT) sessions; beginning with Alpha.03 it is done also
for data that is read by INPUT commands and therefore works for scripts
too.
A sample HP Switch Configuration Backup script is [100]HERE, and its
data file is [101]HERE. This script also illustrates some other new
features of Alpha.03:
MESSAGE text
This lets you put debugging messages in your script that can be
displayed or not, according to SET DEBUG MESSAGE (below). This
way you don't have to change your script for debugging. Hint:
In Unix, invoke the script like this:
$ DEBUG=1 scriptname arg1 arg2...
and then include the following command in your script:
if defined \$(DEBUG) set debug message on
XMESSAGE text
Like MESSAGE but prints the text with no line terminator, so it
can be continued by subsequent messages.
SET DEBUG MESSAGE { ON, OFF, STDERR }
ON means MESSAGE commands should print to standard output; OFF
means they shouldn't print anything; STDERR means the messages
should be printed to [102]stderr. DEBUG MESSAGE is OFF by
default, i.e. unless you SET it to ON or STDERR.
IF DEBUG command
Executes the command if SET DEBUG MESSAGE is not OFF.
The \v(lastcommand) variable
This variable contains the previous command. You can use it in
debugging and error message to show (for example) exactly what
the command was that just failed, without having to make a copy
of the command:
set host somehost.somecompany.com
if fail exit 1 "FATAL - \v(lastcommand)"
which, if the SET HOST command fails, prints "FATAL - set host
somehost.somecompany.com" and then exits with status 1 (which
normally indicates failure).
Demonstration: HP iLO Blade Configuration
[103]THIS DOCUMENT describes a script in production use at Columbia
University for configuring and deploying racks full of HP blade servers
through their "integrated Lights Out" (iLO) management interface,
bypassing the tedious and error-prone process of configuring the
servers one by one through the vendor-provided point-and-click Web
interface, which is ill-suited to configuring large numbers of blades.
The script illustrates some of C-Kermit 9.0's new features; source code
is available through the link. The code is apt to change from time to
time as new requirements surface.
Demonstration: IBM/Rolm/Siemens CBX Management
[104]THIS DOCUMENT describes a suite of scripts (some in production,
some in development) used to manage the Columbia campus 20,000-line
main telephone switch, along with about 10 satellite switches at
off-campus locations. These switches are 1980s technology*, their
management consoles are serial ports. Access is via Telnet to reverse
terminal servers. The scripts allow for interactive sessions as well as
automatic production (and in some cases formatting) of different
reports required by different groups at different intervals. These
scripts replace a whole assortment of ad-hoc ProComm ASPECT scripts
that were scattered all over the place, with passwords embedded. The
new scripts are intended to be run from a centralized server where
there is a single well-secured configuration file, and where they can
be used on demand, or in cron jobs. They are modular so code
duplication is minimal.
__________________________
* Of course the University is deploying new technology but the but the
old system will be used in parallel for some time to come.
Demonstration: CSV and TSV Files
Contents
* [105]Reading a CSV or TSV Record and Converting it to an Array
* [106]Using \fjoin() to create a Comma- or Tab-Separated Value List
from an Array
* [107]Using CSV or TSV Files
Comma-Separated Value (CSV) format is commonly output by spreadsheets
and databases when exporting data into plain-text files for import into
other applications. Here are the details:
Comma-Separated List Syntax
1. Each record is a series of fields.
2. Records are in whatever format is used by the underlying file
system for lines of text.
3. Fields within records are separated by commas, with zero or more
whitespace characters (space or tab) before and/or after the comma;
such whitespace is considered part of the separator.
4. Fields with embedded commas must be enclosed in ASCII doublequote
characters.
5. Fields with leading or trailing spaces must be enclosed in ASCII
doublequotes.
6. Any field may be enclosed in ASCII doublequotes.
7. Fields with embedded doublequotes must be enclosed in doublequotes
and each interior doublequote is doubled.
Here is an example:
aaa, bbb, has spaces,,"ddd,eee,fff", " has spaces ","Muhammad ""The Greatest"" A
li"
The first two are regular fields. The second is a field that has an
embedded space but in which any leading or trailing spaces are to be
ignored. The fourth is an empty field, but still a field. The fifth is
a field that contains embedded commas. The sixth has leading and
trailing spaces. The last field has embedded quotation marks.
Prior to C-Kermit 9.0 Alpha.06, C-Kermit did not handle CSV files
according to the specification above. Most seriously, there was no
provision for a separator to be surrounded by whitespace that was to be
considered part of the separator. Also there was no provision for
quoting doublequotes inside of a quoted string.
Reading a CSV record
Now the \fsplit() function can handle any CSV-format string if you
include the symbolic include set "CSV" as the 4th parameter. To
illustrate, this program:
def xx {
echo [\fcontents(\%1)]
.\%9 := \fsplit(\fcontents(\%1), &a, \44, CSV)
for \%i 1 \%9 1 { echo "\flpad(\%i,3). [\&a[\%i]]" }
echo "-----------"
}
xx {a,b,c}
xx { a , b , c }
xx { aaa,,ccc," with spaces ",zzz }
xx { "1","2","3","","5" }
xx { this is a single field }
xx { this is one field, " and this is another " }
xx { name,"Mohammad ""The Greatest"" Ali", age, 67 }
xx { """field enclosed in doublequotes""" }
exit
gives the following results:
[a,b,c]
1. [a]
2. [b]
3. [c]
-----------
[ a , b , c ]
1. [a]
2. [b]
3. [c]
-----------
[ aaa,,ccc," with spaces ",zzz ]
1. [aaa]
2. []
3. [ccc]
4. [ with spaces ]
5. [zzz]
-----------
[ "1","2","3","","5" ]
1. [1]
2. [2]
3. [3]
4. []
5. [5]
-----------
[ this is a single field ]
1. [this is a single field]
-----------
[ this is one field, " and this is another " ]
1. [this is one field]
2. [ and this is another ]
-----------
[ name,"Mohammad ""The Greatest"" Ali", age, 67 ]
1. [name]
2. [Mohammad "The Greatest" Ali]
3. [age]
4. [67]
-----------
[ """field enclosed in doublequotes""" ]
1. ["field enclosed in doublequotes"]
-----------
The separator \44 (comma) must still be specified as the break set (3rd
\fsplit() parameter). When "CSV" is specified as the include set:
* The Grouping Mask is automatically set to 1 (which specifies that
the ASCII doublequote character (") is used for grouping;
* The Separator Flag is automatically set to 1 so that adjacent field
separators will not be collapsed;
* All bytes (values 0 through 255) other than the break character are
added to the include set;
* Any leading whitespace is stripped from the first element unless it
is enclosed in doublequotes;
* Any trailing whitespace is trimmed from the end of the last element
unless it is enclosed in doublequotes;
* If the separator character has any spaces or tabs preceding it or
following it, they are ignored and discarded;
* The separator character is treated as an ordinary data character if
it appears in a quoted field;
* A sequence of two doublequote characters ("") within a quoted field
is converted to a single doublequote.
There is also a new TSV symbolic include set, which is like CSV except
without the quoting rules or the stripping of whitespace around the
separator because, by definition, TSV fields do not contain tabs.
Of course you can specify any separator(s) you want with either the
CSV, TSV, or ALL symbolic include sets. For example, if you have a TSV
file in which you want the spaces around each Tab to be discarded, you
can use:
\fsplit(variable, &a, \9, CSV)
\9 is Tab.
The new symbolic include sets can also be used with \fword(), which is
just like \fsplit() except that it retrieves the nth word from the
argument string, rather than an array of all the words. In C-Kermit you
can get information about these or any other functions with the HELP
FUNCTION command, e.g.:
C-Kermit> help func word
Function \fword(s1,n1,s2,s3,n2,n3) - Extracts a word from a string.
s1 = source string.
n1 = word number (1-based) counting from left; if negative, from right.
s2 = optional break set.
s3 = optional include set (or ALL, CSV, or TSV).
n2 = optional grouping mask.
n3 = optional separator flag:
0 = collapse adjacent separators;
1 = don't collapse adjacent separators.
\fword() returns the n1th "word" of the string s1, according to the
criteria specified by the other parameters.
The BREAK SET is the set of all characters that separate words. The
default break set is all characters except ASCII letters and digits.
ASCII (C0) control characters are treated as break characters by default,
as are spacing and punctuation characters, brackets, and so on, and
all 8-bit characters.
The INCLUDE SET is the set of characters that are to be treated as
parts of words even though they normally would be separators. The
default include set is empty. Three special symbolic include sets are
also allowed:
ALL (meaning include all bytes that are not in the break set)
CSV (special treatment for Comma-Separated-Value records)
TSV (special treatment for Tab-Separated-Value records)
For operating on 8-bit character sets, the include set should be ALL.
If the GROUPING MASK is given and is nonzero, words can be grouped by
quotes or brackets selected by the sum of the following:
1 = doublequotes: "a b c"
2 = braces: {a b c}
4 = apostrophes: 'a b c'
8 = parentheses: (a b c)
16 = square brackets: [a b c]
32 = angle brackets: <a b c>
Nesting is possible with {}()[]<> but not with quotes or apostrophes.
Returns string:
Word number n1, if there is one, otherwise an empty string.
Also see:
HELP FUNCTION SPLIT
C-Kermit>
Using \fjoin() to create Comma- or Tab-Separated Value Lists from Arrays
In C-Kermit 9.0, \fsplit()'s inverse function, [108]\fjoin() received
the capability of converting an array into a comma-separated or a
tab-separated value list. Thus, given a CSV, if you split it into an
array with \fsplit() and then join the array with \fjoin(), giving each
function the new CSV parameter in the appropriate argument position,
the result will be will be equivalent to the original, according to the
CSV definition. It might not be identical, because if the result had
extraneous spaces before or after the separating commas, these are
discarded, but that does not affect the elements themselves. The new
syntax for \fjoin() is:
\fjoin(&a,CSV)
Given the array \&a[] or any other valid array designator, joins
its elements into a comma-separated list according to the
[109]rules listed above.
\fjoin(&a,TSV)
Joins the elements of the given array into a tab-separated list,
also described above.
[110]Previous calling conventions for \fjoin() are undisturbed,
including the ability to specify a portion of an array, rather than the
whole array:
declare \&a[] = 1 2 3 4 5 6 7 8 9
echo \fjoin(&a[3:7],CSV)
3,4,5,6,7
Using \fsplit() and \fjoin() it is now possible to convert a
comma-separated value list into a tab-separated value list, and vice
versa (which is not a simple matter of changing commas to tabs or vice
versa).
Applications for CSV Files
Databases such as MS Access or MySQL can export tables or reports in
CSV format, and then Kermit can read the resulting CSV file and do
whatever you like with it; typically something that could not be done
with the database query language itself (or that you didn't know how to
do that way): create reports or datasets based on complex criteria or
procedures, edit or modify some fields, etc, and then use \fjoin() to
put each record back in CSV form so it can be reimported into a
spreadsheet or database.
Here is a simple example in which we purge all records of customers who
have two or more unpaid bills. The file is sorted so that each license
purchase record is followed by its annual maintenance payment records
in chronological order.
#!/usr/local/bin/kermit
.filename = somefile.csv # Input file in CSV format
fopen /read \%c \m(filename) # Open it
if fail exit # Don't go on if open failed
copy \m(filename) ./new # Make a copy of the file
.oldserial = 00000000000 # Multiple records for each serial number
.zeros = 0 # Unpaid bill counter
while true { # Loop
fread /line \%c line # Get a record
if fail exit # End of file
.n := \fsplit(\m(line),&a,\44,CSV) # Split the fields into an array
if not equ "\m(oldserial)" "\&a[6]" { # Have new serial number?
# Remove all records for previous serial number
# if two or more bills were not paid...
if > \m(zeros) 1 {
grep /nomatch \m(oldserial) /output:./new2 ./new
rename ./new2 ./new
}
.oldserial := \&a[6] # To detect next time serial number changes
.zeros = 0 # Reset unpaid bill counter
}
if equ "\&a[5]" "$0.00" { # Element 5 is amount paid
increment zeros # If it's zero, count it.
}
}
fclose \%c
Rewriting the file multiple times is inelegant, but this is a quick and
dirty use-once-and-discard script, so elegance doesn't count. The
example is interesting in that it purges certain records based on the
contents of other records. Maybe there is a way to do this directly
with SQL, but why use SQL when you can use Kermit?
Here is the same task but this time no shelling out, and this time we
do change and add some fields and then join the result back into a CSV
record and write it out to a new file. The object is to create a record
for each license that shows not only the date and purchase price of the
license but also the date and amount of the last maintenance payment,
and to add new fields for sorting by anniversary (month and day):
#!usr/local/bin/kermit +
cd ~/somedirectory # CD to appropriate directory
if fail exit 1 # Make sure we did
.filename := \%1 # Filename from command line
if not def filename { # If none give usage message
exit 1 "Usage: \%0: infile [ outfile ]"
}
fopen /read \%c \m(filename) # Open the input CSV file
if fail exit # Make sure we did
.output := \%2 # Output filename from command line
if not def output { # Supply one if not given
.output := New_\m(filename)
}
fopen /write \%o \m(output) # Open output file
if fail exit # Check that we did
.serial = 00000000000 # Initialize serial number
.licenses = 0 # and license counter
fread /line \%c line # First line is column labels
if fail exit # Check
fwrite /line \%o "\m(line),AMM_DD,AYYYY" # Write new labels line
# Remaining lines are license purchases (K95B) followed by zero or more
# maintenance invoices (K95BM) for each license.
.datepaid = 00/00/0000 # Initialize last maint payment date
.amtpaid = $0.00 # Initialize last maint payment amount
set flag off # For remembering we're at end of file
while not flag { # Loop to read all records
fread /line \%c line # Read a record
if fail set flag on # If EOF set flag for later
.n := \fsplit(\m(line),&a,\44,CSV) # Break record into array
if ( flag || equ "\&a[3]" "K95B" ) { # License or EOF
if fail exit 1 "FAILED: \v(lastcommand)"
if licenses { # If this is not the first license
.\&x[5] := \m(amtpaid) # Substitute most recent amount paid
.\&x[21] := \m(datepaid) # Substitute most recent date paid
void \fsplit(\&x[18],&d,/) # Break up original (anniversary) date
# and put mm_dd and yyyy in separate fields for sorting...
fwrite /line \%o "\fjoin(&x,CSV),\flpad(\&d[1],2,0)_\flpad(\&d[2],2,
0),\&d[3]"
if fail exit 1 WRITE # Check for error
xecho . # Show progress as one dot per record
}
if flag break # We're at EOF so we're finished
increment licenses # New license - count it
array copy &a &x # Keep this record while reading next
.serial := \&a[6] # Remember serial number
.datepaid = 00/00/0000 # Initial maintenance payment date
.amtpaid = $0.00 # and amount
continue # and go back to read next record
}
if not eq "\m(serial)" "\&a[6]" { # Catch out-of-sequence record
echo
echo "SEQUENCE: \m(serial)..\&a[6]: \&a[7] [\&a[1]]"
continue
}
if equ "\&a[5]" "" .\&a[5] = $0.00 # If amount is empty make it $0.00
if not equ "\&a[5]" "$0.00" { # If amount is not $0.00
.datepaid := \&a[21] # remember date paid
.amtpaid := \&a[5] # and amount paid
}
}
fclose ALL # Done - close all files and exit
exit 0 Done.
The result imports back into Excel, where it can be sorted, formatted,
or otherwise manipulated as desired.
Using CSV Files: Extending Kermit's Data Structures
Now that we can parse a CSV record, what would we do with a CSV file -
that is, a sequence of records? If we needed all the data available at
once, we would want to load it into a matrix of (row,column) values.
But Kermit doesn't have matrices. Or does it?
Kermit has several built-in data types, but you can invent your own
data types as needed using Kermit's macro feature:
define variablename value
For example:
define alphabet abcdefghijklmnopqrstuvwxyz
This defines a macro named alphabet and gives it the value
abcdefghijklmnopqrstuvwxyz. A more convenient notation (added in
C-Kermit 7.0, see [111]Table 2) for this is:
.alphabet = abcdefghijklmnopqrstuvwxyz
The two are exactly equivalent: they make a literal copy the "right
hand side" as the value of the macro. Then you can refer to the macro
anywhere in a Kermit command as "\m(macroname)":
echo "Alphabet = \m(alphabet)"
There is a second way to define a macro, which is like the first except
that the right-hand side is evaluated first; that is, any variable
references or function calls in the right-hand side are replaced by
their values before the result is assigned to the macro. The command
for this is ASSIGN rather than DEFINE:
define alphabet abcdefghijklmnopqrstuvwxyz
assign backwards \freverse(\m(alphabet))
echo "Alphabet backwards = \m(backwards)"
which prints:
Alphabet backwards = zyxwvutsrqponmlkjihgfedcba
This kind of assignment can also be done like this:
.alphabet = abcdefghijklmnopqrstuvwxyz
.backwards := \freverse(\m(alphabet))
[112]Any command starting with a period is an assignment, and the
operator (= or :=) tells what to do with the right-hand side before
making the assignment.
In both the DEFINE and ASSIGN commands, the variable name itself is
taken literally. It is also possible, however, to have Kermit compute
the variable name. This is done (as described in [113]Using C-Kermit,
2nd Ed., p.457), using parallel commands that start with underscore:
_DEFINE and _ASSIGN (alias _DEF and _ASG). These are just like DEFINE
and ASSIGN except they evaluate the variable name before making the
assignment. For example:
define \%a one
_define \%a\%a\%a 111
would create a macro named ONEONEONE with a value of 111, and:
define \%a one
define number 111
_assign \%a\%a\%a \m(number)
would create the same macro with the same value, but:
define \%a one
define number 111
_define \%a\%a\%a \m(number)
would give the macro a value of "\m(number)".
You can use the _ASSIGN command to create any kind of data structure
you want; you can find some examples in the [114]Object-Oriented
Programming section of the [115]Kermit Script Library. In the following
program we use this capability to create a two-dimensional array, or
matrix, to hold the all the elements of the CSV file, and then to
display the matrix:
fopen /read \%c data.csv # Open CSV file
if fail exit 1
.\%r = 0 # Row
.\%m = 0 # Maximum columns
while true {
fread /line \%c line # Read a record
if fail break # End of file
.\%n := \fsplit(\m(line),&a,\44,CSV) # Split record into items
incr \%r # Count this row
for \%i 1 \%n 1 { # Assign items to this row of matrix
_asg a[\%r][\%i] \&a[\%i]
}
if > \%i \%m { .\%m := \%i } # Remember width of widest row
}
fclose \%c # Close CSV file
decrement \%m # (because of how FOR loop works)
echo MATRIX A ROWS: \%r COLUMNS: \%m # Show the matrix
for \%i 1 \%r 1 { # Loop through rows
for \%j 1 \%m 1 { # Loop through columns of each row
xecho "\flpad(\m(a[\%i][\%j]),6)"
}
echo
}
exit 0
The matrix is called a and its elements are a[1][1], a[1][2], a[1][3],
... a[2][1], etc, and you can treat this data structure exactly like a
two-dimensional array, in which you can refer to any element by its "X
and Y coordinates". For example, if the CSV file contained numeric data
you could compute row and column sums using simple FOR loops and
Kermit's built-in one-dimensional array data type:
declare \&r[\%r] # Make an array for the row sums
declare \&c[\%m] # Make an array for the column sums
for \%i 1 \%r 1 { # Loop through rows
for \%j 1 \%m 1 { # Loop through columns of each row
increment \&r[\%i] \m(a[\%i][\%j]) # Accumulate row sum
increment \&c[\%j] \m(a[\%i][\%j]) # Accumulate column sum
}
}
Note that the sum arrays don't have to be initialized to zero because
Kermit's INCREMENT command treats empty definitions as zero.
Demonstration Scripts for Webmasters
[116]ksitemap
A C-Kermit 9.0 script to build sitemap.xml for a website,
complete with Google image extensions (this is the file used by
webmasters to get their sites crawled and indexed optimally).
[117]The Weblog Script
Reads a web log, extracts the Google searches, normalizes the
search strings, and prints the top 20 searches, along with their
counts.
[118]The Amazon Script
Reads an Amazon Associate orders report and lists the products
according to the number of orders for each, or the number of
clicks on each.
[119]Photoalbum
Makes a website from a collection of JPG images. Requires
[120]C-Kermit 9.0 or later.
[121]Home [122]Kermit 95 [123]C-Kermit [124]Scripts [125]Current
[126]New [127]FAQ [128]Support
C-Kermit 9.0 / [129]The Kermit Project / [130]Columbia University /
[131]kermit@columbia.edu / [132]validate
References
1. http://www.columbia.edu/
2. mailto:kermit@columbia.edu
3. http://www.columbia.edu/kermit/index.html
4. http://www.columbia.edu/kermit/k95.html
5. http://www.columbia.edu/kermit/ckermit.html
6. http://www.columbia.edu/kermit/ckscripts.html
7. http://www.columbia.edu/kermit/current.html
8. http://www.columbia.edu/kermit/whatsnew.html
9. http://www.columbia.edu/kermit/faq.html
10. http://www.columbia.edu/kermit/support.html
11. http://www.columbia.edu/cu/computinghistory/books/#menagerie
12. http://www.columbia.edu/kermit/ck90tables.html
13. http://www.amazon.com/gp/product/1555581641?ie=UTF8&tag=aleidmoreldom-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=1555581641
14. http://www.columbia.edu/kermit/ckermit.html#download
15. http://www.columbia.edu/kermit/ckermit90.html#LargeFiles
16. http://www.columbia.edu/kermit/ckermit90.html#TestLargeFiles
17. http://www.columbia.edu/kermit/ckermit90.html#Bignums
18. http://www.columbia.edu/kermit/ckermit90.html#force3
19. http://www.columbia.edu/kermit/ckermit90.html#Vareval
20. http://www.columbia.edu/kermit/ckermit90.html#rename
21. http://www.columbia.edu/kermit/ckermit90.html#Other
22. http://www.columbia.edu/kermit/ckermit90.html#Incompatibilities
23. http://www.columbia.edu/kermit/ckermit90.html#NotIn9.0
24. http://www.columbia.edu/kermit/ckermit90.html#LooseEnd
25. http://www.columbia.edu/kermit/ckermit90.html#pop
26. http://www.columbia.edu/kermit/ckermit90.html#HPswitch
27. http://www.columbia.edu/kermit/ckermit90.html#iLO
28. http://www.columbia.edu/kermit/ckermit90.html#Rolm
29. http://www.columbia.edu/kermit/ckermit90.html#CSV
30. http://www.columbia.edu/kermit/ckermit90.html#Otherdemos
31. http://www.columbia.edu/kermit/ck60manual.html
32. http://www.amazon.com/gp/product/B002ACPF9M?ie=UTF8&tag=aleidmoreldom-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B002ACPF9M
33. http://www.columbia.edu/kermit/ckermit70.html
34. http://www.columbia.edu/kermit/ckermit80.html
35. http://www.columbia.edu/kermit/ckscripts.html
36. http://www.columbia.edu/cu/computinghistory/dec20.html
37. mailto:fdc@columbia.edu
38. http://www.columbia.edu/kermit/k95.html
39. http://www.columbia.edu/kermit/cu-bsd-license.html
40. http://www.columbia.edu/kermit/ckermit90.html#LargeFiles
41. http://www.columbia.edu/kermit/ck90tables.html
42. http://www.columbia.edu/kermit/ck90tables.html
43. http://www.columbia.edu/kermit/ckermit90.html#force3
44. http://www.columbia.edu/kermit/ckermit90.html#Vareval
45. http://www.columbia.edu/kermit/ckrename.html
46. http://www.columbia.edu/kermit/csv.html
47. http://www.columbia.edu/kermit/csetnames.html
48. http://www.columbia.edu/kermit/ckermit90.html#HPswitch
49. http://www.columbia.edu/kermit/ckdaily.html
50. http://www.columbia.edu/kermit/cu-bsd-license.html
51. http://www.opensource.org/
52. http://kermit.columbia.edu/ck90tables.html#LF
53. ftp://kermit.columbia.edu/kermit/utils/bigfile.c
54. http://www.columbia.edu/kermit/ckermit80.html#x9
55. http://www.columbia.edu/kermit/ck90tables.html#LF
56. ftp://kermit.columbia.edu/kermit/scripts/ckermit/easter2
57. http://www.columbia.edu/kermit/em-apex.html
58. http://www.iridium.com/
59. http://science1.nasa.gov/science-news/science-at-nasa/2006/09jan_electrichurricanes/
60. http://www.columbia.edu/kermit/ek.html
61. ftp://kermit.columbia.edu/kermit/ek/simirid/
62. http://www.columbia.edu/kermit/ek.html
63. http://www.columbia.edu/kermit/ckermit70.html#x7.10.10
64. http://www.columbia.edu/kermit/csv.html
65. http://www.columbia.edu/kermit/ckermit70.html#x1.11
66. http://www.columbia.edu/kermit/ckermit70.html
67. http://www.columbia.edu/kermit/ckermit80.html#x9
68. http://www.columbia.edu/kermit/csetnames.html
69. http://www.columbia.edu/kermit/ckdaily.html
70. http://www.columbia.edu/kermit/ftpclient.html
71. http://www.columbia.edu/kermit/ckdaily.html
72. http://www.columbia.edu/kermit/csetnames.html
73. http://www.columbia.edu/kermit/ckermit90.html#Otherdemos
74. http://www.columbia.edu/kermit/input_nowrap.html
75. http://www.columbia.edu/~fdc/mm/index.html
76. http://www.columbia.edu/kermit/photoalbum.html
77. http://www.columbia.edu/~fdc/kermit/logserial.html
78. http://www.columbia.edu/kermit/ckermit90.html#message
79. http://www.columbia.edu/kermit/ckermit90.html#NotIn9.0
80. http://www.columbia.edu/kermit/csv.html#join
81. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3767
82. http://www.columbia.edu/kermit/ftp/test/tar/x.zip
83. http://www.mseclab.com/?p=180
84. http://www.theregister.co.uk/2009/07/30/universal_ssl_certificate/
85. http://www.columbia.edu/kermit/ckermit90.html#HPswitch
86. http://www.columbia.edu/kermit/em-apex.html
87. http://www.freebsd.org/releases/8.0R/announce.html
88. http://www.columbia.edu/kermit/security81.html#x4.2.3
89. http://www.columbia.edu/kermit/ckermit80.html#x9
90. http://www.columbia.edu/kermit/ckermit80.html#x8.7.2
91. http://www.columbia.edu/kermit/ckermit80.html#x9
92. http://www.columbia.edu/kermit/ckpackages.html
93. http://docs.hp.com/en/B9106-90013/pty.7.html
94. http://www.columbia.edu/kermit/test/text/ckc299.txt
95. http://www.columbia.edu/kermit/test/text/ckutio.c
96. http://www.columbia.edu/~fdc/mm/pop
97. http://www.columbia.edu/~fdc/mm/
98. http://www.columbia.edu/~fdc/mm/mailcheck
99. http://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol
100. http://www.columbia.edu/kermit/ftp/scripts/ckermit/gethpconfig
101. http://www.columbia.edu/kermit/ftp/scripts/ckermit/TestSwitches.txt
102. http://en.wikipedia.org/wiki/Standard_streams
103. http://kermit.columbia.edu/cudocs/ilosetup.html
104. http://www.columbia.edu/kermit/cudocs/cbx.html
105. http://www.columbia.edu/kermit/ckermit90.html#record
106. http://www.columbia.edu/kermit/ckermit90.html#join
107. http://www.columbia.edu/kermit/ckermit90.html#file
108. http://www.columbia.edu/kermit/ckermit80.html#fjoin
109. http://www.columbia.edu/kermit/ckermit90.html#rules
110. http://www.columbia.edu/kermit/ckermit80.html#fjoin
111. http://www.columbia.edu/kermit/ckermit90.html#varasg
112. http://www.columbia.edu/kermit/ckermit70.html#x7.9
113. http://www.amazon.com/gp/product/1555581641?ie=UTF8&tag=aleidmoreldom-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=1555581641
114. http://www.columbia.edu/kermit/ckscripts.html#oops
115. http://www.columbia.edu/kermit/ckscripts.html
116. http://www.columbia.edu/kermit/ksitemap.html
117. http://www.columbia.edu/kermit/weblog.html
118. http://kermit.columbia.edu/ftp/scripts/ckermit/amazon
119. http://www.columbia.edu/kermit/photoalbum.html
120. http://www.columbia.edu/kermit/ck90.html
121. http://www.columbia.edu/kermit/index.html
122. http://www.columbia.edu/kermit/k95.html
123. http://www.columbia.edu/kermit/ckermit.html
124. http://www.columbia.edu/kermit/ckscripts.html
125. http://www.columbia.edu/kermit/current.html
126. http://www.columbia.edu/kermit/whatsnew.html
127. http://www.columbia.edu/kermit/faq.html
128. http://www.columbia.edu/kermit/support.html
129. http://www.columbia.edu/kermit/index.html
130. http://www.columbia.edu/
131. mailto:kermit@columbia.edu
132. http://validator.w3.org/check?uri=http%3A%2F%2Fkermit.columbia.edu%2Fck90.html