Provided by: tclx8.4-doc_8.4.1-2_all 
NAME
TclX - Extended Tcl: Extended command set for Tcl
SYNOPSIS
package require Tclx
INTRODUCTION
This man page contains the documentation for all of the extensions that are added to Tcl
by Extended Tcl (TclX). TclX extends Tcl's capabilities by adding new commands to it,
without changing the syntax of standard Tcl. Extended Tcl is a superset of standard Tcl
and is built alongside the standard Tcl sources.
Extended Tcl was created by Karl Lehenbauer and Mark Diekhans and is freely
redistributable for any use without license or fee.
Available since 1989, Extended Tcl, also known as TclX, not only adds capabilities to Tcl,
but has also been the source of many of the capabilities of the baseline Tcl release,
including arrays, files, sockets, file events, and date and time handling, among others.
Extended Tcl introduces a set of new commands and a user-extensible library of useful Tcl
procedures, any of which can be automatically loaded on the first attempt to execute it.
The command descriptions are separated into several sections:
• General Commands
• Debugging and Development Commands
• Unix Access Commands
• File Commands
• Network Programming Support
• File Scanning Commands
• Math Commands
• List Manipulation Commands
• Keyed Lists
• String and Character Manipulation Commands
• XPG/3 Message Catalog Commands
• Help Facility
• Tcl Loadable Libraries and Packages
GENERAL COMMANDS
A set of general, useful Tcl commands, includes a command to begin an interactive session
with Tcl, a facility for tracing execution, and a looping command.
dirs This procedure lists the directories in the directory stack.
commandloop ?-async? ?-interactive on | off | tty? ?-prompt1 cmd? ?-prompt2 cmd?
?-endcommand cmd?
Create an interactive command loop reading commands from stdin and writing results
to stdout. Command loops are maybe either be blocking or event oriented. This
command is useful for Tcl scripts that do not normally converse interactively with
a user through a Tcl command interpreter, but which sometimes want to enter this
mode, perhaps for debugging or user configuration. The command loop terminates on
EOF.
The following options are available:
-async A command handler will be associated with stdin. When input is available on
stdin, it will be read and accumulated until a full command is available.
That command will then be evaluated. An event loop must be entered for
input to be read and processed.
-interactive on | off | tty
Enable or disable interactive command mode. In interactive mode, commands
are prompted for and the results of comments are printed. The value maybe
any boolean value or tty. If tty is used, interactive mode is enabled if
stdin is associated with a terminal or terminal emulator. The default is
tty.
-prompt1 cmd
If specified, cmd is used is evaluate and its result used for the main
command prompt. If not specified, the command in tcl_prompt1 is evaluated
to output the prompt. Note the difference in behavior, cmd results is used,
while tcl_prompt1 outputs. This is to allow for future expansion to command
loops that write to other than stdout.
-prompt2 cmd
If specified, cmd is used is evaluate and its result used for the secondary
(continuation) command prompt. If not specified, the command in tcl_prompt2
is evaluated to output the prompt.
-endcommand cmd
If specified, cmd is evaluated when the command loop terminates.
In interactive mode, the results of set commands with two arguments are not
printed.
If SIGINT is configured to generate a Tcl error, it can be used to delete
the current command being type without aborting the program in progress.
echo ?str ...?
Writes zero or more strings to standard output, followed by a newline.
infox option
Return information about Extended Tcl, or the current application. The following
infox command options are available:
version
Return the version number of Extended Tcl. The version number for Extended
Tcl is generated by combining the base version of the standard Tcl code with
another number indicating the version of Extended Tcl being used.
patchlevel
Return the patchlevel for Extended Tcl.
have_fchown
Return 1 if the fchown system call is available. This supports the -fileid
option on the chown and chgrp commands.
have_fchmod
Return 1 if the fchmod system call is available. This supports the -fileid
option on the chmod command.
have_flock
Return 1 if the flock command defined, 0 if it is not available.
have_fsync
Return 1 if the fsync system call is available and the sync command will
sync individual files. 0 if it is not available and the sync command will
always sync all file buffers.
have_ftruncate
Return 1 if the ftruncate or chsize system call is available. If it is, the
ftruncate command -fileid option maybe used.
have_msgcats
Return 1 if XPG message catalogs are available, 0 if they are not. The
catgets is designed to continue to function without message catalogs, always
returning the default string.
have_posix_signals
Return 1 if Posix signals are available (block and unblock options available
for the signal command). 0 is returned if Posix signals are not available.
have_signal_restart
Return 1 if restartable signals are available (-restart option available for
the signal command). 0 is returned if restartable signals are not
available.
have_truncate
Return 1 if the truncate system call is available. If it is, the ftruncate
command may truncate by file path.
have_waitpid
Return 1 if the waitpid system call is available and the wait command has
full functionality. 0 if the wait command has limited functionality.
appname
Return the symbolic application name of the current application linked with
the Extended Tcl library. The C variable tclAppName must be set by the
application to return an application specific value for this variable.
applongname
Return a natural language name for the current application. The C variable
tclLongAppName must be set by the application to return an application
specific value for this variable.
appversion
Return the version number for the current application. The C variable
tclAppVersion must be set by the application to return an application-
specific value for this variable.
apppatchlevel
Return the patchlevel for the current application. The C variable
tclAppPatchlevel must be set by the application to return an application-
specific value for this variable.
for_array_keys var array_name code
This procedure performs a foreach-style loop for each key in the named array. The
break and continue statements work as with foreach.
for_recursive_glob var dirlist globlist code
This procedure performs a foreach-style loop over recursively matched files. All
directories in dirlist are recursively searched (breadth-first), comparing each
file found against the file glob patterns in globlist. For each matched file, the
variable var is set to the file path and code is evaluated. Symbolic links are not
followed.
loop var first limit ?increment? body
Loop is a looping command, similar in behavior to the Tcl for statement, except
that the loop statement achieves substantially higher performance and is easier to
code when the beginning and ending values of a loop are known, and the loop
variable is to be incremented by a known, fixed amount every time through the loop.
The var argument is the name of a Tcl variable that will contain the loop index.
The loop index is set to the value specified by first. The Tcl interpreter is
invoked upon body zero or more times, where var is incremented by increment every
time through the loop, or by one if increment is not specified. Increment can be
negative in which case the loop will count downwards.
When var reaches limit, the loop terminates without a subsequent execution of body.
For instance, if the original loop parameters would cause loop to terminate, say
first was one, limit was zero and increment was not specified or was non-negative,
body is not executed at all and loop returns.
The first, limit and increment are integer expressions. They are only evaluated
once at the beginning of the loop.
If a continue command is invoked within body then any remaining commands in the
current execution of body are skipped, as in the for command. If a break command
is invoked within body then the loop command will return immediately. Loop returns
an empty string.
popd This procedure pops the top directory entry from the directory stack and make it
the current directory.
pushd ?dir?
This procedure pushes the current directory onto the directory stack and cd to the
specified directory. If the directory is not specified, then the current directory
is pushed, but remains unchanged.
recursive_glob dirlist globlist
This procedure returns a list of recursively matches files. All directories in
dirlist are recursively searched (breadth-first), comparing each file found against
the file glob patterns in globlist. Symbolic links are not followed.
showproc ?procname ...?
This procedure lists the definition of the named procedures. Loading them if it is
not already loaded. If no procedure names are supplied, the definitions of all
currently loaded procedures are returned.
try_eval code catch ?finally?
The try_eval command evaluates code in the current context.
If an error occurs during the evaluation and catch is not empty, then catch is evaluated
to handler the error. The result of the command, containing the error message, will be
stored in a global variable errorResult. The global variables errorResult, errorInfo and
errorCode will be imported into the current scope, there is no need to execute a global
command. The result of the catch command becomes the result of the try_eval command. If
the error that caused the catch to be evaluate is to be continued, the following command
should be used:
error $errorResult $errorCode $errorInfo
If the finally argument is supplied and not empty, it is evaluated after the evaluation of
the code and the catch commands. If an error occurs during the evaluation of the finally
command, it becomes the result of the try_eval command. Otherwise, the result of either
code or catch is preserved, as described above.
DEBUGGING AND DEVELOPMENT COMMANDS
This section contains information on commands and procedures that are useful for
developing and debugging Tcl scripts.
cmdtrace level | on ?noeval? ?notruncate? ?procs? ?fileid? ?command cmd?
Print a trace statement for all commands executed at depth of level or below (1 is
the top level). If on is specified, all commands at any level are traced. The
following options are available:
noeval Causes arguments to be printed unevaluated. If noeval is specified, the
arguments are printed before evaluation. Otherwise, they are printed
afterwards.
If the command line is longer than 60 characters, it is truncated to 60 and
a "..." is postpended to indicate that there was more output than was
displayed. If an evaluated argument contains a space, the entire argument
will be enclosed inside of braces (`{}') to allow the reader to visually
separate the arguments from each other.
notruncate
Disables the truncation of commands and evaluated arguments.
procs Enables the tracing of procedure calls only. Commands that aren't procedure
calls (i.e. calls to commands that are written in C, C++ or some object-
compatible language) are not traced if the procs option is specified. This
option is particularly useful for greatly reducing the output of cmdtrace
while debugging.
fileid This is a file id as returned by the open command. If specified, then the
trace output will be written to the file rather than stdout. A stdio buffer
flush is done after every line is written so that the trace may be monitored
externally or provide useful information for debugging problems that cause
core dumps.
command cmd
Call the specified command cmd on when each command is executed instead of
tracing to a file. See the description of the functionally below. This
option may not be specified with a fileid.
The most common use of this command is to enable tracing to a file during the
development. If a failure occurs, a trace is then available when needed. Command
tracing will slow down the execution of code, so it should be removed when code is
debugged. The following command will enable tracing to a file for the remainder of
the program:
cmdtrace on [open cmd.log w]
The command option causes a user specified trace command to be called for each
command executed. The command will have the following arguments appended to it
before evaluation:
command
A string containing the text of the command, before any argument
substitution.
argv A list of the final argument information that will be passed to the command
after command, variable, and backslash substitution.
evalLevel
The Tcl_Eval call level.
procLevel
The procedure call level.
The command should be constructed in such a manner that it will work if additional
arguments are added in the future. It is suggested that the command be a proc with
the final argument being args.
Tracing will be turned off while the command is being executed. The values of the
errorInfo and errorCode variables will be saved and restored on return from the
command. It is the command's responsibility to preserve all other state.
If an error occurs during the execution of command, an error message is dumped to
stderr and the tracing is disabled. The underlying mechanism that this
functionality is built on does not support returning an error to the interpreter.
cmdtrace off
Turn off all tracing.
cmdtrace depth
Returns the current maximum trace level, or zero if trace is disabled.
edprocs ?proc...?
This procedure writes the named procedures, or all currently defined procedures, to
a temporary file, then calls an editor on it (as specified by the EDITOR
environment variable, or vi if none is specified), then sources the file back in if
it was changed.
profile ?-commands? ?-eval? on
profile off arrayVar
This command is used to collect a performance profile of a Tcl script. It collects
data at the Tcl procedure level. The number of calls to a procedure, and the amount
of real and CPU time is collected. Time is also collected for the global context.
The procedure data is collected by bucketing it based on the procedure call stack,
this allows determination of how much time is spent in a particular procedure in
each of it's calling contexts.
The on option enables profile data collection. If the -commands option is
specified, data on all commands within a procedure is collected as well a
procedures. Multiple occurrences of a command within a procedure are not
distinguished, but this data may still be useful for analysis.
The off option turns off profiling and moves the data collected to the array
arrayVar. The array is address by a list containing the procedure call stack.
Element zero is the top of the stack, the procedure that the data is for. The data
in each entry is a list consisting of the procedure call count and the real time
and CPU time in milliseconds spent in the procedure (but not any procedures it
calls). The list is in the form {count real cpu}.
Normally, the variable scope stack is used in reporting where time is spent. Thus
upleveled code is reported in the context that it was executed in, not the context
that the uplevel was called in. If the -eval option is specified, the procedure
evaluation (call) stack is used instead of the procedure scope stack. Upleveled
code is reported in the context of the procedure that did the uplevel.
A Tcl procedure profrep is supplied for reducing the data and producing a report.
On Windows, profile command only reports elapsed real time, CPU time is not
available and is reported as zero.
profrep profDataVar sortKey ?outFile? ?userTitle?
This procedure generates a report from data collect from the profile command.
ProfDataVar is the name of the array containing the data returned by the profile
command. SortKey indicates which data value to sort by. It should be one of
"calls", "cpu" or "real". OutFile is the name of file to write the report to. If
omitted, stdout is assumed. UserTitle is an optional title line to add to output.
Listed with indentation below each procedure or command is the procedure call
stack. The first indented line being the procedure that invoked the reported
procedure or command. The next line is the procedure that invoked the procedure
above it, and so on. If no indented procedures are shown, the procedure or command
was called from the global context. Time actually spent in the global context is
listed on a line labeled <global>. Upleveled code is reported in the context that
it was executed in, not the context that the uplevel was called in.
saveprocs fileName ?proc...?
This procedure saves the definition of the named procedure, or all currently
defined procedures if none is specified, to the named file.
UNIX ACCESS COMMANDS
These commands provide access to many basic Unix facilities, including process handling,
date and time processing, signal handling and the executing commands via the shell.
alarm seconds
Instructs the system to send a SIGALRM signal in the specified number of seconds.
This is a floating point number, so fractions of a section may be specified. If
seconds is 0.0, any previous alarm request is canceled. Only one alarm at a time
may be active; the command returns the number of seconds left in the previous
alarm. On systems without the setitimer system call, seconds is rounded up to an
integer number of seconds.
The alarm command is not available on Windows.
execl ?-argv0 argv0? prog ?arglist?
Do an execl, replacing the current program (either Extended Tcl or an application
with Extended Tcl embedded into it) with prog and passing the arguments in the list
arglist.
The -argv0 options specifies that argv0 is to be passed to the program as argv [0]
rather than prog.
Note: If you are using execl in a Tk application and it fails, you may not do
anything that accesses the X server or you will receive a BadWindow error from the
X server. This includes executing the Tk version of the exit command. We suggest
using the following command to abort Tk applications after an execl failure:
kill [id process]
On Windows, where the fork command is not available, execl starts a new process and
returns the process id.
chroot dirname
Change root directory to dirname, by invoking the POSIX chroot(2) system call.
This command only succeeds if running as root.
fork Fork the current Tcl process. Fork returns zero to the child process and the
process number of the child to the parent process. If the fork fails, a Tcl error
is generated.
If an execl is not going to be performed before the child process does output, or
if a close and dup sequence is going to be performed on stdout or stderr, then a
flush should be issued against stdout, stderr and any other open output file before
doing the fork. Otherwise characters from the parent process pending in the buffers
will be output by both the parent and child processes.
Note: If you are forking in a Tk based application you must execl before doing any
window operations in the child or you will receive a BadWindow error from the X
server.
The fork command is not available on Windows.
id options
This command provides a means of getting, setting and converting user, group and
process ids. The id command has the following options:
id user ?name?
id userid ?uid?
Set the real and effective user ID to name or uid, if the name (or uid) is
valid and permissions allow it. If the name (or uid) is not specified, the
current name (or uid) is returned.
id convert userid uid
id convert user name
Convert a user ID number to a user name, or vice versa.
id group ?name?
id groupid ?gid?
Set the real and effective group ID to name or gid, if the name (or gid) is
valid and permissions allow it. If the group name (or gid) is not
specified, the current group name (or gid) is returned.
id groups
id groupids
Return the current group access list of the process. The option groups
returns group names and groupids returns id numbers.
id convert groupid gid
id convert group name
Convert a group ID number to a group name, or vice versa.
id effective user
id effective userid
Return the effective user name, or effective user ID number, respectively.
id effective group
id effective groupid
Return the effective group name, or effective group ID number, respectively.
id effective groupids
Return all of the groupids the user is a member of.
id host
Return the hostname of the system the program is running on.
id process
Return the process ID of the current process.
id process parent
Return the process ID of the parent of the current process.
id process group
Return the process group ID of the current process.
id process group set
Set the process group ID of the current process to its process ID.
id host
Returns the standard host name of the machine the process is executing on.
On Windows, only the host and process options are implemented.
kill ?-pgroup ?signal? idlist
Send a signal to the each process in the list idlist, if permitted. Signal, if
present, is the signal number or the symbolic name of the signal, see the signal
system call manual page. The leading ``SIG'' is optional when the signal is
specified by its symbolic name. The default for signo is 15, SIGTERM.
If -pgroup is specified, the numbers in idlist are take as process group ids and
the signal is sent to all of the process in that process group. A process group id
of 0 specifies the current process group.
On Windows, the kill command is capable of terminating a process, but not of
sending an arbitrary signal.
link ?-sym? srcpath destpath
Create a directory entry, destpath, linking it to the existing file, srcpath. If
-sym is specified, a symbolic link, rather than a hard link, is created. (The -sym
option is only available on systems that support symbolic links.)
The link command is not available on Windows. Use the Tcl 8.4+ file link command
instead.
nice ?priorityincr?
Change or return the process priority. If priorityincr is omitted, the current
priority is returned. If priorityincr is positive, it is added to the current
priority level, up to a system defined maximum (normally 19),
Negative priorityincr values cumulatively increase the program's priority down to a
system defined minimum (normally -19); increasing priority with negative niceness
values will only work for the superuser.
The new priority is returned.
The nice command is not available on Windows.
readdir ?-hidden? dirPath
Returns a list containing the contents of the directory dirPath. The directory
entries "." and ".." are not returned.
On Windows, -hidden maybe specified to include hidden files in the result. This
flag is ignored on Unix systems.
signal ?-restart? action siglist ?command?
Warning: If signals are being used as an event source (a trap action), rather than
generating an error to terminate a task; one must use the -restart option. This
causes a blocked system call, such as read or waitpid to be restarted rather than
generate an error. Failure to do this may results in unexpected errors when a
signal arrives while in one of these system calls. When available, the -restart
option can prevent this problem.
If -restart is specified, restart blocking system calls rather than generating an
error. The signal will be handled once the Tcl command that issued the system call
completes. The -restart options is not available on all operating systems and its
use will generate an error when it is not supported. Use infox have_signal_restart
to check for availability.
Specify the action to take when a Unix signal is received by Extended Tcl, or a
program that embeds it. Siglist is a list of either the symbolic or numeric Unix
signal (the SIG prefix is optional). Action is one of the following actions to be
performed on receipt of the signal. To specify all modifiable signals, use `*'
(this will not include SIGKILL and SIGSTOP, as they can not be modified).
default
Perform system default action when signal is received (see signal system
call documentation).
ignore Ignore the signal.
error Generate a catchable Tcl error. It will be as if the command that was
running returned an error. The error code will be in the form:
POSIX SIG signame
For the death of child signal, signame will always be SIGCHLD, rather than
SIGCLD, to allow writing portable code.
trap When the signal occurs, execute command and continue execution if an error
is not returned by command. The command will be executed in the global
context. The command will be edited before execution, replacing occurrences
of "%S" with the signal name. Occurrences of "%%" result in a single "%".
This editing occurs just before the trap command is evaluated. If an error
is returned, then follow the standard Tcl error mechanism. Often command
will just do an exit.
get Retrieve the current settings of the specified signals. A keyed list will
be returned were the keys are one of the specified signals and the values
are a list consisting of the action associated with the signal, a 0 if the
signal may be delivered (not block) and a 1 if it is blocked and a flag
indicating if restarting of system calls is specified. The actions maybe
one of `default',`ignore', `error' or `trap'. If the action is trap, the
third element is the command associated with the action. The action
`unknown' is returned if a non-Tcl signal handler has been associated with
the signal.
set Set signals from a keyed list in the format returned by the get. For this
action, siglist is the keyed list of signal state. Signals with an action
of `unknown' are not modified.
block Block the specified signals from being received. (Posix systems only).
unblock
Allow the specified signal to be received. Pending signals will not occur.
(Posix systems only).
The signal action will remain enabled after the specified signal has occurred. The
exception to this is SIGCHLD on systems without Posix signals. For these systems,
SIGCHLD is not be automatically re-enabled. After a SIGCHLD signal is received, a
call to wait must be performed to retrieve the exit status of the child process
before issuing another signal SIGCHLD ... command. For code that is to be portable
between both types of systems, use this approach.
Signals are not processed until after the completion of the Tcl command that is
executing when the signal is received. If an interactive Tcl shell is running,
then the SIGINT will be set to error, non-interactive Tcl sessions leave SIGINT
unchanged from when the process started (normally default for foreground processes
and ignore for processes in the background).
sleep seconds
Sleep the Extended Tcl process for seconds seconds. Seconds, if specified as a
decimal number, is truncated to an integer value.
system cmdstr1 ?cmdstr2...?
Concatenates cmdstr1, cmdstr2 etc with space separators (see the concat command)
into a single command and then evaluates the command using the standard system
shell. On Unix systems, this is /bin/sh and on Windows its command.com. The exit
code of the command is returned.
This command differs from the exec command in that system doesn't return the
executed command's standard output as the result string, and system goes through
the Unix shell to provide wild card expansion, redirection, etc, as is normal from
an sh command line.
sync ?fileId?
If fileId is not specified, or if it is and this system does not support the fsync
system call, issues a sync system call to flush all pending disk output. If fileId
is specified and the system does support the fsync system call, issues an fsync on
the file corresponding to the specified Tcl fileId to force all pending output to
that file out to the disk.
If fileId is specified, the file must be writable. A flush will be issued against
the fileId before the sync.
The infox have_fsync command can be used to determine if "sync fileId" will do a
sync or a fsync.
times
Return a list containing the process and child execution times in the form:
utime stime cutime cstime
Also see the times(2) system call manual page. The values are in milliseconds.
umask ?octalmask?
Sets file-creation mode mask to the octal value of octalmask. If octalmask is
omitted, the current mask is returned.
wait ?-nohang? ?-untraced? ?-pgroup? ?pid?
Waits for a process created with the execl command to terminate, either due to an
untrapped signal or call to exit system call. If the process id pid is specified,
they wait on that process, otherwise wait on any child process to terminate.
If -nohang is specified, then don't block waiting on a process to terminate. If no
process is immediately available, return an empty list. If -untraced is specified
then the status of child processes that are stopped, and whose status has not yet
been reported since they stopped, are also returned. If -pgroup is specified and
pid is not specified, then wait on any child process whose process group ID is they
same as the calling process. If pid is specified with -pgroup, then it is take as a
process group ID, waiting on any process in that process group to terminate.
Wait returns a list containing three elements: The first element is the process id
of the process that terminated. If the process exited normally, the second element
is `EXIT', and the third contains the numeric exit code. If the process terminated
due to a signal, the second element is `SIG', and the third contains the signal
name. If the process is currently stopped (on systems that support SIGSTP), the
second element is `STOP', followed by the signal name.
Note that it is possible to wait on processes to terminate that were create in the
background with the exec command. However, if any other exec command is executed
after the process terminates, then the process status will be reaped by the exec
command and will not be available to the wait command.
On systems without the waitpid system call, the -nohang, -untraced and -pgroup
options are not available. The infox have_waitpid command maybe use to determine
if this functionality is available.
FILE COMMANDS
These commands provide extended file access and manipulation. This includes searching
ASCII-sorted data files, copying files, duplicating file descriptors, control of file
access options, retrieving open file status, and creating pipes with the pipe system call.
Also linking files, setting file, process, and user attributes and truncating files. An
interface to the select system call is available on Unix systems that support it.
It should be noted that Tcl file I/O is implemented on top of the stdio library. By
default, the file is buffered. When communicating to a process through a pipe, a flush
command should be issued to force the data out. Alternatively, the fcntl command may be
used to set the buffering mode of a file to line-buffered or unbuffered.
bsearch fileId key ?retvar? ?compare_proc?
Search an opened file fileId containing lines of text sorted into ascending order
for a match. Key contains the string to match. If retvar is specified, then the
line from the file is returned in retvar, and the command returns 1 if key was
found, and 0 if it wasn't. If retvar is not specified or is a null name, then the
command returns the line that was found, or an empty string if key wasn't found.
By default, the key is matched against the first white-space separated field in
each line. The field is treated as an ASCII string. If compare_proc is specified,
then it defines the name of a Tcl procedure to evaluate against each line read from
the sorted file during the execution of the bsearch command. Compare_proc takes
two arguments, the key and a line extracted from the file. The compare routine
should return a number less than zero if the key is less than the line, zero if the
key matches the line, or greater than zero if the key is greater than the line.
The file must be sorted in ascending order according to the same criteria
compare_proc uses to compare the key with the line, or erroneous results will
occur.
This command does not work on files containing binary data (bytes of zero).
chmod [-fileid] mode filelist
Set permissions of each of the files in the list filelist to mode, where mode is an
absolute numeric mode or symbolic permissions as in the UNIX chmod(1) command. To
specify a mode as octal, it should be prefixed with a "0" (e.g. 0622).
If the option -fileid is specified, filelist is a list of open file identifiers
rather than a list of file names. This option is not available on all Unix
systems. Use the infox have_fchmod command to determine if this functionality is
available.
The chmod command is not available on Windows.
chown [-fileid] owner | {owner group} filelist
Set owner of each file in the list filelist to owner, which can be a user name or
numeric user id. If the first parameter is a list, then the owner is set to the
first element of the list and the group is set to the second element. Group can be
a group name or numeric group id. If group is {}, then the file group will be set
to the login group of the specified user.
If the option -fileid is specified, filelist is a list of open file identifiers
rather than a list of file names. This option is not available on all Unix
systems. Use the infox have_fchown command to determine if this functionality is
available.
The chown command is not available on Windows.
chgrp [-fileid] group filelist
Set the group id of each file in the list filelist to group, which can be either a
group name or a numeric group id.
If the option -fileid is specified, filelist is a list of open file identifiers
rather than a list of file names. This option is not available on all Unix
systems. Use the infox have_fchown command to determine if this functionality is
available.
The chgrp command is not available on Windows.
dup fileId ?targetFileId?
Duplicate an open file. A new file id is opened that addresses the same file as
fileId.
If targetFileId is specified, the the file is dup to this specified file id.
Normally this is stdin, stdout, or stderr. The dup command will handle flushing
output and closing this file. The new file will be buffered, if its needs to be
unbuffered, use the fcntl command to set it unbuffered.
If fileId is a number rather than a Tcl file id, then the dup command will bind
that file to a Tcl file id. This is useful for accessing files that are passed
from the parent process. The argument ?targetFileId? is not valid with this
operation.
On Windows, only stdin, stdout, or stderr or a non-socket file handle number maybe
specified for targetFileId. The dup command does not work on sockets on Windows.
fcntl fileId attribute ?value?
This command either sets or clears a file option or returns its current value. If
value is not specified, then the current value of attribute is returned. All
values are boolean. Some attributes maybe only be gotten, not modified. The
following attributes may be specified:
RDONLY The file is opened for reading only. (Get only)
WRONLY The file is opened for writing only. (Get only)
RDWR The file is opened for reading and writing. (Get only)
READ If the file is readable. (Get only).
WRITE If the file is writable. (Get only).
APPEND The file is opened for append-only writes. All writes will be forced to the end of
the file. (Get or set).
NONBLOCK
The file is to be accessed with non-blocking I/O. See the read system call for a
description of how it affects the behavior of file reads.
CLOEXEC
Close the file on an process exec. If the execl command or some other mechanism
causes the process to do an exec, the file will be closed if this option is set.
NOBUF The file is not buffered. If set, then there no buffering for the file.
LINEBUF
Output the file will be line buffered. The buffer will be flushed when a newline is
written, when the buffer is full, or when input is requested.
KEEPALIVE
Keep a socket connection alive. If SIGPIPE is enabled, then it is sent if
connection is broken and data is written to the socket. If SIGPIPE is ignored, an
error is returned on the write. This attribute is valid only on sockets. By
default, SIGPIPE is ignored in Tcl.
The NONBLOCK, NOBUF and LINEBUF are provided for compatibility with older scripts.
Thefconfigure command is preferred method of getting and setting these attributes.
The APPEND and CLOEXEC options are not available on Windows.
flock options fileId ?start? ?length? ?origin?
This command places a lock on all or part of the file specified by fileId. The
lock is either advisory or mandatory, depending on the mode bits of the file. The
lock is placed beginning at relative byte offset start for length bytes. If start
or length is omitted or empty, zero is assumed. If length is zero, then the lock
always extents to end of file, even if the file grows. If origin is "start", then
the offset is relative to the beginning of the file. If it is "current", it is
relative to the current access position in the file. If it is "end", then it is
relative to the end-of-file (a negative is before the EOF, positive is after). If
origin is omitted, start is assumed.
The following options are recognized:
-read Place a read lock on the file. Multiple processes may be accessing the file
with read-locks.
-write Place a write lock on the file. Only one process may be accessing a file if
there is a write lock.
-nowait
If specified, then the process will not block if the lock can not be
obtained. With this option, the command returns 1 if the lock is obtained
and 0 if it is not.
See your system's fcntl system call documentation for full details of the behavior
of file locking. If locking is being done on ranges of a file, it is best to use
unbuffered file access (see the fcntl command).
The flock command is not available on Windows 95. It is available on Windows NT.
for_file var filename code
This procedure implements a loop over the contents of a file. For each line in
filename, it sets var to the line and executes code.
The break and continue commands work as with foreach.
For example, the command
for_file line /etc/passwd {echo $line}
would echo all the lines in the password file.
funlock fileId ?start? ?length? ?origin?
Remove a locked from a file that was previously placed with the flock command. The
arguments are the same as for the flock command, see that command for more details.
The funlock command is not available on Windows 95. It is available on Windows NT.
fstat fileId ?item? | ?stat arrayvar?
Obtain status information about an open file.
The following keys are used to identify data items:
atime The time of last access.
ctime The time of last file status change
dev The device containing a directory for the file. This value uniquely
identifies the file system that contains the file.
gid The group ID of the file's group.
ino The inode number. This field uniquely identifies the file in a given file
system.
mode The mode of the file (see the mknod system call).
mtime Time when the data in the file was last modified.
nlink The number of links to the file.
size The file size in bytes.
tty If the file is associated with a terminal, then 1 otherwise 0.
type The type of the file in symbolic form, which is one of the following values:
file, directory, characterSpecial, blockSpecial, fifo, link, or socket.
uid The user ID of the file's owner.
If one of these keys is specified as item, then that data item is returned.
If stat arrayvar is specified, then the information is returned in the array
arrayvar. Each of the above keys indexes an element of the array containing the
data.
If only fileId is specified, the command returns the data as a keyed list.
The following values may be returned only if explicitly asked for, it will not be
returned with the array or keyed list forms:
remotehost
If fileId is a TCP/IP socket connection, then a list is returned with the
first element being the remote host IP address. If the remote host name can
be found, it is returned as the second element of the list. The remote host
IP port number is the third element.
localhost
If fileId is a TCP/IP socket connection, then a list is returned with the
first element being the local host IP address. If the local host name can
be found, it is returned as the second element of the list. The local host
IP port number is the third element.
ftruncate [-fileid] file newsize
Truncate a file to have a length of at most newsize bytes.
If the option -fileid is specified, file is an open file identifier, otherwise it
is a file path.
This command is not available or not fully functional if the underlying operating
system support is not available. The command infox have_truncate will indicate if
this command may truncate by file path. The command infox have_ftruncate will
indicate if this command may truncate by file id.
The -fileid option is not available on Windows.
lgets fileId ?varName?
Reads the next Tcl list from the file given by fileId and discards the terminating
newline character. This command differs from the gets command, in that it reads
Tcl lists rather than lines. If the list contains newlines or binary data, then
that newline or bytes of zero will be returned as part of the result. Only a
newline not quoted as part of the list indicates the end of the list. There is no
corresponding command for outputting lists, as puts will do this correctly.
If varName is specified, then the line is placed in the variable by that name and
the return value is a count of the number of characters read (not including the
newline). If the end of the file is reached before reading any characters then -1
is returned and varName is set to an empty string. If varName is specified and an
error occurs, what ever data was read will be returned in the variable, however the
resulting string may not be a valid list.
If varName is not specified then the return value will be the line (minus the
newline character) or an empty string if the end of the file is reached before
reading any characters. An empty string will also be returned if a line contains
no characters except the newline, so eof may have to be used to determine what
really happened.
The lgets command maybe used to read and write lists containing binary data,
however translation must be set to lf or the data maybe corrupted.
If lgets is currently supported on non-blocking files.
pipe ?fileId_var_r fileId_var_w?
Create a pipe. If fileId_var_r and fileId_var_r are specified, then pipe will set
the a variable named fileId_var_r to contain the fileId of the side of the pipe
that was opened for reading, and fileId_var_w will contain the fileId of the side
of the pipe that was opened for writing.
If the fileId variables are not specified, then a list containing the read and
write fileIdw is returned as the result of the command.
read_file ?-nonewline? fileName
read_file fileName numBytes
This procedure reads the file fileName and returns the contents as a string. If
-nonewline is specified, then the last character of the file is discarded if it is
a newline. The second form specifies exactly how many bytes will be read and
returned, unless there are fewer than numBytes bytes left in the file; in this
case, all the remaining bytes are returned.
select readfileIds ?writefileIds? ?exceptfileIds? ?timeout?
This command allows an Extended Tcl program to wait on zero or more files being
ready for for reading, writing, have an exceptional condition pending, or for a
timeout period to expire. readFileIds, writeFileIds, exceptFileIds are each lists
of fileIds, as returned from open, to query. An empty list ({}) may be specified
if a category is not used.
The files specified by the readFileIds list are checked to see if data is available
for reading. The writeFileIds are checked if the specified files are clear for
writing. The exceptFileIds are checked to see if an exceptional condition has
occurred (typically, an error). The write and exception checking is most useful on
devices, however, the read checking is very useful when communicating with multiple
processes through pipes. Select considers data pending in the stdio input buffer
for read files as being ready for reading, the files do. not have to be
unbuffered.
Timeout is a floating point timeout value, in seconds. If an empty list is
supplied (or the parameter is omitted), then no timeout is set. If the value is
zero, then the select command functions as a poll of the files, returning
immediately even if none are ready.
If the timeout period expires with none of the files becoming ready, then the
command returns an empty list. Otherwise the command returns a list of three
elements, each of those elements is a list of the fileIds that are ready in the
read, write and exception classes. If none are ready in a class, then that element
will be the null list. For example:
select {file3 file4 file5} {file6 file7} {} 10.5
could return
{file3 file4} {file6} {}
or perhaps
file3 {} {}
On Windows, only sockets can be used with the select command. Pipes, as returned
by the open command, are not supported.
write_file fileName string ?string...?
This procedure writes the specified strings to the named file.
NETWORK PROGRAMMING SUPPORT
TclX provides functionality to complement the Tcl socket command. The host_info command
is used to get information about a host by name or IP address. In addition, the fstat and
fcntl commands provide options of querying and controlling connected sockets. To obtain
the host name of the system the local system, use the id host command.
host_info option host
Obtain information about an Internet host. The argument host can be either a host
name or an IP address.
The following subcommands are recognized:
addresses
Return the list of IP addresses for host.
official_name
Return official name for host.
aliases
Return the list of aliases for host. (Note that these are IP number
aliases, not DNS CNAME aliases. See ifconfig(2).)
FILE SCANNING COMMANDS
These commands provide a facility to scan files, matching lines of the file against
regular expressions and executing Tcl code on a match. With this facility you can use Tcl
to do the sort of file processing that is traditionally done with awk. And since Tcl's
approach is more declarative, some of the scripts that can be rather difficult to write in
awk are simple to code in Tcl.
File scanning in Tcl centers around the concept of a scan context. A scan context
contains one or more match statements, which associate regular expressions to scan for
with Tcl code to be executed when the expressions are matched.
scancontext ?option?
This command manages file scan contexts. A scan context is a collection of regular
expressions and commands to execute when that regular expression matches a line of
the file. A context may also have a single default match, to be applied against
lines that do not match any of the regular expressions. Multiple scan contexts may
be defined and they may be reused on multiple files. A scan context is identified
by a context handle. The scancontext command takes the following forms:
scancontext create
Create a new scan context. The scanmatch command is used to define patterns in the
context. A contexthandle is returned, which the Tcl programmer uses to refer to
the newly created scan context in calls to the Tcl file scanning commands.
scancontext delete contexthandle
Delete the scan context identified by contexthandle, and free all of the match
statements and compiled regular expressions associated with the specified context.
scancontext copyfile contexthandle ?filehandle?
Set or return the file handle that unmatched lines are copied to. (See scanfile).
If filehandle is omitted, the copy file handle is returned. If no copy file is
associated with the context, {} is returned. If a file handle is specified, it
becomes the copy file for this context. If filehandle is {}, then it removes any
copy file specification for the context.
scanfile ?-copyfile copyFileId? contexthandle fileId
Scan the file specified by fileId, starting from the current file position. Check
all patterns in the scan context specified by contexthandle against it, executing
the match commands corresponding to patterns matched.
If the optional -copyfile argument is specified, the next argument is a file ID to
which all lines not matched by any pattern (excluding the default pattern) are to
be written. If the copy file is specified with this flag, instead of using the
scancontext copyfile command, the file is disassociated from the scan context at
the end of the scan.
This command does not work on files containing binary data (bytes of zero).
scanmatch ?-nocase? contexthandle ?regexp? commands
Specify Tcl commands, to be evaluated when regexp is matched by a scanfile command.
The match is added to the scan context specified by contexthandle. Any number of
match statements may be specified for a give context. Regexp is a regular
expression (see the regexp command). If -nocase is specified as the first
argument, the pattern is matched regardless of alphabetic case.
If regexp is not specified, then a default match is specified for the scan context.
The default match will be executed when a line of the file does not match any of
the regular expressions in the current scancontext.
The array matchInfo is available to the Tcl code that is executed when an
expression matches (or defaults). It contains information about the file being
scanned and where within it the expression was matched.
matchInfo is local to the top level of the match command unless declared global at
that level by the Tcl global command. If it is to be used as a global, it must be
declared global before scanfile is called (since scanfile sets the matchInfo before
the match code is executed, a subsequent global will override the local variable).
The following array entries are available:
matchInfo(line)
Contains the text of the line of the file that was matched.
matchInfo(offset)
The byte offset into the file of the first character of the line that was
matched.
matchInfo(linenum)
The line number of the line that was matched. This is relative to the first
line scanned, which is usually, but not necessarily, the first line of the
file. The first line is line number one.
matchInfo(context)
The context handle of the context that this scan is associated with.
matchInfo(handle)
The file id (handle) of the file currently being scanned.
matchInfo(copyHandle)
The file id (handle) of the file specified by the -copyfile option. The
element does not exist if -copyfile was not specified.
matchInfo(submatch0)
Will contain the characters matching the first parenthesized subexpression.
The second will be contained in submatch1, etc.
matchInfo(subindex0)
Will contain the a list of the starting and ending indices of the string
matching the first parenthesized subexpression. The second will be
contained in subindex1, etc.
All scanmatch patterns that match a line will be processed in the order in which
their specifications were added to the scan context. The remainder of the
scanmatch pattern-command pairs may be skipped for a file line if a continue is
executed by the Tcl code of a preceding, matched pattern.
If a return is executed in the body of the match command, the scanfile command
currently in progress returns, with the value passed to return as its return value.
MATH COMMANDS
Several extended math commands commands make many additional math functions available in
TclX. In addition, a set of procedures provide command access to the math functions
supported by the expr command.
The following procedures provide command interfaces to the expr math functions. They take
the same arguments as the expr functions and may take expressions as arguments.
abs acos asin atan2
atan ceil cos cosh
double exp floor fmod
hypot int log10 log
pow round sin sinh
sqrt tan tanh
max num1 ?..numN?
expr max(num1, num2)
Returns the argument that has the highest numeric value. Each argument may be any
integer or floating point value.
This functionality is also available as a math function max in the Tcl expr
command.
min num1 ?..numN?
expr min(num1, num2)
Returns the argument that has the lowest numeric value. Each argument may be any
integer or floating point value.
This functionality is also available as a math function min in the Tcl expr
command.
random limit | seed ?seedval?
Generate a pseudorandom integer number greater than or equal to zero and less than
limit. If seed is specified, then the command resets the random number generator
to a starting point derived from the seedval. This allows one to reproduce
pseudorandom number sequences for testing purposes. If seedval is omitted, then
the seed is set to a value based on current system state and the current time,
providing a reasonably interesting and ever-changing seed.
LIST MANIPULATION COMMANDS
Extended Tcl provides additional list manipulation commands and procedures.
intersect lista listb
Procedure to return the logical intersection of two lists. The returned list will
be sorted.
intersect3 lista listb
Procedure to intersects two lists, returning a list containing three lists: The
first list returned is everything in lista that wasn't in listb. The second list
contains the intersection of the two lists, and the third list contains all the
elements that were in listb but weren't in lista. The returned lists will be
sorted.
lassign list var ?var...?
Assign successive elements of a list to specified variables. If there are more
variable names than fields, the remaining variables are set to the empty string.
If there are more elements than variables, a list of the unassigned elements is
returned.
For example,
lassign {dave 100 200 {Dave Foo}} name uid gid longName
Assigns name to ``dave'', uid to ``100'', gid to ``200'', and longName to ``Dave
Foo''.
lcontain list element
Determine if the element is a list element of list. If the element is contained in
the list, 1 is returned, otherwise, 0 is returned.
lempty list
Determine if the specified list is empty. If empty, 1 is returned, otherwise, 0 is
returned. This command is an alternative to comparing a list to an empty string,
however it checks for a string of all whitespaces, which is an empty list.
lmatch ?mode? list pattern
Search the elements of list, returning a list of all elements matching pattern. If
none match, an empty list is returned.
The mode argument indicates how the elements of the list are to be matched against
pattern and it must have one of the following values:
-exact The list element must contain exactly the same string as pattern.
-glob Pattern is a glob-style pattern which is matched against each list element
using the same rules as the string match command.
-regexp
Pattern is treated as a regular expression and matched against each list
element using the same rules as the regexp command.
If mode is omitted then it defaults to -glob.
Only the -exact comparison will work on binary data.
lrmdups list
Procedure to remove duplicate elements from a list. The returned list will be
sorted.
lvarcat var string ?string...?
This command treats each string argument as a list and concatenates them to the end
of the contents of var, forming a a single list. The list is stored back into var
and also returned as the result. if var does not exist, it is created.
lvarpop var ?indexExpr? ?string?
The lvarpop command pops (deletes) the element indexed by the expression indexExpr
from the list contained in the variable var. If index is omitted, then 0 is
assumed. If string, is specified, then the deleted element is replaced by string.
The replaced or deleted element is returned. Thus ``lvarpop argv 0'' returns the
first element of argv, setting argv to contain the remainder of the string.
If the expression indexExpr starts with the string end, then end is replaced with
the index of the last element in the list. If the expression starts with len, then
len is replaced with the length of the list.
lvarpush var string ?indexExpr?
The lvarpush command pushes (inserts) string as an element in the list contained in
the variable var. The element is inserted before position indexExpr in the list.
If index is omitted, then 0 is assumed. If var does not exists, it is created.
If the expression indexExpr starts with the string end, then end is replaced with
the index of the last element in the list. If the expression starts with len, then
len is replaced with the length of the list. Note the a value of end means insert
the string before the last element.
union lista listb
Procedure to return the logical union of the two specified lists. Any duplicate
elements are removed.
KEYED LISTS
Extended Tcl defines a special type of list referred to as keyed lists. These lists
provided a structured data type built upon standard Tcl lists. This provides a
functionality similar to structs in the C programming language.
A keyed list is a list in which each element contains a key and value pair. These element
pairs are stored as lists themselves, where the key is the first element of the list, and
the value is the second. The key-value pairs are referred to as fields. This is an
example of a keyed list:
{{NAME {Frank Zappa}} {JOB {musician and composer}}}
If the variable person contained the above list, then keylget person NAME would return
{Frank Zappa}. Executing the command:
keylset person ID 106
would make person contain
{{ID 106} {NAME {Frank Zappa}} {JOB {musician and composer}}
Fields may contain subfields; `.' is the separator character. Subfields are actually
fields where the value is another keyed list. Thus the following list has the top level
fields ID and NAME, and subfields NAME.FIRST and NAME.LAST:
{ID 106} {NAME {{FIRST Frank} {LAST Zappa}}}
There is no limit to the recursive depth of subfields, allowing one to build complex data
structures.
Keyed lists are constructed and accessed via a number of commands. All keyed list
management commands take the name of the variable containing the keyed list as an argument
(i.e. passed by reference), rather than passing the list directly.
keyldel listvar key
Delete the field specified by key from the keyed list in the variable listvar.
This removes both the key and the value from the keyed list.
keylget listvar ?key? ?retvar | {}?
Return the value associated with key from the keyed list in the variable listvar.
If retvar is not specified, then the value will be returned as the result of the
command. In this case, if key is not found in the list, an error will result.
If retvar is specified and key is in the list, then the value is returned in the
variable retvar and the command returns 1 if the key was present within the list.
If key isn't in the list, the command will return 0, and retvar will be left
unchanged. If {} is specified for retvar, the value is not returned, allowing the
Tcl programmer to determine if a key is present in a keyed list without setting a
variable as a side-effect.
If key is omitted, then a list of all the keys in the keyed list is returned.
keylkeys listvar ?key?
Return the a list of the keys in the keyed list in the variable listvar. If keys
is specified, then it is the name of a key field who's subfield keys are to be
retrieve.
keylset listvar key value ?key2 value2 ...?
Set the value associated with key, in the keyed list contained in the variable
listvar, to value. If listvar does not exists, it is created. If key is not
currently in the list, it will be added. If it already exists, value replaces the
existing value. Multiple keywords and values may be specified, if desired.
STRING AND CHARACTER MANIPULATION COMMANDS
The commands provide additional functionality to classify characters, convert characters
between character and numeric values, index into a string, determine the length of a
string, extract a range of character from a string, replicate a string a number of times,
and transliterate a string (similar to the Unix tr program).
ccollate ?-local? string1 string2
This command compares two strings. If returns -1 if string1 is less than string2,
0 if they are equal and 1 if string1 is greater than string2.
If -local is specified, the strings are compared according to the collation
environment of the current locale.
This command does not work with binary or UTF data.
cconcat ?string1? ?string2? ?...?
Concatenate the arguments, returning the resulting string. While string
concatenation is normally performed by the parser, it is occasionally useful to
have a command that returns a string. The is generally useful when a command to
evaluate is required. No separators are inserted between the strings.
This command is UTF-aware.
cequal string string
This command compares two strings for equality. It returns 1 if string1 and
string2 are the identical and 0 if they are not. This command is a short-cut for
string compare and avoids the problems with string expressions being treated
unintentionally as numbers.
This command is UTF-aware and will also work on binary data.
cindex string indexExpr
Returns the character indexed by the expression indexExpr (zero based) from string.
If the expression indexExpr starts with the string end, then end is replaced with
the index of the last character in the string. If the expression starts with len,
then len is replaced with the length of the string.
This command is UTF-aware.
clength string
Returns the length of string in characters. This command is a shortcut for:
string length string
This command is UTF-aware.
crange string firstExpr lastExpr
Returns a range of characters from string starting at the character indexed by the
expression firstExpr (zero-based) until the character indexed by the expression
lastExpr.
If the expression firstExpr or lastExpr starts with the string end, then end is
replaced with the index of the last character in the string. If the expression
starts with len, then len is replaced with the length of the string.
This command is UTF-aware.
csubstr string firstExpr lengthExpr
Returns a range of characters from string starting at the character indexed by the
expression firstExpr (zero-based) for lengthExpr characters.
If the expression firstExpr or lengthExpr starts with the string end, then end is
replaced with the index of the last character in the string. If the expression
starts with len, then len is replaced with the length of the string.
This command is UTF-aware.
ctoken strvar separators
Parse a token out of a character string. The string to parse is contained in the
variable named strvar. The string separators contains all of the valid separator
characters for tokens in the string. All leading separators are skipped and the
first token is returned. The variable strvar will be modified to contain the
remainder of the string following the token.
This command does not work with binary data.
ctype ?-failindex var? class string
ctype determines whether all characters in string are of the specified class. It
returns 1 if they are all of class, and 0 if they are not, or if the string is
empty. This command also provides another method (besides format and scan) of
converting between an ASCII character and its numeric value. The following ctype
commands are available:
ctype ?-failindex var? alnum string
Tests that all characters are alphabetic or numeric characters as defined by
the character set.
ctype ?-failindex var? alpha string
Tests that all characters are alphabetic characters as defined by the
character set.
ctype ?-failindex var? ascii string
Tests that all characters are an ASCII character (a non-negative number less
than 0200).
ctype char number
Converts the numeric value, string, to an ASCII character. Number must be
in the range 0 through the maximum Unicode values.
ctype ?-failindex var? cntrl string
Tests that all characters are ``control characters'' as defined by the
character set.
ctype ?-failindex var? digit string
Tests that all characters are valid decimal digits, i.e. 0 through 9.
ctype ?-failindex var? graph string
Tests that all characters within are any character for which ctype print is
true, except for space characters.
ctype ?-failindex var? lower string
Tests that all characters are lowercase letters as defined by the character
set.
ctype ord character
Convert a character into its decimal numeric value. The first character of
the string is converted to its numeric Unicode value.
ctype ?-failindex var? space string
Tests that all characters are either a space, horizontal-tab, carriage
return, newline, vertical-tab, or form-feed.
ctype ?-failindex var? print string
Tests that all characters are a space or any character for which ctype alnum
or ctype punct is true or other ``printing character'' as defined by the
character set.
ctype ?-failindex var? punct string
Tests that all characters are made up of any of the characters other than
the ones for which alnum, cntrl, or space is true.
ctype ?-failindex var? upper string
Tests that all characters are uppercase letters as defined by the character
set.
ctype ?-failindex var? xdigit string
Tests that all characters are valid hexadecimal digits, that is 0 through 9,
a through f or A through F.
If -failindex is specified, then the index into string of the first character that
did not match the class is returned in var.
replicate string countExpr
Returns string, replicated the number of times indicated by the expression
countExpr.
This command is UTF-aware and will work with binary data.
translit inrange outrange string
Translate characters in string, changing characters occurring in inrange to the
corresponding character in outrange. Inrange and outrange may be list of characters
or a range in the form `A-M'. For example:
translit a-z A-Z foobar
This command currently only supports characters in ASCII range; UTF-8 characters
out of this range will generate an error.
XPG/3 MESSAGE CATALOG COMMANDS
These commands provide a Tcl interface to message catalogs that are compliant with the
X/Open Portability Guide, Version 3 (XPG/3).
Tcl programmers can use message catalogs to create applications that are language-
independent. Through the use of message catalogs, prompts, messages, menus and so forth
can exist for any number of languages, and they can altered, and new languages added,
without affecting any Tcl or C source code, greatly easing the maintenance difficulties
incurred by supporting multiple languages.
A default text message is passed to the command that fetches entries from message
catalogs. This allows the Tcl programmer to create message catalogs containing messages
in various languages, but still have a set of default messages available regardless of the
presence of any message catalogs, and allow the programs to press on without difficulty
when no catalogs are present.
Thus, the normal approach to using message catalogs is to ignore errors on catopen, in
which case catgets will return the default message that was specified in the call.
The Tcl message catalog commands normally ignore most errors. If it is desirable to
detect errors, a special option is provided. This is normally used only during debugging,
to insure that message catalogs are being used. If your Unix implementation does not have
XPG/3 message catalog support, stubs will be compiled in that will create a version of
catgets that always returns the default string. This allows for easy porting of software
to environments that don't have support for message catalogs.
Message catalogs are global to the process, an application with multiple Tcl interpreters
within the same process may pass and share message catalog handles.
catopen ?-fail | -nofail? catname
Open the message catalog catname. This may be a relative path name, in which case
the NLSPATH environment variable is searched to find an absolute path to the
message catalog. A handle in the form msgcatN is returned. Normally, errors are
ignored, and in the case of a failed call to catopen, a handle is returned to an
unopened message catalog. (This handle may still be passed to catgets and
catclose, causing catgets to simply return the default string, as described above.
If the -fail option is specified, an error is returned if the open fails. The
option -nofail specifies the default behavior of not returning an error when
catopen fails to open a specified message catalog. If the handle from a failed
catopen is passed to catgets, the default string is returned.
catgets catHandle setnum msgnum defaultstr
Retrieve a message form a message catalog. CatHandle should be a Tcl message
catalog handle that was returned by catopen. Setnum is the message set number, and
msgnum is the message number. If the message catalog was not opened, or the message
set or message number cannot be found, then the default string, defaultstr, is
returned.
catclose ?-fail | -nofail? cathandle
Close the message catalog specified by cathandle. Normally, errors are ignored.
If -fail is specified, any errors closing the message catalog file are returned.
The option -nofail specifies the default behavior of not returning an error. The
use of -fail only makes sense if it was also specified in the call to catopen.
mainloop
This procedure sets up a top-level event loop. Events are processed until there
are no more active event sources, at which time the process exits. It is used to
build event oriented programs using the TclX shell in a style similar to that used
with wish. If the global variable tcl_interactive exists and has a true value an
interactive command handler is started as well. If the command handler is
terminated by an EOF, the process will be exited.
HELP FACILITY
The help facility allows one to look up help pages which where extracted from the standard
Tcl manual pages and Tcl scripts during Tcl installation. Help files are structured as a
multilevel tree of subjects and help pages. Help files are found by searching directories
named help in the directories listed in the auto_path variable. All of the files in the
list of help directories form a virtual root of the help tree. This method allows
multiple applications to provide help trees without having the files reside in the same
directory.
The help facility can be accessed in two ways, as interactive commands in the Extended Tcl
shell or as an interactive Tk-based program (if you have built Extended Tcl with Tk).
To run the Tk-based interactive help program:
tclhelp ?addpaths?
Where addpaths are additional paths to search for help directories. By default, only the
auto_path used by tclhelp is search. This will result in help on Tcl, Extended Tcl and
Tk.
The following interactive Tcl commands and options are provided with the help package:
help
Help, without arguments, lists of all the help subjects and pages under the current
help subject.
help subject
Displays all of help pages and lower level subjects (if any exist) under the
subject subject.
help subject/helppage
Display the specified help page. The help output is passed through a simple pager
if output exceeds 23 lines, pausing waiting for a return to be entered. If any
other character is entered, the output is terminated.
helpcd ?subject?
Change the current subject, which is much like the Unix current directory. If
subject is not specified, return to the top-level of the help tree. Help subject
path names may also include ``..'' elements.
helppwd
Displays the current help subject.
help help | ?
Displays help on the help facility at any directory level.
apropos pattern
This command locates subjects by searching their one-line descriptions for a
pattern. Apropos is useful when you can remember part of the name or description
of a command, and want to search through the one-line summaries for matching lines.
Full regular expressions may be specified (see the regexp command).
TCL LOADABLE LIBRARIES AND PACKAGES
Extended Tcl supports standard Tcl tclIndex libraries and package libraries. A package
library file can contain multiple independent Tcl packages. A package is a named
collection of related Tcl procedures and initialization code.
The package library file is just a regular Unix text file, editable with your favorite
text editor, containing packages of Tcl source code. The package library file name must
have the suffix .tlib. An index file with the same prefix name and the suffix .tndx
resides the same directory as the .tlib file. The .tndx will be automatically created
whenever it is out of date or missing (provided there is write access to the directory).
The variable auto_path contains a list of directories that are searched for libraries.
The first time an unknown command trap is take, the indexes for the libraries are loaded
into memory. If the auto_path variable is changed during execution of a program, it will
be re-searched. Only the first package of a given name found during the execution of a
program is loaded. This can be overridden with loadlibindex command.
The start of a package is delimited by:
#@package: package_name proc1 ?..procN?
These lines must start in column one. Everything between the #@package: keyword and the
next #@package: keyword or a #@packend keyword, or the end of the file, becomes part of
the named package. The specified procedures, proc1..procN, are the entry points of the
package. When a command named in a package specification is executed and detected as an
unknown command, all code in the specified package will be sourced. This package should
define all of the procedures named on the package line, define any support procedures
required by the package and do any package-specific initialization. Packages declarations
maybe continued on subsequent lines using standard Tcl backslash line continuations. The
#@packend keyword is useful to make sure only the minimum required section of code is
sourced. Thus for example a large comment block at the beginning of the next file won't
be loaded.
Care should be taken in defining package_name, as the first package found in the path by
with a given name is loaded. This can be useful in developing new version of packages
installed on the system.
For example, in a package source file, the presence of the following line:
#@package: directory_stack pushd popd dirs
says that the text lines following that line in the package file up to the next package
line or the end of the file is a package named directory_stack and that an attempt to
execute either pushd, popd or dirs when the routine is not already defined will cause the
directory_stack portion of the package file to be loaded.
PACKAGE LIBRARY MANAGEMENT COMMANDS
Several commands are available for building and managing package libraries. Commands that
are extended versions of the standard Tcl library commands are listed here. All of the
standard Tcl library management commands and variables are also supported.
auto_commands ?-loaders?
Lists the names of all known loadable procedures and commands procedures. If
-loaders is specified, the command that will be executed to load the command will
also be returned.
buildpackageindex libfilelist
Build index files for package libraries. The argument libfilelist is a list of
package libraries. Each name must end with the suffix .tlib. A corresponding
.tndx file will be built. The user must have write access to the directory
containing each library.
convert_lib tclIndex packagelib ?ignore?
Convert a Ousterhout style tclIndex index file and associate source files into a
package library packagelib. If packagelib does not have a .tlib extension, one
will be added. Any files specified in tclIndex that are in the list ignore will be
skipped. Files listed in ignore should just be the base file names, not full
paths.
loadlibindex libfile.tlib
Load the package library index of the library file libfile (which must have the
suffix .tlib). Package library indexes along the auto_path are loaded
automatically on the first demand_load; this command is provided to explicitly load
libraries that are not in the path. If the index file (with a .tndx suffix) does
not exists or is out of date, it will be rebuilt if the user has directory
permissions to create it. If a package with the same name as a package in
libfile.tlib has already been loaded, its definition will be overridden by the new
package. However, if any procedure has actually been used from the previously
defined package, the procedures from libfile.tlib will not be loaded.
auto_packages ?-location?
Returns a list of the names of all defined packages. If -location is specified, a
list of pairs of package name and the .tlib path name, offset and length of the
package within the library.
auto_load_file file
Source a file, as with the source command, except search auto_path for the file.
searchpath path file
Search all directories in the specified path, which is a Tcl list, for the
specified file. Returns the full path name of the file, or an empty string if the
requested file could not be found.