NAME

       tclsh - Simple shell containing Tcl interpreter


SYNOPSIS

       tclsh ?fileName arg arg ...?
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DESCRIPTION

       Tclsh  is a shell-like application that reads Tcl commands
       from its standard input or from a file and evaluates them.
       If  invoked  with no arguments then it runs interactively,
       reading Tcl commands from standard input and printing com­
       mand  results  and  error messages to standard output.  It
       runs until the exit command is invoked or until it reaches
       end-of-file on its standard input.  If there exists a file
       .tclshrc (or tclshrc.tcl on the Windows platforms) in  the
       home  directory of the user, tclsh evaluates the file as a
       Tcl script just before  reading  the  first  command  from
       standard input.


SCRIPT FILES

       If tclsh is invoked with arguments then the first argument
       is the name of a script file and any additional  arguments
       are made available to the script as variables (see below).
       Instead of reading commands from standard input tclsh will
       read  Tcl  commands  from the named file;  tclsh will exit
       when it reaches the end of the file.  There  is  no  auto­
       matic  evaluation of .tclshrc in this case, but the script
       file can always source it if desired.

       If you create a Tcl script in a file whose first line is
              #!/usr/local/bin/tclsh
       then you can invoke the script  file  directly  from  your
       shell  if  you  mark the file as executable.  This assumes
       that tclsh has been installed in the default  location  in
       /usr/local/bin;   if  it's  installed  somewhere else then
       you'll have to modify the above line to match.  Many  UNIX
       systems  do not allow the #! line to exceed about 30 char­
       acters in length, so be sure that the tclsh executable can
       be accessed with a short file name.

       An even better approach is to start your script files with
       the following three lines:
              #!/bin/sh
              # the next line restarts using tclsh \
              exec tclsh "$0" "$@"
       This approach has three advantages over  the  approach  in
       the  previous paragraph.  First, the location of the tclsh
       binary doesn't have to be hard-wired into the script:   it
       can  be  anywhere  in  your shell search path.  Second, it

       ous  approach.   Third,  this  approach  will work even if
       tclsh is itself a shell script (this is done on some  sys­
       tems  in order to handle multiple architectures or operat­
       ing systems:  the tclsh  script  selects  one  of  several
       binaries to run).  The three lines cause both sh and tclsh
       to process the script, but the exec is  only  executed  by
       sh.   sh processes the script first;  it treats the second
       line as a comment and executes the third line.   The  exec
       statement  cause  the shell to stop processing and instead
       to start up tclsh to reprocess the  entire  script.   When
       tclsh  starts  up,  it treats all three lines as comments,
       since the backslash at the end of the second  line  causes
       the third line to be treated as part of the comment on the
       second line.


VARIABLES

       Tclsh sets the following Tcl variables:

       argc           Contains a count of the number of arg argu­
                      ments  (0  if none), not including the name
                      of the script file.

       argv           Contains a Tcl list whose elements are  the
                      arg arguments, in order, or an empty string
                      if there are no arg arguments.

       argv0          Contains  fileName  if  it  was  specified.
                      Otherwise, contains the name by which tclsh
                      was invoked.

       tcl_interactive
                      Contains 1 if  tclsh  is  running  interac­
                      tively (no fileName was specified and stan­
                      dard input is a  terminal-like  device),  0
                      otherwise.


PROMPTS

       When  tclsh  is  invoked interactively it normally prompts
       for each command with ``% ''.  You can change  the  prompt
       by  setting the variables tcl_prompt1 and tcl_prompt2.  If
       variable tcl_prompt1 exists then it must consist of a  Tcl
       script to output a prompt;  instead of outputting a prompt
       tclsh will evaluate the script in tcl_prompt1.  The  vari­
       able  tcl_prompt2  is used in a similar way when a newline
       is typed but the current command isn't  yet  complete;  if
       tcl_prompt2  isn't set then no prompt is output for incom­
       plete commands.


KEYWORDS

       argument, interpreter, prompt, script file, shell


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