tclsh

NAME

       tclsh - Simple shell containing Tcl interpreter

SYNOPSIS

       tclsh ?fileName arg arg ...?

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 in the home directory of the user,  tclsh  evalu-
       ates  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 exe-
       cutable.  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 characters 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 gets
       around the 30-character file name limit  in  the  previous
       approach.  Third, this approach will work even if tclsh is
       itself a shell script (this is done  on  some  systems  in
       order  to  handle multiple architectures or operating sys-
       tems:  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 back-
       slash 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