tclsh(1)							 Tcl Applications							  tclsh(1)

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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 command 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 automatic 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 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 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.

       You should note that it is also common practise to install tclsh with its version number as part of the name.  This has	the  advantage	of |
       allowing  multiple versions of Tcl to exist on the same system at once, but also the disadvantage of making it harder to write scripts that |
       start up uniformly across different versions of Tcl.

VARIABLES

       Tclsh sets the following Tcl variables:

       argc	      Contains a count of the number of arg arguments (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 interactively (no fileName was specified and standard 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  out-
       putting	a prompt tclsh will evaluate the script in tcl_prompt1.  The variable 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 incomplete commands.

KEYWORDS

       argument, interpreter, prompt, script file, shell

Tcl																	  tclsh(1)