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NAME    [Toc]    [Back]

       tclsh - Simple shell containing Tcl interpreter

SYNOPSIS    [Toc]    [Back]

       tclsh ?fileName arg arg ...?

DESCRIPTION    [Toc]    [Back]

       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    [Toc]    [Back]

       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
       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:
	      # 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.

VARIABLES    [Toc]    [Back]

       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

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

		      Contains 1 if tclsh is running interactively  (no  file-
		      Name was specified and standard input is a terminal-like
		      device), 0 otherwise.

PROMPTS    [Toc]    [Back]

       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  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    [Toc]    [Back]

       argument, interpreter, prompt, script file, shell

Tcl								      tclsh(1)
[ Back ]
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