NAME

       tclsh - Simple shell containing Tcl interpreter

SYNOPSIS

       tclsh ?-encoding name? ?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, interactive 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 few arguments specify the name of a script  file,  and,
       optionally,  the  encoding of the text data stored in that script file. 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.  The
       end of the file may be marked either by the physical end of the medium, or  by  the  character,  (“\x1A”,
       control-Z).  If this character is present in the file, the tclsh application will read text up to but not
       including the character.  An application that requires this character in the file may safely encode it as
       “\x1A”; or may generate it by use of commands such as format or binary.  There is no automatic evaluation
       of  .tclshrc  when  the name of a script file is presented on the tclsh command line, 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 is installed
       somewhere else then you will 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" ${1+"$@"}

       This approach has three advantages over the approach in the previous paragraph.  First, the  location  of
       the tclsh binary does not 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 practice 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.

       Alternatively, you can use /usr/bin/env to locate tclsh on the path, like this:

              #!/usr/bin/env tclsh

       That  has  the advantages of being succinct and simple, but the disadvantage of not being flexible in the
       face of varying names for the binary.

VARIABLES

       Tclsh sets the following global Tcl variables in addition to those created  by  the  Tcl  library  itself
       (such as env, which maps environment variables such as PATH into Tcl):

       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 global 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 is not yet complete; if  tcl_prompt2  is  not  set  then  no  prompt  is  output  for
       incomplete commands.

STANDARD CHANNELS

       See Tcl_StandardChannels for more explanations.

ZIPFS VIRTUAL FILE SYSTEM

       When  a zipfile is concatenated to the end of a tclsh, on startup the contents of the zip archive will be
       mounted under a virtual file system (VFS). The root of that VFS can be retrieved  using  the  zipfs  root
       command.  The  zip archive is mounted under the app directory within the VFS. If a file named main.tcl is
       present in the top level directory of the zip archive, it will  be  sourced  instead  of  tclsh's  normal
       command  line handing. If a top level directory tcl_library is present in the zip archive, it will become
       the directory loaded as env(TCL_LIBRARY). If a file named main.tcl is present in the top level  directory
       of the zip archive, it will be sourced instead of the shell's normal command line handling.

       Only  one  zipfile  can  be  concatenated  to  the  end of executable image (tclsh, or wish). However, if
       multiple zipfiles are concatenated, only the last one is used.

       This filesystem is read-only. Files cannot be added or modified within this  mounted  file  system.   See
       zipfs(3tcl) for complete details.

SEE ALSO

       auto_path(3tcl), encoding(3tcl), env(3tcl), fconfigure(3tcl), zipfs(3tcl)

KEYWORDS

       application, argument, interpreter, prompt, script file, shell, zipfs

Tcl                                                                                                     tclsh(1)