tclsh is an application created by default by the core distribution of tcl. It is a simple shell interpreter, and is frequently used by developers for writing and executing tcl scripts.
A user of tclsh (or of wish, the interactive tcl shell with Tk automatically loaded), should be aware that there are a few differences between typing tcl statements to the shell in interactive mode and saving tcl commands into a file and then asking tclsh to execute that command file.
The differences between tclsh in interactive mode and command file behavior include:
1. the tcl_interactive variable
2. unknown proc differences - if tclsh is unable to recognize a command, the unknown proc is invoked.
3. command abbreviations
set fp [op $myfile]
and see tclsh execute the open proc .
4. standard output displayed
5. byte-compilation
People writing scripts to be loaded from the tclsh command line should be aware that \u001a is an end-of-file character in scripts.
Leibniz would have loved an interactive tclsh: "Es wird dann beim Auftreten von Streitfragen für zwei Philosophen nicht mehr Aufwand an wissenschaftlichem Gespräch erforderlich sein als für zwei Rechnerfachleute. Es wird genügen, Schreibzeug zur Hand zu nehmen, sich vor das Rechengerät zu setzen und zueinander (wenn es gefällt, in freundschaftlichem Ton) zu sagen: Laßt uns rechnen."
Category Application, a part of the Tcl package.