Practical Programming in Tcl & Tk, Third Edition

Predefined Variables

Table 2-2. Variables defined by tclsh and wish.

argc	The number of command-line arguments.
argv	A list of the command-line arguments.
argv0	The name of the script being executed. If being used interactively, argv0 is the name of the shell program.
embed_args	The list of arguments in the <EMBED> tag. Tcl applets only. See page 298.
env	An array of the environment variables. See page 117.
tcl_interactive	True (one) if the tclsh is prompting for commands.
tcl_library	The script library directory.
tcl_patchLevel	Modified version number, e.g., 8.0b1.
tcl_platform	Array containing operating system information. See page 182.
tcl_prompt1	If defined, this is a command that outputs the prompt.
tcl_prompt2	If defined, this is a command that outputs the prompt ...