The following global variables have special meaning to the Extended Tcl interpreter (the programs tcl and wishx):
argc
Number of command-line arguments, not including the name of the script file
argv
List containing command-line arguments
argv0
Filename being interpreted, or name by which script was invoked
auto_path
Path to search to locate autoload libraries
tcl_interactive
1 if running interactively, 0 otherwise
tcl_prompt1
Primary prompt
tcl_prompt2
tclx_library
Location of Extended Tcl libraries
tkx_library
Location of Extended Tcl Tk libraries
TCLXENV
Array containing information about Tcl procedures