The '''main script''' is the primary script that is executed by the interpreter, e.g. [tclsh] or [wish].



** Description **

One common technique is to have a script run a self test if it detects that it
is the main script.  The detection routine usually looks something like this: 

======
if {[info exists argv0] && $argv0 eq [info script]} {
    #do stuff
}
======

Examples of the following, more complicated test can be found:

======
#unneeded complexity ?
if {[info exists argv0] && [file tail [info script]] eq [file tail $argv0]} {
    #do stuff
}
======

but I ([PYK]) don't see a scenario in which is needed, as `[info script]`
always has the same value as `$argv0` in all the cases I tested.