I have a script that can run with a GUI or not, depending on if the user specifies a -g option. The GUI is Tk based. Some of my users don't have Tk installed - they should still be able to run the script in console mode.
First, I tried:

if ($opt_g) {
   use Tk;
   <Tk code>
}
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but the 'use' would complain even of not finding the Tk module (for those without it installed) when the -g option was missing.
Then I tried:

if ($opt_g) {
   eval "use Tk; 1" or die "Tk not installed. Can't run GUI.\n";
   <Tk code>
}
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This lets the script work in console mode, but with -g specified, the script fails to bring up the GUI, the script just exits back to the command prompt - no errors or anything.

Any help would be appreciated.