Mac Forum / Programming / Perl / September 2006

This is a newbie question: how can I determine if a specific module  
is installed on a client machine?
I would like to do something like this:
if (MacPerl installed is true) {

Although I don't think this is an OS X specific issue I can't find  
any place to seek help (there seems to be a GnuPG list but it is  
defunct or inactive). If someone knows of a better resource please  
let me know.

For months I've been trying to figure out what's causing some perl  
zombie processes on my system.  Looks like it might be the script  
menu.  I have a script menu item called "tunnels.pl" that establishes  
some SSH tunnels, and it works fine.  But after I run it, I see this: