in reply to
I'm curious, what is the end result you're try to accomplish? Instead of reinventing the wheel, you could (amongst other possibilities) install the set of nagios plugins. They work on a large number of different platforms. I believe check_vsz (not perl) is their native plugin to monitor what you want, but there's other stuff for nagios people have written, including a fair number of perl scripts.
"This alcoholism thing, I think it's just clever propaganda produced by people who want you to buy more bottled water." -- pedestrianwolf