For your future reference, please use markup to make your posts more readily legible.

<c>...</c> around code and data and <p>...</p> to mark paragraphs. THIS IS SPELLED OUT AROUND THE INPUT TEXT BOX... and explained in geater detail in Markup in the Monastery.

And, it's "Perl" but not "PERL." Granted, this is minor, but the difference is important to a few persnickety didacts.

More important, for you as a "beginner in PERL" is to incloude use strict in your header. It's apt to toss out notice of problems you won't even recognize without it. And use warnings is often a better choice than -w which may prompt warnings from modules (you'll want to be using some of them, soon) about coding that's perfectly alright.

Attend also to Corion's note about error checking (and while you're at it, read about 3 arg opens.