How have you come to be a code contributor on a Perl project without first having a working knowledge of Perl? Rather than doing your project for you, we should be assisting you in gaining sufficient proficiency in Perl to accomplish this trivial task yourself.

So where can we start? I suggest spending 20 to 30 minutes with perlintro. Then follow some of the links in that document to dive deeper into file IO, and regular expressions. An hour or two later you'll be competent to solve this, and many future problems yourself. And when you do come up with stumbling blocks in the future (as we all do), you'll be equipped with enough understanding of the Perl basics to be able to ask informed questions.