You say a very basic Perl operation "appears very complicated" and then repeat the tactics you've used to get others to do your work -- posting a code sample that's essentially no more than a few lines of boilerplate.

This time, what you're looking for is scarcely more than an extension or adaptation of the advice (and solutions) you've been given previously.

You'll do better to start now to try to solve your own homework(?) or $work(?). Twenty-one posts with little evidence that you've made a serious attempt to think through your own questions is not a good reflection on your desire to learn... which is what PM is largely about.