h@kim:

Did you check http://cpan.org? I did a quick search using "Diff" and found a few modules that look like they'd be useful to you. If you look them over, you may find that one gives you a set of results in a structure that greatly simplifies your task. The ones I thought looked interesting are: String::Diff, Text::Diff, and Algorithm::Diff. The last one looks like it returns the results in a very useful form for tasks like what you're attempting. I think I'll install it and goof around this afternoon.

...roboticus

When your only tool is a hammer, all problems look like your thumb.