Thank you. Tomorrow I will test it against my 500k data file, but I'm sure it's just the thing I needed. Thank you for the solution, and thank you for the books. I would say "the books that had taught me everything I know about Perl", but as you see, I don't know much, so I'll write this: Thanks for the great books you wrote, for if I don't know much about Perl, it's not their fault.