http://www.perlmonks.org?node_id=964428


in reply to Pattern matching across two files, Need something better than grep -f!

Sorry, but I'm afraid that I'm not understanding the problem here. Just to suggest that you choose carefully your variable names:

if($split[0] eq $split1[0] && $split[1] eq $split1[1])

Lines like this are artificially hard to read. Is really easy to miss the "one" before the "[". You'll realize also that to name a new variable with the same name of a common function was not so great idea when you'll need to debug or expand your code some months later.