in reply to Pulling out data from one file thats not in another
$ perl -nle '(1..eof)?$h{$_}++:$h{$_}||print' completed master 1ao8A 1jkxA 1juvA 1mejA 1meoA 1n0uA 1pjqA [download]
(sorry, couldn't resist golfing :)