http://qs321.pair.com?node_id=1002996


in reply to remove lines matching list of strings

grep -v -F -f file2 file1

English translation: using the Unix grep command, search file1 for lines which do not match ( -v ) the fixed strings ( -F ) ( as opposed to regular expressions ) found in file2 ( -f file2 ).

There are versions of grep available for Windows. Mac OS has a Unix basis, so it already has it.

If you absolutely have to do it in Perl, I would use the lines from file2 as the keys of a hash, assigning the number 1 as a value. Then, as I read the other file, it's trivial to check whether it is present in the hash.

As Occam said: Entia non sunt multiplicanda praeter necessitatem.