http://www.perlmonks.org?node_id=963286


in reply to Filtering Source Text File with 2nd Text File of Terms

Please note that unescaped special characters in strings used as patterns could give unpredictable results!!!

Example: the term "www.thisisannoying.com" will also match lines with "wwwithisisannoyingacom"...

If the terms from the list are single words, probably the test from previous posts should be:

print "$source\n" unless grep { $source =~ /\b$_\b/ } @terms;

where \b is used to check for word boundaries, so "googleeee" won't be matched by "google" term.