use strict; use warnings; ... open MATCHING_FILE, $TEXT_FILE; my %seen; while (my $file = ){ chomp $file; if ( $file =~ /[\d]{1,3}\.[\d]{1,3}\.[\d]{1,3}\.[\d]{1,3}|password|(ssn=)/i){ $seen{$file}++; } } print "$_\n" for keys %seen;