http://www.perlmonks.org?node_id=1031260


in reply to ignore duplicates and show unique values between 2 text files

An easier way is to use List::Compare:
#!/usr/bin/perl -l use strict; use warnings; use List::Compare; my (@Llist) = qw(abc def 121 xyz); my (@Rlist) = qw(def 121); my $lc = List::Compare->new( \@Llist, \@Rlist ); my (@sdiff) = $lc->get_symmetric_difference; foreach my $sdiff(@sdiff) { print $sdiff; }