while () { chomp; ($gcos) = (split /:/)[4]; ($real) = split(/,/, $gcos); ($first) = split(/\s+/, $real); $seen{$first}++; { print "$gcos\n"; print "$real\n"; #print "$first $seen\n"; #print "$real\n"; } } foreach (keys %seen) { if ($seen{$_} > 1) { print "$_ was seen $seen{$_} times\n"; } }