>dog, 3
>cat, 2
>sheep, 1

##</code><code>##

use strict;
use warnings;

my $i;
my $j;
my @data;

for my $file (@ARGV) {

open (RAW, "./$file") || die "Cannot open specified file to be processed\n";

while(<RAW>) {

        @data = join('', $_ =~ /^(\d\d\d\d)-(\d\d)-(\d\d) (\d+):(\d+):(\d+)/);

for $i (@data) {
        my $cnt = 0;
for $j (@data){
        if ($i eq $j) {
                $cnt = $cnt + 1;
                print "$i, $j, $cnt\n";
                                }
                        }
                }
        }
}