#! /usr/bin/env perl

use strict;
use warnings;

my %pet_hate;

while (<>) {
    my ($pet)  = /pet="(\w+)"/  or next;
    my ($hate) = /hate="(\w+)"/ or next;
    my ($like) = /like="(\w+)"/ or next;

    $pet_hate{"$pet:$hate"} //= {
        pet  => $pet,
        hate => $hate,
        like => $like,
    };
}

foreach (values %pet_hate) {
    printf(qq{pet="%s"|hate="%s"|like="%s"\n},
	   $_->{pet},
	   $_->{hate},
	   $_->{like});
}