use strict;
use warnings;

my %pairings;
my $file;

open(XML,$file) || die "Unable to open file '$file':  $!\n";
while (<XML>) {
    my $check = 0;
    foreach my $key (keys %pairings) {
        if (!(Check_Line($key,$_))) {
            $check++;
            last;
        }
    }
    if ($check == 0) {print;}
}
close(XML);

sub Initialize_Pairings {
    push @{$pairings{cat}},"tail","meow";
    push @{$pairings{dog}},"tail","bark";
}

sub Check_Line {
    my $tag = shift;
    my $line = shift;
    foreach my $i (0 .. $@{$pairings{$tag}}) {
        my $attrib = $pairings{$tag}[$i];
        if ($line !~ m/<$tag .*$attrib=\s+/i) {
            return 0;
        }
    }
    return 1;
}