use strict;
use warnings;

my @titles;
my $source = <<TEXT;
<title id='1'>www.perlmonks.org</title>
<title id='2'>somewhere else</title>
TEXT

push @titles, $source =~ m/<title\s+id='(\d+)'>(.+?)<\/title>/igs;

while (@titles) {
    my @pair = splice @titles, 0, 2;
    print "$pair[0]: $pair[1]\n";
}

##</code><code>##

1: www.perlmonks.org
2: somewhere else