use Web::Query 'wq';
use YAML::XS qw(DumpFile);
my @ports = …
my %results;
for my $port (@ports) {
    my $w = wq "http://wwwdev.ebi.ac.uk/interpro/ISearch?query=$port";
    $results{$port} = [$w->find('.prot_fam a')->text]
        if $w->find('.prot_fam a')->size;
}
DumpFile 'results.txt', \%results;