Perl NS Query with Net::DNS

dns.md

Methods

1. The new method of the Net::DNS::Resolver class returning a Net::DNS::Resolver object

2. The query method of the Net::DNS::Resolver class returning a Net::DNS::Packet object

3. The answer method of Net::DNS::Packet class returning a list of Net::DNS::RR objects

4. The type method: of the Net::DNS::RR class returning a standard DNS record type string

5. The nsdname method of the Net::DNS::RR::NS class returning a domain string

---

Get the packet with query, and then records from the packet with answer, check the record's type to get the appropriate value (eg. with nsdname).

dns.pl

my $file = path('dns.txt')->openw;
my $resolver = Net::DNS::Resolver->new;
for my $domain (@domains) {
    my $packet = $resolver->query($domain, 'NS');
    my @records = $packet->answer if defined $packet;
    my @nsdnames;
    for my $record (@records) {
        if ($record->type eq 'NS') {
            push @nsdnames, $record->nsdname;
        }
    }
    printf "%s: %s\n", $domain, join(' ', @nsdnames);
    $file->printf("%s: %s\n", $domain, join(' ', @nsdnames));
}