#!/usr/bin/perl

use strict;
use warnings;

use IO::Async::Loop;
use IO::Async::Resolver::DNS;

my $loop = IO::Async::Loop->new;
my $resolver = $loop->resolver;

$resolver->res_query(
   dname => $ARGV[0],
   type  => "PTR",
)->on_done( sub {
   my ( $pkt, @names ) = @_;

   foreach my $name ( @names ) {
      print "$name\n";
   }
})->get;