8 my $hostlist = shift @ARGV or die "usage: $0 list_of_hosts [nameserver]";
10 die "$0: cannot read $hostlist";
12 my $nameserver = shift @ARGV;
16 warn "$0: performing DNS query with server($nameserver)";
17 $res = Net::DNS::Resolver->new(
18 nameservers => [$nameserver],
22 warn "$0: use system default nameservers";
23 $res = Net::DNS::Resolver->new;
27 open my $list, '<', $hostlist or die "$0: filename: $!";
28 while (my $host = <$list>) {
30 my $query = $res->send($host);
33 if ($res->errorstring ne 'NOERROR') {
34 print $res->errorstring, "\n";
37 foreach my $rr ($query->answer) {
38 if ($rr->type eq 'A') {
39 print $rr->address, " ";
41 elsif ($rr->type eq 'PTR') {
42 print $rr->ptrdname, " ";
48 warn "$0: query failed: ", $res->errorstring, "\n";