Looks up whois server for domain on rs.internic.net then looks up that domain on that whois server. really really simple :)
#!/usr/bin/perl -w use strict; use vars qw/$server $sock $port @data $whois/; use IO::Socket; $|++; $server = "rs.internic.net"; $port = "43"; die "Usage: $0 <domain>" unless(defined($ARGV[0])); $sock = IO::Socket::INET->new(PeerAddr=>$server,PeerPort=>$port,Proto= +>'tcp'); print $sock $ARGV[0],"\r\n"; @data = <$sock>; undef($sock); map { if ($_ =~ /Whois Server: (\S+)$/) { $whois = $1; } if (defined($whois)) { $sock = IO::Socket::INET->new(PeerAddr=>$whois,PeerPor +t=>$port,Proto=>'tcp'); print $sock $ARGV[0],"\r\n"; print <$sock>; undef($sock); exit(0); } } @data; print @data; exit(0);