my $socket = IO::Socket::INET->new(
   Broadcast => 1, Blocking => 1, ReuseAddr => 1,
   Type => SOCK_DGRAM, Proto => 'udp', PeerPort => 9999,
   LocalPort => 0,
   PeerAddr => inet_ntoa(INADDR_BROADCAST)) ||
confess "error: failed to create broadcast udp socket - $!";
$socket->send('Q', 0);
my ($srcaddr, $data);
$srcaddr = $socket->recv($data, 100, 0);
die "recv: $!" if !defined($srcaddr);
close $socket;