sub scan {
    $host = "$net.$hosts[$li]";
    $socket = IO::Socket::INET->new(
        Proto => "tcp",
        PeerAddr => $host,
        PeerPort => 80) or die $!;
        
    $socket->autoflush(1);
    print $socket "HEAD / HTTP/1.0\015\012\015\012";
    
    while (<$socket>) {
        print;
        last if /^$/;
    }
close($socket);
}