use strict;
use IO::Socket;

my $host = "localhost";
my $sock;
print "Open ports:\n";
for(my $port=1; $port < 1024; $port++) {
	$sock = new IO::Socket::INET(PeerAddr => $host, PeerPort => $port, Proto => 'tcp');
	if ($sock) {
		print "$port\n";
		close $sock;	
	}
}