static int quickPortCheck_timeout = 5000;

// returns hello message or null
static S quickPortCheck(int port) {
  try {
    Socket socket = new Socket();
    try {
      socket.setSoTimeout(quickPortCheck_timeout);
      socket.connect(new InetSocketAddress("localhost", port), quickPortCheck_timeout);
      //if (verbose) print("Connected to " + ip + ":" + port);
      BufferedReader in = new BufferedReader(
        new InputStreamReader(socket.getInputStream(), "UTF-8"));
      ret or(in.readLine(), "?");
    } finally {
      socket.close();
    }
  } catch (Exception ex) {
    return null;
  }
}