import java.net.*;
import java.io.*;

public class LowPortScanner {
	public static void main(String[] args) {
		String host = "localhost";
		if (args.length > 0) {
			host = args[0];
		}
		for (int i = 1; i < 1024; i++) {
		  try {
			  Socket s = new Socket(host, i);
			  System.out.println("There is a server on port " + i + " of " + host);
		  }
		  catch (UnknownHostException ex) {
			  System.err.println(ex);
			  break;
		  }
		  catch (IOException ex) {}
		}
	}
}