import java.net.Socket;
import java.net.UnknownHostException;
import java.io.IOException;

public class PortProbe {
    public static void main (String[] args) {
	if (args.length < 1) {
	    System.err.println("Usage: PortProbe <IP address>");
	    return;
	}
	String host = args[0];
	int[] ports = {  7,   // ping
			 13,  // daytime
			 21,  // ftp
			 23,  // telnet
			 71,  // finger
			 80,  // http
			 119, // nntp
			 161  // snmp
	};
	for (int i=0; i < ports.length; i++) {
	    try {
		Socket sock = new Socket (host, ports[i]);
		System.out.println (host + " listening on port " + ports[i]);
		sock.close();
	    }
	    catch (UnknownHostException e) {
		System.err.println (e);
		return;
	    }
	    catch (IOException e) {
		System.out.println (host + " not listening on port " + ports[i]);
	    }
	}
    }
}