/**
 * UdpClientDemo13 shows typical UDP/IP client programming in Java. It
 * sends an empty packet to UDP port 13 on another machine, waits to 
 * receive one packet, prints it and quits.
 *
/* Copyright (c) 1999-2002 E. W. Grundke.  All rights reserved.
 * @author  E. W. Grundke
 */

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

public class UdpClientDemo13 {
    private final static int PORT=13;  // the time-of-day port
    public static void main (String args[]) {

        BufferedReader input=null;
        if (args.length < 1) { // must have 1+ command-line parameters
            System.out.println("Usage:   java UdpClientDemo13 <HostNameOrIPAddress>");
            System.out.println("Example: java UdpClientDemo13 borg.cs.dal.ca");
            System.out.println("Example: java UdpClientDemo13 129.173.66.61");
            System.exit(1);
        }
        try { 
	    DatagramSocket s = new DatagramSocket();
	    InetAddress addr = InetAddress.getByName(args[0]);

	    byte[] sendBuffer = new byte[0];  // send 0 bytes!
	    DatagramPacket pkt = new DatagramPacket(sendBuffer, 0, addr, PORT);
	    s.send(pkt);

	    byte[] rbuffer = new byte[1500];
	    DatagramPacket rpkt = new DatagramPacket(rbuffer, rbuffer.length);
	    s.receive(rpkt);
            System.out.println ("Received " + rpkt.getLength() + " bytes" + 
				" from host " + rpkt.getAddress().getHostName() + 
				" port " + rpkt.getPort() + ":");
	    System.out.println(new String(rpkt.getData()));
        }
        catch (Exception e) {System.out.println(e);}
    }
}