/**
 * UdpPerturb.java
 *
 * Created: Sat Jul  8 15:19:57 2000
 *
 * @author David Green
 * @version
 */

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

public class UdpPerturb {
    
    public static void main(String[] args) throws IOException {
        int remotePort;
        InetAddress remoteHost;
        byte [] sendBuffer;
        byte [] receiveBuffer = new byte[1400];
        String userText;
        
        PrintWriter console = new PrintWriter( System.out );
        BufferedReader keyboard =
            new BufferedReader(new InputStreamReader(System.in));

        if ( args.length != 2 ) {
            console.println( "Usage:  java UdpPerturb host port");
            console.flush();
            return ;
        }

        try {
            remotePort = Integer.parseInt( args[1], 10 );
            remoteHost = InetAddress.getByName( args[0] );
        }
        catch ( IOException ex ) {
            console.println( "Bad parameters: " + ex );
            return;
        }
        
        DatagramSocket s = new DatagramSocket( );

        DatagramPacket receiveP =
            new DatagramPacket( receiveBuffer, receiveBuffer.length);

        while ( true ) {
            console.print( "Send: " );
            console.flush();
            
            userText = keyboard.readLine();
            sendBuffer = userText.getBytes();
            DatagramPacket sendP =
                new DatagramPacket( sendBuffer, sendBuffer.length,
                                    remoteHost, remotePort );

            // note - you must reset the buffer length since the buffer
            //        length is both 'how much space there is' pre-recieve
            //        and how many were received (post-receive)
            
            receiveP.setLength( receiveBuffer.length );
            
            s.send( sendP );

            console.println("Sent!  Now waiting on response...");

            s.receive( receiveP );

            console.println("Received: " +
                            new String( receiveP.getData(),
                                        0,
                                        receiveP.getLength()
                                        )
                            );
            console.flush();
        }
    }
} // UdpPerturb