/*
* Copyright (c) 2001 Sun Microsystems, Inc. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Sun Microsystems, Inc. for Project JXTA."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA",
* nor may "JXTA" appear in their name, without prior written
* permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL SUN MICROSYSTEMS OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of Project JXTA. For more
* information on Project JXTA, please see
* <http://www.jxta.org/>.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*
* $Id: talk.java,v 1.67 2007/02/09 23:12:46 hamada Exp $
*/
package net.jxta.impl.shell.bin.talk;
import net.jxta.discovery.DiscoveryEvent;
import net.jxta.discovery.DiscoveryListener;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
import net.jxta.document.MimeMediaType;
import net.jxta.endpoint.InputStreamMessageElement;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.MessageElement;
import net.jxta.endpoint.StringMessageElement;
import net.jxta.id.IDFactory;
import net.jxta.impl.shell.ShellApp;
import net.jxta.impl.shell.ShellEnv;
import net.jxta.impl.shell.ShellObject;
import net.jxta.peergroup.PeerGroup;
import net.jxta.pipe.InputPipe;
import net.jxta.pipe.OutputPipe;
import net.jxta.pipe.PipeID;
import net.jxta.pipe.PipeService;
import net.jxta.protocol.DiscoveryResponseMsg;
import net.jxta.protocol.PipeAdvertisement;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowEvent;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
/**
* talk Shell command: send and receive message from other users.
*/
public class talk extends ShellApp implements Runnable, DiscoveryListener {
@SuppressWarnings("serial")
static class ImageWindow extends Frame {
static ImageWindow currentWin = null;
Image currentImage = null;
boolean sizeDone = false;
public ImageWindow() {
super();
enableEvents(WindowEvent.WINDOW_CLOSING |
WindowEvent.WINDOW_CLOSED |
ComponentEvent.COMPONENT_RESIZED);
}
private void initSize(int width, int height) {
if (sizeDone) {
return;
}
if (width > 640) {
width = 640;
} else if (width < 100) {
width = 100;
}
if (height > 480) {
height = 480;
} else if (height < 100) {
height = 100;
}
setSize(width, height);
sizeDone = true;
}
@Override
public boolean imageUpdate(Image img,
int infoflags,
int x,
int y,
int width,
int height) {
if ((infoflags & (WIDTH | HEIGHT)) == (WIDTH | HEIGHT)) {
initSize(width, height);
}
// Make sure events keep comming until we have the size done.
return super.imageUpdate(img, infoflags, x, y, width, height) || !sizeDone;
}
private void setImageData(byte[] data) {
sizeDone = false;
currentImage = getToolkit().createImage(data);
// Get the image size.
int width = currentImage.getWidth(this);
int height = currentImage.getHeight(this);
if ((width != -1) && (height != -1)) {
initSize(width, height);
}
}
// For some reason resizing a frame does not repaint it
// unless the new size is bigger in both dimensions !
@Override
protected void processComponentEvent(ComponentEvent e) {
if (e.getID() == ComponentEvent.COMPONENT_RESIZED) {
repaint();
}
super.processComponentEvent(e);
}
@Override
protected void processWindowEvent(WindowEvent e) {
if (e.getID() == WindowEvent.WINDOW_CLOSING) {
dispose();
} else if (e.getID() == WindowEvent.WINDOW_CLOSED) {
currentWin = null;
}
super.processWindowEvent(e);
}
@Override
public void paint(Graphics g) {
if (currentImage != null) {
if (sizeDone) {
g.drawImage(currentImage, 0, 0, getSize().width, getSize().height, this);
}
}
}
static void showImageFromData(String title, byte[] data) {
if (currentWin == null) {
currentWin = new ImageWindow();
currentWin.pack();
// currentWin.show();
currentWin.setVisible(true);
}
currentWin.setTitle(title);
currentWin.setImageData(data);
}
}
private boolean doImages = true;
private String handleImageFromMsg(String sender, Message msg) {
String textVersion = "";
try {
MessageElement imageElem = msg.getMessageElement("talkx", "image");
if (imageElem != null) {
textVersion = "<image>";
String title = "from " + sender;
MessageElement captionElem =
msg.getMessageElement("talkx", "image_caption");
if (captionElem != null) {
String caption = captionElem.toString();
title = title + " : " + caption;
textVersion = "<image caption=" + caption + ">";
}
if (doImages) {
byte[] data = imageElem.getBytes(false);
ImageWindow.showImageFromData(title, data);
textVersion = "";
}
}
} catch (Exception e) {
printStackTrace("failure getting image from message", e);
doImages = false;
}
return textVersion;
}
private static final int WaitingTime = 500; // 1/2 second
private static final int MAXRETRIES = 20; // 20 times WaitingTime = 10 seconds
public static final String TalkNameTag = "JxtaTalkUserName";
public static final String TalkIDTag = "JxtaTalkPipeID";
private static final String EnvName = "talkd";
private static final String SenderName = "JxtaTalkSenderName";
private static final String SenderMessage = "JxtaTalkSenderMessage";
private static final String SENDERGROUPNAME = "GrpName";
private DiscoveryService discovery = null;
private ShellEnv env = null;
private String userName = null;
private Thread thread = null;
private InputPipe pipeIn = null;
private List<PipeAdvertisement> results;
/**
* {@inheritDoc}
*/
public int startApp(String[] args) {
if ((args == null) || (args.length == 0)) {
return syntaxError();
}
env = getEnv();
discovery = getGroup().getDiscoveryService();
if (args[0].equals("-register") || args[0].equals("-r")) {
return registerNewUser(args);
}
if (args[0].equals("-login") || args[0].equals("-l")) {
return login(args);
}
if (args[0].equals("-logout") || args[0].equals("-lo")) {
return logout(args);
}
if (args[0].equals("-search") || args[0].equals("-f")) {
return findUsers();
}
return sendMessage(args);
}
private boolean deamonRunning(String name) {
ShellObject obj = env.get(EnvName + "." + name + "@" + (getGroup().getPeerGroupAdvertisement()).getName());
return obj != null;
}
private int login(String[] args) {
if (args.length != 2) {
return syntaxError();
}
String name = args[1];
if (deamonRunning(name)) {
consoleMessage("user " + name + " is already listening");
return ShellApp.appMiscError;
}
PipeAdvertisement adv = findUserAdv(name);
if (adv == null) {
consoleMessage(name + " is not a registered user");
return ShellApp.appMiscError;
}
runDeamon(name, adv);
return ShellApp.appNoError;
}
private int findUsers() {
discovery.getRemoteAdvertisements(null,
DiscoveryService.ADV,
PipeAdvertisement.NameTag,
TalkNameTag + ".*",
200,
null);
for (int i = 0; i <= MAXRETRIES; i++) {
try {
Thread.sleep(WaitingTime);
print(".");
} catch (Exception e) {
//ignored
}
}
println("");
try {
Enumeration<Advertisement> each = discovery.getLocalAdvertisements(DiscoveryService.ADV,
PipeAdvertisement.NameTag,
TalkNameTag + ".*");
if (each.hasMoreElements()) {
consoleMessage("Found the following talk registrations:");
while (each.hasMoreElements()) {
try {
PipeAdvertisement adv = (PipeAdvertisement) each.nextElement();
String name = adv.getName();
if (name.startsWith(TalkNameTag)) {
name = name.substring(TalkNameTag.length() + 1);
}
println(name + "\t\t[" +adv.getType() + "]");
} catch (Exception e) {
//ignored
}
}
}
} catch (Exception e) {
printStackTrace("Discovery failed", e);
return ShellApp.appMiscError;
}
return ShellApp.appNoError;
}
/**
* {@inheritDoc}
*/
public void discoveryEvent(DiscoveryEvent event) {
DiscoveryResponseMsg res = event.getResponse();
if (res.getDiscoveryType() == DiscoveryService.ADV) {
Enumeration<Advertisement> each = res.getAdvertisements();
synchronized (this) {
while (each.hasMoreElements()) {
try {
Advertisement adv = each.nextElement();
if (adv instanceof PipeAdvertisement) {
if (null == results) {
results = new ArrayList<PipeAdvertisement>();
}
results.add((PipeAdvertisement) adv);
}
} catch (Exception ex) {
//ignored
}
}
notify();
}
}
}
private int logout(String[] args) {
if (args.length != 2) {
return syntaxError();
}
String name = args[1];
if (!deamonRunning(name)) {
consoleMessage("User '" + name + "' is not listening.");
return ShellApp.appMiscError;
}
stopDeamon(name);
return ShellApp.appNoError;
}
private int sendMessage(String[] args) {
String name;
String srcName;
if (args[0].equals("-u")) {
if (args.length != 3) {
return syntaxError();
}
srcName = args[1];
name = args[2];
// check if the name is registered
if (!deamonRunning(srcName)) {
consoleMessage("User '" + srcName + "' is not logged in.");
return ShellApp.appMiscError;
}
} else {
name = args[0];
// There is no name for the person sending message
// use the peer nameinstead.
srcName = getGroup().getPeerName();
}
PipeAdvertisement adv = findUserAdv(name);
if (adv == null) {
consoleMessage("User '" + name + "' is not a registered.");
return ShellApp.appMiscError;
}
OutputPipe pipeOut = null;
consoleMessage("Found advertisement for '" + name + "'. Attempting to connect");
for (int i = 0; i < 2; i++) {
try {
pipeOut = getGroup().getPipeService().createOutputPipe(adv, 25000);
if (pipeOut != null) {
break;
}
print(".");
} catch (Exception e) {
//timeout exception
}
}
if (pipeOut == null) {
consoleMessage("User " + name + " is not listening. Try again later");
return ShellApp.appMiscError;
}
// Get the user text
consoleMessage("Connection established to user " + name);
consoleMessage("Type your message. To exit, type \".\" at beginning of line");
Message msg;
String userInput;
while (true) {
try {
userInput = waitForInput();
if (userInput == null) {
break;
}
if (userInput.equals(".")) {
break;
}
String imagePath = null;
String imageCaption = null;
if (userInput.startsWith(".image")) {
int nextColon = userInput.indexOf(":");
if (nextColon == -1)
continue;
userInput = userInput.substring(nextColon + 1);
nextColon = userInput.indexOf(":");
if (nextColon != -1) {
imagePath = userInput.substring(0, nextColon);
userInput = userInput.substring(nextColon + 1);
} else {
imagePath = userInput;
userInput = "";
}
nextColon = userInput.indexOf(":");
if (nextColon != -1) {
imageCaption = userInput.substring(0, nextColon);
userInput = userInput.substring(nextColon + 1);
} else {
imageCaption = userInput;
userInput = "";
}
}
// Build a message
msg = new Message();
msg.addMessageElement(new StringMessageElement(SenderMessage, userInput, null));
if (srcName != null) {
msg.addMessageElement(new StringMessageElement(SenderName, srcName, null));
}
try {
if (imagePath != null && !imagePath.equals("")) {
InputStream imageFile = new FileInputStream(imagePath);
msg.replaceMessageElement("talkx",
new InputStreamMessageElement("image", MimeMediaType.AOS, imageFile, null));
imageFile.close();
}
if (imageCaption != null && !imageCaption.equals("")) {
msg.replaceMessageElement("talkx",
new StringMessageElement("image_caption", imageCaption, null));
}
} catch (Exception any) {
printStackTrace("Failure doing image processing", any);
}
msg.addMessageElement(new StringMessageElement(SENDERGROUPNAME, getGroup().getPeerGroupName(), null));
pipeOut.send(msg);
} catch (Exception ex) {
printStackTrace("Failed to send message to user :" + name, ex);
return ShellApp.appMiscError;
}
}
pipeOut.close();
return ShellApp.appNoError;
}
private int registerNewUser(String[] args) {
if ((args.length != 2) && (args.length != 3)) {
return syntaxError();
}
String name = args[1];
String type;
if (args.length == 3) {
// Type has been specified
String t = args[2];
if (t.equals("-secure") || t.equals("-s")) {
type = PipeService.UnicastSecureType;
} else if (t.equals("-propagate") || t.equals("-p")) {
type = PipeService.PropagateType;
} else {
// Default is unicast
type = PipeService.UnicastType;
}
} else {
type = PipeService.UnicastType;
}
// Check if there is already a registered user of the
// same name.
consoleMessage("Creating pipe named :" + name + " of type :" + type);
PipeAdvertisement adv = findUserAdv(name);
if (adv != null) {
consoleMessage("Sorry, user " + name + " is already registered");
return ShellApp.appMiscError;
}
try {
// Create a pipe advertisement for this pipe.
adv = (PipeAdvertisement)
AdvertisementFactory.newAdvertisement(PipeAdvertisement.getAdvertisementType());
} catch (Exception all) {
printStackTrace("Advertisement document could not be created", all);
return ShellApp.appMiscError;
}
ShellObject obj = env.get("stdgroup");
// extract the advertisement
PeerGroup group = (PeerGroup) obj.getObject();
adv.setPipeID(IDFactory.newPipeID(group.getPeerGroupID()));
adv.setName(TalkNameTag + "." + name);
adv.setDescription("Created by JXTA Shell 'talk' command");
adv.setType(type);
try {
// Save the document into the public folder
discovery.publish(adv, DiscoveryService.INFINITE_LIFETIME, DiscoveryService.DEFAULT_EXPIRATION);
} catch (Exception e2) {
printStackTrace("Advertisement could not be saved", e2);
return ShellApp.appMiscError;
}
consoleMessage("User '" + name + "' is now registered");
return ShellApp.appNoError;
}
private boolean checkUserAdv(PipeAdvertisement adv, String name) {
if (adv == null) {
return false;
}
if (adv.getName() == null) {
return false;
}
String str = adv.getName();
return (str.startsWith(TalkNameTag) && str.endsWith(name));
}
private PipeAdvertisement findUserAdv(String name) {
Enumeration advs;
if (name.toUpperCase().equals("IP2PGRP")) {
return getMyJxtaPipeAdv();
}
// First look in the local storage
try {
advs = discovery.getLocalAdvertisements(DiscoveryService.ADV,
PipeAdvertisement.NameTag,
TalkNameTag + "." + name);
PipeAdvertisement adv;
while (advs.hasMoreElements()) {
try {
adv = (PipeAdvertisement) advs.nextElement();
if (adv.getName().endsWith(name)) {
if (checkUserAdv(adv, name)) {
return adv;
}
}
} catch (Exception e) {
continue;
}
if (checkUserAdv(adv, name)) {
return adv;
}
}
} catch (Exception e) {
//ignored
}
// Now, search remote
discovery.getRemoteAdvertisements(null,
DiscoveryService.ADV,
PipeAdvertisement.NameTag,
TalkNameTag + "." + name,
2,
this);
// Wait a bit in order to get an answer.
int i = 0;
while (true) {
try {
if (i > MAXRETRIES) {
println("");
break;
}
Thread.sleep(WaitingTime);
print(".");
i++;
//one more query
if (i == MAXRETRIES / 2) {
discovery.getRemoteAdvertisements(null,
DiscoveryService.ADV,
PipeAdvertisement.NameTag,
TalkNameTag + "." + name,
2,
this);
}
} catch (Exception e) {
//ignored
}
try {
synchronized (this) {
if (results != null) {
for (Object result : results) {
try {
PipeAdvertisement adv = (PipeAdvertisement) result;
if (checkUserAdv(adv, name)) {
return adv;
}
} catch (Exception e) {
//ignored
}
}
results.clear();
}
}
} catch (Exception e) {
//ignored
}
}
return null;
}
private void runDeamon(String name, PipeAdvertisement adv) {
userName = name;
try {
pipeIn = getGroup().getPipeService().createInputPipe(adv);
} catch (Exception ex) {
printStackTrace("Could not open InputPipe for " + adv.getPipeID(), ex);
return;
}
if (pipeIn == null) {
consoleMessage("Could not open InputPipe for " + adv.getPipeID());
return;
}
thread = new Thread(this, "Talk:Talk Deamon for " + name + "@" + getGroup().getPeerGroupName());
thread.setDaemon(true);
thread.start();
CleanupShellObject daemon = new CleanupShellObject("Talk Deamon for : " + name + "@" + getGroup().getPeerGroupName(), this);
// Store this object
env.add(EnvName + "." + name + "@" + getGroup().getPeerGroupName(), daemon);
}
/**
* Stops the talk daemon thread
*/
private static class CleanupShellObject extends ShellObject<talk> {
CleanupShellObject(String name, talk object) {
super(name, object);
}
/**
* {@inheritDoc}
* <p/>
* <p/>Closes the pipe if it is still open.
*/
@Override
protected void finalize() throws Throwable {
super.finalize();
talk daemon = getObject();
synchronized (daemon) {
if (null != daemon.pipeIn) {
daemon.pipeIn.close();
}
}
}
}
private void stopDeamon(String name) {
// full name is required to find the object
String dname = EnvName + "." + name + "@" + getGroup().getPeerGroupName();
ShellObject obj = env.get(dname);
if (obj == null) {
// Notify user that the logout failed
consoleMessage("Daemon(" + dname + ") for " + name + " not found");
return;
}
try {
talk daemon = (talk) obj.getObject();
env.remove(dname);
synchronized (daemon) {
if (null != daemon.pipeIn) {
daemon.pipeIn.close();
}
}
} catch (Exception e) {
printStackTrace("Could not stop deamon for " + name, e);
}
}
/**
* {@inheritDoc}
*/
public void run() {
try {
// Listen on the pipe
while (true) {
Message msg;
try {
msg = pipeIn.waitForMessage();
if (null == msg) {
consoleMessage("Stop listening for " + userName);
break;
}
} catch (InterruptedException woken) {
Thread.interrupted();
consoleMessage("Stop listening for " + userName);
return;
}
String senderName;
// Get sender information
MessageElement nameEl = msg.getMessageElement(SenderName);
if (nameEl != null) {
senderName = nameEl.toString();
} else {
println("received an unknown message");
continue;
}
if (null == senderName) {
senderName = "Anonymous";
}
String senderMessage;
MessageElement msgEl = msg.getMessageElement(SenderMessage);
if (msgEl != null) {
senderMessage = msgEl.toString();
} else {
println("received an unknown message");
continue;
}
senderMessage += handleImageFromMsg(senderName, msg);
// Get message
if (senderMessage == null) {
consoleMessage(senderName + " to " + userName + "> [empty message]");
continue;
}
consoleMessage(senderName + " to " + userName + "> " + senderMessage);
}
} catch (Throwable all) {
printStackTrace("Uncaught Throwable in thread :" + Thread.currentThread().getName(), all);
} finally {
synchronized (this) {
pipeIn = null;
thread = null;
}
}
}
/**
* Generate uniquePipeID that is independantly unique within a group
*
* @return The uniquePipeID value
*/
private PipeAdvertisement getMyJxtaPipeAdv() {
byte[] preCookedPID = {
(byte) 0xD1, (byte) 0xD1, (byte) 0xD1, (byte) 0xD1,
(byte) 0xD1, (byte) 0xD1, (byte) 0xD1, (byte) 0xD1,
(byte) 0xD1, (byte) 0xD1, (byte) 0xD1, (byte) 0xD1,
(byte) 0xD1, (byte) 0xD1, (byte) 0xD1, (byte) 0xD1};
PipeID id = IDFactory.newPipeID(getGroup().getPeerGroupID(), preCookedPID);
PipeAdvertisement pipeAdv = (PipeAdvertisement)
AdvertisementFactory.newAdvertisement(
PipeAdvertisement.getAdvertisementType());
pipeAdv.setPipeID(id);
pipeAdv.setName("JXME chat demo");
pipeAdv.setType(PipeService.PropagateType);
return pipeAdv;
}
private int syntaxError() {
consoleMessage(getDescription());
println("Usage: talk -[r]egister <userName> [-[s]ecure | -[p]ropagate]");
println(" talk -[l]ogin <userName> ");
println(" talk -[lo]gout <userName> ");
println(" talk -[u] <senderName> <userName> ");
println(" talk -search || -f <userName>");
return ShellApp.appParamError;
}
/**
* {@inheritDoc}
*/
@Override
public String getDescription() {
return "Talk to another peer";
}
/**
* {@inheritDoc}
*/
@Override
public void help() {
println("NAME");
println(" talk - " + getDescription());
println(" ");
println("SYNOPSIS");
println(" ");
println(" talk -[r]egister <userName> [-[s]ecure | -[p]ropagate]");
println(" talk -[l]ogin <userName> ");
println(" talk -[lo]gout <userName> ");
println(" talk -[u] <senderName> <userName> ");
println(" talk -search || -f");
println(" ");
println("DESCRIPTION");
println(" ");
println("The 'talk command implements a simple instant messaging command");
println("where two users on two remote peers can exchange messages.");
println("Messages are displayed on the Shell stdout. In order");
println("to use 'talk' the user needs to register himself. This is done");
println("via the following steps:");
println("Step 1: Register via 'talk -register <username>' command. This command");
println(" creates a Talk advertisement for that user. This has to");
println(" be done only once, the first time the user registers with");
println(" talk. The system remembers it accross reboot.");
println(" -secure can be added in order to establish a secure talk session.");
println(" -propagate can be added in order to establish a chatroom style talk session.");
println(" ");
println("Step 2: Login via 'talk -login <username>' command. This command");
println(" logs the user and starts a listener daemon. This has to");
println(" to be done everytime the peer is restarted.");
println(" ");
println("Step 3: User can talk to another user via the command");
println(" 'talk -u <myusername> <destusername>'. This command will prompt the user");
println(" to enter the message he/she wants to send");
println(" ");
println(" JXTA>talk -u moi mike");
println(" # talk : Connected to user mike");
println(" Type your message. To exit, type '.' at beginning of line");
println(" ");
println("To stop receiving any more talk messages. The user can stop the talk");
println("listener daemon by entering the command 'talk -logout <username>'");
println(" ");
println("OPTIONS");
println(" ");
println(" -register register a new user name.");
println(" -login log user and set default user.");
println(" -logout logout.");
println(" -search search for talk users.");
println(" -u specify current user name");
println(" ");
println("EXAMPLES");
println(" ");
println(" JXTA>talk -register me");
println(" JXTA>talk -login me");
println(" JXTA>talk -search");
println(" JXTA>talk -u me you");
println(" ");
println("This example shows how a new user 'me' can register and log into talk,");
println(" an talk to the user 'you'. User 'you' needs to be registered and logged on.");
println(" ");
println("SEE ALSO");
println(" ");
println(" xfer sftp mkpipe");
}
}