Programming Jabber

The Simplest Jabber Client

Now that we know how a conversation with a Jabber server is started, let’s try it ourselves. At a stretch, one could say that the simplest Jabber client, just like the simplest HTTP client, or the simplest client that has to interact with any server that employs a text-based protocol over a socket connection, is telnet.

Simply point telnet to a Jabber server, specifying port 5222, and send an opening tag. You will receive an opening tag, from the server, in response:

yak:~$ telnet localhost 5222
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
<?xml version='1.0'?>
<stream:stream xmlns:stream='http://etherx.jabber.org/streams' to='yak' 
      xmlns='jabber:client'>
<?xml version='1.0'?><stream:stream xmlns:stream='http://etherx.jabber.org/streams' 
      id='3AFD839E' xmlns='jabber:client' from='yak'>

If you don’t have a Jabber server to experiment with, see Chapter 3 on how to set one up.

Using telnet is a great way to find out more about the way the Jabber protocol works. Perhaps the next thing to do is try out the user registration and authentication steps described in Chapter 7. But watch out—send some invalid XML and the server will close the connection on you!