Question

How to make php client to client, like the chat way ? One client connects and sends something to the other client and only he recieve not all clients.

Answer 1

Your Question?

If I understand correctly you want one-to-one(private) messaging.

Socket Programming using PHP

You need to learn Socket programming with PHP. You could start by studying this tutorial. This has scaling problems written all over it, because PHP does not have non blocking IO, proper thread model. I advise you to just use it for fun little projects.

Non blocking IO using PHP

You could try and use PHP-MIO. I have not yet tried this, but I guess it might scale. But then again from Apache(PHP) side you will have the same problems. But when using this from both sides it could work…

long-polling(blocking IO) using PHP

P.S: got bored so I have not completely tested this 😉

Download

Below I present two solutions(prototypes) which do NOT scale. One solution uses Redis pubsub. For this you need to install(compile) redis. For this you a POSIX OS is desired, although some people have ported it to Windows. You can also use the free redistogo.com instance. The Redis solution is the prefered solution. I have put everything in an archive which you can download from here.

I also give a solution which uses named pipes. This solution does not require you to use Redis, but instead this approach needs access to the file system. I believe that this approach should also work on Windows(You have to change the filename to windows-style). I would like for somebody to try this out :). I can not test this anymore, because I have completely switched to POSIX OS(Ubuntu) a long time ago.

Requirements

At least PHP 5.3 and preferable a POSIX OS, redis.

How to use

To use both solutions you need to open two browsers(Browser A/B). I assume you are using localhost for development and that you can access files from http://localhost/6646733.

1. point browser A to http://localhost/6646733/redis?me=somebodyelse&to=alfred you should replace redis with pipe when trying out named pipes.
2. Point browser B to http://localhost/6646733/redis?me=alfred&to=somebodyelse
3. In browser A type a message into the textarea, which will be sent to browser B.
4. In browser B read the message just sent from browser A

Solutions not using PHP

The solutions below scale.

Pusher(Hosted)

With for example the hosted solution Pusher you can do chat/messaging without the scaling nightmare. Pusher even is generous to provide a free plan. But be aware that the cheap plans do NOT offer SSL so the messages can be intercepted. You should never sent private information over the wire, when not using SSL. Users/developers have provided a nice little library to use Pusher from PHP. The problem with this approach is that you are not in control, but pusher is, but then again you don’t have to worry about any details.

Socket.io(open-source)

I really like socket.io, but there are off course a lot of other solutions like for example tornado. You could use Redis to efficiently communicate between PHP and the other solution(socket.io).