Need help about using sockets

[niroshan]

Hi everyone,
I want to write a chat program using sockets. But the thing i dont undestand is how to connect more than one client to a server. I mean when using a socket we have to provide a specific port. so lets say it is port 2000. so this is fine for a single client. because he can communicate with the server using that port 2000.

But the problem arises when the second cllient logs in. Because the client one is using the port 2000 the client two can not use it. (I don't have a clear idea about it but i think it is true, right? ,If any body can clear my undestanding about this i would really appreciate it.)

So for the second client i have to provide a diferent port. How can i do this? Do I have to store an array of ports for this? If so how can i know which ports are free and which are not?

If anybody can help me I would really appreciate it. If anyone knows any articles written about this please let me know.

thanx

regards,
Niroshan

[Mordecai]

Your server should know how to open a port back after someone's made a connection. Take for instance an IRCd: hundreds or thousands of people connect to certain IRCds on port 6667. The server tells the user that they have connected--when the message is sent back, the port is reopened and can be used again. This takes some programming on your server, unless you're connecting to a pre-built server (in which case, it's probably already done).