I am new to C Socket Programming. I know how to write for TCP and UDP as different programs.
But only one server should handle both the clients.
Can anyone tell me how to write a sever that handles both TCP and UDP clients?
You cannot listen to TCP and UDP clients using 1 server socket. You can however create 2 server sockets (one TCP-server and one UDP-server). Note that it would not even make sense to have 1 server for both: UDP is connectionless so the first question arises when you try to do
accept on your server socket (since it is a hypothetical hybrid version, what should
Anyway, I assume you want two servers in the same event loop (if you don't know what it is, it is enough for you to think of it as your main-function). Since C sockets are blocking by default, you cannot run two servers right out of the box.
You can use
select (Google it). If you don't know what it is, I would recommend to try it in Python first. In Python it's fairly straight forward and it will give you some insight of the concept. Basically what you do is: create multiple server sockets than "switch" between those sockets, see what sockets have read events (be it new connections or messages) and then process those events.
I can recommend libuv. It is a C library that is originally built for Node.js. Prior to libuv, they used platform-dependent event loop implementations (libev). Libuv originated as an effort to create a multi-platform library for non-blocking IO (TCP, UDP, fs, etc.). However, even if you don't want to write multi-platform code, it comes with a great API to create server sockets and listen to multiple sockets in the same event loop.