Question

i am trying to write udp chat server in c language. i have written tcp chat server before and it is ok.

in tcp server, accept function returns an fd number and server communicate with a specific client according to this fd number.

but in udp, how can i listen a specific client?

In my tcp server, after a client connect to server, a thread is created and it listen this client. So for each client, there is a thread that listen to according to fd number that is returned from accept function. so any message can send according to this fd number to specific client.

How can i achieve this in udp server?

Thanks for answers.

Answer 1

You use recvfrom to find out the source IP/port and then reply with sendto. You only need to bind to select a server port. You don’t accept. All connect does for UDP is set the default destination (which you plan to override with sendto).