Programming

if i have a server which wants to connect to exactly 5 clients, does that mean i need 5 socket file descriptors and use
listen(socket_fd,1);
for each one

or just do

listen(socket_fd,5)

also whats the second parameter number mean? what happens if i put 0 there?


also if i am connected to five clients, and i have listen(socket_fd,5), does that mean while one of the 5 is being handled, it has support for the other 4 to continue waiting?, or I am not sure what its doing here, can I even put a 0 there, if I have 5 clients connected, will that work?

For your requirement to connect your server to exactly 5 clients,
listen(socket_fd,5) is the right option.

>>also whats the second parameter number mean? what happens if i put 0 there?


The second parameter is the limit on the maximum number of incoming connection requests to your server socket that can remian pending waiting to be accepted.

You could start different threads for each accepted connection and process each separately. In the main thread you could poll the listen socket for an incoming connection request and accept the same.

I dont know the answer to what happens if you put a 0 for teh second parameter, but my guess is if a second connection request arrives when you already have one in the listen queue and it has not been accepted yet by your application, then this would immediately be dropped.

when u say to have
listen(socket_fd,5)
do u mean like
listen(socket_fd1,5)
listen(socket_fd2,5)
listen(socket_fd3,5)
listen(socket_fd4,5)
listen(socket_fd5,5)

or just one?

You need just one. Your socket_fd is usually not the socket with which the client and server communicate. It is rather just the point where the client connects to first and then waits for the server to open another socket on which the real data exchange takes place.
So if you have

listen(socket_fd, 5);

This means that 5 connetions are allowed to be in the queue and wait to be served. If all of these slots are taken, they will be blocked.
You can then accept the connections in this queue with the accept() call and this function will return a new file descripter which marks the direct connetion to the client.

i have this other problem
when i run my server, it works fine, and i get the connection from the client, but right after if i test it again
i get
ERROR on binding: Address already in use
but if I change the port, and compile, then change the port to what it was before, and compile, then run it , then it works again, then the whole thing happens again

does anyone know why this could be happening?

---------- Post updated at 01:51 PM ---------- Previous update was at 12:36 PM ----------

nvm i fixed it

---------- Post updated at 01:52 PM ---------- Previous update was at 01:51 PM ----------

but to keep a server and client running for more than one iteration, i dont understand how to do that

where do you put the while(1 ) {} block
what goes in the block?

Anything you want to run repeatedly.

i mean like
in the while loop do i need to redefine all the sockets declarations?

---------- Post updated at 02:19 PM ---------- Previous update was at 02:18 PM ----------

say i want exactly 5 connections
does the
listen(soc,5);
go in the while loop?