accept and work at same time

I’m trying to create a small server/client tier architecture. You might think this should be posted under socket programming. But my question is of another kind.
I have seen programs that are able to accept keyboard input – yet are able to work and throw output on the screen. My goal is to create a small dos based chat relay server as a start.
How would I accomplish this?

So do you really mean DOS, or do you mean that black rectangle in the middle of your screen which has a "C:\>" prompt in it?

haha, that little black box with the c:\> is dos. Well an altered version of course from Microsoft called the command prompt. If it helps im using windows XP.

Originally Posted by multielements

haha, that little black box with the c:\> is dos. Well an altered version of course from Microsoft called the command prompt. If it helps im using windows XP.

ha ha... you're wrong...

My first thought would be multithreading but I dont know anything about that or networking, but read up on it to see if that is what you want.

You are wanting to use asynchronous socket operations. What I think he/she is saying is that accept() is causing a block which is causing him/her to have a delay between when he/she can type and when he/she is ready to type. So off to google with ya, I'm too lazy to copy/paste from msdn.

>My first thought would be multithreading but I dont know anything about that or networking, but read up on it to see if that is what you want.

Well this will strictly depend on what you are planning on doing. A lot of programs make new threads for each individual client. Its always an option you can spend time thinking about.

You can use a thread running as your receiver and have it check every interval if the socket is readible. If it is, you can receive data and process it accordingly. All of your sending can be done in a blocking manner. To illustrate:

Code:

void ReceiveThread(void *pSomething) {
  while (socket is good) {
    if (socket is readible) {
      receive(some data);
      if (it is a chat message)
        print(the chat message on the screen);
    }
  }
}

int main() {
  connect(to a server);
  start(your ReceiveThread);
  read (some text from keyboard);
  send(some text to server);
  return 0;
}

Something along those lines. Keep in mind, of course, that this is a very simplistic pseudocode view from the top of a really tall ladder and there are many other details that must be taken into consideration. But this is a general structure that should do the job for you.

> haha, that little black box with the c:\> is dos.
Wrong - it's called a console.

Console programs are 32-bit (DOS was 16), have access to far more memory and a much wider set API calls.

Poor old DOS. She's just an old lady sitting in her rocking chair waiting to die.

multielements:
You can look into the function select(), that will tell you whether there's any clients waiting to connect, and if there are THEN you call accept() and it won't block. Otherwise, you could switch to asynchronous winsock of sorts. The same goes for recv().

Also look into _kbhit(), it's a nonstandard function that lets you know if a key has been pressed, that way you don't have to wait while get() or getline() etc. blocks either.