Thread: Sockets: send/receive continuous stream of data?

Hey all,

I'm trying to create a TCP client app and TCP server app using C (sockets w/ linux and winsock with windows)

I think I have the opening/closing sockets part down for both apps. The problem I'm facing is figuring out how to send and receive the data. The info to be sent is a series of ever changing number values. To emulate what I'd actually need I was thinking I could create an endless loop that sent random number data (client end) to the server. Right now I'm only trying to send individual strings typed in by the user...however, I don't think I have a good idea of how to really put the data into a buffer to send and receive it.

Also really quick question... whenever I call accept(), subsequent terminal output becomes all weird. I need to specify a newline before and after each statement I printf or wierd stuff happens. Namely, I'll get a newline but no text. Any ideas why?

It'd be awesome if someone can help me create a skeleton for send/recv or give me a conceptual description of how to set up send/rcv for my situation. The code I've attached is for rx and tx (only the relevant portion of the application's code)... let me know if the rest is necessary.

Code:

//from client app (winsock)
    //____________________________________________
    // SEND data
    char *txMsg = "Hello World!";
    vRet = send (dataTx, txMsg, (int)strlen(txMsg), 0);
   
    if (vRet == SOCKET_ERROR)
    {
        cout << "\nError sending data... Exiting";
        cout << "\nsend failed with error: " << WSAGetLastError();
        cout << "\n";
        system("PAUSE");
        closesocket(dataTx);
        return 0;
    }

    else
    {
        cout << "Sent data.\n";
        //return 0;
    }

Code:

//from server app
    {
        //the accept function waits if there are no pending connections
        dataTx = accept (dataRx, (struct sockaddr*)&remote, &remLen );

        printf("\n");
        printf("-> [Connected to client %s]", inet_ntoa(remote.sin_addr) );
        printf("\n");
        
        do
        {
            char *recvBuff;
            recvBuff = malloc (4 * sizeof(char));
            
            if (numBytes = recv (dataTx, recvBuff, recvBuffSize, 0) > 0)
            {
                printf("\n-> Bytes Received: %d \n", numBytes);    //why always one?
                printf("\n-> Message Received: %s \n", recvBuff);
                
                if (!(strcmp(recvBuff, quitString)))
                    {   printf("\nshould quit\n");
                        exFlag = 1;     }
                        
                free (recvBuff);
                recvBuff = NULL;
            }
            
            
        } while (exFlag != 1);
        
        
        printf("\n-> [Closed connection]\n");
        
        close(dataTx);
    }

Thanks!
d02