sample_server.c

#include <stdio.h>
#include <stdlib.h>
#include "udp.h"

int main(int argc, char *argv[])
{

    // This function opens a UDP socket,
    // binding it to all IP interfaces of this machine,
    // and port number SERVER_PORT
    // (See details of the function in udp.h)
    int sd = udp_socket_open(SERVER_PORT);

    assert(sd > -1);

    // Server main loop
    while (1) 
    {
        // Storage for request and response messages
        char client_request[BUFFER_SIZE], server_response[BUFFER_SIZE];

        // Demo code (remove later)
        //printf("Server is listening on port %d\n", SERVER_PORT);

        // Variable to store incoming client's IP address and port
        struct sockaddr_in client_address;
    
        // This function reads incoming client request from
        // the socket at sd.
        // (See details of the function in udp.h)
        int rc = udp_socket_read(sd, &client_address, client_request, BUFFER_SIZE);

        // Successfully received an incoming request
        if (rc > 0)
        {
            // Demo code: send a SAY command back to client
            strcpy(server_response, "say$ Server received your message!");

            // This function writes back to the incoming client,
            // whose address is now available in client_address, 
            // through the socket at sd.
            // (See details of the function in udp.h)
            rc = udp_socket_write(sd, &client_address, server_response, BUFFER_SIZE);

            // Demo code (remove later)
            //printf("Request served...\n");
        }
    }

    return 0;
}