sample_client.c

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

#define CLIENT_PORT 10000

// client code
int main(int argc, char *argv[])
{
    // This function opens a UDP socket,
    // binding it to all IP interfaces of this machine,
    // and port number CLIENT_PORT.
    // (See details of the function in udp.h)
    printf("opening socket... \n");

    int sd = udp_socket_open(0);

    // Variable to store the server's IP address and port
    // (i.e. the server we are trying to contact).
    // Generally, it is possible for the responder to be
    // different from the server requested.
    // Although, in our case the responder will
    // always be the same as the server.
    struct sockaddr_in server_addr, responder_addr;

    // Initializing the server's address.
    // We are currently running the server on localhost (127.0.0.1).
    // You can change this to a different IP address
    // when running the server on a different machine.
    // (See details of the function in udp.h)
    printf("setting up port... \n");
    int rc = set_socket_addr(&server_addr, "127.0.0.1", SERVER_PORT);

    // Storage for request and response messages
    char client_request[BUFFER_SIZE], server_response[BUFFER_SIZE];

    // Demo code (remove later)
    strcpy(client_request, "conn Alice");

    // This function writes to the server (sends request)
    // through the socket at sd.
    // (See details of the function in udp.h)
    printf("sending...\n");
    rc = udp_socket_write(sd, &server_addr, client_request, BUFFER_SIZE);
    printf("sent: %s\n", client_request);
    if (rc > 0)
    {
        // This function reads the response from the server
        // through the socket at sd.
        // In our case, responder_addr will simply be
        // the same as server_addr.
        // (See details of the function in udp.h)
        printf("reading...\n");
        int rc = udp_socket_read(sd, &responder_addr, server_response, BUFFER_SIZE);

        // Demo code (remove later)
        printf("server_response: %s\n", server_response);
    }

    return 0;
}