source: network-game/client/Client/main.cpp@ 1912323

/* UDP client in the internet domain */
#include <sys/types.h>

#include <winsock2.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <iostream>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

void error(const char *);
int main(int argc, char *argv[])
{
   int sock, n;
   int length;
   struct sockaddr_in server, from;
   struct hostent *hp;
   char buffer[256];
   
        if (argc != 3) {
                printf("Usage: server port\n");
                exit(1);
        }

        WORD wVersionRequested;
        WSADATA wsaData;
        int wsaerr;

        wVersionRequested = MAKEWORD(2, 2);
        wsaerr = WSAStartup(wVersionRequested, &wsaData);
        
        if (wsaerr != 0) {
                printf("The Winsock dll not found.\n");
                exit(1);
        }else
                printf("The Winsock dll was found.\n");
        
        sock= socket(AF_INET, SOCK_DGRAM, 0);
        if (sock < 0) error("socket");

        server.sin_family = AF_INET;
        hp = gethostbyname(argv[1]);
        if (hp==0) error("Unknown host");

        memcpy((char *)&server.sin_addr,
                        (char *)hp->h_addr,
                        hp->h_length);
   server.sin_port = htons(atoi(argv[2]));
   length=sizeof(struct sockaddr_in);
   printf("Please enter the message: ");
   memset(buffer, 0, 256);
   fgets(buffer,255,stdin);
   n=sendto(sock,buffer,
            strlen(buffer),0,(const struct sockaddr *)&server,length);
        if (n < 0) error("Sendto");
        n = recvfrom(sock,buffer,256,0,(struct sockaddr *)&from, &length);
        if (n < 0) error("recvfrom");

        buffer[n] = '\0';
        cout << "Got an ack: " << endl;
        cout << buffer << endl;

        closesocket(sock);

        WSACleanup();

        return 0;
}

void error(const char *msg)
{
    perror(msg);
        WSACleanup();
    exit(1);
}