time_client.cpp

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>

#include <iostream>
/*
argv[0] ---> nombre del programa
argv[1] ---> primer argumento (char *)

./time_client 127.0.0.1 3000 t
argv[0] = "./time_client"
argv[1] = "127.0.0.1"
argv[2] = "3000"
argv[3] = "t"
|
|
V
res->ai_addr ---> (socket + bind)
*/
int main(int argc, char **argv) {
    time_t time_;
    struct tm *tm_;
    struct addrinfo hints;
    struct addrinfo *res;

    // ---------------------------------------------------------------------- //
    // INICIALIZACIÓN SOCKET//
    // ---------------------------------------------------------------------- //

    memset(&hints, 0, sizeof(struct addrinfo));

    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_DGRAM;

    int rc = getaddrinfo(argv[1], argv[2], &hints, &res);

    
    if (rc != 0) {
        std::cerr << "getaddrinfo: " << gai_strerror(rc) << std::endl;
        return -1;
    }

    
    int sd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);

    freeaddrinfo(res);
// ---------------------------------------------------------------------- //
// ENVIO MENSAJE DE CLIENTE //
// ---------------------------------------------------------------------- //
char buffer[80];
char host[NI_MAXHOST];
char service[NI_MAXSERV];

struct sockaddr client_addr;
socklen_t client_len = sizeof(struct sockaddr);

 sendto(sd, argv[3], 2, 0, &client_addr, client_len);


ssize_t bytes = recvfrom(sd, buffer, 79 * sizeof(char), 0, &client_addr,
&client_len);

if ( bytes == -1)
{
std::cerr << "recvfrom: " << std::endl;
return -1;
}

std::cout << buffer << std::endl;
}