#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

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

char* get_tod() {
    time_t t = time(NULL);
    struct tm *tm = localtime(&t);
    char* res = malloc(64);

    int len = strftime(res, 64, "%c\n", tm);

    res[len] = '\0';

    return res;
}

int main(int argc, char *argv[]) {
  int sockfd;
  int newsockfd;
  int port = 13;
  socklen_t clilen;
  struct sockaddr_in serv_addr, cli_addr;
  int n;
  char* tod;

  sockfd = socket(AF_INET, SOCK_STREAM, 0);
  if (sockfd < 0) die("error opening socket.");

  bzero((char *) &serv_addr, sizeof(serv_addr));
  serv_addr.sin_family = AF_INET;
  serv_addr.sin_addr.s_addr = INADDR_ANY;
  serv_addr.sin_port = htons(port);
  if (bind(sockfd, (struct sockaddr *) &serv_addr,
     sizeof(serv_addr)) < 0) die("error binding socket.");

  clilen = sizeof(cli_addr);

  while (1) {
    listen(sockfd, 5);

    newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
    if (newsockfd < 0) die("error accepting");

    tod = get_tod();
    n = write(newsockfd, tod, 64);
    if (n < 0) die("error writing to socket");
    free(tod);
    close(newsockfd);
  }

  close(sockfd);
  return 0;
}