I need help with UDP chat in C

See more:

C

UDP

Chat

sockets

Hello,
I am trying to make chat for two users(using select()), but i am stuck on this code:

<pre>#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>


void chat(int sock_fd, struct sockaddr_in *peer){
  
  int ret;
  ssize_t bytes;
  char buffer[1024];
  char sendto_buffer[1024];
  fd_set readfds;
  FD_ZERO(&readfds);
  FD_SET(STDIN_FILENO, &readfds);
  FD_SET(sock_fd, &readfds);

  while (1) {
    select(sock_fd + 1, &readfds, NULL, NULL, NULL);
    
  
      if (FD_ISSET(STDIN_FILENO, &readfds)) {
        bytes = read(0, sendto_buffer, sizeof(sendto_buffer));
        if (bytes < 0) {
          printf("Error\n");
          break;
        }
        printf("Sending: %.*s\n", (int)bytes, sendto_buffer);
        bytes = sendto(sock_fd, sendto_buffer, bytes, 0,(struct sockaddr *)peer, sizeof(struct sockaddr_in));
        if (bytes < 0) {
          printf("Error sendto \n");
          break;
        }
      }
    
      if(FD_ISSET(sock_fd, &readfds)) {
        bytes = recvfrom(sock_fd, buffer, sizeof(buffer), 0, NULL, NULL);
        if (bytes < 0) {
          printf("Error recvfrom\n");
          break;
        }
        if (bytes > 0) {
          printf("Received: %.*s\n", (int)bytes, buffer);
        }
      }
    }
  }


int main(int argc, char *argv[]){
  
  int localport;
  int remoteport;
  int sock_fd;
  struct sockaddr_in server_addr;
  struct sockaddr_in peer_addr;

 if (argc < 4) {
    printf("Usage %s <local port> <remote host> <remote port>\n", argv[0]);
    return 1;
  }
  localport = strtoul(argv[1], NULL, 0);
  emoteport = strtoul(argv[3], NULL, 0);

  peer_addr.sin_family = AF_INET;
  peer_addr.sin_port = htons(remoteport);
  peer_addr.sin_addr.s_addr = INADDR_ANY;

  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
  if(sock_fd == -1){
    perror("Socket error ");
    return 1;
  }

  server_addr.sin_family = AF_INET;
  server_addr.sin_addr.s_addr = INADDR_ANY;
  server_addr.sin_port = htons(localport);
  int local_bind = bind(sock_fd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
    if(local_bind == -1){
      perror("Bind error ");
      return 1;
    }
  chat(sock_fd, &peer_addr);

  close(sock_fd);

  return 0;
}

Can someone give me some advice?
Thanks

What I have tried:

I tried to use select for this, but I think that I miss something important.