// time client
// daron spektor 2005 

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

int word2int(unsigned char *p) {
  int result;
  result =((int)p[0])<<24;
  result|=((int)p[1])<<16;
  result|=((int)p[2])<<8;
  result|=(int)p[3];
  return result;
}

int main() {
  struct sockaddr_in server;
  struct sockaddr_in me;
  struct sockaddr_in sender;
  char *msg = "send";
  char recvd[4];
  int rlen=0;
  int sock=0;
  
  
  /////////////////////// select() stuff
  struct timeval timer;
  fd_set readfds;
  fd_set masterfds;
  FD_ZERO(&masterfds);
  FD_ZERO(&readfds);
  ///////////////////////
  
  bzero(recvd, 4);
  
  me.sin_family = AF_INET;
  me.sin_port = htons(0); // any available port, i dont care
  me.sin_addr.s_addr = htonl(INADDR_ANY); // my address
  bzero(&(me.sin_zero), 8);
  
  server.sin_family = AF_INET;
  server.sin_port = htons(12221);
  server.sin_addr.s_addr = inet_addr("127.0.0.1"); //ip of server here
  bzero(&(server.sin_zero), 8);

  sock=socket(AF_INET, SOCK_DGRAM, 0);
  bind(sock, (struct sockaddr *)&me, sizeof(struct sockaddr));
  sendto(sock, msg, 5, 0, (struct sockaddr *)&server, sizeof(struct sockaddr));
  
  FD_SET(sock, &masterfds);
  
  while (1) {
    timer.tv_sec=2;
    timer.tv_usec=0; 
    readfds=masterfds;
    select(sock+1, &readfds, NULL, NULL, &timer);
    if (FD_ISSET(sock, &readfds)) {
      recvfrom(sock, recvd, 4, 0, (struct sockaddr *)&sender, &rlen);
      printf(">> %d\n", word2int(recvd));
      fflush(stdout);
      FD_CLR(sock, &readfds);
    } else {
      printf("timeout... trying again\n");
      fflush(stdout);
      sendto(sock, msg, 5, 0, (struct sockaddr *)&server, sizeof(struct sockaddr));
    }
  }
  return 0;
}