#include <stdio.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h> /* htohs */
#include <inttypes.h>   /* htohs */
#include <unistd.h>     /* read , sleep */
#include <netdb.h>
#include <errno.h>
#include <string.h>  /* memset */

#define PORT 8888
void *thr_main();
int value;

int main(int argc, char *argv[]){
  pthread_t thrID;
  int sock, size, padSize;
  char rbuf[12], *sbuf = "Hi";
  struct sockaddr_in my_addr, paddr;

  if( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0 )
    perror("socket");
  memset(&my_addr, 0, sizeof(struct sockaddr_in));
  my_addr.sin_addr.s_addr = htons(INADDR_ANY);
  my_addr.sin_family = AF_INET;
  my_addr.sin_port   = htons(PORT);
  bind(sock, (struct sockaddr *)&my_addr, sizeof(my_addr));

  pthread_create(&thrID, NULL, thr_main, NULL);

  padSize = sizeof(paddr);
  recvfrom(sock, rbuf, 11, 0, (struct sockaddr *)&paddr, &padSize);
  rbuf[11] = '\0';
  printf("Client said: %s\n",rbuf);
  fflush(stdout);
  sendto(sock, sbuf, sizeof(sbuf), 0, (struct sockaddr *)&paddr, padSize);
  pthread_join(thrID, NULL);


  return(0);
}

void *thr_main(int *arg){
  int sock, sadSize;
  struct hostent *hstr;
  struct sockaddr_in sad;
  char *buf = "How are you";
  char rbuf[3];

  sleep(1);
  sock = socket(AF_INET, SOCK_DGRAM, 0);
  if( (hstr = gethostbyname("ren.eecis.udel.edu")) == NULL )
    perror("gethostbyname");

  memcpy((char *)&(sad.sin_addr.s_addr), hstr->h_addr, hstr->h_length);
  sad.sin_family = AF_INET;
  sad.sin_port   = htons(PORT);

  sendto(sock, buf, strlen(buf), 0, (struct sockaddr *)&sad, sizeof(sad) );
  sadSize = sizeof(sad);
  recvfrom(sock, rbuf, 2, 0, (struct sockaddr *)&sad, &sadSize);
  rbuf[2] = '\0';
  printf("Server said: %s\n",rbuf);
  fflush(stdout);

  close(sock);
}