/* socket Internet de type datagramme - COTE EMETTEUR */
/* gcc em_UDP.c -o em_UDP -lsocket -lnsl */

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

#define NUM_PORT_REC		9001

main(int argc, char *argv[])

{  int sock, i, lg_mes;
   struct sockaddr_in nom_rec;
   struct hostent *hp;
   char message[100];

   /* construction du nom externe du socket local */ 
   
   if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
     {
      printf ("erreur creation socket\n");
      exit (1);
     }     

   /* construction du nom externe du socket recepteur */ 

   if ((hp = gethostbyname("192.168.101.101")) == NULL)
     {
      printf ("erreur gethostbyname\n");
      exit (1);
     }      
   nom_rec.sin_family = AF_INET;
   nom_rec.sin_port = NUM_PORT_REC;
   bcopy(hp->h_addr, (char *)&(nom_rec.sin_addr.s_addr), hp->h_length);


   /* construction et envoi des messages */ 

    strcpy(message,"Toulouse");
    lg_mes = strlen(message);

    for (i=0; i< 5; i++) 
      {
       sendto(sock,message,lg_mes,0,(struct sockaddr*)&nom_rec,sizeof(nom_rec));
       printf ("message envoye : %s\n", message);
      }
    sleep(1);

   /* fermeture du socket */ 

    close(sock);
    exit(0);
}