Multicast Sender

sender.c

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <string.h>
#include <stdio.h>


#define HELLO_PORT 12345
#define HELLO_GROUP "225.0.0.37"

int
main(int argc, char *argv[])
{
  struct sockaddr_in addr;
  int fd, cnt;
  struct ip_mreq mreq;
  char *message=argv[1];

  /* create what looks like an ordinary UDP socket */
  if ((fd=socket(AF_INET,SOCK_DGRAM,0)) < 0) {
    perror("socket");
    exit(1);
  }

  /* set up destination address */
  memset(&addr,0,sizeof(addr));
  addr.sin_family=AF_INET;
  addr.sin_addr.s_addr=inet_addr(HELLO_GROUP);
  addr.sin_port=htons(HELLO_PORT);

  /* now just sendto() our destination! */
  while (1) {
    if (sendto(fd,message,sizeof(message),0,(struct sockaddr *) &addr,
               sizeof(addr)) < 0) {
      perror("sendto");
      exit(1);
    }
    sleep(1);
  }
}