int main(int argc, char *argv[]) {
char buf[BUFSIZE];
ssize_t bytesread;
char hostinfo[BUFSIZE];
int mcastfd;
u_buf_t mcastinfo;
u_port_t mcastport;
u_buf_t senderinfo;
if (argc != 3) {
fprintf(stderr, "Usage: %s multicast-address multicast-port\n", argv[0]);
return 1;
}
mcastport = (u_port_t)atoi(argv[2]); /* join the multicast group */
if ((mcastfd = u_join(argv[1], mcastport, &mcastinfo)) == -1) {
perror("Failed to join multicast group");
return 1;
}
u_gethostinfo(&mcastinfo, buf, BUFSIZE);
fprintf(stderr, "Info: %s\n", buf);
fprintf(stderr, "mcastfd is %d\n", mcastfd);
/* read information from multicast, send to standard output */
while ((bytesread = u_recvfrom(mcastfd, buf, BUFSIZE, &senderinfo)) > 0) {
u_gethostinfo(&senderinfo, hostinfo, BUFSIZE);
if ((r_write(STDOUT_FILENO, hostinfo, strlen(hostinfo)) == -1) ||
(r_write(STDOUT_FILENO, buf, bytesread) == -1)) {
perror("Failed to echo message received to standard output");
break;
}
}
return 0;
}
int main(int argc, char *argv[]) {
char buf[BUFSIZE];
char host_info[BUFSIZE];
int mcastfd;
u_buf_t mcast_info;
u_port_t mcastport;
ssize_t nbytes_read;
u_buf_t sender_info;
int count;
if (argc != 3) {
fprintf(stderr, "Usage: %s Multicast-Address Multicast-Port\n", argv[0]);
return 1;
}
/* join the multicast group */
mcastport = (u_port_t)atoi(argv[2]);
if ((mcastfd = u_join(argv[1], mcastport, &mcast_info)) == -1) {
perror("Receiver failed to join multicast group");
return 1;
}
u_gethostinfo(&mcast_info,buf,BUFSIZE);
fprintf(stderr,"Info: %s\n",buf);
fprintf(stderr,"mcastfd is %d\n",mcastfd);
/* multicast information read from standard input */
count = 0;
while ((nbytes_read = u_recvfrom(mcastfd, buf, BUFSIZE, &sender_info)) > 0) {
u_gethostinfo(&sender_info, host_info, BUFSIZE);
if ((r_write(STDOUT_FILENO, host_info, strlen(host_info)) == -1) ||
(r_write(STDOUT_FILENO, buf, nbytes_read) == -1)) {
perror("Error echoing sender or message to standard output");
break;
}
count++;
if (count == 5) {
fprintf(stderr,"Leaving group\n");
if (u_leave(mcastfd,&mcast_info) == -1)
perror("Error leaving group");
}
}
return 0;
}