zeromq pub/sub example in c (libzmq) - c

Question

Can someone show me "Hello World" example for zeromq pub/sub in c using libzmq. I have done coding req/rep example It's well documented but I couldn't find good hello world example for pub/sub that works fine with me.
Here is my try.
pub.c
#include <zmq.h>
#include <string.h>
int main()
{
void *context = zmq_ctx_new();
void *publisher = zmq_socket(context, ZMQ_PUB);
zmq_bind(publisher, "tcp://127.0.0.1:5555");
char message[15] = "Hello World!";
while(1)
{
zmq_msg_t msg;
zmq_msg_init_size(&message, strlen(message));
memcpy(zmq_msg_data(&msg), message, strlen(message));
zmq_msg_send(publisher, &msg, 0);
zmq_msg_close(&msg);
}
zmq_close(publisher);
zmq_ctx_destroy(context);
return 0;
}
sub.c
#include <zmq.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
int main()
{
void *context = zmq_ctx_new();
void *subscriber = zmq_socket(context, ZMQ_SUB);
int rc = zmq_connect(subscriber, "tcp://127.0.0.1:5555");
assert(rc == 0);
zmq_setsockopt(subscriber, ZMQ_SUBSCRIBE, "", 0);
char message[15] = "";
while(1)
{
zmq_msg_t msg;
zmq_msg_init(&msg);
zmq_msg_recv(subscriber, &msg, 0);
int size = zmq_msg_size(&msg);
memcpy(message, zmq_msg_data(&msg), size);
zmq_msg_close(&msg);
printf("%s\n", message);
}
zmq_close(subscriber);
zmq_ctx_destroy(context);
return 0;
}
Thanks in advance

Answer 1

Finally this code works with me
pub.c
#include <stdio.h>
#include <assert.h>
#include <zmq.h>
int main()
{
void *context = zmq_ctx_new();
void *publisher = zmq_socket(context, ZMQ_PUB);
int rc = zmq_bind(publisher, "tcp://127.0.0.1:5556");
assert(rc == 0);
while(1)
{
rc = zmq_send(publisher, "Hello World!", 12, 0);
assert(rc == 12);
}
zmq_close(publisher);
zmq_ctx_destroy(context);
return 0;
}
sub.c
#include <stdio.h>
#include <assert.h>
#include <zmq.h>
int main()
{
void *context = zmq_ctx_new();
void *subscriber = zmq_socket(context, ZMQ_SUB);
int rc = zmq_connect(subscriber, "tcp://127.0.0.1:5556");
assert(rc == 0);
rc = zmq_setsockopt(subscriber, ZMQ_SUBSCRIBE, "", 0);
assert(rc == 0);
char message[12];
while(1)
{
rc = zmq_recv(subscriber, message, 12, 0);
assert(rc != -1);
printf("%s\n", message);
}
zmq_close(subscriber);
zmq_ctx_destroy(context);
return 0;
}