a simple publisher and subscriber using zeromq

pubsub.c

########################### pub.c ##########################################
#include "zmq.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char **argv) {
  void *context = zmq_init(1);
  void *socket = zmq_socket(context, ZMQ_PUB);
  zmq_connect(socket, "tcp://127.0.0.1:12345");
  sleep(1);
  char message[1000] = "testing\n";
  while(1) {
    zmq_msg_t out_msg;
    zmq_msg_init_size(&out_msg, strlen(message));
    memcpy(zmq_msg_data(&out_msg), message, strlen(message));
    zmq_send(socket, &out_msg, 0);
    zmq_msg_close(&out_msg);
    sleep(1);
  }
}


########################### sub.c ##########################################

#include "zmq.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char **argv) {
  void *context = zmq_init(1);
  void *socket = zmq_socket(context, ZMQ_SUB);
  zmq_connect(socket, "tcp://127.0.0.1:12345");
  zmq_setsockopt(socket, ZMQ_SUBSCRIBE, "", 0);

  char string[1000] = "";
  while(1) {
    zmq_msg_t in_msg;
    zmq_msg_init(&in_msg);
    zmq_recv(socket, &in_msg, 0);
    int size = zmq_msg_size (&in_msg);
    memcpy(string, zmq_msg_data(&in_msg), size);
    zmq_msg_close(&in_msg);
    string[size] = 0;
    printf("%s\n", string);

    sleep(1);
  }
}