16_3_chainlistener.c

#include <czmq.h>
int main(int argc, char ** argv) {

  char *zmqserver;
  char *topic;

  if (argc < 3) {
    printf("\nUSAGE:\nchainlistener <tcp://localhost:port> <topic>\n\n");
    return 0;
  } else {
    zmqserver = argv[1];
    topic = argv[2];
  }

  zsock_t *socket = zsock_new_sub(zmqserver, topic);
  assert(socket);

  while(1) {
    zmsg_t *msg;
    int rc = zsock_recv(socket, "m", &msg);
    assert(rc == 0);

    char *header = zmsg_popstr(msg);
    zframe_t *zdata = zmsg_pop(msg);
    unsigned int *no = (unsigned int*)zmsg_popstr(msg);

    char *data = zframe_strhex(zdata);
    int len = zframe_size(zdata);
    printf("Size: %d\n", len);
    printf("Data: %s", data);
    printf("\nNo: %d\n", *no);

    free(header);
    free(data);
    free(no);
    free(zdata);
    zmsg_destroy(&msg);
    sleep(1);
 }
  zsock_destroy(&socket);
  return 0;
}