client.c

//
//  Hello World client
//  Connects REQ socket to tcp://localhost:5555
//  Sends "Hello" to server, expects "World" back
//

#define ROLE "Client"
#include "common.h"

#define URL "tcp://localhost:5555"


int main (void)
{
  void *context = zmq_init (1);

  printf ("Connecting to server...\n");
  void *requester = zmq_socket (context, ZMQ_REQ);
  zmq_connect (requester, URL);

  zmq_msg_t request, reply;

  msgpack_sbuffer sbuf;
  msgpack_packer_init (&mpkg, &sbuf, msgpack_sbuffer_write);

  msgpack_zone mempool;
  msgpack_zone_init(&mempool, 2048);

  msgpack_packer mpkg;
  msgpack_object deserialized;


  int i;
  for (i = 0; i != 10; i++) {

    msgpack_sbuffer_init (&sbuf);

    msgpack_pack_array (&mpkg, 2);
    msgpack_pack_int (&mpkg, i);
    msgpack_pack_str (&mpkg, "/i/am/a/clinet/");

    zmq_msg_init_size (&request, sbuf.size);

    memcpy (zmq_msg_data (&request), sbuf.data, sbuf.size);

    msgpack_unpack (sbuf.data, sbuf.size,
        NULL, &mempool, &deserialized);

    msg_info (deserialized, "Sending\t\t");

    zmq_send (requester, &request, 0);
    zmq_msg_close (&request);

    zmq_msg_init (&reply);
    zmq_recv (requester, &reply, 0);

    msgpack_unpack (zmq_msg_data(&reply), zmq_msg_size(&reply),
        NULL, &mempool, &deserialized);

    msg_info (deserialized, "Received Reply\t\t");

    zmq_msg_close (&reply);

  }

  msgpack_zone_destroy(&mempool);
  msgpack_sbuffer_destroy(&sbuf);

  zmq_close (requester);
  zmq_term (context);
  return 0;
}

common.h

#ifndef COMMON_H
#define COMMON_H

#include <zmq.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <msgpack.h>

#define msg_info(d, t) do {\
  printf ("%s %s : ", ROLE, t);\
  msgpack_object_print (stdout, d);\
  puts ("");\
} while (0)

#define msgpack_pack_str(p, s) do {\
  msgpack_pack_raw (p, sizeof(s));\
  msgpack_pack_raw_body (p, s, sizeof(s));\
} while (0)

#endif /* COMMON_H */

makefile

CFLAGS += -lzmq -lmsgpack -g

PROGS = server client

all: $(PROGS)

clean:
	-rm -f $(PROGS)

server.c

//
//  Hello World server
//  Binds REP socket to tcp://*:5555
//  Expects "Hello" from client, replies with "World"
//
#define ROLE "Server"
#include "common.h"

int main (void)
{
  void *context = zmq_init (1);

  void *responder = zmq_socket (context, ZMQ_REP);
  zmq_bind (responder, "tcp://*:5555");

  zmq_msg_t request, reply;

  msgpack_sbuffer sbuf;
  msgpack_sbuffer_init (&sbuf);

  msgpack_zone mempool;
  msgpack_zone_init(&mempool, 2048);

  msgpack_packer mpkg;
  msgpack_object deserialized;

  while (1) {

    zmq_msg_init (&request);
    zmq_recv (responder, &request, 0);

    msgpack_unpack (zmq_msg_data(&request), zmq_msg_size(&request),
        NULL, &mempool, &deserialized);

    msg_info (deserialized, "Recieved\t\t");

    zmq_msg_close (&request);

    sleep (1);

    msgpack_packer_init (&mpkg, &sbuf, msgpack_sbuffer_write);

    msgpack_pack_array (&mpkg, 2);
    msgpack_pack_int (&mpkg, -1);
    msgpack_pack_str (&mpkg, "/i/am/a/server/");

    zmq_msg_init_size (&reply, sbuf.size);

    memcpy (zmq_msg_data (&reply), sbuf.data, sbuf.size);

    msgpack_unpack (sbuf.data, sbuf.size,
        NULL, &mempool, &deserialized);

    msg_info (deserialized, "Sending Reply\t\t");

    zmq_send (responder, &reply, 0);
    zmq_msg_close (&reply);

  }

  msgpack_zone_destroy(&mempool);
  msgpack_sbuffer_destroy(&sbuf);

  zmq_close (responder);
  zmq_term (context);
  return 0;
}