Hello World server in C

//
// Hello World server
// Binds REP socket to tcp://*:5555
// Expects "Hello" from client, replies with "World"
//
#include <zmq.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

int main (void)
{
void *context = zmq_ctx_new ();

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

while (true) {
// Wait for next request from client
zmq_msg_t request;
zmq_msg_init (&request);
zmq_msg_recv (&request, responder, 0);
printf ("Received Hello\n");
zmq_msg_close (&request);

// Do some 'work'
sleep (1);

// Send reply back to client
zmq_msg_t reply;
zmq_msg_init_size (&reply, 5);
memcpy (zmq_msg_data (&reply), "World", 5);
zmq_msg_send (&reply, responder, 0);
zmq_msg_close (&reply);
}
// We never get here but if we did, this would be how we end
zmq_close (responder);
zmq_ctx_destroy (context);
return 0;
}