How can I get to the message data in ZMQ using C++? - c++

Question

Within C++ ZMQ, I'm having trouble printing ( or otherwise analyzing ) data, which is pushed to consumers.In Python and scala it works great, but C++ the output is either null or some un-decodable junk.From official helper example:
//I added the printf line:
static std::string s_recv (zmq::socket_t & socket) {
zmq::message_t message;
socket.recv(&message);
printf ("[-] Message: %s\n", (char*)message.data());
return std::string(static_cast<char*>(message.data()), message.size());
}
The following is the context of where s_recv is called from:
int main () { // Official ZMQ Hello World example
zmq::context_t context (1); // Prepare our context and socket
zmq::socket_t socket ( context,
ZMQ_REP // REP-side of a REQ/REP pattern
);
socket.bind ( "tcp://*:5555" );
while (true) {
zmq::message_t request;
// Wait for next request from client
// socket.recv (&request); // commented out to treat as string
s_recv(socket); // added for same reason as above
std::cout << "Received Hello" << std::endl;
sleep(1); // Do some 'work'
zmq::message_t reply (5); // Send reply back to client
memcpy ((void *) reply.data (), "World", 5);
socket.send (reply);
}
return 0;
}
The output:
[-] Message: #
In my non-hello world code, I get output resembling some kind of encoding error, my terminal throws a bunch of "?".
How can I get to the messages in ZMQ using C++?
Edit for more info:
In my non-hello world code, I use PUSH / PULL, not a REQ / REP.
Sample pushing code, same problem with both code bases:
ifstream file(filePath.c_str(), ios::in|ios::binary);
file.read(&chunk_data[0], chunk_size);
memcpy((void*)message.data(), &chunk_data[0], this_chunk_size);
socket.send(message);
Output and binary garbage:
[-] Message: �_�z�