Zeromq: How to access tcp message in c++
c++, tcp, zeromq
Solution
The hello world example goes only half way and outputs the hard-coded values:
std::cout << "Received Hello" << std::endl;
Printing the actual response can be done as follows:
zmq::message_t reply;
socket.recv (&reply);
std::string rpl = std::string(static_cast<char*>(reply.data()), reply.size());
std::cout << rpl << std::endl;
There are some other useful examples in zhelpers.hpp.
Problem
I am a new-by to ZeroMQ and make my way through the C++ hello-world example of the echo client-server pattern (Request-Reply). The server looks like: ``` // // Hello World server in C++ // Binds REP socket to tcp://*:5555 // Expects "Hello" from client, replies with "World" // #include <zmq.hpp> #include <string> #include <iostream> #include <unistd.h> int main () { // Prepare our context and socket zmq::context_t context (1); zmq::socket_t socket (context, ZMQ_REP); socket.bind ("tcp://*:5555"); while (true) { zmq::message_t request; // Wait for next request from client socket.recv (&request); std::cout << "Received Hello" << std::endl; // Do some 'work' sleep (1); // Send reply back to client zmq::message_t reply (5); memcpy ((void *) reply.data (), "World", 5); socket.send (reply); } return 0; } ``` Now my question: How can I access / read the real data that socket.recv() ? Trying: ``` std::cout << request << std::endl; ``` resulted in an error message: ``` error: no match for ‘operator<<’ in ‘std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&) (& std::cout)), ((const char*)"Received Hello")) << request’ ``` The same goes for the client side that is sending the message. I don't find a way to display the real message...