Zeromq:如何在c ++中访问tcp消息

Question

我是ZeroMQ的新手,并通过回显客户端 - 服务器模式(Request-Reply)的C++ hello-world示例.服务器看起来像:

//
// 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;
}

现在我的问题:如何访问/读取socket.recv()的真实数据？试:

 std::cout << request << std::endl;

导致错误消息:

 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’

发送消息的客户端也是如此.我找不到显示真实信息的方法......

Answer 1

hello world示例只进行了一半并输出了硬编码值:

std::cout << "Received Hello" << std::endl;

打印实际响应可以按如下方式进行:

zmq::message_t reply;
socket.recv (&reply);

std::string rpl = std::string(static_cast<char*>(reply.data()), reply.size());

std::cout << rpl << std::endl;

zhelpers.hpp中还有一些其他有用的示例.