c++写一段tcp心跳包代码

在C++中，TCP心跳包通常用于检查连接是否依然活跃。这里是一个简单的示例，展示如何创建一个发送心跳包的基本客户端和服务器程序。这个例子使用了`boost::asio`库来进行网络编程：

#include <boost/asio.hpp>
#include <iostream>

// 心跳数据
const std::string HEARTBEAT = "Hello, Heartbeat!";

// 客户端函数
void send_heartbeat(tcp::socket& socket) {
    boost::array<char, HEARTBEAT.size() + 1> buffer;
    std::copy(HEARTBEAT.begin(), HEARTBEAT.end(), buffer.begin());
    buffer[buffer.size() - 1] = '\0'; // 添加结束符

    boost::asio::write(socket, boost::asio::buffer(buffer));
}

// 服务器函数（接收并回应心跳）
void handle_heartbeat(tcp::socket& socket) {
    char data[HEARTBEAT.size() + 1];
    size_t len = boost::asio::read(socket, boost::asio::buffer(data), HEARTBEAT.size());

    if (len == HEARTBEAT.size()) {
        std::cout << "Received heartbeat, responding..." << std::endl;
        send_heartbeat(socket); // 发送回应
    } else {
        std::cerr << "Invalid heartbeat received." << std::endl;
    }
}

int main() {
    try {
        boost::asio::io_context io;

        tcp::resolver resolver(io);
        tcp::resolver::results_type endpoints = resolver.resolve("localhost", "8080");

        for (auto endpoint : endpoints) {
            tcp::socket socket(io);
            boost::asio::connect(socket, endpoint);

            std::cout << "Connected to server at " << endpoint.address() << ':' << endpoint.port() << std::endl;

            send_heartbeat(socket); // 发送初始心跳包
            handle_heartbeat(socket); // 开始处理心跳循环
        }

        io.run();
    }
    catch (std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}