C++ 网络编程：使用 Boost.Asio 实现简易 HTTP 客户端

Boost.Asio 简介

Boost.Asio 是一个跨平台的网络和底层 I/O 库，支持同步/异步操作。

同步 HTTP GET 请求

#include <boost/asio.hpp>

#include <iostream>

#include <string>



using boost::asio::ip::tcp;



int main() {

    boost::asio::io_context io;

    tcp::resolver resolver(io);

    tcp::socket socket(io);



    // 解析域名

    auto endpoints = resolver.resolve("httpbin.org", "80");

    boost::asio::connect(socket, endpoints);



    // 发送请求

    std::string request = "GET /get HTTP/1.1\r\nHost: httpbin.org\r\nConnection: close\r\n\r\n";

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



    // 读取响应

    boost::asio::streambuf response;

    boost::asio::read_until(socket, response, "\r\n\r\n");



    std::istream response_stream(&response);

    std::string header;

    while (std::getline(response_stream, header) && header != "\r");



    std::cout << "Response header received" << std::endl;

    return 0;

}

异步示例

socket.async_connect(endpoints, [&](boost::system::error_code ec) {

    if (!ec) {

        socket.async_write_some(boost::asio::buffer(request), callback);

    }

});

io.run();

Boost.Asio 是 C++ 高性能网络编程的首选库，也是 C++20 网络库的基础。