在Linux下,C++可以使用多种网络库来进行网络编程。以下是一些常用的网络库及其基本用法:
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <iostream>
int main() {
int server_fd, new_socket;
struct sockaddr_in address;
int opt = 1;
int addrlen = sizeof(address);
// 创建socket文件描述符
if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
perror("socket failed");
exit(EXIT_FAILURE);
}
// 设置socket选项
if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
perror("setsockopt");
exit(EXIT_FAILURE);
}
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(8080);
// 绑定socket到地址
if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
perror("bind failed");
exit(EXIT_FAILURE);
}
// 监听连接
if (listen(server_fd, 3) < 0) {
perror("listen");
exit(EXIT_FAILURE);
}
// 接受连接
if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
perror("accept");
exit(EXIT_FAILURE);
}
// 读取数据
char buffer[1024] = {0};
read(new_socket, buffer, 1024);
std::cout << buffer << std::endl;
// 发送数据
send(new_socket, "Hello from server", 17, 0);
// 关闭socket
close(new_socket);
close(server_fd);
return 0;
}
#include <boost/asio.hpp>
#include <iostream>
using boost::asio::ip::tcp;
int main() {
try {
boost::asio::io_context io_context;
tcp::acceptor acceptor(io_context, tcp::endpoint(tcp::v4(), 8080));
tcp::socket socket(io_context);
// 等待客户端连接
acceptor.accept(socket);
// 读取数据
char buffer[1024] = {0};
boost::system::error_code error;
size_t bytes_transferred = boost::asio::read(socket, boost::asio::buffer(buffer), error);
if (!error) {
std::cout << "Received: " << buffer << std::endl;
}
// 发送数据
const char* response = "Hello from Boost.Asio";
boost::asio::write(socket, boost::asio::buffer(response, strlen(response)));
// 关闭socket
socket.close();
} catch (std::exception& e) {
std::cerr << "Exception: " << e.what() << std::endl;
}
return 0;
}
#include <curl/curl.h>
#include <iostream>
#include <string>
size_t WriteCallback(void* contents, size_t size, size_t nmemb, void* userp) {
((std::string*)userp)->append((char*)contents, size * nmemb);
return size * nmemb;
}
int main() {
CURL* curl;
CURLcode res;
std::string readBuffer;
curl_global_init(CURL_GLOBAL_DEFAULT);
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
res = curl_easy_perform(curl);
if(res != CURLE_OK) {
std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
} else {
std::cout << readBuffer << std::endl;
}
curl_easy_cleanup(curl);
}
curl_global_cleanup();
return 0;
}
在使用这些库之前,你需要确保它们已经安装在你的Linux系统上。对于Boost.Asio和libcurl,你可以使用包管理器来安装它们,例如在Debian或Ubuntu上:
sudo apt-get install libboost-all-dev
sudo apt-get install libcurl4-openssl-dev
编译上述示例代码时,你需要链接相应的库。例如,对于Boost.Asio示例,你可以使用以下命令:
g++ -o asio_example asio_example.cpp -lboost_system -lpthread
对于libcurl示例:
g++ -o curl_example curl_example.cpp -lcurl
请根据你的具体需求选择合适的网络库,并参考相应的文档进行编程。