Linux C++开发中如何进行网络编程

在 Linux 中进行 C++ 网络编程，通常需要使用套接字（socket）库

1. 包含头文件：

#include <iostream>
#include <string>
#include <cstring>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>

2. 创建套接字：

int sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
    std::cerr << "Error creating socket" << std::endl;
    return 1;
}

3. 配置服务器地址：

struct sockaddr_in server_addr;
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(8080);
inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

4. 连接到服务器：

if (connect(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
    std::cerr << "Error connecting to server" << std::endl;
    return 1;
}

5. 向服务器发送数据：

std::string message = "Hello, Server!";
if (send(sockfd, message.c_str(), message.size(), 0) < 0) {
    std::cerr << "Error sending data" << std::endl;
    return 1;
}

6. 从服务器接收数据：

char buffer[1024];
memset(buffer, 0, sizeof(buffer));
int received = recv(sockfd, buffer, sizeof(buffer) - 1, 0);
if (received < 0) {
    std::cerr << "Error receiving data" << std::endl;
    return 1;
}
std::string response(buffer);

7. 关闭套接字：

close(sockfd);

8. 编写服务器端代码（以相同的方式创建套接字、绑定地址、监听连接、接受连接、发送和接收数据）：

int server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (server_sockfd < 0) {
    std::cerr << "Error creating server socket" << std::endl;
    return 1;
}

struct sockaddr_in server_addr;
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(8080);
inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

if (bind(server_sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
    std::cerr << "Error binding server address" << std::endl;
    return 1;
}

if (listen(server_sockfd, 10) < 0) {
    std::cerr << "Error listening on server" << std::endl;
    return 1;
}

struct sockaddr_in client_addr;
memset(&client_addr, 0, sizeof(client_addr));
socklen_t client_addr_size = sizeof(client_addr);
int client_sockfd = accept(server_sockfd, (struct sockaddr*)&client_addr, &client_addr_size);
if (client_sockfd < 0) {
    std::cerr << "Error accepting client connection" << std::endl;
    return 1;
}

std::string message = "Hello, Client!";
if (send(client_sockfd, message.c_str(), message.size(), 0) < 0) {
    std::cerr << "Error sending data to client" << std::endl;
    return 1;
}

char buffer[1024];
memset(buffer, 0, sizeof(buffer));
int received = recv(client_sockfd, buffer, sizeof(buffer) - 1, 0);
if (received < 0) {
    std::cerr << "Error receiving data from client" << std::endl;
    return 1;
}
std::string response(buffer);

close(client_sockfd);
close(server_sockfd);

9. 编译和运行代码：

g++ -o server server.cpp
g++ -o client client.cpp
./server
./client

这个简单的示例展示了如何在 Linux 上使用 C++ 进行基本的网络编程。实际应用中，你可能需要处理错误、使用多线程或多进程处理多个客户端连接等。