c++中socket通信例子

在C++中，Socket通信通常用于网络应用程序，比如客户端服务器模型。下面是一个简单的TCP套接字通信的例子，展示了一个基础的服务器如何接收客户端的消息：

#include <iostream>
#include <sys/socket.h> // For socket functions
#include <netinet/in.h>  // For Internet address structures
#include <arpa/inet.h>   // For inet_pton function
#include <unistd.h>      // For read and write

// Server code
int main() {
    int server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket == -1) {
        std::cerr << "Failed to create socket" << std::endl;
        return 1;
    }

    sockaddr_in server_addr;
    server_addr.sin_family = AF_INET;           // IPv4
    server_addr.sin_port = htons(8000);         // Port number, in network byte order
    inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

    bind(server_socket, (sockaddr*)&server_addr, sizeof(server_addr));
    listen(server_socket, 5);                    // Maximum of 5 pending connections

    sockaddr_in client_addr;
    socklen_t client_len = sizeof(client_addr);
    int client_socket = accept(server_socket, (sockaddr*)&client_addr, &client_len);

    char buffer[1024];
    while (true) {                              // Infinite loop for receiving messages
        size_t bytes_received = recv(client_socket, buffer, sizeof(buffer), 0);
        if (bytes_received > 0) {
            std::cout << "Client says: " << buffer << std::endl;
            send(client_socket, "Echo received", strlen("Echo received"), 0); // Send reply
        } else if (bytes_received == 0) {
            std::cout << "Client disconnected" << std::endl;
            break;
        } else {
            perror("Error reading from client");
            break;
        }
    }

    close(client_socket);
    close(server_socket);
    return 0;
}

// Client code (not shown here, but similar)
int main() {
    // Create a socket, connect to the server, and send/receive data
    // ...
    return 0;
}

在这个例子中，服务器创建一个监听套接字，等待客户端连接。当有客户端连接并发送数据时，服务器接收数据，打印出来，并回送一个简单的确认消息。

注意这只是一个基本示例，实际应用中需要处理更多的细节，如错误检查、线程安全以及网络连接关闭等。