C++ 套接字通信：发送和接收程序示例

本文提供 C++ 代码示例，演示如何使用套接字编程实现发送和接收数据。包括创建套接字、连接服务器、发送数据、绑定端口、监听连接、接收数据等步骤。

发送程序

#include <iostream>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <cstring>

int main() {
    // 创建套接字
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        std::cerr << 'Failed to create socket' << std::endl;
        return 1;
    }

    // 设置服务器地址
    sockaddr_in serverAddress{};
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_port = htons(12345);  // 设置服务器监听的端口号
    inet_pton(AF_INET, '127.0.0.1', &(serverAddress.sin_addr));

    // 连接到服务器
    if (connect(sock, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) == -1) {
        std::cerr << 'Failed to connect to server' << std::endl;
        return 1;
    }

    // 发送数据
    std::string message = 'Hello, server!';
    if (send(sock, message.c_str(), message.size(), 0) == -1) {
        std::cerr << 'Failed to send data' << std::endl;
        return 1;
    }

    // 关闭套接字
    close(sock);

    return 0;
}

接收程序

#include <iostream>
#include <sys/socket.h>
#include <netinet/in.h>
#include <cstring>

int main() {
    // 创建套接字
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        std::cerr << 'Failed to create socket' << std::endl;
        return 1;
    }

    // 设置服务器地址
    sockaddr_in serverAddress{};
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_port = htons(12345);  // 设置服务器监听的端口号
    serverAddress.sin_addr.s_addr = INADDR_ANY;

    // 绑定套接字到地址
    if (bind(sock, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) == -1) {
        std::cerr << 'Failed to bind socket' << std::endl;
        return 1;
    }

    // 监听连接
    if (listen(sock, 1) == -1) {
        std::cerr << 'Failed to listen for connections' << std::endl;
        return 1;
    }

    // 接受连接
    sockaddr_in clientAddress{};
    socklen_t clientAddressLength = sizeof(clientAddress);
    int clientSock = accept(sock, (struct sockaddr *)&clientAddress, &clientAddressLength);
    if (clientSock == -1) {
        std::cerr << 'Failed to accept connection' << std::endl;
        return 1;
    }

    // 接收数据
    char buffer[1024];
    int bytesRead = recv(clientSock, buffer, sizeof(buffer), 0);
    if (bytesRead == -1) {
        std::cerr << 'Failed to receive data' << std::endl;
        return 1;
    }

    // 打印接收到的数据
    std::cout << 'Received data: ' << buffer << std::endl;

    // 关闭套接字
    close(clientSock);
    close(sock);

    return 0;
}

以上代码分别实现了套接字通信的发送和接收程序。发送程序连接到指定的服务器地址和端口，发送数据后关闭套接字。接收程序绑定到指定的端口，接受连接后接收数据并打印，然后关闭套接字。