了解基于TCP/IP协议的Socket客户端程序编写（Python/C/C++）。

基于TCP/IP协议的Socket编程是一种网络通信的基础技术，用于创建应用程序间的连接。以下是使用Python、C和C++分别编写Socket客户端的基本步骤：

**Python**:

import socket

def client():
    # 创建socket对象
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    
    # 连接到服务器
    server_address = ('localhost', 12345)  # 服务器地址和端口
    sock.connect(server_address)
    
    # 发送数据
    message = 'Hello, Server!'
    sock.sendall(message.encode('utf-8'))
    
    # 接收响应
    response = sock.recv(1024).decode('utf-8')
    print(f'Received: {response}')
    
    # 关闭连接
    sock.close()

if __name__ == '__main__':
    client()

**C** (使用POSIX sockets):

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>

int main() {
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(12345); // 端口号
    inet_pton(AF_INET, "localhost", &server_addr.sin_addr);

    connect(sock, (struct sockaddr *)&server_addr, sizeof(server_addr));

    char message[] = "Hello, Server!";
    send(sock, message, strlen(message), 0);

    char buffer[1024];
    recv(sock, buffer, sizeof(buffer), 0);
    printf("Received: %s\n", buffer);

    close(sock);
    return 0;
}

**C++**:

#include <iostream>
#include <boost/asio.hpp>

int main() {
    try {
        boost::asio::io_context io_context;
        boost::asio::ip::tcp::socket socket(io_context);
        
        boost::asio::ip::tcp::resolver resolver(io_context);
        boost::asio::ip::tcp::resolver::query query("localhost", "12345");
        boost::asio::ip::tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
        
        socket.connect(*endpoint_iterator);
        
        std::string message = "Hello, Server!";
        boost::asio::write(socket, boost::asio::buffer(message));
        
        boost::array<char, 1024> receive_buffer;
        boost::asio::read(socket, boost::asio::dynamic_buffer(receive_buffer));
        std::cout << "Received: " << std::string(receive_buffer.data(), receive_buffer.size()) << std::endl;

    } catch (std::exception& e) {
        std::cerr << "Exception: " << e.what() << "\n";
    }

    return 0;
}