多人聊天系统模拟c++

多人聊天系统模拟是一个常见的网络编程项目，通常使用C++来实现。这个系统允许多个客户端通过服务器进行实时的文本通信。以下是一个基本的实现思路：

1. **服务器端**：
- **套接字编程**：使用C++的套接字库（如Boost.Asio或原生套接字）来创建服务器端套接字，监听客户端连接。
- **多线程处理**：为每个连接的客户端创建一个独立的线程或使用线程池来处理并发连接。
- **消息广播**：接收来自一个客户端的消息，并将其广播给所有其他连接的客户端。

2. **客户端**：
- **套接字编程**：使用C++的套接字库来创建客户端套接字，连接到服务器。
- **输入输出处理**：从用户那里接收输入，并将其发送到服务器；同时，从服务器接收消息并显示给用户。

以下是一个简单的示例代码，展示了如何实现一个基本的多人聊天系统：

// 服务器端代码 (server.cpp)
#include <iostream>
#include <vector>
#include <thread>
#include <mutex>
#include <string>
#include <cstring>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>

std::vector<int> clients;
std::mutex clients_mutex;

void broadcast_message(const std::string& message, int sender_socket) {
    std::lock_guard<std::mutex> guard(clients_mutex);
    for (int client : clients) {
        if (client != sender_socket) {
            send(client, message.c_str(), message.size(), 0);
        }
    }
}

void handle_client(int client_socket) {
    char buffer[1024];
    while (true) {
        int bytes_received = recv(client_socket, buffer, sizeof(buffer), 0);
        if (bytes_received <= 0) {
            std::cout << "Client disconnected." << std::endl;
            close(client_socket);
            break;
        }
        std::string message(buffer, bytes_received);
        std::cout << "Received message: " << message << std::endl;
        broadcast_message(message, client_socket);
    }
}

int main() {
    int server_socket = socket(AF_INET, SOCK_STREAM, 0);
    sockaddr_in server_address;
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = INADDR_ANY;
    server_address.sin_port = htons(8080);

    bind(server_socket, (sockaddr*)&server_address, sizeof(server_address));
    listen(server_socket, 5);

    std::cout << "Server is listening on port 8080" << std::endl;

    while (true) {
        sockaddr_in client_address;
        socklen_t client_length = sizeof(client_address);
        int client_socket = accept(server_socket, (sockaddr*)&client_address, &client_length);

        {
            std::lock_guard<std::mutex> guard(clients_mutex);
            clients.push_back(client_socket);
        }

        std::thread(handle_client, client_socket).detach();
        std::cout << "New client connected." << std::endl;
    }

    close(server_socket);
    return 0;
}

// 客户端代码 (client.cpp)
#include <iostream>
#include <thread>
#include <string>
#include <cstring>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>

void receive_messages(int client_socket) {
    char buffer[1024];
    while (true) {
        int bytes_received = recv(client_socket, buffer, sizeof(buffer), 0);
        if (bytes_received <= 0) {
            std::cout << "Disconnected from server." << std::endl;
            break;
        }
        std::string message(buffer, bytes_received);
        std::cout << "Received: " << message << std::endl;
    }
}

int main() {
    int client_socket = socket(AF_INET, SOCK_STREAM, 0);
    sockaddr_in server_address;
    server_address.sin_family = AF_INET;
    server_address.sin_port = htons(8080);
    server_address.sin_addr.s_addr = inet_addr("127.0.0.1");

    connect(client_socket, (sockaddr*)&server_address, sizeof(server_address));

    std::thread(receive_messages, client_socket).detach();

    std::string message;
    while (true) {
        std::getline(std::cin, message);
        send(client_socket, message.c_str(), message.size(), 0);
    }

    close(client_socket);
    return 0;
}