用c++实现一个简单的聊天程序要求有1. 使用基于socket的程序设计方法设计聊天客户端和服务器端程序。2.程序至少能够实现传输文字的功能。3.能够实现多人聊天的功能

以下是一个基于socket的简单聊天程序的实现，包括服务器端和客户端代码。这个程序可以实现多人聊天的功能，用户可以通过输入文字进行聊天。

服务器端代码：

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

#define PORT 8080
using namespace std;

int main() {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[1024] = {0};
    vector<int> clients;

    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    if (bind(server_fd, (struct sockaddr*)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    if (listen(server_fd, 3) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    cout << "Waiting for connections..." << endl;

    while (true) {
        if ((new_socket = accept(server_fd, (struct sockaddr*)&address, (socklen_t*)&addrlen)) < 0) {
            perror("accept");
            exit(EXIT_FAILURE);
        }

        clients.push_back(new_socket);

        cout << "New connection: " << inet_ntoa(address.sin_addr) << ":" << ntohs(address.sin_port) << endl;

        send(new_socket, "Welcome to the chatroom!\n", strlen("Welcome to the chatroom!\n"), 0);

        for (int i = 0; i < clients.size(); ++i)
            send(clients[i], "New user joined the chatroom.\n", strlen("New user joined the chatroom.\n"), 0);

        while (true) {
            memset(buffer, 0, sizeof(buffer));
            valread = recv(new_socket, buffer, sizeof(buffer), 0);

            if (strcmp(buffer, "exit\n") == 0) {
                cout << "Connection closed: " << inet_ntoa(address.sin_addr) << ":" << ntohs(address.sin_port) << endl;
                close(new_socket);
                clients.erase(remove(clients.begin(), clients.end(), new_socket), clients.end());
                for (int i = 0; i < clients.size(); ++i)
                    send(clients[i], "User left the chatroom.\n", strlen("User left the chatroom.\n"), 0);
                break;
            }

            for (int i = 0; i < clients.size(); ++i)
                send(clients[i], buffer, strlen(buffer), 0);
        }
    }

    return 0;
}

客户端代码：

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

#define PORT 8080
using namespace std;

int main(int argc, char const *argv[]) {

    int sock = 0, valread;
    struct sockaddr_in serv_addr;
    char buffer[1024] = {0};
    char message[1024];

    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        cout << "\n Socket creation error \n" << endl;
        return -1;
    }

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);

    if (inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr) <= 0) {
        cout << "\nInvalid address/ Address not supported \n" << endl;
        return -1;
    }

    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        cout << "\nConnection Failed \n" << endl;
        return -1;
    }

    while (true) {
        memset(buffer, 0, sizeof(buffer));
        valread = recv(sock, buffer, sizeof(buffer), 0);
        cout << buffer << endl;
        if (strcmp(buffer, "Welcome to the chatroom!\n") == 0)
            continue;
        cout << "Enter message: ";
        fgets(message, 1024, stdin);
        send(sock, message, strlen(message), 0);
        if (strcmp(message, "exit\n") == 0)
            break;
    }
    close(sock);

    return 0;
}

注意，这只是一个简单的示例程序，没有进行错误检查和安全性检查，请不要在生产环境中使用。