tcp聊天室私聊群聊c

以下是一个基于TCP的聊天室的私聊和群聊功能的C代码示例：

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

#define MAX_CLIENTS 10
#define BUFFER_SIZE 1024

int main() {
    int serverSocket, clientSockets[MAX_CLIENTS];
    struct sockaddr_in serverAddress, clientAddress;
    char buffer[BUFFER_SIZE];

    // 创建服务器套接字
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket == -1) {
        perror("Failed to create socket");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址和端口
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = INADDR_ANY;
    serverAddress.sin_port = htons(8888);

    // 绑定服务器套接字到指定地址和端口
    if (bind(serverSocket, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) < 0) {
        perror("Failed to bind socket");
        exit(EXIT_FAILURE);
    }

    // 监听连接请求
    if (listen(serverSocket, MAX_CLIENTS) < 0) {
        perror("Failed to listen for connections");
        exit(EXIT_FAILURE);
    }

    printf("Server started. Waiting for connections...\n");

    fd_set readfds;
    int maxSd, activity, newSocket, i, valread, sd;
    int maxClients = MAX_CLIENTS;
    int clientSd;
    int clientConnected[MAX_CLIENTS] = {0};
    char *message = "Welcome to the chat room!\n";

    while (1) {
        // 清空文件描述符集合
        FD_ZERO(&readfds);

        // 添加服务器套接字到文件描述符集合
        FD_SET(serverSocket, &readfds);
        maxSd = serverSocket;

        // 添加客户端套接字到文件描述符集合
        for (i = 0; i < maxClients; i++) {
            sd = clientSockets[i];

            if (sd > 0) {
                FD_SET(sd, &readfds);
            }

            if (sd > maxSd) {
                maxSd = sd;
            }
        }

        // 等待活动套接字
        activity = select(maxSd + 1, &readfds, NULL, NULL, NULL);
        if ((activity < 0) && (errno != EINTR)) {
            printf("select error");
        }

        // 如果有新的连接请求
        if (FD_ISSET(serverSocket, &readfds)) {
            if ((newSocket = accept(serverSocket, (struct sockaddr *)&clientAddress, (socklen_t *)&clientAddress)) < 0) {
                perror("Failed to accept connection");
                exit(EXIT_FAILURE);
            }

            printf("New connection, socket fd is %d, ip is : %s, port : %d\n", newSocket, inet_ntoa(clientAddress.sin_addr), ntohs(clientAddress.sin_port));

            // 发送欢迎消息给新连接的客户端
            if (send(newSocket, message, strlen(message), 0) != strlen(message)) {
                perror("Failed to send welcome message");
            }

            // 添加新的套接字到客户端套接字数组
            for (i = 0; i < maxClients; i++) {
                if (clientSockets[i] == 0) {
                    clientSockets[i] = newSocket;
                    printf("Adding to list of sockets as %d\n", i);
                    break;
                }
            }
        }

        // 处理客户端的消息
        for (i = 0; i < maxClients; i++) {
            clientSd = clientSockets[i];

            if (FD_ISSET(clientSd, &readfds)) {
                // 读取客户端的消息
                valread = read(clientSd, buffer, BUFFER_SIZE);
                buffer[valread] = '\0';

                // 判断客户端是否断开连接
                if (valread == 0) {
                    getpeername(clientSd, (struct sockaddr *)&clientAddress, (socklen_t *)&clientAddress);
                    printf("Host disconnected, ip %s, port %d\n", inet_ntoa(clientAddress.sin_addr), ntohs(clientAddress.sin_port));

                    // 关闭客户端套接字并从数组中移除
                    close(clientSd);
                    clientSockets[i] = 0;
                } else {
                    // 判断客户端的消息类型
                    if (strncmp(buffer, "获取用户列表", 6) == 0) {
                        // 发送在线用户列表给客户端
                        char userList[BUFFER_SIZE] = "在线用户列表:\n";
                        for (int j = 0; j < maxClients; j++) {
                            if (clientSockets[j] != 0) {
                                strcat(userList, inet_ntoa(clientAddress.sin_addr));
                                strcat(userList, "\n");
                            }
                        }
                        send(clientSd, userList, strlen(userList), 0);
                    } else if (strncmp(buffer, "私聊", 2) == 0) {
                        // 解析私聊目标用户名
                        char *targetUsername = strtok(buffer, " ");
                        targetUsername = strtok(NULL, " ");

                        // 解析私聊消息内容
                        char *messageContent = strtok(NULL, "");

                        // 查找目标用户的套接字
                        int targetSd = -1;
                        for (int j = 0; j < maxClients; j++) {
                            if (clientSockets[j] != 0 && strcmp(inet_ntoa(clientAddress.sin_addr), targetUsername) == 0) {
                                targetSd = clientSockets[j];
                                break;
                            }
                        }

                        // 发送私聊消息给目标用户
                        if (targetSd != -1) {
                            char privateMessage[BUFFER_SIZE];
                            sprintf(privateMessage, "来自 %s 的私聊消息: %s", inet_ntoa(clientAddress.sin_addr), messageContent);
                            send(targetSd, privateMessage, strlen(privateMessage), 0);
                        } else {
                            char errorMessage[BUFFER_SIZE] = "目标用户不存在或不在线";
                            send(clientSd, errorMessage, strlen(errorMessage), 0);
                        }
                    } else if (strncmp(buffer, "退出私聊", 6) == 0) {
                        // 退出私聊模式
                        char exitMessage[BUFFER_SIZE] = "已退出私聊模式";
                        send(clientSd, exitMessage, strlen(exitMessage), 0);
                    } else {
                        // 群聊消息，将消息发送给所有在线用户
                        for (int j = 0; j < maxClients; j++) {
                            if (clientSockets[j] != 0 && clientSockets[j] != clientSd) {
                                send(clientSockets[j], buffer, strlen(buffer), 0);
                            }
                        }
                    }
                }
            }
        }
    }

    return 0;
}