使用Linux系统用C语言来编写一个用web服务器构建一个多人聊天室的代码

以下是基于 Linux 系统用 C 语言编写的一个用 web 服务器构建多人聊天室的代码示例：

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

#define MAX_CLIENTS 100
#define MAX_MSG_LEN 1024
#define PORT 8000

int client_sockets[MAX_CLIENTS];
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void *handle_client(void *arg) {
    int client_sock = *((int *)arg);
    char msg[MAX_MSG_LEN];
    ssize_t bytes_read;

    while ((bytes_read = recv(client_sock, msg, MAX_MSG_LEN, 0)) > 0) {
        // 广播消息给所有客户端
        pthread_mutex_lock(&mutex);
        for (int i = 0; i < MAX_CLIENTS; i++) {
            if (client_sockets[i] > 0 && client_sockets[i] != client_sock) {
                send(client_sockets[i], msg, bytes_read, 0);
            }
        }
        pthread_mutex_unlock(&mutex);
    }

    // 客户端断开连接
    pthread_mutex_lock(&mutex);
    for (int i = 0; i < MAX_CLIENTS; i++) {
        if (client_sockets[i] == client_sock) {
            client_sockets[i] = 0;
            break;
        }
    }
    pthread_mutex_unlock(&mutex);

    close(client_sock);
    pthread_exit(NULL);
}

int main() {
    int server_sock, client_sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    pthread_t thread_id;

    // 创建 socket
    if ((server_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 绑定端口
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);
    if (bind(server_sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 监听端口
    if (listen(server_sock, MAX_CLIENTS) == -1) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    // 循环接受客户端连接
    while ((client_sock = accept(server_sock, (struct sockaddr *)&client_addr, &client_addr_len)) > 0) {
        // 将客户端 socket 加入数组
        pthread_mutex_lock(&mutex);
        for (int i = 0; i < MAX_CLIENTS; i++) {
            if (client_sockets[i] == 0) {
                client_sockets[i] = client_sock;
                break;
            }
        }
        pthread_mutex_unlock(&mutex);

        // 创建线程处理客户端消息
        if (pthread_create(&thread_id, NULL, handle_client, (void *)&client_sock) != 0) {
            perror("pthread_create");
            exit(EXIT_FAILURE);
        }
    }

    if (client_sock == -1) {
        perror("accept");
        exit(EXIT_FAILURE);
    }

    close(server_sock);
    exit(EXIT_SUCCESS);
}

上述代码通过创建一个 socket，绑定端口，监听端口，循环接受客户端连接的方式来实现聊天室的服务端。客户端连接后，将其 socket 加入数组，然后创建线程处理客户端消息，收到消息后将消息广播给所有客户端。