用c语言编写一个聊天服务器和聊天的客户端，实现基本的即时聊天功能。服务器在一个端口上进行监听，接收客户端的连接请求；客户端连接到服务器，发布自己的消息；服务器接收客户端的消息并转发给其他客户端。

好的，以下是使用C语言实现基本即时聊天功能的服务器和客户端程序。

服务器程序：

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

#define SERVER_PORT 8888
#define MAX_CLIENTS 10

int client_count = 0;
int client_sockets[MAX_CLIENTS];
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void *handle_client(void *arg) {
    int client_socket = *(int*)arg;
    char buffer[1024];
    int read_size;
    
    while ((read_size = recv(client_socket, buffer, sizeof(buffer), 0)) > 0) {
        buffer[read_size] = '\0';
        printf("Received message: %s", buffer);
        
        pthread_mutex_lock(&mutex);
        
        // 转发消息给其他客户端
        for (int i = 0; i < client_count; i++) {
            if (client_sockets[i] != client_socket) {
                send(client_sockets[i], buffer, strlen(buffer), 0);
            }
        }
        
        pthread_mutex_unlock(&mutex);
    }
    
    // 关闭连接
    close(client_socket);
    
    pthread_mutex_lock(&mutex);
    
    // 从客户端列表中删除
    for (int i = 0; i < client_count; i++) {
        if (client_sockets[i] == client_socket) {
            client_sockets[i] = 0;
            break;
        }
    }
    client_count--;
    
    pthread_mutex_unlock(&mutex);
    
    pthread_exit(NULL);
}

int main() {
    int server_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;

    // 创建socket对象
    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 绑定IP和端口
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(SERVER_PORT);

    if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 开始监听
    if (listen(server_socket, MAX_CLIENTS) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    printf("Server is listening on port %d\n", SERVER_PORT);

    // 等待客户端连接
    while (1) {
        socklen_t client_len = sizeof(client_addr);
        client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &client_len);
        if (client_socket < 0) {
            perror("accept");
            exit(EXIT_FAILURE);
        }

        printf("New client connected: %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
        
        pthread_mutex_lock(&mutex);
        
        // 添加到客户端列表
        for (int i = 0; i < MAX_CLIENTS; i++) {
            if (client_sockets[i] == 0) {
                client_sockets[i] = client_socket;
                client_count++;
                break;
            }
        }
        
        pthread_mutex_unlock(&mutex);
        
        // 创建新线程处理客户端消息
        pthread_t thread;
        if (pthread_create(&thread, NULL, handle_client, (void*)&client_socket) < 0) {
            perror("pthread_create");
            exit(EXIT_FAILURE);
        }
    }

    return 0;
}

客户端程序：

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

#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 8888

int main() {
    int client_socket;
    struct sockaddr_in server_addr;

    // 创建socket对象
    client_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (client_socket < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 连接服务器
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);
    server_addr.sin_port = htons(SERVER_PORT);

    if (connect(client_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    // 发送消息
    char buffer[1024];
    printf("Enter message: ");
    fgets(buffer, sizeof(buffer), stdin);
    send(client_socket, buffer, strlen(buffer), 0);

    // 接收服务器返回的消息
    memset(buffer, 0, sizeof(buffer));
    recv(client_socket, buffer, sizeof(buffer), 0);
    printf("Received message: %s", buffer);

    // 关闭连接
    close(client_socket);

    return 0;
}

这是一个比较基础的聊天服务器和客户端程序，您可以根据自己的需求进行改进和扩展。