使用C语言设计基于UDP的简易聊天室代码

以下是使用C语言设计基于UDP的简易聊天室的代码示例：

服务器端代码：

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

#define BUF_SIZE 1024

// 客户端信息结构体
typedef struct {
    struct sockaddr_in addr;
    int connfd;
} client_info;

// 客户端信息列表
client_info *clients[10];
int num_clients = 0;

// UDP Socket对象和地址信息
int server_socket;
struct sockaddr_in server_addr;

// 发送数据的线程函数
void *send_data(void *arg) {
    char buffer[BUF_SIZE];
    while (1) {
        // 从标准输入获取数据
        fgets(buffer, BUF_SIZE, stdin);
        // 将数据发送给所有客户端
        for (int i = 0; i < num_clients; i++) {
            sendto(server_socket, buffer, strlen(buffer), 0, (struct sockaddr *)&(clients[i]->addr), sizeof(clients[i]->addr));
        }
    }
    return NULL;
}

// 接收数据的线程函数
void *recv_data(void *arg) {
    char buffer[BUF_SIZE];
    while (1) {
        // 接收数据报
        struct sockaddr_in client_addr;
        socklen_t client_addr_len = sizeof(client_addr);
        int n = recvfrom(server_socket, buffer, BUF_SIZE, 0, (struct sockaddr *)&client_addr, &client_addr_len);
        if (n > 0) {
            buffer[n] = '\0';
            printf("%s:%d说：%s", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), buffer);
            // 转发数据给所有客户端
            for (int i = 0; i < num_clients; i++) {
                if (memcmp(&client_addr, &clients[i]->addr, sizeof(client_addr)) != 0) {
                    sendto(server_socket, buffer, strlen(buffer), 0, (struct sockaddr *)&(clients[i]->addr), sizeof(clients[i]->addr));
                }
            }
        }
    }
    return NULL;
}

int main(int argc, char *argv[]) {
    // 创建UDP Socket对象
    server_socket = socket(AF_INET, SOCK_DGRAM, 0);
    if (server_socket < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 设置地址信息
    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(8888);

    // 绑定地址信息
    if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 创建发送数据的线程
    pthread_t send_thread;
    if (pthread_create(&send_thread, NULL, send_data, NULL) != 0) {
        perror("pthread_create");
        exit(EXIT_FAILURE);
    }

    // 创建接收数据的线程
    pthread_t recv_thread;
    if (pthread_create(&recv_thread, NULL, recv_data, NULL) != 0) {
        perror("pthread_create");
        exit(EXIT_FAILURE);
    }

    // 接收客户端连接
    while (1) {
        struct sockaddr_in client_addr;
        socklen_t client_addr_len = sizeof(client_addr);
        char buffer[BUF_SIZE];
        int n = recvfrom(server_socket, buffer, BUF_SIZE, 0, (struct sockaddr *)&client_addr, &client_addr_len);
        if (n > 0) {
            buffer[n] = '\0';
            int already_connected = 0;
            // 检查客户端是否已经连接
            for (int i = 0; i < num_clients; i++) {
                if (memcmp(&client_addr, &clients[i]->addr, sizeof(client_addr)) == 0) {
                    already_connected = 1;
                    break;
                }
            }
            if (!already_connected) {
                // 添加新的客户端信息到列表中
                client_info *info = (client_info *)malloc(sizeof(client_info));
                info->addr = client_addr;
                info->connfd = server_socket;
                clients[num_clients++] = info;
                printf("%s:%d已连接\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
            }
        }
    }

    return 0;
}

客户端代码：

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

#define BUF_SIZE 1024

// UDP Socket对象和地址信息
int client_socket;
struct sockaddr_in server_addr;

// 发送数据的线程函数
void *send_data(void *arg) {
    char buffer[BUF_SIZE];
    while (1) {
        // 从标准输入获取数据
        fgets(buffer, BUF_SIZE, stdin);
        // 将数据发送到服务器
        sendto(client_socket, buffer, strlen(buffer), 0, (struct sockaddr *)&server_addr, sizeof(server_addr));
    }
    return NULL;
}

// 接收数据的线程函数
void *recv_data(void *arg) {
    char buffer[BUF_SIZE];
    while (1) {
        // 接收数据报
        struct sockaddr_in server_addr;
        socklen_t server_addr_len = sizeof(server_addr);
        int n = recvfrom(client_socket, buffer, BUF_SIZE, 0, (struct sockaddr *)&server_addr, &server_addr_len);
        if (n > 0) {
            buffer[n] = '\0';
            printf("%s:%d说：%s", inet_ntoa(server_addr.sin_addr), ntohs(server_addr.sin_port), buffer);
        }
    }
    return NULL;
}

int main(int argc, char *argv[]) {
    // 创建UDP Socket对象
    client_socket = socket(AF_INET, SOCK_DGRAM, 0);
    if (client_socket < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址信息
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(8888);

    // 创建发送数据的线程
    pthread_t send_thread;
    if (pthread_create(&send_thread, NULL, send_data, NULL) != 0) {
        perror("pthread_create");
        exit(EXIT_FAILURE);
    }

    // 创建接收数据的线程
    pthread_t recv_thread;
    if (pthread_create(&recv_thread, NULL, recv_data, NULL) != 0) {
        perror("pthread_create");
        exit(EXIT_FAILURE);
    }

    // 等待线程结束
    pthread_join(send_thread, NULL);
    pthread_join(recv_thread, NULL);

    return 0;
}

以上是使用C语言设计基于UDP的简易聊天室的代码示例，您可以根据需求进行相应的修改和完善。需要注意的是，这只是一个简单的示例，实际应用中还需要考虑一些其他的因素，比如数据的安全性、数据的可靠性等。