用c语言写一个聊天软件

写一个完整的聊天软件需要考虑很多方面，包括网络通信、用户界面、聊天记录存储等。下面是一个简单的示例，用C语言实现一个基于TCP协议的简单聊天程序。

1. 服务器端代码

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

#define BUF_SIZE 100
#define MAX_CLIENTS 10

typedef struct {
    int socket;
    struct sockaddr_in address;
    char name[BUF_SIZE];
} client_info;

client_info clients[MAX_CLIENTS];
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void *handle_client(void *arg)
{
    int client_socket = *(int *)arg;
    char buf[BUF_SIZE];
    char message[BUF_SIZE + BUF_SIZE + 2];
    int i;

    // 接收客户端的名字
    if (recv(client_socket, buf, BUF_SIZE, 0) <= 0) {
        close(client_socket);
        return NULL;
    }
    strncpy(clients[client_socket].name, buf, BUF_SIZE - 1);

    // 广播欢迎消息
    sprintf(message, "%s joined the chat.\n", clients[client_socket].name);
    pthread_mutex_lock(&mutex);
    for (i = 0; i < MAX_CLIENTS; i++) {
        if (clients[i].socket > 0 && clients[i].socket != client_socket) {
            send(clients[i].socket, message, strlen(message), 0);
        }
    }
    pthread_mutex_unlock(&mutex);

    while (1) {
        int bytes_received = recv(client_socket, buf, BUF_SIZE, 0);
        if (bytes_received <= 0) {
            // 客户端断开连接
            sprintf(message, "%s left the chat.\n", clients[client_socket].name);
            pthread_mutex_lock(&mutex);
            for (i = 0; i < MAX_CLIENTS; i++) {
                if (clients[i].socket > 0 && clients[i].socket != client_socket) {
                    send(clients[i].socket, message, strlen(message), 0);
                }
            }
            pthread_mutex_unlock(&mutex);
            break;
        }
        // 发送消息给所有客户端
        sprintf(message, "%s: %s", clients[client_socket].name, buf);
        pthread_mutex_lock(&mutex);
        for (i = 0; i < MAX_CLIENTS; i++) {
            if (clients[i].socket > 0 && clients[i].socket != client_socket) {
                send(clients[i].socket, message, strlen(message), 0);
            }
        }
        pthread_mutex_unlock(&mutex);
    }

    // 移除客户端信息
    pthread_mutex_lock(&mutex);
    for (i = 0; i < MAX_CLIENTS; i++) {
        if (clients[i].socket == client_socket) {
            clients[i].socket = -1;
            break;
        }
    }
    pthread_mutex_unlock(&mutex);

    close(client_socket);
    return NULL;
}

int main(int argc, char *argv[])
{
    int server_socket, client_socket;
    struct sockaddr_in server_address, client_address;
    socklen_t client_address_len;
    pthread_t thread_id;
    int i;

    // 创建服务器端套接字
    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 绑定地址和端口
    memset(&server_address, 0, sizeof(server_address));
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = INADDR_ANY;
    server_address.sin_port = htons(8888);
    if (bind(server_socket, (struct sockaddr *)&server_address, sizeof(server_address)) == -1) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 监听连接请求
    if (listen(server_socket, MAX_CLIENTS) == -1) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    // 初始化客户端列表
    for (i = 0; i < MAX_CLIENTS; i++) {
        clients[i].socket = -1;
    }

    // 等待客户端连接
    while (1) {
        client_address_len = sizeof(client_address);
        client_socket = accept(server_socket, (struct sockaddr *)&client_address, &client_address_len);
        if (client_socket == -1) {
            perror("accept");
            continue;
        }
        // 添加客户端信息
        for (i = 0; i < MAX_CLIENTS; i++) {
            if (clients[i].socket == -1) {
                clients[i].socket = client_socket;
                clients[i].address = client_address;
                strcpy(clients[i].name, "");
                break;
            }
        }
        if (i == MAX_CLIENTS) {
            printf("Too many clients\n");
            close(client_socket);
            continue;
        }
        // 创建线程处理客户端连接
        pthread_create(&thread_id, NULL, handle_client, (void *)&client_socket);
    }

    close(server_socket);
    return 0;
}

2. 客户端代码

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

#define BUF_SIZE 100

void *receive_message(void *arg)
{
    int socket = *(int *)arg;
    char buf[BUF_SIZE];

    while (1) {
        int bytes_received = recv(socket, buf, BUF_SIZE, 0);
        if (bytes_received <= 0) {
            printf("Server disconnected\n");
            break;
        }
        printf("%s", buf);
    }

    close(socket);
    exit(EXIT_SUCCESS);
}

int main(int argc, char *argv[])
{
    int socket_fd;
    struct sockaddr_in server_address;
    pthread_t thread_id;
    char name[BUF_SIZE];
    char message[BUF_SIZE];

    // 创建客户端套接字
    socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_fd == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 连接服务器
    memset(&server_address, 0, sizeof(server_address));
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_address.sin_port = htons(8888);
    if (connect(socket_fd, (struct sockaddr *)&server_address, sizeof(server_address)) == -1) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    // 输入名字
    printf("Enter your name: ");
    fgets(name, BUF_SIZE, stdin);
    name[strlen(name) - 1] = '\0';
    send(socket_fd, name, strlen(name), 0);

    // 创建接收消息的线程
    pthread_create(&thread_id, NULL, receive_message, (void *)&socket_fd);

    // 发送消息
    while (1) {
        fgets(message, BUF_SIZE, stdin);
        if (send(socket_fd, message, strlen(message), 0) == -1) {
            perror("send");
            break;
        }
    }

    close(socket_fd);
    return 0;
}

以上代码仅提供参考，具体实现还需要根据实际需求进行修改和完善。