使用WINSOCK 通讯编写一个C/S通讯程序

好的，下面是一个简单的C/S通讯程序的代码示例，使用Winsock库进行通讯：

Server端代码：

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib") // 链接库文件

int main() {
    WSADATA wsaData;
    SOCKET serverSocket, clientSocket;
    SOCKADDR_IN serverAddr, clientAddr;
    int clientAddrLen = sizeof(clientAddr);
    int ret;

    // 初始化Winsock库
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock.\n");
        return 1;
    }

    // 创建套接字
    serverSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (serverSocket == INVALID_SOCKET) {
        printf("Failed to create socket.\n");
        WSACleanup();
        return 1;
    }

    // 绑定套接字到本地IP地址和端口
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);
    serverAddr.sin_port = htons(8888);
    ret = bind(serverSocket, (SOCKADDR*)&serverAddr, sizeof(serverAddr));
    if (ret == SOCKET_ERROR) {
        printf("Failed to bind socket.\n");
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    // 监听客户端连接
    ret = listen(serverSocket, 5);
    if (ret == SOCKET_ERROR) {
        printf("Failed to listen on socket.\n");
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    printf("Server started, waiting for client...\n");

    // 等待客户端连接
    clientSocket = accept(serverSocket, (SOCKADDR*)&clientAddr, &clientAddrLen);
    if (clientSocket == INVALID_SOCKET) {
        printf("Failed to accept client.\n");
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    printf("Client connected: %s:%d\n", inet_ntoa(clientAddr.sin_addr), ntohs(clientAddr.sin_port));

    // 接收客户端发送的数据
    char recvBuf[1024];
    int recvLen;
    while (1) {
        recvLen = recv(clientSocket, recvBuf, sizeof(recvBuf), 0);
        if (recvLen <= 0) {
            break;
        }
        printf("Received data from client: %s\n", recvBuf);
    }

    // 关闭套接字
    closesocket(clientSocket);
    closesocket(serverSocket);

    // 卸载Winsock库
    WSACleanup();

    return 0;
}

Client端代码：

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib") // 链接库文件

int main() {
    WSADATA wsaData;
    SOCKET clientSocket;
    SOCKADDR_IN serverAddr;
    int ret;

    // 初始化Winsock库
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock.\n");
        return 1;
    }

    // 创建套接字
    clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (clientSocket == INVALID_SOCKET) {
        printf("Failed to create socket.\n");
        WSACleanup();
        return 1;
    }

    // 连接服务器
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    serverAddr.sin_port = htons(8888);
    ret = connect(clientSocket, (SOCKADDR*)&serverAddr, sizeof(serverAddr));
    if (ret == SOCKET_ERROR) {
        printf("Failed to connect to server.\n");
        closesocket(clientSocket);
        WSACleanup();
        return 1;
    }

    printf("Connected to server: %s:%d\n", inet_ntoa(serverAddr.sin_addr), ntohs(serverAddr.sin_port));

    // 发送数据到服务器
    char sendBuf[1024];
    while (1) {
        printf("Enter data to send: ");
        gets_s(sendBuf, sizeof(sendBuf));
        if (strlen(sendBuf) <= 0) {
            break;
        }
        ret = send(clientSocket, sendBuf, strlen(sendBuf), 0);
        if (ret == SOCKET_ERROR) {
            printf("Failed to send data.\n");
            closesocket(clientSocket);
            WSACleanup();
            return 1;
        }
    }

    // 关闭套接字
    closesocket(clientSocket);

    // 卸载Winsock库
    WSACleanup();

    return 0;
}

注意事项：

1. 在编译时需要链接`ws2_32.lib`库文件；
2. 在使用`inet_addr`函数将IP地址转换为网络字节序时，需要注意将点分十进制形式的IP地址转换为整数后再调用`htonl`函数转换为网络字节序；
3. 代码中没有对输入进行安全处理，实际使用时需要注意输入合法性和缓冲区溢出等问题。