用C语言编写服务器端和客户端的代码实现windows系统的Socket编程，

以下是一个简单的Windows系统下的Socket编程示例代码，包括服务器端和客户端的代码，可以用于建立TCP连接并互相发送数据：

服务器端代码：

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

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

int main()
{
    WSADATA wsaData;
    SOCKET listenSock, clientSock;
    SOCKADDR_IN serverAddr, clientAddr;
    char buffer[1024];
    int ret, addrLen;

    // 初始化WinSock库
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        printf("WSAStartup failed!\n");
        return 1;
    }

    // 创建Socket
    listenSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (listenSock == INVALID_SOCKET)
    {
        printf("socket failed!\n");
        WSACleanup();
        return 1;
    }

    // 设置Socket地址信息
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(12345);
    serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);

    // 绑定Socket到地址
    if (bind(listenSock, (SOCKADDR*)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR)
    {
        printf("bind failed!\n");
        closesocket(listenSock);
        WSACleanup();
        return 1;
    }

    // 监听Socket连接
    if (listen(listenSock, SOMAXCONN) == SOCKET_ERROR)
    {
        printf("listen failed!\n");
        closesocket(listenSock);
        WSACleanup();
        return 1;
    }

    while (1)
    {
        printf("Waiting for client...\n");

        // 接受客户端连接请求
        addrLen = sizeof(clientAddr);
        clientSock = accept(listenSock, (SOCKADDR*)&clientAddr, &addrLen);
        if (clientSock == INVALID_SOCKET)
        {
            printf("accept failed!\n");
            closesocket(listenSock);
            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
        ret = recv(clientSock, buffer, sizeof(buffer), 0);
        if (ret > 0)
        {
            buffer[ret] = '\0';
            printf("Received from client: %s\n", buffer);
        }
        else
        {
            printf("recv failed!\n");
            closesocket(clientSock);
            continue;
        }

        // 发送数据给客户端
        sprintf(buffer, "Hello, client!");
        ret = send(clientSock, buffer, strlen(buffer), 0);
        if (ret == SOCKET_ERROR)
        {
            printf("send failed!\n");
            closesocket(clientSock);
            continue;
        }

        // 关闭客户端Socket
        closesocket(clientSock);

        printf("Client disconnected!\n");
    }

    // 关闭监听Socket
    closesocket(listenSock);

    // 释放WinSock库资源
    WSACleanup();

    return 0;
}

客户端代码：

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

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

int main()
{
    WSADATA wsaData;
    SOCKET sock;
    SOCKADDR_IN addr;
    char buffer[1024];
    int ret;

    // 初始化WinSock库
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        printf("WSAStartup failed!\n");
        return 1;
    }

    // 创建Socket
    sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sock == INVALID_SOCKET)
    {
        printf("socket failed!\n");
        WSACleanup();
        return 1;
    }

    // 设置Socket地址信息
    addr.sin_family = AF_INET;
    addr.sin_port = htons(12345);
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    // 连接到服务器
    if (connect(sock, (SOCKADDR*)&addr, sizeof(addr)) == SOCKET_ERROR)
    {
        printf("connect failed!\n");
        closesocket(sock);
        WSACleanup();
        return 1;
    }

    // 发送数据
    sprintf(buffer, "Hello, server!");
    ret = send(sock, buffer, strlen(buffer), 0);
    if (ret == SOCKET_ERROR)
    {
        printf("send failed!\n");
        closesocket(sock);
        WSACleanup();
        return 1;
    }

    // 接收服务器发送的数据
    ret = recv(sock, buffer, sizeof(buffer), 0);
    if (ret > 0)
    {
        buffer[ret] = '\0';
        printf("Received from server: %s\n", buffer);
    }
    else
    {
        printf("recv failed!\n");
        closesocket(sock);
        WSACleanup();
        return 1;
    }

    // 关闭Socket
    closesocket(sock);

    // 释放WinSock库资源
    WSACleanup();

    return 0;
}

需要注意的是，服务器端需要在一个循环中不断接受客户端连接请求，并处理客户端发送的数据。客户端需要先连接到服务器，然后发送数据并接收服务器返回的数据。