windows下使用标准c语言实现一个web服务器，实现网页打开一个css文件，jpg或者文本文件

要实现一个web服务器，需要使用socket编程，可以使用Winsock API来实现。以下是一个简单的示例：

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

#define PORT 80
#define MAX_CLIENTS 30
#define BUFFER_SIZE 1024

int main()
{
    WSADATA wsaData;
    SOCKET listenSocket, clientSocket;
    struct sockaddr_in serverAddr, clientAddr;
    char buffer[BUFFER_SIZE];
    int clientAddrLen, bytesRead;
    FILE *file;
    char *contentType;
    char *extension;
    char *fileName;

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

    // 创建监听socket
    listenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (listenSocket == INVALID_SOCKET) {
        printf("socket failed\n");
        WSACleanup();
        return 1;
    }

    // 绑定地址和端口号
    memset(&serverAddr, 0, sizeof(serverAddr));
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);
    serverAddr.sin_port = htons(PORT);

    if (bind(listenSocket, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR) {
        printf("bind failed\n");
        closesocket(listenSocket);
        WSACleanup();
        return 1;
    }

    // 监听客户端连接
    if (listen(listenSocket, MAX_CLIENTS) == SOCKET_ERROR) {
        printf("listen failed\n");
        closesocket(listenSocket);
        WSACleanup();
        return 1;
    }

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

    // 进入主循环，等待客户端连接
    while (1) {
        // 接收客户端连接
        clientAddrLen = sizeof(clientAddr);
        clientSocket = accept(listenSocket, (struct sockaddr *)&clientAddr, &clientAddrLen);
        if (clientSocket == INVALID_SOCKET) {
            printf("accept failed\n");
            closesocket(listenSocket);
            WSACleanup();
            return 1;
        }

        // 接收客户端发送的数据
        memset(buffer, 0, BUFFER_SIZE);
        bytesRead = recv(clientSocket, buffer, BUFFER_SIZE, 0);
        if (bytesRead == SOCKET_ERROR) {
            printf("recv failed\n");
            closesocket(clientSocket);
            closesocket(listenSocket);
            WSACleanup();
            return 1;
        }

        // 解析HTTP请求
        fileName = strtok(buffer + 4, " ");
        contentType = "text/plain";

        // 根据文件扩展名确定Content-Type
        extension = strrchr(fileName, '.');
        if (extension != NULL) {
            if (strcmp(extension, ".html") == 0 || strcmp(extension, ".htm") == 0)
                contentType = "text/html";
            else if (strcmp(extension, ".css") == 0)
                contentType = "text/css";
            else if (strcmp(extension, ".jpg") == 0 || strcmp(extension, ".jpeg") == 0)
                contentType = "image/jpeg";
            else if (strcmp(extension, ".gif") == 0)
                contentType = "image/gif";
            else if (strcmp(extension, ".png") == 0)
                contentType = "image/png";
        }

        // 打开文件并发送响应
        file = fopen(fileName, "rb");
        if (file == NULL) {
            printf("open file failed\n");
            closesocket(clientSocket);
            continue;
        }

        // 发送HTTP响应头
        sprintf(buffer, "HTTP/1.1 200 OK\r\nContent-Type: %s\r\n\r\n", contentType);
        send(clientSocket, buffer, strlen(buffer), 0);

        // 发送文件内容
        while ((bytesRead = fread(buffer, 1, BUFFER_SIZE, file)) > 0) {
            send(clientSocket, buffer, bytesRead, 0);
        }

        fclose(file);
        closesocket(clientSocket);
    }

    closesocket(listenSocket);
    WSACleanup();

    return 0;
}

这个示例实现了一个简单的Web服务器，可以处理GET请求，支持打开html、css、jpg、gif、png等文件。当收到GET请求时，根据请求的文件名确定Content-Type，然后打开相应的文件并发送响应。注意，这个示例没有处理POST请求和其他HTTP方法，也没有实现动态网页。如果需要实现更完整的Web服务器，还需要处理这些问题。