怎么用c语言爬虫

#include <curl/curl.h>

CURL *curl;
CURLcode res;

char *buffer;
long response_code;

int main() {
    // 创建 HTTP 请求
    curl = curl_easy_init();
    curl_easy_setopt(curl, CURLOPT_URL, "https://www.google.com");
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, NULL);

    // 执行请求
    res = curl_easy_perform(curl);

    // 获取响应代码
    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);

    // 解析响应
    if (res == CURLE_OK && response_code == 200) {
        // 分配缓冲区
        buffer = malloc(1024);

        // 存储响应主体
        curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &buffer);

        // 提取标题
        char *start_tag = strstr(buffer, "<title>");
        char *end_tag = strstr(buffer, "</title>");
        if (start_tag != NULL && end_tag != NULL) {
            printf("%s\n", start_tag + strlen("<title>"));
        }

        // 释放缓冲区
        free(buffer);
    }

    // 清理句柄
    curl_easy_cleanup(curl);
    return 0;
}