libcurl 获取服务器文件大小

static size_t save_header(void *ptr, size_t size, size_t nmemb, void *data)
{
        return (size_t)(size * nmemb);
}

 

double getDownloadFileLenth(const char *url){

      double len= 0.0;

      CURL *handle = curl_easy_init();

     curl_easy_setopt(handle, CURLOPT_URL, url);

     curl_easy_setopt(handle, CURLOPT_HEADER, 1);    //只要求header头

     curl_easy_setopt(handle, CURLOPT_NOBODY, 1);    //不需求body

     curl_easy_setopt(handle, CURLOPT_HEADERFUNCTION, save_header);

     if (curl_easy_perform(handle) == CURLE_OK) {

          if(CURLE_OK == curl_easy_getinfo(handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &len)){

                ;

          }else {

            pirntf("curl_easy_getinfo failed!\n");

          }

     } else {

       len= -1;

    }

    return len;

}