#include <stdio.h>

 #include <iostream.h>

 #include <curl/curl.h>

 using namespace std;

 int download(string url, string local_file, int down_speed)

 {

   CURL *image;

   CURLcode imgresult;

   FILE *fp;

   //url_download.c_str();

     image = curl_easy_init();

     if( image )

      {

         //Open File

         fp = fopen(local_file.c_str(), "w");

         if( fp == NULL ) cout << "File cannot be opened";

         curl_easy_setopt(image, CURLOPT_WRITEFUNCTION, NULL);

         curl_easy_setopt(image, CURLOPT_WRITEDATA, fp);

         curl_easy_setopt(image, CURLOPT_URL, url.c_str());

         curl_easy_setopt(image, CURLOPT_FOLLOWLOCATION, );

 //这里限速 100KB/s

         curl_easy_setopt(image, CURLOPT_MAX_RECV_SPEED_LARGE, (curl_off_t) * );

         curl_easy_setopt(image, CURLOPT_NOPROGRESS, );

         //CURLOPT_RESUME_FROM

         // Grab image

         imgresult = curl_easy_perform(image);

         if( imgresult )

             {

                 cout << "Cannot grab the File!\n";

             }

     }

     //Clean up the resources

     curl_easy_cleanup(image);

     //Close the file

     fclose(fp);

     return ;

 }