使用curl下载文件
curl是一个非常好的网络传输库，使用也很简单。常用的使用方式是用它来下载资源文件，以下提供一个下载方法
1 #include <stdio.h> 2 #include <iostream.h> 3 #include <curl/curl.h> 4 5 using namespace std; 6 7 int download(string url, string local_file, int down_speed) 8 { 9 CURL *image; 10 CURLcode imgresult; 11 FILE *fp; 12 //url_download.c_str(); 13 14 image = curl_easy_init(); 15 if( image ) 16 { 17 //Open File 18 fp = fopen(local_file.c_str(), "w"); 19 if( fp == NULL ) cout << "File cannot be opened"; 20 21 curl_easy_setopt(image, CURLOPT_WRITEFUNCTION, NULL); 22 curl_easy_setopt(image, CURLOPT_WRITEDATA, fp); 23 curl_easy_setopt(image, CURLOPT_URL, url.c_str()); 24 curl_easy_setopt(image, CURLOPT_FOLLOWLOCATION, 1); 25 //这里限速 100KB/s 26 curl_easy_setopt(image, CURLOPT_MAX_RECV_SPEED_LARGE, (curl_off_t)100 * 1024); 27 curl_easy_setopt(image, CURLOPT_NOPROGRESS, 0); 28 //CURLOPT_RESUME_FROM 29 30 // Grab image 31 imgresult = curl_easy_perform(image); 32 if( imgresult ) 33 { 34 cout << "Cannot grab the File!\n"; 35 } 36 } 37 //Clean up the resources 38 curl_easy_cleanup(image); 39 //Close the file 40 fclose(fp); 41 return 0; 42 }
