C++ 如何使用c+下载文件+；使用curl编码？

我不知道如何使用curl liblary下载.exe文件。 我搜索了整个互联网，只找到了以下代码：

int main(void)
{
    CURL *curl;
    FILE *fp;
    CURLcode res;
    char *url = "http://stackoverflow.com";
    char outfilename[FILENAME_MAX] = "page.html";
    curl = curl_easy_init();                                                                                                                                                                                                                                                           
    if (curl)
    {   
        fp = fopen(outfilename,"wb");
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, NULL);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
        res = curl_easy_perform(curl);
        curl_easy_cleanup(curl);
        fclose(fp);
    }   
    return 0;
}

问题是此代码只下载页面代码。但是如何从云上下载.exe/txt文件（比如googledrive/GitHub）

提前感谢您的回答

我不知道如何使用curl liblary下载.exe文件。我搜索了整个互联网，只找到了这个代码

你搜索得不够努力。libcurl的官方网站是

它有一个示例部分，位于 有很多例子。最简单的示例之一位于，特别是一个简单的“文件下载”示例可在此处找到：

/***************************************************************************
*                                  _   _ ____  _
*项目|
*                             / __| | | | |_) | |
*|（| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |要求“xxxx.html”到“xxxx.exe”？我会尝试这样做的！感谢您的回复！您正在将
NULL
传递到
CURLOPT_WRITEFUNCTION
。您需要的是一个将写入
fp
的函数。请看一看。该代码在我从任何页面下载图片时起作用。exe（dropbox）文件仍然下载HTML代码@RemyLebeau@super如果将
CURLOPT\u WRITEDATA
作为
CURLOPT\u WRITEFUNCTION
传递到
NULL
，则默认操作是将数据写入
CURLOPT\u WRITEDATA
提供的文件描述符，在本例中为
fp
。
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/ 
/* <DESC>
 * Download a given URL into a local file named page.out.
 * </DESC>
 */ 

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <curl/curl.h>

static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
{
  size_t written = fwrite(ptr, size, nmemb, (FILE *)stream);
  return written;
}

int main(int argc, char *argv[])
{
  CURL *curl_handle;
  static const char *pagefilename = "page.out";
  FILE *pagefile;

  if(argc < 2) {
    printf("Usage: %s <URL>\n", argv[0]);
    return 1;
  }

  curl_global_init(CURL_GLOBAL_ALL);

  /* init the curl session */ 
  curl_handle = curl_easy_init();

  /* set URL to get here */ 
  curl_easy_setopt(curl_handle, CURLOPT_URL, argv[1]);

  /* Switch on full protocol/debug output while testing */ 
  curl_easy_setopt(curl_handle, CURLOPT_VERBOSE, 1L);

  /* disable progress meter, set to 0L to enable and disable debug output */ 
  curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);

  /* send all data to this function  */ 
  curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);

  /* open the file */ 
  pagefile = fopen(pagefilename, "wb");
  if(pagefile) {

    /* write the page body to this file handle */ 
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, pagefile);

    /* get it! */ 
    curl_easy_perform(curl_handle);

    /* close the header file */ 
    fclose(pagefile);
  }

  /* cleanup curl stuff */ 
  curl_easy_cleanup(curl_handle);

  curl_global_cleanup();

  return 0;
}