curl断点续载

摘自http://blog.csdn.net/zmy12007/article/details/37157297

摘自http://www.linuxidc.com/Linux/2014-10/107509.htm

curl断点续传，下载过程中关闭控制台，然后重新启动，又会接着下载

#include "stdafx.h"

#include <io.h>

#include "curl/curl.h"

#include <string>/*注意包含这个头文件后必须把share.h重命名一下，可能是stl里面也有这个头文件，比如curl_share.h,然后把包含到的地方替换一下*/

#include "curl/easy.h"

using namespace std;

static size_t downLoadPackage(void *ptr, size_t size, size_t nmemb, void *userdata)

{

FILE *fp = (FILE*)userdata;

size_t written = fwrite(ptr, size, nmemb, fp);

return written;

}

int assetsManagerProgressFunc(void *ptr, double totalToDownload, double nowDownloaded, double totalToUpLoad, double nowUpLoaded)

{

static int percent = 0;

int tmp = 0;

long localLen = *(long*)ptr;

if ( totalToDownload > 0 )

{

tmp = (int)((nowDownloaded + (double)localLen) / (totalToDownload + (double)localLen) * 100);

}

printf("下载进度%0d%%\r", tmp);

return 0;

}

long GetLocalFileLenth(const char* fileName)

{

char strTemp[256] = {0};

strcpy_s(strTemp,fileName);

FILE* fp = fopen(strTemp, "rb");

if(fp != NULL)

{

long localLen = _filelength(_fileno(fp));

fclose(fp);

return localLen;

}

return 0;

}

/************************************************************************/

/* 获取要下载的远程文件的大小 */

/************************************************************************/

long getDownloadFileLenth(const char *url){

long downloadFileLenth = 0;

CURL *handle = curl_easy_init();

curl_easy_setopt(handle, CURLOPT_URL, url);

curl_easy_setopt(handle, CURLOPT_HEADER, 1); //只需要header头

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

if (curl_easy_perform(handle) == CURLE_OK)

{

curl_easy_getinfo(handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &downloadFileLenth);

}

else

{

downloadFileLenth = -1;

}

return downloadFileLenth;

}

bool downLoad(void *_curl, std::string _packageUrl, std::string _storagePath, std::string fileName )

{

// Create a file to save package.

const string outFileName = _storagePath + fileName;

//================断点续载===================

long localLen = GetLocalFileLenth(outFileName.c_str());

FILE *fp = fopen(outFileName.c_str(), "a+b");

if (! fp)

{

return false;

}

fseek(fp, 0, SEEK_END);

// Download pacakge

CURLcode res;

curl_easy_setopt(_curl, CURLOPT_URL, _packageUrl.c_str());

curl_easy_setopt(_curl, CURLOPT_WRITEFUNCTION, downLoadPackage);

curl_easy_setopt(_curl, CURLOPT_WRITEDATA, fp);

curl_easy_setopt(_curl, CURLOPT_NOPROGRESS, false);

curl_easy_setopt(_curl, CURLOPT_PROGRESSFUNCTION, assetsManagerProgressFunc);

curl_easy_setopt(_curl, CURLOPT_NOSIGNAL, 1L);

curl_easy_setopt(_curl, CURLOPT_LOW_SPEED_LIMIT, 1L);

curl_easy_setopt(_curl, CURLOPT_LOW_SPEED_TIME, 5L);

curl_easy_setopt(_curl, CURLOPT_HEADER, 0L);

curl_easy_setopt(_curl, CURLOPT_NOBODY, 0L);

curl_easy_setopt(_curl, CURLOPT_FOLLOWLOCATION, 1L);

curl_easy_setopt(_curl, CURLOPT_RESUME_FROM, localLen);

curl_easy_setopt(_curl, CURLOPT_PROGRESSDATA, &localLen);

res = curl_easy_perform(_curl);

curl_easy_cleanup(_curl);

if (res != 0)

{

fclose(fp);

return false;

}

fclose(fp);

return true;

}

int _tmain(int argc, _TCHAR* argv[])

{

CURL* _curl = curl_easy_init();

if (! _curl)

{

return 0;

}

downLoad(_curl, "http://ardownload.adobe.com/pub/adobe/reader/win/11.x/11.0.01/en_US/AdbeRdr11001_en_US.exe", "./", "AdbeRdr11001_en_US.exe");

//downLoad(_curl, "http://localhost/MyWebServer.rar", "./", "MyWebServer.rar");

getchar();

return 0;

}