在C ++中使用Curl 7.47.1重定向URL

Question

I'm using Curl 7.47.1 to download a Redirect url. However, it always returns

CURLE_UNSUPPORTED_PROTOCOL

char *url = "http://www.foxitsoftware.com/downloads/latest.php?product=Foxit-Reader&platform=Windows";

CURL * m_curl;

FILE pFile = fopen(outfilename,"wb");


m_curl = curl_easy_init();

curl_easy_setopt(m_curl, CURLOPT_URL, url);

curl_easy_setopt(m_curl, CURLOPT_FOLLOWLOCATION, 1);

curl_easy_setopt(m_curl, CURLOPT_WRITEFUNCTION, write_data);

curl_easy_setopt(m_curl, CURLOPT_WRITEDATA, pFile);

curl_easy_setopt(m_curl, CURLOPT_HEADER, 1L);

curl_easy_setopt(m_curl, CURLOPT_HEADERFUNCTION, HeaderCallback);

CURLcode res =  curl_easy_perform(m_curl);

Answer 1

1. Add CURLOPT_VERBOSE set to 1L to get some additional information.
2. The error code CURLE_UNSUPPORTED_PROTOCOL means you're asking for a resource/URL over a protocol that your libcurl build doesn't support. As you're following redirects, that could mean that the first server redirects you over to an non-supported protocol. You may need to rebuild libcurl to make it support the protocol, or you're using a rarer protocol that libcurl doesn't support at all.