**************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
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*
* Copyright (C) 1998 - 2017, 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.
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* 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.
*
**************************************************************************

CURLOPT_AUTOREFERER - automatically update the referer header #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_AUTOREFERER, long autorefer); Pass a parameter set to 1 to enable this. When enabled, libcurl will automatically set the Referer: header field in HTTP requests where it follows a Location: redirect. 0, disabled HTTP

CURL *curl = curl_easy_init();
if(curl) {
 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");

 /* follow redirects */
 curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);

 /* set Referer: automatically when following redirects */
 curl_easy_setopt(curl, CURLOPT_AUTOREFERER, 1L);

 ret = curl_easy_perform(curl);

 curl_easy_cleanup(curl);
}

Along with HTTP Returns CURLE_OK if HTTP is supported, and CURLE_UNKNOWN_OPTION if not. CURLOPT_REFERER "(3), " CURLOPT_FOLLOWLOCATION "(3), "