CURLOPT_AUTOREFERER - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_AUTOREFERER, long autorefer);

Pass a long parameter set to 1 to enable this. When enabled, libcurl will automatically set the Referer: header field in HTTP requests to the full URL where it follows a Location: redirect.

The automatic referer is set to the full previous URL even when redirects are done cross-origin or following redirects to insecure protocols. This is considered a minor privacy leak by some.

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),

curl_easy_setopt(3).