DOKK / manpages / debian 12 / libcurl4-doc / CURLOPT_AUTOREFERER.3.en
CURLOPT_AUTOREFERER(3) curl_easy_setopt options CURLOPT_AUTOREFERER(3)

CURLOPT_AUTOREFERER - automatically update the referer header

#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),

January 2, 2023 libcurl 7.88.1