CURLOPT_REFERER - the HTTP referer header

Added in curl 7.1

NULL

Pass a pointer to a null-terminated string as parameter. It is used to set the Referer: header field in the HTTP request sent to the remote server. You can set any custom header with CURLOPT_HTTPHEADER(3). The application does not have to keep the string around after setting this option. Using this option multiple times makes the last set string override the previous ones. Set it to NULL to disable its use again.

int main(void) { CURL *curl = curl_easy_init(); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); /* tell it where we found the link to this place */ curl_easy_setopt(curl, CURLOPT_REFERER, "https://example.org/me.html"); curl_easy_perform(curl); } }

CURLOPT_REFERER - the HTTP referer header

This functionality affects http only

curl_easy_setopt(3) returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLINFO_REDIRECT_URL(3), CURLINFO_REFERER(3), CURLOPT_HTTPHEADER(3), CURLOPT_USERAGENT(3) libcurl 2025-06-16 CURLOPT_REFERER(3)

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_REFERER, char *where);