CURLOPT_PROXYHEADER - custom HTTP headers to pass to proxy
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXYHEADER,
struct curl_slist *headers);
Pass a pointer to a linked list of HTTP headers to pass in your HTTP request
sent to a proxy. The rules for this list is identical to the
The headers set with this option is only ever used in requests sent to a proxy -
when there's also a request sent to a host.
The first line in a request (containing the method, usually a GET or POST) is
NOT a header and cannot be replaced using this option. Only the lines
following the request-line are headers. Adding this method line in this list
of headers will only cause your request to send an invalid header.
Pass a NULL to this to reset back to no custom headers.
CURL *curl = curl_easy_init();
struct curl_slist *list;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy.example.com:80");
list = curl_slist_append(NULL, "Shoesize: 10");
list = curl_slist_append(list, "Accept:");
curl_easy_setopt(curl, CURLOPT_PROXYHEADER, list);
curl_slist_free_all(list); /* free the list again */
Added in 7.37.0
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.