DOKK / manpages / debian 11 / libcurl4-doc / CURLOPT_HAPROXYPROTOCOL.3.en
CURLOPT_HAPROXYPROTOCOL(3) curl_easy_setopt options CURLOPT_HAPROXYPROTOCOL(3)

CURLOPT_HAPROXYPROTOCOL - send HAProxy PROXY protocol v1 header

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HAPROXYPROTOCOL,
long haproxy_protocol);

A long parameter set to 1 tells the library to send an HAProxy PROXY protocol v1 header at beginning of the connection. The default action is not to send this header.

This option is primarily useful when sending test requests to a service that expects this header.

Most applications do not need this option.

0, do not send any HAProxy PROXY protocol header

HTTP

CURL *curl = curl_easy_init();
if(curl) {

CURLcode ret;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_HAPROXYPROTOCOL, 1L);
ret = curl_easy_perform(curl); }

Along with HTTP. Added in 7.60.0.

Returns CURLE_OK if HTTP is enabled, and CURLE_UNKNOWN_OPTION if not.

November 4, 2020 libcurl 7.74.0