CURLOPT_HAPROXYPROTOCOL(3)                            Library Functions Manual

NAME
       CURLOPT_HAPROXYPROTOCOL - send HAProxy PROXY protocol v1 header

SYNOPSIS
       #include <curl/curl.h>

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

DESCRIPTION
       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.

DEFAULT
       0, do not send any HAProxy PROXY protocol header

PROTOCOLS
       This functionality affects all supported protocols

EXAMPLE
       int main(void)
       {
         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);
         }
       }

AVAILABILITY
       Added in curl 7.60.0

RETURN VALUE
       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).

SEE ALSO
       CURLOPT_PROXY(3)

libcurl                           2025-11-13        CURLOPT_HAPROXYPROTOCOL(3)