.\" generated by cd2nroff 0.1 from CURLOPT_HAPROXYPROTOCOL.md
.TH CURLOPT_HAPROXYPROTOCOL 3 "2026-06-24" libcurl
.SH NAME
CURLOPT_HAPROXYPROTOCOL \- send HAProxy PROXY protocol v1 header
.SH SYNOPSIS
.nf
#include <curl/curl.h>

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

Note that the HAProxy protocol message is only is sent over a freshly setup
connection. A subsequent transfer that reuses a previous connection does not
send it again.

Most applications do not need this option.
.SH DEFAULT
0, do not send any HAProxy PROXY protocol header
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_HAPROXYPROTOCOL, 1L);
    result = curl_easy_perform(curl);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.60.0
.SH RETURN VALUE
\fIcurl_easy_setopt(3)\fP returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see
\fIlibcurl\-errors(3)\fP.
.SH SEE ALSO
.BR CURLOPT_PROXY (3)