CURLOPT_HTTP_VERSION(3) 				     curl_easy_setopt options					   CURLOPT_HTTP_VERSION(3)

NAME

       CURLOPT_HTTP_VERSION - specify HTTP protocol version to use

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTP_VERSION, long version);

DESCRIPTION

       Pass  version a long, set to one of the values described below. They ask libcurl to use the specific HTTP versions. This is not sensible to
       do unless you have a good reason. You have to set this option if you want to use libcurl's HTTP/2 support.

       Note that the HTTP version is just a request. libcurl will still prioritize to re-use an existing connection so it might then re-use a con-
       nection using a HTTP version you haven't asked for.

       CURL_HTTP_VERSION_NONE
	      We don't care about what version the library uses. libcurl will use whatever it thinks fit.

       CURL_HTTP_VERSION_1_0
	      Enforce HTTP 1.0 requests.

       CURL_HTTP_VERSION_1_1
	      Enforce HTTP 1.1 requests.

       CURL_HTTP_VERSION_2_0
	      Attempt HTTP 2 requests. libcurl will fall back to HTTP 1.1 if HTTP 2 can't be negotiated with the server. (Added in 7.33.0)

	      The alias CURL_HTTP_VERSION_2 was added in 7.43.0 to better reflect the actual protocol name.

       CURL_HTTP_VERSION_2TLS
	      Attempt  HTTP  2	over TLS (HTTPS) only. libcurl will fall back to HTTP 1.1 if HTTP 2 can't be negotiated with the HTTPS server. For
	      clear text HTTP servers, libcurl will use 1.1. (Added in 7.47.0)

       CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE
	      Issue non-TLS HTTP requests using HTTP/2 without HTTP/1.1 Upgrade. It requires prior  knowledge  that  the  server  supports  HTTP/2
	      straight away. HTTPS requests will still do HTTP/2 the standard way with negotiated protocol version in the TLS handshake. (Added in
	      7.49.0)

DEFAULT

       CURL_HTTP_VERSION_NONE

PROTOCOLS

       HTTP

EXAMPLE

       TODO

AVAILABILITY

       Along with HTTP

RETURN VALUE

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

SEE ALSO

       CURLOPT_SSLVERSION(3), CURLOPT_HTTP200ALIASES(3),

libcurl 7.54.0							   May 01, 2016 					   CURLOPT_HTTP_VERSION(3)