Name
easy:SetOpt_HTTP_Version -- specify HTTP protocol version to use
Synopsis
easy:SetOpt_HTTP_Version(version)
Function
Pass version as a value, 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 connection 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)

Inputs
version
input value

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