103 lines
3.9 KiB
Groff
103 lines
3.9 KiB
Groff
.\" **************************************************************************
|
|
.\" * _ _ ____ _
|
|
.\" * Project ___| | | | _ \| |
|
|
.\" * / __| | | | |_) | |
|
|
.\" * | (__| |_| | _ <| |___
|
|
.\" * \___|\___/|_| \_\_____|
|
|
.\" *
|
|
.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
.\" *
|
|
.\" * This software is licensed as described in the file COPYING, which
|
|
.\" * you should have received as part of this distribution. The terms
|
|
.\" * are also available at https://curl.se/docs/copyright.html.
|
|
.\" *
|
|
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
.\" * copies of the Software, and permit persons to whom the Software is
|
|
.\" * furnished to do so, under the terms of the COPYING file.
|
|
.\" *
|
|
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
.\" * KIND, either express or implied.
|
|
.\" *
|
|
.\" * SPDX-License-Identifier: curl
|
|
.\" *
|
|
.\" **************************************************************************
|
|
.\"
|
|
.TH CURLOPT_HTTP_VERSION 3 "August 22, 2023" "ibcurl 8.3.0" libcurl
|
|
|
|
.SH NAME
|
|
CURLOPT_HTTP_VERSION \- HTTP protocol version to use
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <curl/curl.h>
|
|
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTP_VERSION, long version);
|
|
.fi
|
|
.SH DESCRIPTION
|
|
Pass \fIversion\fP a long, set to one of the values described below. They ask
|
|
libcurl to use the specific HTTP versions.
|
|
|
|
Note that the HTTP version is just a request. libcurl still prioritizes to
|
|
reuse existing connections so it might then reuse a connection using a HTTP
|
|
version you have not asked for.
|
|
|
|
.IP CURL_HTTP_VERSION_NONE
|
|
We do not care about what version the library uses. libcurl uses whatever it
|
|
thinks fit.
|
|
.IP CURL_HTTP_VERSION_1_0
|
|
Enforce HTTP 1.0 requests.
|
|
.IP CURL_HTTP_VERSION_1_1
|
|
Enforce HTTP 1.1 requests.
|
|
.IP CURL_HTTP_VERSION_2_0
|
|
Attempt HTTP 2 requests. libcurl falls back to HTTP 1.1 if HTTP 2 cannot be
|
|
negotiated with the server. (Added in 7.33.0)
|
|
|
|
When libcurl uses HTTP/2 over HTTPS, it does not itself insist on TLS 1.2 or
|
|
higher even though that is required by the specification. A user can add this
|
|
version requirement with \fICURLOPT_SSLVERSION(3)\fP.
|
|
|
|
The alias \fICURL_HTTP_VERSION_2\fP was added in 7.43.0 to better reflect the
|
|
actual protocol name.
|
|
.IP CURL_HTTP_VERSION_2TLS
|
|
Attempt HTTP 2 over TLS (HTTPS) only. libcurl falls back to HTTP 1.1 if HTTP 2
|
|
cannot be negotiated with the HTTPS server. For clear text HTTP servers,
|
|
libcurl uses 1.1. (Added in 7.47.0)
|
|
.IP 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
|
|
still do HTTP/2 the standard way with negotiated protocol version in the TLS
|
|
handshake. (Added in 7.49.0)
|
|
.IP CURL_HTTP_VERSION_3
|
|
(Added in 7.66.0) This option makes libcurl attempt to use HTTP/3 to the host
|
|
given in the URL, with fallback to earlier HTTP versions if needed.
|
|
.IP CURL_HTTP_VERSION_3ONLY
|
|
(Added in 7.88.0) Setting this makes libcurl attempt to use HTTP/3 directly to
|
|
server given in the URL and does not downgrade to earlier HTTP version if the
|
|
server does not support HTTP/3.
|
|
.SH DEFAULT
|
|
Since curl 7.62.0: CURL_HTTP_VERSION_2TLS
|
|
|
|
Before that: CURL_HTTP_VERSION_1_1
|
|
.SH PROTOCOLS
|
|
HTTP
|
|
.SH EXAMPLE
|
|
.nf
|
|
CURL *curl = curl_easy_init();
|
|
if(curl) {
|
|
CURLcode ret;
|
|
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
|
|
curl_easy_setopt(curl, CURLOPT_HTTP_VERSION,
|
|
(long)CURL_HTTP_VERSION_2TLS);
|
|
ret = curl_easy_perform(curl);
|
|
if(ret == CURLE_HTTP_RETURNED_ERROR) {
|
|
/* an HTTP response error problem */
|
|
}
|
|
}
|
|
.fi
|
|
.SH AVAILABILITY
|
|
Along with HTTP
|
|
.SH RETURN VALUE
|
|
Returns CURLE_OK if HTTP is supported, and CURLE_UNKNOWN_OPTION if not.
|
|
.SH "SEE ALSO"
|
|
.BR CURLOPT_SSLVERSION "(3), " CURLOPT_HTTP200ALIASES "(3), "
|
|
.BR CURLOPT_HTTP09_ALLOWED "(3), " CURLOPT_ALTSVC "(3) "
|