curl/docs/cmdline-opts/http2-prior-knowledge.md
Daniel Stenberg aa18891dda
docs/cmdline-opts: unify HTTP version style in --help output
$ curl -h all | grep -- --http

Now:

     --http0.9                      Allow HTTP/0.9 responses
 -0, --http1.0                      Use HTTP/1.0
     --http1.1                      Use HTTP/1.1
     --http2                        Use HTTP/2
     --http2-prior-knowledge        Use HTTP/2 without HTTP/1.1 Upgrade
     --http3                        Use HTTP/3
     --http3-only                   Use HTTP/3 only

Before:

     --http0.9                      Allow HTTP 0.9 responses
 -0, --http1.0                      Use HTTP 1.0
     --http1.1                      Use HTTP 1.1
     --http2                        Use HTTP/2
     --http2-prior-knowledge        Use HTTP 2 without HTTP/1.1 Upgrade
     --http3                        Use HTTP v3
     --http3-only                   Use HTTP v3 only

Closes #16542
2025-03-03 23:09:19 +01:00

29 lines
853 B
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: http2-prior-knowledge
Tags: Versions
Protocols: HTTP
Added: 7.49.0
Mutexed: http1.1 http1.0 http2 http3
Requires: HTTP/2
Help: Use HTTP/2 without HTTP/1.1 Upgrade
Category: http
Multi: boolean
See-also:
- http2
- http3
Example:
- --http2-prior-knowledge $URL
---
# `--http2-prior-knowledge`
Issue a non-TLS HTTP requests using HTTP/2 directly 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.
Since 8.10.0 if this option is set for an HTTPS request then the application
layer protocol version (ALPN) offered to the server is only HTTP/2. Prior to
that both HTTP/1.1 and HTTP/2 were offered.