curl/docs/cmdline-opts/alt-svc.md

---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: alt-svc
Arg: <filename>
Protocols: HTTPS
Help: Enable alt-svc with this cache file
Added: 7.64.1
Category: http
Multi: append
See-also:
  - resolve
  - connect-to
Example:
  - --alt-svc svc.txt $URL
---

# `--alt-svc`

Enable the alt-svc parser. If the filename points to an existing alt-svc cache
file, that gets used. After a completed transfer, the cache is saved to the
filename again if it has been modified.

Specify a "" filename (zero length) to avoid loading/saving and make curl just
handle the cache in memory.

If this option is used several times, curl loads contents from all the
files but the last one is used for saving.
docs/cmdline: change to .md for cmdline docs - switch all invidual files documenting command line options into .md, as the documentation is now markdown-looking. - made the parser treat 4-space indents as quotes - switch to building the curl.1 manpage using the "mainpage.idx" file, which lists the files to include to generate it, instead of using the previous page-footer/headers. Also, those files are now also .md ones, using the same format. I gave them underscore prefixes to make them sort separately: _NAME.md, _SYNOPSIS.md, _DESCRIPTION.md, _URL.md, _GLOBBING.md, _VARIABLES.md, _OUTPUT.md, _PROTOCOLS.md, _PROGRESS.md, _VERSION.md, _OPTIONS.md, _FILES.md, _ENVIRONMENT.md, _PROXYPREFIX.md, _EXITCODES.md, _BUGS.md, _AUTHORS.md, _WWW.md, _SEEALSO.md - updated test cases accordingly Closes #12751 2024-01-21 06:18:43 +08:00			`---`
copyright: update all copyright lines and remove year ranges - they are mostly pointless in all major jurisdictions - many big corporations and projects already don't use them - saves us from pointless churn - git keeps history for us - the year range is kept in COPYING checksrc is updated to allow non-year using copyright statements Closes #10205 2023-01-02 20:51:48 +08:00			`c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.`
docs/cmdline-opts: add copyright and license identifier to each file gen.pl now insists on C: and SPDX-License-Identifier: fields to be present in all files. Closes #9002 2022-06-14 06:12:03 +08:00			`SPDX-License-Identifier: curl`
alt-svc: the curl command line bits 2019-03-03 18:17:52 +08:00			`Long: alt-svc`
docs: more language cleanups - present tense - avoid bad words Closes #13003 2024-02-27 17:35:28 +08:00			`Arg: <filename>`
alt-svc: the curl command line bits 2019-03-03 18:17:52 +08:00			`Protocols: HTTPS`
			`Help: Enable alt-svc with this cache file`
			`Added: 7.64.1`
docs: add categories to all cmdline opts Adapted gen.pl with 'listcats' This commit is a part of "--help me if you can" Closes #5680 2020-07-13 20:15:04 +08:00			`Category: http`
cmdline/docs: add a required 'multi' keyword for each option The keyword specifies how option works when specified multiple times: - single: the last provided value replaces the earlier ones - append: it supports being provided multiple times - boolean: on/off values - mutex: flag-like option that disable anoter flag The 'gen.pl' script then outputs the proper and unified language for each option's multi-use behavior in the generated man page. The multi: header is requires in each .d file and will cause build error if missing or set to an unknown value. Closes #9759 2022-10-18 16:39:43 +08:00			`Multi: append`
docs/cmdline: change to .md for cmdline docs - switch all invidual files documenting command line options into .md, as the documentation is now markdown-looking. - made the parser treat 4-space indents as quotes - switch to building the curl.1 manpage using the "mainpage.idx" file, which lists the files to include to generate it, instead of using the previous page-footer/headers. Also, those files are now also .md ones, using the same format. I gave them underscore prefixes to make them sort separately: _NAME.md, _SYNOPSIS.md, _DESCRIPTION.md, _URL.md, _GLOBBING.md, _VARIABLES.md, _OUTPUT.md, _PROTOCOLS.md, _PROGRESS.md, _VERSION.md, _OPTIONS.md, _FILES.md, _ENVIRONMENT.md, _PROXYPREFIX.md, _EXITCODES.md, _BUGS.md, _AUTHORS.md, _WWW.md, _SEEALSO.md - updated test cases accordingly Closes #12751 2024-01-21 06:18:43 +08:00			`See-also:`
			`- resolve`
			`- connect-to`
			`Example:`
			`- --alt-svc svc.txt $URL`
alt-svc: the curl command line bits 2019-03-03 18:17:52 +08:00			`---`
docs/cmdline: change to .md for cmdline docs - switch all invidual files documenting command line options into .md, as the documentation is now markdown-looking. - made the parser treat 4-space indents as quotes - switch to building the curl.1 manpage using the "mainpage.idx" file, which lists the files to include to generate it, instead of using the previous page-footer/headers. Also, those files are now also .md ones, using the same format. I gave them underscore prefixes to make them sort separately: _NAME.md, _SYNOPSIS.md, _DESCRIPTION.md, _URL.md, _GLOBBING.md, _VARIABLES.md, _OUTPUT.md, _PROTOCOLS.md, _PROGRESS.md, _VERSION.md, _OPTIONS.md, _FILES.md, _ENVIRONMENT.md, _PROXYPREFIX.md, _EXITCODES.md, _BUGS.md, _AUTHORS.md, _WWW.md, _SEEALSO.md - updated test cases accordingly Closes #12751 2024-01-21 06:18:43 +08:00
			# `--alt-svc`

cmdline-opts: language cleanups Use imperative mood consistently for the first sentence describing an option. "Set this" instead "tell curl to set" or "this sets..." Plus some extra cleanups and rephrasing. Closes #13106 2024-03-12 17:34:58 +08:00			`Enable the alt-svc parser. If the filename points to an existing alt-svc cache`
			`file, that gets used. After a completed transfer, the cache is saved to the`
			`filename again if it has been modified.`
alt-svc: the curl command line bits 2019-03-03 18:17:52 +08:00
docs: more language cleanups - present tense - avoid bad words Closes #13003 2024-02-27 17:35:28 +08:00			`Specify a "" filename (zero length) to avoid loading/saving and make curl just`
			`handle the cache in memory.`
alt-svc: the curl command line bits 2019-03-03 18:17:52 +08:00
cmdline-docs: use present tense, not future + some smaller cleanups Closes #11821 2023-09-08 20:32:29 +08:00			`If this option is used several times, curl loads contents from all the`
			`files but the last one is used for saving.`