curl/docs/cmdline-opts/engine.md

---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: engine
Arg: <name>
Help: Crypto engine to use
Protocols: TLS
Category: tls
Added: 7.9.3
Multi: single
See-also:
  - ciphers
  - curves
Example:
  - --engine flavor $URL
---

# `--engine`

Select the OpenSSL crypto engine to use for cipher operations. Use --engine
list to print a list of build-time supported engines. Note that not all (and
possibly none) of the engines may be available at runtime.
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`
cmdline-docs: more options converted over 2016-11-16 06:44:58 +08:00			`Long: engine`
			`Arg: <name>`
			`Help: Crypto engine to use`
			`Protocols: TLS`
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: tls`
cmdline-opts: made the 'Added:' field mandatory Since "too old" versions are no longer included in the generated man page, this field is now mandatory so that it won't be forgotten and then not included in the documentation. Closes #7786 2021-09-28 17:50:07 +08:00			`Added: 7.9.3`
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: single`
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:`
			`- ciphers`
			`- curves`
			`Example:`
			`- --engine flavor $URL`
cmdline-docs: more options converted over 2016-11-16 06:44:58 +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
			# `--engine`

cmdline-opts: formatting fixes 2016-12-18 06:56:50 +08:00			`Select the OpenSSL crypto engine to use for cipher operations. Use --engine`
docs/cmdline: fix grammar and typos 2021-07-16 15:34:18 +08:00			`list to print a list of build-time supported engines. Note that not all (and`
docs: lots of minor language polish Mostly based on recent language decisions from "everything curl": - remove contractions (isn't => is not) - an HTTP (consistency) - runtime (no hyphen) - backend (no hyphen) - URL is uppercase Closes #8646 2022-03-29 19:58:11 +08:00			`possibly none) of the engines may be available at runtime.`