fish-shell/doc_src/cmds/fish.rst

.. _cmd-fish:
.. program::fish

fish - the friendly interactive shell
=====================================

Synopsis
--------

.. synopsis::

    fish [OPTIONS] [FILE [ARG ...]]
    fish [OPTIONS] [-c COMMAND [ARG ...]]

Description
-----------

:command:`fish` is a command-line shell written mainly with interactive use in mind.
This page briefly describes the options for invoking :command:`fish`.
The :ref:`full manual <intro>` is available in HTML by using the :command:`help` command from inside fish, and in the `fish-doc(1)` man page.
The :ref:`tutorial <tutorial>` is available as HTML via ``help tutorial`` or in `man fish-tutorial`.


The following options are available:

**-c** or **--command=COMMAND**
    Evaluate the specified commands instead of reading from the commandline, passing additional positional arguments through ``$argv``.

**-C** or **--init-command=COMMANDS**
    Evaluate specified commands after reading the configuration but before executing command specified by **-c** or reading interactive input.

**-d** or **--debug=DEBUG_CATEGORIES**
    Enables debug output and specify a pattern for matching debug categories.
    See :ref:`Debugging <debugging-fish>` below for details.

**-o** or **--debug-output=DEBUG_FILE**
    Specifies a file path to receive the debug output, including categories and  :envvar:`fish_trace`.
    The default is stderr.

**-i** or **--interactive**
    The shell is interactive.

**-l** or **--login**
    Act as if invoked as a login shell.

**-N** or **--no-config**
    Do not read configuration files.

**-n** or **--no-execute**
    Do not execute any commands, only perform syntax checking.

**-p** or **--profile=PROFILE_FILE**
    when :command:`fish` exits, output timing information on all executed commands to the specified file.
    This excludes time spent starting up and reading the configuration.

**--profile-startup=PROFILE_FILE** 
    Will write timing for ``fish`` startup to specified file.

**-P** or **--private**
    Enables :ref:`private mode <private-mode>`: **fish** will not access old or store new history.

**--print-rusage-self**
    When :command:`fish` exits, output stats from getrusage.

**--print-debug-categories**
    Print all debug categories, and then exit.

**-v** or **--version**
    Print version and exit.

**-f** or **--features=FEATURES**
    Enables one or more comma-separated :ref:`feature flags <featureflags>`.

The ``fish`` exit status is generally the :ref:`exit status of the last foreground command <variables-status>`.

.. _debugging-fish:

Debugging
---------

While fish provides extensive support for :ref:`debugging fish scripts <debugging>`, it is also possible to debug and instrument its internals.
Debugging can be enabled by passing the **--debug** option.
For example, the following command turns on debugging for background IO thread events, in addition to the default categories, i.e. *debug*, *error*, *warning*, and *warning-path*:
::

    > fish --debug=iothread

Available categories are listed by ``fish --print-debug-categories``. The **--debug** option accepts a comma-separated list of categories, and supports glob syntax.
The following command turns on debugging for *complete*, *history*, *history-file*, and *profile-history*, as well as the default categories:
::

    > fish --debug='complete,*history*'

Debug messages output to stderr by default. Note that if :envvar:`fish_trace` is set, execution tracing also outputs to stderr by default. You can output to a file using the **--debug-output** option:
::

    > fish --debug='complete,*history*' --debug-output=/tmp/fish.log --init-command='set fish_trace on'

These options can also be changed via the :envvar:`FISH_DEBUG` and :envvar:`FISH_DEBUG_OUTPUT` variables.
The categories enabled via **--debug** are *added* to the ones enabled by $FISH_DEBUG, so they can be disabled by prefixing them with **-** (**reader-*,-ast*** enables reader debugging and disables ast debugging).

The file given in **--debug-output** takes precedence over the file in :envvar:`FISH_DEBUG_OUTPUT`.
Docs: Switch back to vanilla :ref: for commands that should be linked Unfortunately, currently :program: doesn't link to the program's page. So we use the old-school :ref: again where we should link, i.e. for everything that's not the program the current page is about. Fixes #8438 2021-11-13 01:02:56 +08:00			`.. _cmd-fish:`
Long march towards more structured text 2021-11-12 20:20:51 +08:00			`.. program::fish`
docs: Add labels to all commands This allows us to use :ref: references, which don't require hardcoding it as html [ci skip] 2019-03-31 17:05:09 +08:00
Switch command docs from \section to reStructuredText 2018-12-17 09:39:33 +08:00			`fish - the friendly interactive shell`
Fix command section separator line lengths 2019-01-03 12:10:47 +08:00			`=====================================`
Switch command docs from \section to reStructuredText 2018-12-17 09:39:33 +08:00
Migrate the 'synopsis' sections to .rst format 2018-12-18 09:58:24 +08:00			`Synopsis`
			`--------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs synopsis: add HTML highlighing and automate manpage markup Recent synopsis changes move from literal code blocks to [RST line blocks]. This does not translate well to HTML: it's not rendered in monospace, so aligment is lost. Additionally, we don't get syntax highlighting in HTML, which adds differences to our code samples which are highlighted. We hard-wrap synopsis lines (like code blocks). To align continuation lines in manpages we need [backslashes in weird places]. Combined with the *, , and `` markup, it's a bit hard to get the alignment right. Fix these by moving synopsis sources back to code blocks and compute HTML syntax highlighting and manpage markup with a custom Sphinx extension. The new Pygments lexer can tokenize a synopsis and assign the various highlighting roles, which closely matches fish's syntax highlighing: - command/keyword (dark blue) - parameter (light blue) - operator like and/or/not/&&/\|\| (cyan) - grammar metacharacter (black) For manpage output, we don't project the fish syntax highlighting but follow the markup convention in GNU's man(1): bold text type exactly as shown. italic text replace with appropriate argument. To make it easy to separate these two automatically, formalize that (italic) placeholders must be uppercase; while all lowercase text is interpreted literally (so rendered bold). This makes manpages more consistent, see string-join(1) and and(1). Implementation notes: Since we want manpage formatting but Sphinx's Pygments highlighing plugin does not support manpage output, add our custom "synopsis" directive. This directive parses differently when manpage output is specified. This means that the HTML and manpage build processes must not share a cache, because the parsed doctrees are cached. Work around this by using separate cache locations for build targets "sphinx-docs" (which creates HTML) and "sphinx-manpages". A better solution would be to only override Sphinx's ManualPageBuilder but that would take a bit more code (ideally we could override ManualPageWriter but Sphinx 4.3.2 doesn't really support that). --- Alternative solution: stick with line blocks but use roles like :command: or :option: (or custom ones). While this would make it possible to produce HTML that is consistent with code blocks (by adding a bit of CSS), the source would look uglier and is harder to maintain. (Let's say we want to add custom formatting to the [\|] metacharacters in HTML. This is much easier with the proposed patch.) --- [RST line blocks]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#line-blocks [backslashes in weird places]: https://github.com/fish-shell/fish-shell/pull/8626#discussion_r782837750 2022-01-09 22:09:46 +08:00			`.. synopsis::`

			`fish [OPTIONS] [FILE [ARG ...]]`
			`fish [OPTIONS] [-c COMMAND [ARG ...]]`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
Convert \\subsection sections into rst format 2018-12-19 10:44:30 +08:00			`Description`
Fix command section separator line lengths 2019-01-03 12:10:47 +08:00			`-----------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			:command:`fish` is a command-line shell written mainly with interactive use in mind.
			This page briefly describes the options for invoking :command:`fish`.
			The :ref:`full manual <intro>` is available in HTML by using the :command:`help` command from inside fish, and in the `fish-doc(1)` man page.
			The :ref:`tutorial <tutorial>` is available as HTML via ``help tutorial`` or in `man fish-tutorial`.

Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
			`The following options are available:`

doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-c or --command=COMMAND`
			Evaluate the specified commands instead of reading from the commandline, passing additional positional arguments through ``$argv``.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-C or --init-command=COMMANDS`
			`Evaluate specified commands after reading the configuration but before executing command specified by -c or reading interactive input.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-d or --debug=DEBUG_CATEGORIES`
			`Enables debug output and specify a pattern for matching debug categories.`
			See :ref:`Debugging <debugging-fish>` below for details.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-o or --debug-output=DEBUG_FILE`
			Specifies a file path to receive the debug output, including categories and :envvar:`fish_trace`.
			`The default is stderr.`
Introduce the fish log, a replacement for debug() This adds a new mechanism for logging, intended to replace debug(). The entry points are FLOG and FLOGF. FLOG can be used to log a sequence of arguments, FLOGF is for printf-style formatted strings. Each call to FLOG and FLOGF requires a category. If logging for a category is not enabled, there is no effect (and arguments are not evaluated). Categories may be enabled on the command line via the -d option. 2019-04-20 15:15:51 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-i or --interactive`
			`The shell is interactive.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-l or --login`
			`Act as if invoked as a login shell.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-N or --no-config`
			`Do not read configuration files.`
document `--no-config` 2021-07-28 04:52:11 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-n or --no-execute`
			`Do not execute any commands, only perform syntax checking.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-p or --profile=PROFILE_FILE`
			when :command:`fish` exits, output timing information on all executed commands to the specified file.
			`This excludes time spent starting up and reading the configuration.`
Add a separate --profile-startup option to profile startup This goes to a separate file because that makes option parsing easier and allows profiling both at the same time. The "normal" profile now contains only the profile data of the actual run, which is much more useful - you can now profile a function by running fish -C 'source /path/to/thing' --profile /tmp/thefunction.prof -c 'thefunction' and won't need to filter out extraneous information. 2021-01-09 00:25:00 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`--profile-startup=PROFILE_FILE`
			Will write timing for ``fish`` startup to specified file.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-P or --private`
			Enables :ref:`private mode <private-mode>`: fish will not access old or store new history.
docs/cmds/fish: Document private mode there as well Oversight, see #2376. [ci skip] 2019-06-30 19:54:03 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`--print-rusage-self`
			When :command:`fish` exits, output stats from getrusage.
Add print-rusage-self to fish This adds an option --print-rusage-self to the fish executable. When set, this option prints some getrusage stats to the console in a human-readable way. This will be used by upcoming benchmarking support. 2019-04-11 04:58:29 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`--print-debug-categories`
			`Print all debug categories, and then exit.`
Introduce the fish log, a replacement for debug() This adds a new mechanism for logging, intended to replace debug(). The entry points are FLOG and FLOGF. FLOG can be used to log a sequence of arguments, FLOGF is for printf-style formatted strings. Each call to FLOG and FLOGF requires a category. If logging for a category is not enabled, there is no effect (and arguments are not evaluated). Categories may be enabled on the command line via the -d option. 2019-04-20 15:15:51 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-v or --version`
			`Print version and exit.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`-f or --features=FEATURES`
			Enables one or more comma-separated :ref:`feature flags <featureflags>`.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			The ``fish`` exit status is generally the :ref:`exit status of the last foreground command <variables-status>`.
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`.. _debugging-fish:`

			`Debugging`
			`---------`

fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			While fish provides extensive support for :ref:`debugging fish scripts <debugging>`, it is also possible to debug and instrument its internals.
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`Debugging can be enabled by passing the --debug option.`
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			`For example, the following command turns on debugging for background IO thread events, in addition to the default categories, i.e. debug, error, warning, and warning-path:`
			`::`
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`> fish --debug=iothread`

doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			Available categories are listed by ``fish --print-debug-categories``. The --debug option accepts a comma-separated list of categories, and supports glob syntax.
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			`The following command turns on debugging for complete, history, history-file, and profile-history, as well as the default categories:`
			`::`
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`> fish --debug='complete,history'`

doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			Debug messages output to stderr by default. Note that if :envvar:`fish_trace` is set, execution tracing also outputs to stderr by default. You can output to a file using the --debug-output option:
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			`::`
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`> fish --debug='complete,history' --debug-output=/tmp/fish.log --init-command='set fish_trace on'`
fish documentation manpages: omit NAME for non-commands Documents like fish-tutorial don't need the NAME portion below. (they also shoudln't be in section 1! These should be section 7, they aren't for programs.) the manpage writer will skip NAME if given an empty sstring as the description. -- FISH-TUTORIAL(1) fish-shell FISH-TUTORIAL(1) NAME fish-tutorial - fish-shell tutorial 2021-11-05 22:46:27 +08:00
Documentation WIP: Start doing the envvar:: directives and cut some copy. These should be linking up now. 2021-11-05 20:14:02 +08:00			These options can also be changed via the :envvar:`FISH_DEBUG` and :envvar:`FISH_DEBUG_OUTPUT` variables.
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			`The categories enabled via --debug are added to the ones enabled by $FISH_DEBUG, so they can be disabled by prefixing them with - (*reader-,-ast*** enables reader debugging and disables ast debugging).`
Introduce $FISH_DEBUG and $FISH_DEBUG_OUTPUT variables Same as the `--debug` and `--debug-output` options, can be enabled when the option can't be passed, e.g. in linux shebangs. Fixes #7359. 2020-09-28 23:10:40 +08:00
doc_src: Continue the slog through the letter F. We are using only :: in a synopsis for fishscript examples given of the command being documented. 2021-12-18 07:16:47 +08:00			The file given in --debug-output takes precedence over the file in :envvar:`FISH_DEBUG_OUTPUT`.