fish-shell/doc_src/cmds/fish.rst

.. _cmd-fish:

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

Synopsis
--------

**fish** [*OPTIONS*] [*FILE* [*ARGS* ...]]

**fish** [*OPTIONS*] [**-c** *COMMAND* [*ARGS* ...]]

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=COMMANDS`` evaluate the specified commands instead of reading from the commandline, passing any additional positional arguments via :envvar:`$argv`.
  Note that, unlike other shells, the first argument is *not* the name of the program (:envvar:`$0`), but simply the first normal argument.

- ``-C`` or ``--init-command=COMMANDS`` evaluate the specified commands after reading the configuration, before running the command specified by ``-c`` or reading interactive input.

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

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

- ``-i`` or ``--interactive`` specify that fish is to run in interactive mode

- ``-l`` or ``--login`` specify that fish is to run 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 information for fish's startup to the specified file. This is useful to profile your configuration.

- ``-P`` or ``--private`` enables :ref:`private mode <private-mode>`, so fish will not access old or store new history.

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

- ``--print-debug-categories`` outputs the list of debug categories, and then exits.

- ``-v`` or ``--version`` display version and exit.

- ``-f`` or ``--features=FEATURES`` enables one or more :ref:`feature flags <featureflags>` (separated by a comma).
  These are how fish stages changes that might break scripts.

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 ``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: 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			`.. _cmd-fish:`

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
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			`fish [OPTIONS] [FILE [ARGS ...]]`
Migrate the 'synopsis' sections to .rst format 2018-12-18 09:58:24 +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			`fish [OPTIONS] [-c COMMAND [ARGS ...]]`
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:`

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			- ``-c`` or ``--command=COMMANDS`` evaluate the specified commands instead of reading from the commandline, passing any additional positional arguments via :envvar:`$argv`.
Remove Copyright sectionf from doc pages, and a couple missing bits ... from fish.rst 2021-11-05 04:26:54 +08:00			Note that, unlike other shells, the first argument is not the name of the program (:envvar:`$0`), but simply the first normal argument.
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			- ``-C`` or ``--init-command=COMMANDS`` evaluate the specified commands after reading the configuration, before running the 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
Add fish debugging examples 2020-05-16 06:54:45 +08:00			- ``-d`` or ``--debug=DEBUG_CATEGORIES`` enable 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
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			- ``-o`` or ``--debug-output=DEBUG_FILE`` specify 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
Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +08:00			- ``-i`` or ``--interactive`` specify that fish is to run in interactive mode
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +08:00			- ``-l`` or ``--login`` specify that fish is to run as a login shell
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
document `--no-config` 2021-07-28 04:52:11 +08:00			- ``-N`` or ``--no-config`` do not read configuration files

Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +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
Remove Copyright sectionf from doc pages, and a couple missing bits ... from fish.rst 2021-11-05 04:26:54 +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
			- ``--profile-startup=PROFILE_FILE`` will write timing information for fish's startup to the specified file. This is useful to profile your configuration.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs/cmds/fish: Document private mode there as well Oversight, see #2376. [ci skip] 2019-06-30 19:54:03 +08:00			- ``-P`` or ``--private`` enables :ref:`private mode <private-mode>`, so fish will not access old or store new history.

Remove Copyright sectionf from doc pages, and a couple missing bits ... from fish.rst 2021-11-05 04:26:54 +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
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			- ``--print-debug-categories`` outputs the list of debug categories, and then exits.

Remove Copyright sectionf from doc pages, and a couple missing bits ... from fish.rst 2021-11-05 04:26:54 +08:00			- ``-v`` or ``--version`` display version and exit.
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			- ``-f`` or ``--features=FEATURES`` enables one or more :ref:`feature flags <featureflags>` (separated by a comma).
			`These are how fish stages changes that might break scripts.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
fish --help: remove outdated information about exit status 2020-05-16 16:33:13 +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.
			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:`
			`::`
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`> fish --debug=iothread`

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			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:`
			`::`
Add fish debugging examples 2020-05-16 06:54:45 +08:00
			`> fish --debug='complete,history'`

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			Debug messages output to stderr by default. Note that if ``fish_trace`` is set, execution tracing also outputs to stderr by default. You can output to a file using the ``--debug-output`` option:
			`::`
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'`
Introduce $FISH_DEBUG and $FISH_DEBUG_OUTPUT variables Same as the `--debug` and `--debug-output` options, can be enabled when the option can't be passed, e.g. in linux shebangs. Fixes #7359. 2020-09-28 23:10:40 +08:00
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			These options can also be changed via the :envvar:`$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).
Introduce $FISH_DEBUG and $FISH_DEBUG_OUTPUT variables Same as the `--debug` and `--debug-output` options, can be enabled when the option can't be passed, e.g. in linux shebangs. Fixes #7359. 2020-09-28 23:10:40 +08:00
fish.rst: do better This fixes the indentation problem for the SYNOPSIS section by not inserting the :: literal block. Format it the same way Sphinx does their own manpages for commands. Use more semantic markup, like :command:, so that commands are highlighted in the man pages. Split by sentence to give `man` a chance to ascertain lines. Long-term, it should be possible to teach Sphinx to turn :command:s into references and get us automatic links to articles for matching cmds/*. 2021-11-05 04:07:30 +08:00			The file given in ``--debug-output`` takes precedence over the file in :envvar:`$FISH_DEBUG_OUTPUT`.