fish-shell/doc_src/cmds/functions.rst

.. _cmd-functions:

functions - print or erase functions
====================================

Synopsis
--------

.. synopsis::

    functions [-a | --all] [-n | --names]
    functions [-D | --details] [-v] FUNCTION
    functions -c OLDNAME NEWNAME
    functions -d DESCRIPTION FUNCTION
    functions [-e | -q] FUNCTION ...

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

``functions`` prints or erases functions.

The following options are available:

**-a** or **--all**
    Lists all functions, even those whose name starts with an underscore.

**-c** or **--copy** *OLDNAME* *NEWNAME*
    Creates a new function named *NEWNAME*, using the definition of the *OLDNAME* function.

**-d** or **--description** *DESCRIPTION*
    Changes the description of this function.

**-e** or **--erase**
    Causes the specified functions to be erased. This also means that it is prevented from autoloading in the current session. Use :doc:`funcsave <funcsave>` to remove the saved copy.

**-D** or **--details**
    Reports the path name where the specified function is defined or could be autoloaded, ``stdin`` if the function was defined interactively or on the command line or by reading standard input, **-** if the function was created via :doc:`source <source>`, and ``n/a`` if the function isn't available. (Functions created via :doc:`alias <alias>` will return **-**, because ``alias`` uses ``source`` internally. Copied functions will return where the function was copied.) If the **--verbose** option is also specified then five lines are written:

    - the path name as already described,
    - if the function was copied, the path name to where the function was originally defined, otherwise ``autoloaded``, ``not-autoloaded`` or ``n/a``,
    - the line number within the file or zero if not applicable,
    - ``scope-shadowing`` if the function shadows the vars in the calling function (the normal case if it wasn't defined with **--no-scope-shadowing**), else ``no-scope-shadowing``, or ``n/a`` if the function isn't defined,
    - the function description minimally escaped so it is a single line, or ``n/a`` if the function isn't defined or has no description.

    You should not assume that only five lines will be written since we may add additional information to the output in the future.

**--no-details**
    Turns off function path reporting, so just the definition will be printed.

**-n** or **--names**
    Lists the names of all defined functions.

**-q** or **--query**
    Tests if the specified functions exist.

**-v** or **--verbose**
    Make some output more verbose.

**-H** or **--handlers**
    Show all event handlers.

**-t** or **--handlers-type** *TYPE*
    Show all event handlers matching the given *TYPE*.

**-h** or **--help**
    Displays help about using this command.

The default behavior of ``functions``, when called with no arguments, is to print the names of all defined functions. Unless the ``-a`` option is given, no functions starting with underscores are included in the output.

If any non-option parameters are given, the definition of the specified functions are printed.

Copying a function using ``-c`` copies only the body of the function, and does not attach any event notifications from the original function.

Only one function's description can be changed in a single invocation of ``functions -d``.

The exit status of ``functions`` is the number of functions specified in the argument list that do not exist, which can be used in concert with the ``-q`` option.


Examples
--------


::

    functions -n
    # Displays a list of currently-defined functions
    
    functions -c foo bar
    # Copies the 'foo' function to a new function called 'bar'
    
    functions -e bar
    # Erases the function ``bar``

See more
--------

For more explanation of how functions fit into fish, see :ref:`Functions <syntax-function>`.
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-functions:`

Switch command docs from \section to reStructuredText 2018-12-17 09:39:33 +08:00			`functions - print or erase functions`
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`
			`--------`
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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::`

			`functions [-a \| --all] [-n \| --names]`
			`functions [-D \| --details] [-v] FUNCTION`
			`functions -c OLDNAME NEWNAME`
			`functions -d DESCRIPTION FUNCTION`
			`functions [-e \| -q] FUNCTION ...`
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			`-----------`
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Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +08:00			``functions`` prints or erases functions.
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			`The following options are available:`

docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-a or --all`
			`Lists all functions, even those whose name starts with an underscore.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-c or --copy OLDNAME NEWNAME`
			`Creates a new function named NEWNAME, using the definition of the OLDNAME function.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-d or --description DESCRIPTION`
			`Changes the description of this function.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-e or --erase`
docs: Use :doc: role when linking to commands This makes it so we link to the very top of the document instead of a special anchor we manually include. So clicking e.g. :doc:`string <cmds/string>` will link you to cmds/string.html instead of cmds/string.html#cmd-string. I would love to have a way to say "this document from the root of the document path", but that doesn't appear to work, I tried `/cmds/string`. So we'll just have to use cmds/string in normal documents and plain `string` from other commands. 2022-09-24 01:57:49 +08:00			Causes the specified functions to be erased. This also means that it is prevented from autoloading in the current session. Use :doc:`funcsave <funcsave>` to remove the saved copy.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-D or --details`
functions --copy: store file and lineno (#9542) Keeps the location of original function definition, and also stores where it was copied. `functions` and `type` show both locations, instead of none. It also retains the line numbers in the stack trace. 2023-02-13 23:59:28 +08:00			Reports the path name where the specified function is defined or could be autoloaded, ``stdin`` if the function was defined interactively or on the command line or by reading standard input, - if the function was created via :doc:`source <source>`, and ``n/a`` if the function isn't available. (Functions created via :doc:`alias <alias>` will return -, because ``alias`` uses ``source`` internally. Copied functions will return where the function was copied.) If the --verbose option is also specified then five lines are written:
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
functions --copy: store file and lineno (#9542) Keeps the location of original function definition, and also stores where it was copied. `functions` and `type` show both locations, instead of none. It also retains the line numbers in the stack trace. 2023-02-13 23:59:28 +08:00			`- the path name as already described,`
			- if the function was copied, the path name to where the function was originally defined, otherwise ``autoloaded``, ``not-autoloaded`` or ``n/a``,
docs: Remove `-#` formatting That was supposed to be displayed like a list item, but it's displayed verbatim in the html output at least, so it looks weird. [ci skip] 2019-06-05 04:07:06 +08:00			`- the line number within the file or zero if not applicable,`
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			- ``scope-shadowing`` if the function shadows the vars in the calling function (the normal case if it wasn't defined with --no-scope-shadowing), else ``no-scope-shadowing``, or ``n/a`` if the function isn't defined,
Clarify `functions -Dv`'s output 2022-01-03 22:04:42 +08:00			- the function description minimally escaped so it is a single line, or ``n/a`` if the function isn't defined or has no description.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`You should not assume that only five lines will be written since we may add additional information to the output in the future.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`--no-details`
			`Turns off function path reporting, so just the definition will be printed.`
functions: Add "--no-details" flag and use it in funced This inhibits the function path comment which is annoying in `funced`. Fixes #7879. 2021-03-30 22:51:27 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-n or --names`
			`Lists the names of all defined functions.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-q or --query`
			`Tests if the specified functions exist.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-v or --verbose`
			`Make some output more verbose.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-H or --handlers`
			`Show all event handlers.`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
docs: standardise on definition lists for options Harmonizes the option listing including formatting in a similar manner to the synopsis of each entry. 2022-03-11 23:56:20 +08:00			`-t or --handlers-type TYPE`
			`Show all event handlers matching the given TYPE.`
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docs: omnibus cleanup Includes harmonizing the display of options and arguments, standardising terminology, using the envvar directive more broadly, adding help options to all commands that support them, simplifying some language, and tidying up multiple formatting issues. string documentation is not changed. 2022-03-12 00:18:41 +08:00			`-h or --help`
			`Displays help about using this command.`

correct description of -a param regarding _(\w*) removed the word "not" to resolve an (unintended) negation of negation. 2020-09-08 23:35:42 +08:00			The default behavior of ``functions``, when called with no arguments, is to print the names of all defined functions. Unless the ``-a`` option is given, no functions starting with underscores are included in the output.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-17 05:08:41 +08:00
			`If any non-option parameters are given, the definition of the specified functions are printed.`

Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +08:00			Copying a function using ``-c`` copies only the body of the function, and does not attach any event notifications from the original function.
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			Only one function's description can be changed in a single invocation of ``functions -d``.
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			The exit status of ``functions`` is the number of functions specified in the argument list that do not exist, which can be used in concert with the ``-q`` option.
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			`Examples`
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

Switch \fish sections to rst format 2018-12-19 11:14:04 +08:00			`::`

			`functions -n`
			`# Displays a list of currently-defined functions`

			`functions -c foo bar`
			`# Copies the 'foo' function to a new function called 'bar'`

			`functions -e bar`
Switch backticks to double backticks for rst compatibility 2018-12-20 04:02:45 +08:00			# Erases the function ``bar``
Switch \fish sections to rst format 2018-12-19 11:14:04 +08:00
docs: Links for the function-related commands 2021-05-08 18:12:56 +08:00			`See more`
			`--------`

			For more explanation of how functions fit into fish, see :ref:`Functions <syntax-function>`.