2019-03-31 17:05:09 +08:00
.. _cmd-functions:
2018-12-17 09:39:33 +08:00
functions - print or erase functions
2019-01-03 12:10:47 +08:00
====================================
2018-12-17 09:39:33 +08:00
2018-12-18 09:58:24 +08:00
Synopsis
--------
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 ::
functions [-a | --all] [-n | --names]
functions [-D | --details] [-v] FUNCTION
functions -c OLDNAME NEWNAME
functions -d DESCRIPTION FUNCTION
functions [-e | -q] FUNCTION ...
2018-12-17 05:08:41 +08:00
2018-12-19 10:44:30 +08:00
Description
2019-01-03 12:10:47 +08:00
-----------
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
`` functions `` prints or erases functions.
2018-12-17 05:08:41 +08:00
The following options are available:
2018-12-20 04:02:45 +08:00
- `` -a `` or `` --all `` lists all functions, even those whose name starts with an underscore.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -c OLDNAME NEWNAME `` or `` --copy OLDNAME NEWNAME `` creates a new function named NEWNAME, using the definition of the OLDNAME function.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -d DESCRIPTION `` or `` --description=DESCRIPTION `` changes the description of this function.
2018-12-17 05:08:41 +08:00
2022-01-03 23:03:29 +08:00
- `` -e `` or `` --erase `` causes the specified functions to be erased. This also means that it is prevented from autoloading in the current session. Use :ref: `funcsave <cmd-funcsave>` to remove the saved copy.
2018-12-17 05:08:41 +08:00
2020-03-21 04:10:46 +08:00
- `` -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 stdin, `` - `` if the function was created via :ref: `source <cmd-source>` , and `` n/a `` if the function isn't available. (Functions created via :ref: `alias <cmd-alias>` will return `` - `` , because `` alias `` uses `` source `` internally.) If the `` --verbose `` option is also specified then five lines are written:
2018-12-17 05:08:41 +08:00
2019-06-05 04:07:06 +08:00
- the pathname as already described,
- `` 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,
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.
2018-12-17 05:08:41 +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.
2021-03-30 22:51:27 +08:00
- `` --no-details `` turns off function path reporting, so just the definition will be printed.
2018-12-20 04:02:45 +08:00
- `` -n `` or `` --names `` lists the names of all defined functions.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -q `` or `` --query `` tests if the specified functions exist.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -v `` or `` --verbose `` will make some output more verbose.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -H `` or `` --handlers `` will show all event handlers.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
- `` -t `` or `` --handlers-type TYPE `` will show all event handlers matching the given type
2018-12-17 05:08:41 +08:00
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.
2018-12-17 05:08:41 +08:00
If any non-option parameters are given, the definition of the specified functions are printed.
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.
2018-12-17 05:08:41 +08:00
2018-12-20 04:02:45 +08:00
Only one function's description can be changed in a single invocation of `` functions -d `` .
2018-12-17 05:08:41 +08:00
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.
2018-12-17 05:08:41 +08:00
2018-12-19 10:44:30 +08:00
Examples
2019-01-03 12:10:47 +08:00
--------
2018-12-17 05:08:41 +08:00
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
2018-12-20 04:02:45 +08:00
# Erases the function `` bar ``
2018-12-19 11:14:04 +08:00
2021-05-08 18:12:56 +08:00
See more
--------
For more explanation of how functions fit into fish, see :ref: `Functions <syntax-function>` .
