fish-shell/doc_src/cmds/functions.rst

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.. _cmd-functions:
functions - print or erase functions
====================================
Synopsis
--------
::
functions [ -a | --all ] [ -n | --names ]
functions [ -D | --details ] [ -v ] FUNCTION
functions -c OLDNAME NEWNAME
functions -d DESCRIPTION FUNCTION
functions [ -e | -q ] FUNCTIONS...
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 OLDNAME NEWNAME`` or ``--copy OLDNAME NEWNAME`` creates a new function named NEWNAME, using the definition of the OLDNAME function.
- ``-d DESCRIPTION`` 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.
- ``-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:
- 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,
- the function description minimally escaped so it is a single line or ``n/a`` if the function isn't defined.
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`` will make some output more verbose.
- ``-H`` or ``--handlers`` will show all event handlers.
- ``-t`` or ``--handlers-type TYPE`` will show all event handlers matching the given type
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
--------
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::
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``
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See more
--------
For more explanation of how functions fit into fish, see :ref:`Functions <syntax-function>`.