fish-shell/doc_src/cmds/while.rst

.. _cmd-while:

while - perform a set of commands multiple times
================================================

Synopsis
--------

**while** *CONDITION*; *COMMANDS*; **end**

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

**while** repeatedly executes ``CONDITION``, and if the exit status is 0, then executes ``COMMANDS``.

The exit status of the **while** loop is the exit status of the last iteration of the ``COMMANDS`` executed, or 0 if none were executed. (This matches other shells and is POSIX-compatible.)

You can use :ref:`and <cmd-and>` or :ref:`or <cmd-or>` for complex conditions. Even more complex control can be achieved with ``while true`` containing a :ref:`break <cmd-break>`.

Example
-------

::

    while test -f foo.txt; or test -f bar.txt ; echo file exists; sleep 10; end
    # outputs 'file exists' at 10 second intervals,
    # as long as the file foo.txt or bar.txt exists.
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 09:05:09 +00:00			`.. _cmd-while:`

Change "while" command title to match "for" one Closes #8409 2021-11-06 13:59:53 +00:00			`while - perform a set of commands multiple times`
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Switch command docs from \section to reStructuredText 2018-12-17 01:39:33 +00:00
Migrate the 'synopsis' sections to .rst format 2018-12-18 01:58:24 +00:00			`Synopsis`
			`--------`
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docs synopses: use ellipsis with singular words We use plural "OPTIONS" more often than "OPTION...", so let's do that everywhere. In some other places where we do have an ellipsis, make sure to use singular, since the ellipsis already means repetition. This change is incomplete, and I'm not sure if this is worth it, since it's subjective, so I might drop it. 2022-01-09 08:42:36 +00:00			`while CONDITION; COMMANDS; end`
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Convert \\subsection sections into rst format 2018-12-19 02:44:30 +00:00			`Description`
Fix command section separator line lengths 2019-01-03 04:10:47 +00:00			`-----------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
More synopsis work. A great leap forward 2021-12-22 01:24:47 +00:00			while repeatedly executes ``CONDITION``, and if the exit status is 0, then executes ``COMMANDS``.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
More synopsis work. A great leap forward 2021-12-22 01:24:47 +00:00			The exit status of the while loop is the exit status of the last iteration of the ``COMMANDS`` executed, or 0 if none were executed. (This matches other shells and is POSIX-compatible.)
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
docs: Use more command labels 2019-03-31 09:24:04 +00:00			You can use :ref:`and <cmd-and>` or :ref:`or <cmd-or>` for complex conditions. Even more complex control can be achieved with ``while true`` containing a :ref:`break <cmd-break>`.
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Convert \\subsection sections into rst format 2018-12-19 02:44:30 +00:00			`Example`
Fix command section separator line lengths 2019-01-03 04:10:47 +00:00			`-------`
Copy doc_src to sphinx_doc_src and add a TOC 2018-12-16 21:08:41 +00:00
Switch \fish sections to rst format 2018-12-19 03:14:04 +00:00			`::`

			`while test -f foo.txt; or test -f bar.txt ; echo file exists; sleep 10; end`
docs: Make more code lines shorter 2021-02-02 07:35:38 +00:00			`# outputs 'file exists' at 10 second intervals,`
			`# as long as the file foo.txt or bar.txt exists.`
Switch \fish sections to rst format 2018-12-19 03:14:04 +00:00