fish-shell/sphinx_doc_src/cmds/while.rst

while - perform a command multiple times
==========================================

Synopsis
--------

while CONDITION; COMMANDS...; end


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

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

If the exit status of ``CONDITION`` is non-zero on the first iteration, ``COMMANDS`` will not be
executed at all, and the exit status of the loop set to the exit status of ``CONDITION``.

The exit status of the loop is 0 otherwise.

You can use <a href="#and">``and``</a> or <a href="#or">``or``</a> for complex conditions. Even more complex control can be achieved with ``while true`` containing a <a href="#break">break</a>.

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.