\section while while - perform a command multiple times

\subsection while-synopsis Synopsis
\fish{synopsis}
while CONDITION; COMMANDS...; end
\endfish

\subsection while-description 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 <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>.

\subsection while-example Example

\fish
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.
\endfish