\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`. If the exit status of `CONDITION` is non-zero on the first iteration, `COMMANDS` will not be executed at all. You can use `and` or `or` for complex conditions. Even more complex control can be achieved with `while true` containing a break. \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