command script run at system shutdown
When the system is administratively shut down using either the
is invoked with the argument
which checks for the existence of a
script to run before halting the system.
This script, like
is entirely for commands added by the system administrator.
script is also executed by
if a keyboard-requested halt is issued (for architectures that support this).
sets the variable
will attempt to power down the machine after it has halted.