=head1 NAME
aa-shutdown - Helper to trigger a reboot/power off/halt of the machine
=head1 SYNOPSIS
B<aa-shutdown> [B<-r> | B<-p> | B<-H>]
=head1 OPTIONS
=over
=item B<-H, --halt>
Halts the machine.
=item B<-h, --help>
Show help screen and exit.
=item B<-p, --poweroff>
Powers off the machine.
=item B<-r, --reboot>
Reboots the machine.
=item B<-V, --version>
Show version information and exit.
=back
=head1 DESCRIPTION
B<aa-shutdown>(1) is a simple helper that will send the appropriate commands to
B<s6-svscan> (using B<s6-svscanctl>).
It obviously expects it to be running (as PID 1) using I</run/services/.scandir>
as its scandir.
Additionally, if called as B<halt>, B<reboot> or B<poweroff> then it
automatically defaults to the corresponding action. This allows to use symlinks
by those names pointing to B<aa-shutdown>(1). Note that in this case:
- An option isn't required; i.e. calling it as `reboot` will trigger the
reboot, as would `aa-shutdown --reboot` have done;
- If an option is specified, it takes precedence. So calling it `reboot -p` will
power off the machine.