Now that shutdown(8) provides info why we are shutting down to the
shutdown scripts, add an optional local hook /etc/rc.shutdown.final
called last in the shutdown sequence and passed the reason.

This allows for easy local integration of special UPS commands before
we power down (e.g. to restart the UPS after some delay in case
utility power is restored too early and the machine has already powered
down and will only restart when it's power input is restored after being
off for a few seconds)

branches: 1.9.46;
PR/46601 - Jim Bernard -- add support for rc_directories

branches: 1.8.58; 1.8.60;
Add two new rc.conf(5) variables:
rc_rcorder_flags extra flags to rcorder(8) in /etc/rc
rcshutdown_rcorder_flags extra flags to rcorder(8) in /etc/rc.shutdown

This can be used to specify extra directories to search for rc.d scripts in.
For example, adding the following to rc.conf(5):
rc_rcorder_flags="/usr/pkg/etc/rc.d/*"
rcshutdown_rcorder_flags="/usr/pkg/etc/rc.d/*"
will add the files in /usr/pkg/etc/rc.d to the list of files that rcorder(8)
uses to build the list of scripts to start or stop.

I proposed this functionality on tech-userlevel@ over one month ago.
Closes the recent [misc/16888], which asked for a similar feature.

use reverse_list() (from rc.subr) to reverse the list

- Implement an optional global watchdog timeout for rc.shutdown, which is
enabled by setting $rcshutdown_timeout to a number of seconds to wait for
before terminating rc.shutdown. This is disabled by default.
- Use symbolic names rather than numbers when defining a trap.
- Improve some comments.

- describe what rc.shutdown does, and what invokes it
- remove `.sh' suffix on script name in description

run rcorder with `-k shutdown', so that only the scripts with a
`shutdown' keyword get run at shutdown time.

branches: 1.3.4;
if checkyesno do_rcshutdown, run scripts in /etc/rc.d/* in the
reverse order returned by rcorder

Check for location of xdm's pid file as suggested by Simon Burge.
Fixes PR misc/6828 by Paul Goyette.

A basic /etc/rc.shutdown. Bails out if do_rcshutdown!=YES in /etc/rc.conf
(default is YES). Kills xdm and waits for it to terminate if it was enabled
in rc.conf (based on a code snippet from Ignatios).