Thanks for this extensive reports on shutdown technology.
Me too, I looked for a clear answer to that question a while ago and didn't find such clear (and sometimes not concise at all) bits of CLI help. So I stuck with
su.
[Kudos to
rg3 for
dbus-send --print-reply --system --dest=org.freedesktop.Hal /org/freedesktop/Hal/devices/computer org.freedesktop.Hal.Device.SystemPowerManagement.Shutdown that's my favourite so far. While indeed I havent tried it.]
To cut it short,
su is not your ennemy. For those of you that don't like pushing a (sometimes faraway) button, or play with sudoers files, I've always done this:
(which is close to sudo but doesn't require any edit of configs)
And it's in the feeble range of my goldfish-grade brains memory, so I never forget this one.
I know it's not what you asked for, but still simple.
Albeit you have to give the password.
Cheers; I am bookmarking this post for my next install.
Jean-Philippe
http://www.tropicalicecube.net