Some are fairly obvious. Specifically, I am referring to:
-h halt or power off after shutdown
-H halt after shutdown (implies -h)
-P power off after shutdown (implies -h)
Isn't halting or powering off kind of expected when you're shutting down? Aren't these redundant?
-c cancel a running shutdown
How on earth would you use this? In my experience, once a shutdown has begun, you don't get much opportunity to enter more commands until the machine is off.
-k only send warnings, don't shutdown
Why does shutdown
have an option that makes it not shut down?
What's the deal here? Does "shutdown" mean more than simply turning the machine off?