On modern Fedora Linux installations, pressing the computer's "power off" button does not actually shut it down, but rather hibernates it, which is very convenient.
However, this is only true if I run the default Gnome window manager. If I use a different window manager (my favorite is the old-school ctwm), this doesn't happen - the power-off button shuts down the system instead of hibernating.
My question is: How can I tell my system (I don't mind a little coding, and it doesn't need to be inside ctwm) to do something else - and not a shutdown - when the poweroff button is pressed. Without Gnome.
I did a little digging, and it appears that I have "upowerd" running. However, it is running just the same when ctwm and Gnome are the current window manager, so Gnome must somehow be telling upowerd not to power-off the computer and instead either do something else (like hibernate) or send Gnome that the event happened. But I couldn't find any documentation on how that's done, or how I can do something similar without Gnome.