How to determine why system wakeup occurred

Is it possible to determine the cause of system wakeup from sleep in OS X from Cocoa, a lower-level API method, or a terminal command (less preferable)? Possible reasons for wakeup include:

• A keyboard button was pressed
• The laptop lid was opened
• Network activity was detected
• A schedul开发者_StackOverflowed wakeup time (set with IOPMSchedulePowerEvent) occurred

I am trying in particular to detect the last reason, so that I can put the system to sleep for 10 minutes and then automatically into hibernation (aka safe sleep). To do so, I am scheduling a wakeup 10 minutes out, followed by a hibernate event. But I don't want to accidentally hibernate the system if the user activated a wakeup at roughly the same time.

FYI, this is apparently possible in Windows 7.

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The terminal commands pmset -g log and pmset -g rawlog should help do what you need.

The manual for pmset documents these options; note the manual page shipped with Mac OS X 10.7 lists many more options.