can zsh detect return from hibernation?

[Ray Andrews <rayandrews@xxxxxxxxxxx>]

Of course it's not really a zsh issue, but when my machine returns from 
hibernation it always spins up all disks.  System level things can spin 
themdown, but on thaw, I'm back to my xfce4 desktop and xfce4 is the 
culprit spinning up the disks.  It seems that there's no way of getting 
xfce4 to reset the spindown, so I'm wondering if zsh can detect that 
it's resumed from hibernationso that I can add something to zshrc to 
perform "hdparm -y /dev/sdb" but only the one time that it's needed. 
It's hardly a big problem but I'd not be surprised if zsh can handle it.