locking screen after suspend/hibernate

[Jose Rodriguez <josec.rodriguez@gmail.com>]

I want my screen to be locked when resuming from
suspend/hibernate. I don't use any desktop environment, so I
tried uncommented the following line
from /etc/hibernate/common.conf :

LockXtrLock yes

and installed xtrlock. This does nothing, though. A little
script on resume would do just fine, I suppose but I don't know how
to make hibernate to call it. 

Any hint?