March 12th, 2012, 06:30 PM
Your $USERS variable will be set to the 'top 10' users, so will have a value such as /home/a /home/b /home/c ... etc.
With the loop for $USRDIR in $USERS the $USRDIR variable will be set to each home directory in turn.
Your du -a $USRDIR ... command will then produse the top 10 files within that home directory.
The moon on the one hand, the dawn on the other:
The moon is my sister, the dawn is my brother.
The moon on my left and the dawn on my right.
My brother, good morning: my sister, good night.
-- Hilaire Belloc