0 andyjpb@robusta ~
$ echo $LESS
$LESS       $LESSCLOSE  $LESSOPEN   

0 andyjpb@robusta ~
$ echo $LESS
-X -F

0 andyjpb@robusta ~
$ echo $LESSCLOSE 
/usr/bin/lesspipe %s %s

0 andyjpb@robusta ~
$ echo $LESSOPEN 
| /usr/bin/lesspipe %s