http://www.perlmonks.org?node_id=1179691


in reply to Some help with my project:

This is the only line that could generate that message (although it doesn't look like line 35):
my $monit_percentual = ( $avail / $avail+$used ) * 100 ;

UPDATE (dave_the_m): That means $avail is probably 0 ($avail+$used)=0 (probably both variables are 0). Tip #2 from the Basic debugging checklist: print

Also: