#load hash after some parsing in a foreach loop push(@{$jobs{$JobName}{1}}, $blah); ... $level =1; $nextlevel = 2; while ($level <= 10) { foreach my $dep (keys %jobs) { foreach (@{$jobs{$dep}{$level}}) { print "$dep $level $_\n"; push( @{$jobs{$dep}{$nextlevel}},@{$jobs{$_}{$level}} ); next if ${$jobs{$_}{$level}}[0] eq "$dep"; last if ${$jobs{$_}{$level}}[0] eq ''; #this cancels the loop if any of the dependencies don't have dependencies, which is a problem if there's additional } } $level++; $nextlevel++; }