It's easy to sort a hash by it's key, but to sort by it's value, the subroutines below are a life safer!

From: http://www.perlfect.com/articles/sorting.shtml

my %HASH = (
   'cats' => 29,
   'dogs' => 85
);

# ascending, $a <=> $b
foreach my $k ( sort { $HASH{$a} <=> $HASH{$b} } keys %HASH ) {
   printf "%6d %s\n",$HASH{$k},$k;
}

# descending, $b <=> $a
foreach my $k ( sort { $HASH{$b} <=> $HASH{$a} } keys %HASH ) {
   printf "%6d %s\n",$HASH{$k},$k;
}