That sort routine doesn't work too well when sorting string fields. When sorting string fields, number are considered greater than strings. In ASCII, it's the other way around.

>perl -le "print '123' <=> 'abc'"
1

>perl -le "print '123' cmp 'abc'"
-1
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It would be better if you knew if the field was numerical or a string in advance. The following makes all decision making in advance, speeding up the sorting.

my $orderby   = 'age';
my $numerical = 1;
my $direction = 'ASC';

my $sorter;

if ($direction eq 'ASC') {
   if ($numerical) {
      $sorter = sub { $hash{$a}{$orderby} <=> $hash{$b}{$orderby} };
   } else {
      $sorter = sub { $hash{$a}{$orderby} cmp $hash{$b}{$orderby} };
   }
} else {
   if ($numerical) {
      $sorter = sub { $hash{$b}{$orderby} <=> $hash{$a}{$orderby} };
   } else {
      $sorter = sub { $hash{$b}{$orderby} cmp $hash{$a}{$orderby} };
   }
}

@sorted = sort { &$sorter } keys %hash;
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