Your specification is rather sparse. However a big heads up in your code is that you are using nested loops. That just ain't going to work. Every time you add a level to your hash you will need to add another nested loop and you really don't want to go there.

The common technique is to write a recursive sub to do the work. Consider:

use strict;
use warnings;
use 5.010;

my %categories = (
    level1 => {
        'level1-1' => {},
        'level1-2' => {'level1-2-1' => {}},
        'level1-3' => {},
        },
    level2 => {'level2-1' => {}},
    );

dumpHash(\%categories);

sub dumpHash {
    my ($subHash, $indent) = @_;

    $indent //= '';

    given (ref $subHash) {
        when ('') {print "$indent$subHash\n" if defined $subHash}
        when ('HASH') {
            for my $key (sort keys %$subHash) {
                print "$indent$key\n";
                dumpHash($subHash->{$key}, "$indent   ");
            }
        }
    }
}

[download]

Prints:

level1
   level1-1
   level1-2
      level1-2-1
   level1-3
level2
   level2-1

[download]
True laziness is hard work

In reply to Re: Printing a tree-view of a hash of hashes by GrandFather
in thread Printing a tree-view of a hash of hashes by pdxperl

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