#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

my %dir_tree;
my $root_dir = '.';

build_dir_tree(\%dir_tree, $root_dir);

sub build_dir_tree {
    my ($tree, $path) = @_;

    opendir(my $dh, $path);

    for (readdir $dh) {
        next if /^(?:\.|\.\.)$/;

        if (-d "$path/$_") {
            $tree->{$_} = {};
            build_dir_tree($tree->{$_}, "$path/$_");
        }
        else {
            $tree->{$_} = -s "$path/$_";
        }
    }
}

{
    use Data::Dumper;
    local $Data::Dumper::Indent = 1;
    local $Data::Dumper::Sortkeys = 1;
    print Dumper \%dir_tree;
}

##</code><code>##

  ...
  'pm_multi_line_match.pl' => 1025,
  'pm_multi_mod_distro_test' => {
    'My-Example' => {
      'Build.PL' => 651,
      'Changes' => 92,
      'MANIFEST' => 136,
      'Makefile.PL' => 730,
      'README' => 1316,
      'ignore.txt' => 120,
      'lib' => {
        'My' => {
          'Example.pm' => 5155
        }
      },
      't' => {
        '00.load.t' => 117,
        'perlcritic.t' => 454,
        'pod-coverage.t' => 437,
        'pod.t' => 405
      }
    }
  },
  'pm_multiline_parse.pl' => 835,
  'pm_multiline_parse_hdb_prob.pl' => 601,
  ...