use strict;
use warnings;

my $tree = {};
read_it('D:', $tree);

{
  my $durchlauf;
  sub read_it {
    my ($dir, $tree) = @_;

    my $name;
    $name = (split(/\\/, $dir))[-1] if ($durchlauf);
    $name = $dir unless ($durchlauf);
    $durchlauf = 1;

    my @file = ();
    my @dir = ();

    opendir(VERZ, $dir);
    while (my $read = readdir(VERZ)) {
      if (-d "$dir\\$read") {
       push (@dir, "$dir\\$read") if ($read !~ /(\.)$/);
      }
      else {
        push @file, $read;
      }
    }
    closedir(VERZ);

    $tree -> {$name} =  { files => \@file };

    foreach my $directory (@dir) {
      read_it("$directory", \%{ $tree -> {$name} })
    }
  }
}