#!/usr/bin/perl
use warnings;
use strict;
use File::Slurp::Tree;

# The tree datastructure is a hash of hashes.  The keys of  
# each hash are names of directories or files.  Directories  
# have hash references as their value, files have a scalar  
# which holds the contents of the file.  

my $dir = shift || '.';
my %tree;
my $tree = slurp_tree($dir);

my $depth = 0;
print "$dir\n";
print_keys($tree);

sub print_keys {
    my $href = shift;
    $depth++;
    foreach ( keys %$href ) {
        print '    ' x $depth, "--$_\n";
        print_keys( $href->{$_} ) if ref $href->{$_} eq 'HASH';
    }
    $depth--;
}