#!/usr/bin/perl

use strict;

my $debug = 0;

my ($dir_init, $show_level) = @ARGV;

my (@ls, @dirs, $size, $parent);
my %dir_size = ();
my %parent_of_dir = ();
my %level_of_dir = ();
my $sep = "~" x 80;
my $form = "%20s  %s\n";

my $files = 0;
#	Get the list of files using readdir.
push(@dirs, $dir_init);
$dir_size{$dir_init} = 0;
$level_of_dir{$dir_init} = 0;

foreach my $directory (@dirs) {
	print "\n\n------- starting directory scan -------- in $directory" if ($debug);
	opendir (DIR, $directory) or die ("Can't open dir: '$directory'.\nReason: $!");
	@ls = readdir(DIR);
	closedir (DIR);

#	Then go through the results of ls and work out the files..
	FILE: foreach my $file (@ls)
	{
#		print "\n* * * * *  $file" if ($debug);
		next if ($file =~ m/^\.\.?$/);
		$files++;
		SWITCH:
		{
			if (-d "$directory/$file") {
				print "\n$file\tis DIRECTORY" if ($debug);
				push(@dirs, "$directory/$file");
				$level_of_dir{"$directory/$file"} = $level_of_dir{$directory} + 1;
				$parent_of_dir{"$directory/$file"} = $directory;

				$dir_size{"$directory/$file"} = 0;
				last SWITCH;
			}
			if (-l "$directory/$file") {
				print "\n$file is a symbolic link" if ($debug);
				last SWITCH;
			}
			if (-f "$directory/$file") {
				print "\n$file is a plain file" if ($debug);
#				($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks)= stat "$directory/$file";
				$size = (-s "$directory/$file");
				print "\tsize: $size" if ($debug);
				$dir_size{"$directory"} += $size;

				$parent = $parent_of_dir{$directory};
#				print "\ntry with parent as: $parent if ($debug);
				while ($parent)
				{
					$dir_size{$parent} += $size;
					$parent = $parent_of_dir{$parent};
#					print "\ntry with parent as: $parent" if ($debug);
				}

				last SWITCH;
			}
			else
			{
				print "\n$file\tis of UNKNOWN type";
			}
		}
	}
}
print "\n------- finished directory scans --------" if ($debug);
print "Total number of files/directories examined: $files\n";

print $sep . "\n";
foreach my $k (sort keys %dir_size)
{
	next if ($show_level  &&  ($show_level < $level_of_dir{$k}));
	print "\t\t" x $level_of_dir{$k};
	printf $form, commify($dir_size{$k}), $k;
#	printf $form, $dir_size{$k}, $k;
}
print $sep . "\n";

print "\n" if ($debug);
foreach my $k (keys %parent_of_dir)
{
	print "\n $k: $parent_of_dir{$k}" if ($debug);
}

sub commify {
    my $text = reverse $_[0];
    $text =~ s/(\d\d\d)(?=\d)(?!\d*\.)/$1,/g;
    return scalar reverse $text;
}

__OUTPUT__
Total number of files/directories examined: 1489
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          58,192,935  P:\dev\perl
		             145,431  P:\dev\perl/0735712891Code
		           1,129,217  P:\dev\perl/Compress-Zlib-1.33
		          34,215,542  P:\dev\perl/DPL
		             507,956  P:\dev\perl/Regexp-Common-2.113
		              71,412  P:\dev\perl/albums
		             508,041  P:\dev\perl/calendar
		              65,996  P:\dev\perl/formalware
		              53,356  P:\dev\perl/guestbook
		               1,714  P:\dev\perl/hoch
		              12,139  P:\dev\perl/http
		          11,692,406  P:\dev\perl/modules
		             100,426  P:\dev\perl/oracle
		              31,036  P:\dev\perl/perl-xml-quickstart
		             758,171  P:\dev\perl/updf
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~