#! perl -slw
use strict;
use Win32::DirSize;
use Data::Dumper;

dir_size( 'p:\\', my $info );

print Dumper $info;

## As a string
print $info->{DirSize};

## Same field as an integer
print 0+$info->{DirSize};

## Same value by combining the high and low parts into a float
printf "%.f\n", ( $info->{HighSize} * 2**32 ) + $info->{LowSize};

my $dirsize = $info->{DirSize};

if(    $dirsize < 2**10 ) { printf "%d bytes\n",$dirsize         }
elsif( $dirsize < 2**20 ) { printf "%.2f KB\n", $dirsize / 2**10 }
elsif( $dirsize < 2**30 ) { printf "%.2f MB\n", $dirsize / 2**20 }
elsif( $dirsize < 2**40 ) { printf "%.2f GB\n", $dirsize / 2**30 }
elsif( $dirsize < 2**50 ) { printf "%.2f TB\n", $dirsize / 2**40 }
elsif( $dirsize < 2**60 ) { printf "%.2f PB\n", $dirsize / 2**50 }
else{ print "This number is probably wrong: $dirsize";           }

__END__
[ 1:15:03.82] P:\test>DirSize.pl
$VAR1 = {
          'DirCount' => 3866,
          'LowSizeOnDisk' => 140623872,
          'HighSizeOnDisk' => 4,
          'FileCount' => 67685,
          'DirSizeOnDisk' => '17320493056',
          'DirSize' => '46480798709',
          'LowSize' => 3531125749,
          'Errors' => [],
          'HighSize' => 10
        };

46480798709
46480798709
46480798709
43.29 GB