get drive space size (Perl + WMI)

wmi_drive_space.pl

use strict;
use warnings;
use Win32::OLE;

sub getDriveSpace {
    my ($drive) = @_;
    my $wql = 'SELECT DeviceID, FreeSpace FROM Win32_LogicalDisk';
    my $items = Win32::OLE->GetObject('winmgmts:/root/CIMV2')->ExecQuery($wql);
    my %info = map {uc($_->DeviceID) => $_->FreeSpace} Win32::OLE::in $items;
    return $info{uc($drive)} || 0;
}

if (!caller) {
    my $drive = ($ARGV[0])? $ARGV[0]: 'c:';
    print getDriveSpace($drive);
}