Directory::read

<?php while ($row=$dir->read())  ?>
// will break as soon as $row can be casted to false, which is the case for a directory named "0"

<?php while (false !== ($row=$dir->read())) ?>
// will do the job as expected

use 
while ($row=$dir->read()){
// your code
} 
to get a list of all files and directories. You can definitely use the "for" and other loops.