php DO not use trailing slash DIR_NAME tmp dh opendir DIR_NAME while f

<?php

# DO not use trailing slash!!!
$DIR_NAME = '/tmp';

$dh = opendir($DIR_NAME);
while(false !== ($row = readdir($dh))) {
    if ('.' == $row or '..' == $row) {
        continue;
    }
    if (is_dir($DIR_NAME . '/'  . $row)) {
        print 'foobar' . $row . "\n";
    }
}

?>