PHP Recursively list directories and files; recursive listing scan and traversal

PHP List directory files and folders.

error_reporting(E_ALL | E_STRICT);
ini_set('display_errors', 1);

header('Content-Type: text/plain');

$dir = dirname(__FILE__);

foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir)) as $item) {
    if ($item->isFile() || $item->isDir()) {
        echo $item . PHP_EOL;
    }
}