Get all files recursively

get-files.php

<?php
/**
* @param $dir
 * @param array $files
 * @return array
 */
protected function getFiles($dir, array &$files = [])
{
    foreach (scandir($dir) as $file) {
        if (in_array($file, [".", ".."])) {
            continue;
        }

        $fullPath = $dir.'/'.$file;

        if (is_dir($fullPath)) {
            $this->getFiles($fullPath, $files);
        } else {
            $files[] = $fullPath;
        }
    }
     return $files;
}

OOP way is http://php.net/manual/ru/class.recursivedirectoryiterator.php