Phalcon\Build\Util::cleanDirectory PHP Method

    public static function cleanDirectory($dir)
    {
        $iterator = new \DirectoryIterator($dir);
        foreach ($iterator as $entry) {
            /** @var $entry \DirectoryIterator */
            if ($entry->isDot() || $entry->getBasename() == 'tests') {
                continue;
            }
            if ($entry->isDir() && !$entry->isLink()) {
                self::cleanDirectory($entry->getPathname());
                rmdir($entry->getPathname());
            } else {
                if (is_writable($dir)) {
                    unlink($entry->getPathname());
                }
            }
        }
    }

 /**
  * Delete all files in target directories
  */
 public function cleanBuildDirectories()
 {
     foreach ($this->settings as $setting) {
         Util::cleanDirectory($setting['dir']);
     }
 }