build/controllers/DevController.php
protected function listSubDirs($dir)
    {
        $list = [];
        $handle = opendir($dir);
        if ($handle === false) {
            throw new InvalidParamException("Unable to open directory: $dir");
        }
        while (($file = readdir($handle)) !== false) {
            if ($file === '.' || $file === '..') {
                continue;
            }
            // ignore hidden directories
            if ($file[0] === '.') {
                continue;
            }
            if (is_dir("$dir/$file")) {
                $list[] = "$dir/$file";
            }
        }
        closedir($handle);
        return $list;
    }
protected function listSubDirs($dir)
    {
        $list = [];
        $handle = opendir($dir);
        if ($handle === false) {
            throw new InvalidParamException("Unable to open directory: $dir");
        }
        while (($file = readdir($handle)) !== false) {
            if ($file === '.' || $file === '..') {
                continue;
            }
            // ignore hidden directories
            if ($file[0] === '.') {
                continue;
            }
            if (is_dir("$dir/$file")) {
                $list[] = "$dir/$file";
            }
        }
        closedir($handle);
        return $list;
    }
Get a list of subdirectories for directory specified.
@param string $dir directory to read

@return array list of subdirectories