Cut an arabic string

PHP Snippet 1:

mb_internal_encoding('UTF-8');

PHP Snippet 2:

return '...'.mb_substr($str, 0, $limit - 3, "UTF-8"); // UTF-8 is optional

PHP Snippet 3:

 public static function shorten_arabic_text($text, $lenght)
        {
            mb_internal_encoding('UTF-8');
            $out = mb_strlen($text) > $lenght ? mb_substr($text, 0, $lenght) . " ..." : $text;
            return $out;
        }