How to make CodeIgniter's ellipsize() support Chinese truncation_PHP tutorial

function ellipsize($codepage = 'UTF-8',
                                                                                                 $position = 1, $ellipsis = '...')
{
// Strip tags
$str = trim(strip_tags($str));

// Is the string long enough to ellipsize?
if (mb_strlen($str, $codepage) <= $max_length)
{
return $str;
}

$beg = mb_substr($ str, 0, floor($max_length * $position), $codepage);

$position = ($position > 1) ? 1 : $position;

if ($position = == 1)
{
$end = mb_substr($str, 0,
-($max_length - mb_strlen($beg, $codepage)), $codepage);
}
else
{
$end = mb_substr($str,
-($max_length - mb_strlen($beg, $codepage)), $max_length, $codepage);
}

Return $beg.$ellipsis.$end;
}