php smarty truncate UTF8乱码问题解决办法

/**
* Smarty truncate modifier plugin
*
* Type: modifier<br>
* Name: truncate<br>
* Purpose: Truncate a string to a certain length if necessary,
* optionally splitting in the middle of a word, and
* appending the $etc string or inserting $etc into the middle.
* @link http://smarty.php.net/manual/en/language.modifier.truncate.php
* truncate (Smarty online manual)
* @author Monte Ohrt <monte at ohrt dot com>
* @param string
* @param integer
* @param string
* @param boolean
* @param boolean
* @return string
*/
function smarty_modifier_truncate2( $string,$length = 80,$etc='…',$count_words = true ) {
return $returnstr =substr_utf8($string, 0, $length).$etc;

}

function substr_utf8($str, $start=0, $length=-1, $return_ary=false) {
$len = strlen($str);if ($length == -1) $length = $len;
$r = array();
$n = 0;
$m = 0;

for($i = 0; $i < $len; $i++) {
$x = substr($str, $i, 1);
$a = base_convert(ord($x), 10, 2);
$a = substr('00000000'.$a, -8);
if ($n < $start) {
if (substr($a, 0, 1) == 0) {
}elseif (substr($a, 0, 3) == 110) {
$i += 1;
}elseif (substr($a, 0, 4) == 1110) {
$i += 2;
}
$n++;
}else {
if (substr($a, 0, 1) == 0) {
$r[] = substr($str, $i, 1);
}elseif (substr($a, 0, 3) == 110) {
$r[] = substr($str, $i, 2);
$i += 1;
}elseif (substr($a, 0, 4) == 1110) {
$r[] = substr($str, $i, 3);
$i += 2;
}else {
$r[] = '';
}
if (++$m >= $length) {
break;
}
}
}

return $return_ary ? $r : implode("",$r);
}
/* vim: set expandtab: */
?>

samrty的插件体系还是比较智能而且容易修改的。