php 特殊字符处理函数

<?php
function dhtmlspecialchars($string) {
if(is_array($string)) {
foreach($string as $key => $val) {
$string[$key] = dhtmlspecialchars($val);
}
} else {
$string = preg_replace('/&((#(\d{3,5}|x[a-fA-F0-9]{4})|[a-zA-Z][a-z0-9]{2,5});)/', '&\\1',
str_replace(array('&', '"', '<', '>'), array('&', '"', '<', '>'), $string));
}
return $string;
}
?>