php 正则只保留 汉字 字母 数字

$str = "?><？》”"《喂喂喂555？》《|“：L}{P+_)In thsdff0?><M<>"s~!@#$%^&*()+_)(*&dsdffsde~！@#￥%……&*5545445（）+——）（*&……%￥#@！~ 电影_后天 230809-peopl.e die我d.(*&^%$#@!!~";
echo match_chinese($str);
 
function match_chinese($chars,$encoding='utf8')
{
$pattern =($encoding=='utf8')?'/[x{4e00}-x{9fa5}a-zA-Z0-9]/u':'/[x80-xFF]/';
preg_match_all($pattern,$chars,$result);
$temp =join('',$result[0]);
return $temp;
}