php 过滤html标签 截取部分内容

fdsfsdfhref';
echo htmlspecialchars($str).'
';
echo strip_tags($str);
 
?>

//编辑器中的内容
$active = $this->truncate($list['content'],510);



//截取html方法：
function truncate($string,$length,$append = true){
    $string = trim($string);
    $strlength =strlen($string);
    if ($length == 0 ||$length >=$strlength){
        return $string;
    }elseif ($length < 0){
        $length =$strlength +$length;
        if ($length < 0)
        {
            $length =$strlength;
        }
    }
    if (function_exists('mb_substr')){
        $newstr = mb_substr($string, 0,$length,"UTF-8");
    }elseif (function_exists('iconv_substr')){
        $newstr = iconv_substr($string, 0,$length,"UTF-8");
    }else{
      for($i=0;$i<$length;$i++){
            $tempstring=substr($string,0,1);
            if(ord($tempstring)>127){
               $i++;
               if($i<$length){
                  $newstring[]=substr($string,0,3);
                  $string=substr($string,3);
               }
            }else{
               $newstring[]=substr($string,0,1);
               $string=substr($string,1);
            }
         }
      $newstr =join($newstring);
    }
    if ($append &&$string !=$newstr){
        $newstr .='...';
    }
    return $newstr;
}