php生成xml文件

function cleanstring($str){
 $str = rawurldecode($str);
 $badchars = array("<", ">", ".", "/", "?", "#", "*", "(", ")", "[", "]", "{", "}", "\", ",", "=", '"', "'", ":", ";", "^", "@", "~", "!", " ");
 $clean = "";
 for($i=0; $i   if(array_search($str[$i], $badchars) === false){
   $clean .= $str[$i];
  }
 }
 return $clean;
}
$name = rawurlencode($_post['fname']);
$message = rawurlencode($_post['message']);
$xml = '';
$xml .= $_post['xml'];
$xml .="";
$t = time();

$filename = 'data/'.'99999'.$t.'_'.cleanstring($name).'.xml';
$file = fopen($filename, "w");
fwrite($file, strips教程lashes($xml));
fclose($file);