public static function valid_ext($fn)
{
$_ext = strtolower(self::get_ext($fn));
$ext = self::check_ext($_ext, 0) ? $_ext : 'file';
if (self::$forceExt !== false) {
(empty($_ext) || strlen($_ext) > 4 || $ext == 'file') && ($ext = self::$forceExt);
return $ext;
}
if (!self::$validext) {
return $ext;
}
$ext_array = explode(',', strtolower(self::$config['allow_ext']));
if (in_array($_ext, $ext_array)) {
return $ext;
} else {
self::$ERROR = self::_error(array('code' => 0, 'state' => 'TYPE'));
return false;
}
}