CFile::GetTempName

static function GetTempName($dir_name = false, $file_name = '')
{
	//accidentally $file_name can contain "?params"
	if(($pos = mb_strpos($file_name, "?")) !== false)
	{
		$file_name = mb_substr($file_name, 0, $pos);
	}
	return CTempFile::GetFileName($file_name);
}