code: static public function createTempFile ($session_id, $name, $context)
  	{
  		$dir = self::$temp . DIRECTORY_SEPARATOR . $session_id;
  		if (!is_dir($dir)) {
  			mkdir($dir, 0777, TRUE);
  		}
  		$file_path_name = $dir . DIRECTORY_SEPARATOR . uniqid() . "-{$name}";
  		if (file_put_contents($file_path_name, $context)) {
  			return $file_path_name;
  		}
  		else {
  			return FALSE;
  		}
  	}
docs: 创建临时文件
  
  @param $session_id
  @param $name
  @param $context
  
  @return bool|string