事件：'open'

¥Event: 'open'

• fd <integer> <fs.ReadStream> 使用的整数文件描述符。

  ¥fd <integer> Integer file descriptor used by the <fs.ReadStream>.

当 <fs.ReadStream> 的文件描述符被打开时触发。

¥Emitted when the <fs.ReadStream>'s file descriptor has been opened.