为此，要用到地图文件—一个纯文本文件。

You do this with a map file - a flat text file.

youdao

幸运的是，您根本不需要手工构造地图文件。

Luckily, you rarely need to build the map file by hand.

youdao

幸运的是，您根本不需要手工构造地图文件。

Luckily, you rarely need to build the map file by hand.

youdao