C++写的一个小型的FAT文件系统，磁盘用一个大文件来模拟。基于此文件系统实现了类DOS的shell界面，提供了一些基本功能，如cd，dir，mkdir，edit。-A small FAT file system in C++, disk with a large file to simulate. Class DOS-shell interface, based on this file system provides some basic functions, such as the cd,