说明：  此程序是模拟文件管理系统的磁盘空间管理,外存管理,目录管理(单级目录)的一个模拟程序,也是高校计算机操作系统课程设计的一个案例,仅供大家参考
(this procedure is simulated document management system disk space management, Disk Management, directory management (single-level directory) of a simulation program, as well as university computer courses on operating system design a case, we only reference)