文件目录管理，设计一个n个用户的文件系统，每次用户可保存m个文件，用户在一次运行中能打开p个文件，对文件必须设置保护措施，且至少有Create、delete、open、close、read、write等命令。-File directory management, the design of a n-user file system, each user can be stored m file, the user can run in an open p documents, the document must be set up protective measures, and at least Create, delete, open, close , read, write and other commands.