操作系统课设作业。在磁盘空间模拟一个linux文件系统，并提供基本的文件操作命令（如mk, cp, mkdir, rmdir, cd, ls, cat, chmod, chown, chgrp, chnam等）。文件系统的实现采用混合索引式文件结构，包括使用空闲节点号栈管理空闲节点和成组链接管理空闲盘块。(Simulate a Linux file system in disk space and provide basic file operation commands (such as MK, CP, MKDIR, rmdir, CD, LS, cat, Chmod, chown, chgrp, chnam, etc.). The implementation of file system is based on hybrid index file structure, including using idle node stack to manage idle nodes and group links to manage idle disk blocks.)