通过利用磁盘文件，完成实现操作系统的文件管理功能，主要包括目录结构的管理、外存空间的分配与释放以及空闲空间管理三部分，掌握文件管理的相关文件操作的过程。-Through the use of a disk file, complete the operating system s file management functions, including the management of the directory structure, external memory space allocation and release, as well as free space management of three parts master file management file operations.