Introduction - If you have any usage issues, please Google them yourself
Multi-user multi-level directory of the file system, (1) has a login (user login) (2) system initialization (construction paper roll, providing registry module) (3) the creation of documents: create (4) file to open: open (5) paper read: read (6) to write the document: write (7) document Close: close (8) delete the file: delete (9) create a directory (the establishment of a subdirectory): mkdir (10) to change the current directory: cd (11) are listed in directory: dir (12) Exit: logout