Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!columbia!rutgers!topaz.rutgers.edu!hedrick From: hedrick@topaz.rutgers.edu (Charles Hedrick) Newsgroups: comp.unix.wizards Subject: Re: stupidity in directory management? Message-ID: <13497@topaz.rutgers.edu> Date: Fri, 24-Jul-87 00:28:00 EDT Article-I.D.: topaz.13497 Posted: Fri Jul 24 00:28:00 1987 Date-Received: Sat, 25-Jul-87 11:38:02 EDT References: <8414@brl-adm.ARPA> <1495@ihdev.ATT.COM> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 16 pdg@ihdev.uucp mentioned that he couldn't think of any use for invisible files on TOPS-20. Invisible files were added for the archive system. You want to keep information about the file in the directory, so that you can do directories of all archived files, move files back and forth between online and offline status etc. On the other hand, when you do "dir" you don't want to see all your 5-year-old junk. So the compromise was that when you archive a file, it stays in the directory, but is set to be invisible. Unix also has invisible files, which are used for similar reasons. They are names beginning with a dot. On TOPS-20, invisibility is just a bit in the fdb (inode), like deleted. gtjfn (open) has an extra option to control whether it is allowed to open invisible files. The only use I know of for invisible files outside the archive system is scaring users. If somebody leaves a job logged in in a public room, people sometimes set all their files invisible. (At less friendly installations, people are known to delete them.)