Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!ukc!dcl-cs!gdt!gdr!exspes
From: exspes@gdr.bath.ac.uk (P E Smee)
Newsgroups: comp.unix.questions
Subject: Re: drawtree for Unix/Sun/curses?
Message-ID: <1989Dec7.204908.19690@gdt.bath.ac.uk>
Date: 7 Dec 89 20:49:08 GMT
References: <5250@abaa.UUCP> <11976@phoenix.Princeton.EDU>
Reply-To: exspes@gdr.bath.ac.uk (P E Smee)
Organization: University of Bristol c/o University of Bath
Lines: 37

In article <11976@phoenix.Princeton.EDU> subbarao@phoenix.Princeton.EDU (Kartik Saligrama Subbarao) writes:
>    Here is a question I have been wanting to ask for a long time but
> always forgot to. WHY doesn't someone make a whole NORTON UTILITES
> for UNIX? I mean, it is SO easy to unerase files in MS-DOS. If UNIX
> is a superior operating system, why hasn't someone come up with a 
> qu command to unerase files, an ncd to change directories and some of
> the other goodies we get with the Norton Utilities 4.5 Advanced
> Edition?

Probably because the Unix filesystem is designed around a totally
different set of concepts than the MS-DOS filesystem, made worse by the
fact that Unix is a multi-user system and MS-DOS (usually, at least) is
not.

Norton will only successfully unerase a file IF you have not written
anything to the disk (except re-writing the directory) since you erased
the file.  The odds that *someone* won't have written something to the
disk since you erased your file must be vanishingly small on any Unix
of any size.

Plus, in MS-DOS, you own the particular bit of disk real-estate
involved.  In Unix you don't own any particular bit of the disk
surface.  (In IBM VM/CMS you do, and that creates nightmares of it's
own, including vast amounts of disk wastage.)  Bit hard to see how,
even if you forced a delay between rm'ing a file and the actual
vanishing of the inode where it really lives (and associated disk
bits), you could give individual users an unerase command without
giving them the potential to look through everything else which has
been deleted recently.

You can sort of simulate the effect my making yourself an erase command
which moves the file to some special dir like $HOME/Trash, and a bit in
your .login, .profile, or .logout which really removes anything that's
been in there for some amount of time.
-- 
 Paul Smee, Univ. of Bristol Comp. Centre, Bristol BS8 1TW (Tel +44 272 303132)
 Smee@bristol.ac.uk   :-)   (..!uunet!ukc!gdr.bath.ac.uk!exspes if you HAVE to)