In article <22lq2d$j92@hdxu03.telecom.ptt.nl> arthur@ptt-iat.uucp (Arthur Donkers) writes:
quoted text
>The finer point here is that you may enter from DCL the command :
>
>    set default [directory.which.does.not.exist]
>
>and it does not complain until you start working from this directory, i.e.
>show default. As a side-effect your previous default directory setting is
>lost.
>
>Whereas in Unix (any flavour I know of anyway) the command
>
>    cd /directory/which/does/not/exist
>
>will _immediately_ complain about the fact that this directory does not
>exist and leave you RIP in this directory.
The Unix equivalent of the above DCL statements would probably be
(in sh):

$ HOME=/does/not/exist
$ cd
/does/not/exist: bad directory

And yes, Your previous HOME has gone also. If You start another
shell from such a screwed up shell, all environment variables that
refer to HOME (e.g. PATH) will be screwed up as well.

The moral is this (this is supposed to be an excuse for a thread
which doesn't belong in this group in the first place):
sh/csh/bash/whateversh and DCL all allow some constructions which
result in apparent misbehavior of the system (ever thought about
the student who defined the environment variable TERM as an
abbreviation for the rather lengthy filename of his term paper?
And why does vi $TERM not work #@$!?). Removing those `holes' would
result in (even?) less flexibility, and is therefore not desirable.
You need to know a few things to use either without accidents.

About OS: Operating Systems are usually chosen not for their
theoretical merits, but rather because one wants to run a certain
software:  I bought an Atari ST in 1987 because that was the cheapest
way to get a Windowing System and TeX to write my thesis. It is
probably true that Unix offers the widest range of tools for a
developer, but that's not what is important for most users: they
only need a word processor and a spreadsheet. Ever heard of the
sucess of MS, they know this! My father bought an RS/6000 for his
pharmacy because that was what the software was written for. He
didn't even know he was using a Unix box until I told him.  Any
system is OK if it offers the tools You need. Everything else is
a matter of taste and/or religion. So go ahead, all You OS-Ayatollahs,
flame me, but in private e-mail please.

                                Andreas

user of CP/M, MS-DOS, Atari TOS/GEM, Mac, VMS, and Unix Enthusiast
-- 
=================================================
Dr. Andreas Mueller <afm@mathi.uni-heidelberg.de>
Mathematisches Institut der Univeristaet
Im Neuenheimer Feld 288      D - 69120 Heidelberg