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From: Zoltan Hidvegi <hzoli@cs.elte.hu>
Message-Id: <199805240751.CAA21301@hzoli.home>
Subject: Re: PWD parameter
In-Reply-To: <980523225726.ZM5196@candle.brasslantern.com> from Bart Schaefer at "May 23, 98 10:57:26 pm"
To: schaefer@brasslantern.com (Bart Schaefer)
Date: Sun, 24 May 1998 02:51:55 -0500 (CDT)
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Bart Schaefer wrote:
> On May 23, 11:44pm, Zoltan Hidvegi wrote:
> } Subject: PWD parameter
> }
> } The standard does not mention PWD or OLDPWD in the descriprion of the
> } shell special parameters
> 
> Personally, I rather like having PWD be a special parameter.  If you go
> by the letter of that standard you quoted, PWD would not be set at all
> when the shell first started up; it would only become set after a "cd".
> That's surely bogus.

My patch does set PWD and OLDPWD on startup.  The standard allows that
but does not require it.  Why do you think that PWD is better be a
special parameter?  Scripts do set PWD and if we want to allow people to
use zsh as /bin/sh then we have to allow them to write PWD.  That was my
main reason for the patch, not the standard, since I link /bin/sh to zsh.
If PWD is special, assignments will write directly to the internal pwd
variable which can cause unexpected shell behavior.  That's why PWD was
read-only.  Alternatively, you can just ignore assignments to PWD without
giving an error message, but that's a bad solution.

As long as you do not try to assign PWD, my patch does not change zsh's
behavior, other than exporting OLDPWD which was not exported before.

Zoltan