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From: "Bart Schaefer" <schaefer@brasslantern.com>
Message-Id: <990206151920.ZM31760@candle.brasslantern.com>
Date: Sat, 6 Feb 1999 15:19:20 -0800
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To: zsh-workers@sunsite.auc.dk
Subject: `unset`, zerr(), and `eval`
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X-Mailing-List: <zsh-workers@sunsite.auc.dk> 5300

Consider the two following zsh snippets:

unset IFS
for i in "${(O)${(@f)$(set)}%%\=*}"
do unset $(eval echo $i)
done

unset IFS
for i in "${(O)${(@f)$(set)}%%\=*}"
do eval unset $i
done

The first loop terminates as soon as it hits the first read-only parameter
(which happens to be "status" in this case).  The second loop spits out a
warning message for every readonly parameter, and continues until it has
unset every parameter that it can.  (Both loops crash if you don't apply
the OLDPWD patch I sent this afternoon.)

Seems there could be two problems here.  Isn't it overkill to get zerr()'d
when attempting to unset a readonly parameter?  Is it intentional that an
"eval" will mask such errors?  (It's kinda perl-ish, I admit, but ...)

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com