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Re: Ill positioned 'until' keyword

From: Andreas Schwab
Subject: Re: Ill positioned 'until' keyword
Date: Thu, 15 Dec 2011 10:44:05 +0100
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.92 (gnu/linux)

Bob Proulx <address@hidden> writes:

> Peng Yu wrote:
>> I looks a little wired why 'until' is the way it is now.
>> ...
>> until test-commands; do consequent-commands; done
>> while ! test-commands; do consequent-commands; done
> In the original Bourne shell there is no '!' operator.  The 'until'
> was a way to negate the expression without using a '!' which didn't
> exist in that shell.  An 'if' could operate using the 'else' clause.
> But there wasn't any other way to do it in a while loop.

You could always do

  while test-commands; test $? -ne 0; do ...; done


Andreas Schwab, address@hidden
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