Re: New GSoC microproject ideas

From: David Kastrup <dak@gnu.org>
Date: Mar 12, 2014, 21:12 UTC
Message-ID: <87k3bzi0j4.fsf@fencepost.gnu.org>
In-Reply-To: <20140312204453.GA9702@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 19 quoted lines

> On Wed, Mar 12, 2014 at 09:37:41PM +0100, David Kastrup wrote:
>
>> > Try:
>> >
>> >   zippo() {
>> >     echo $XXX
>> >   }
>> >   XXX=8 zippo
>> >   zippo
>> >
>> > XXX remains set after the first call under dash (but not bash). I
>> > believe "ash" has the same behavior.
>> 
>> Yes.  I would lean towards considering this a bug.  But I agree that it
>> does not help.
>
> Dash's behavior is POSIX (and "bash --posix" behaves the same way).
>
>   http://article.gmane.org/gmane.comp.version-control.git/137095

In that case I consider it a standard-compliant bug (namely being a serious problem regarding the usefulness of shell functions). Which makes it unlikely to go away. It makes it easier to interpret, say

zippo() {
  XXX=$XXX
}

XXX=8 zippo echo $XXX

as shell functions presumably should be able to assign to shell variables like built-ins do. But that's not really much of an advantage.

The behavior does not make sense to me also with regard to special built-ins. Bash does

dak@lola:/usr/local/tmp/git$ XXX=8 : dak@lola:/usr/local/tmp/git$ echo $XXX

dak@lola:/usr/local/tmp/git$

And that makes sense to me.  Whatever, does not help.

-- 
David Kastrup