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From: Chris Rees <crees@FreeBSD.org>
Date: Fri, 25 May 2012 17:52:04 +0100
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To: RW <rwmaillists@googlemail.com>
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Cc: ports@freebsd.org
Subject: Re: portdowngrade and meta ports
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On 25 May 2012 14:09, RW <rwmaillists@googlemail.com> wrote:
> On Thu, 24 May 2012 22:43:08 +0100
> Chris Rees wrote:
>
>
>> For the archive-- just thought-- even though I did a typo there,
>> DON'T use:
>>
>> mv file file.bak && echo something > file
>>
>> at least with csh, file will be clobbered before mv gets to it....
>
> I tried that in bash and csh and it worked correctly in both.
>
> e.g. in csh:
>
> =A0%echo nothing > foo
> =A0%mv foo bar && echo something > foo
> =A0%cat foo
> =A0something
> =A0%cat bar
> =A0nothing
>
> If a shell supports short-circuiting then mv must complete before echo
> can start, so I don't see how it can fail unless the shell opens the
> file before it runs mv.
>
> Are you perhaps mixing this up with what happens with:
>
> =A0cat foo bar > foo

Perhaps.  Just being overcautious, sorry :)

Chris