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From: Eric Blake <eblake@redhat.com>
To: Aragon Gouveia <aragon@phat.za.net>
Cc: dash@vger.kernel.org
Subject: Re: setvar MIA?
Date: Tue, 11 Jan 2011 10:00:33 -0700	[thread overview]
Message-ID: <4D2C8CB1.4070204@redhat.com> (raw)
In-Reply-To: <4D2C8B2C.3060001@phat.za.net>

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On 01/11/2011 09:54 AM, Aragon Gouveia wrote:
> I wasn't sure of its status in POSIX.  It is useful for declaring
> variable variables - tidier than eval and I imagine faster, eg.
> 
> index="1"
> setvar var_${index} "value"
> 
> Will emulate it with a local function - thanks.

Indeed, it looks like FreeBSD introduced it as shorthand for:

setvar() { eval $1=\$2; }

The speed difference between that function doing an eval and a shell
builtin would be in the noise.  I don't know why FreeBSD even bothered
to pollute the namespace with a builtin like that.

-- 
Eric Blake   eblake@redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org


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  reply	other threads:[~2011-01-11 17:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-11 15:54 setvar MIA? Aragon Gouveia
2011-01-11 16:10 ` Eric Blake
2011-01-11 16:54   ` Aragon Gouveia
2011-01-11 17:00     ` Eric Blake [this message]
2011-01-11 19:58       ` Jilles Tjoelker

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