From: "Nicolas de Pesloüan" <nicolas.2p.debian@gmail.com>
To: Alexander Kurtz <kurtz.alex@googlemail.com>
Cc: The development of GNU GRUB <grub-devel@gnu.org>
Subject: Re: [PATCH] add proper variable quoting to grub-mkconfig_lib (Debian bug #612417)
Date: Tue, 05 Apr 2011 22:07:46 +0200 [thread overview]
Message-ID: <4D9B7692.2020309@gmail.com> (raw)
In-Reply-To: <1302031960.30533.7.camel@localhost>
Le 05/04/2011 21:32, Alexander Kurtz a écrit :
> Am Dienstag, den 05.04.2011, 21:16 +0200 schrieb Nicolas de Pesloüan:
>> Why do you use construct like "${x}" instead of "$x"?
>
> Because code isn't written once and then stays untouched forever. It
> changes over time and may be used in situations you did not anticipate.
> Writing solid code (and in shell scripts that definitely includes
> quoting your variables) avoids unnecessary bugs like this one.
>
> I've just seen too many poorly written shell scripts with hidden
> (sometimes even security-relevant) bugs to not do things properly.
>
> And it looks cleaner ;-)
>
> Best regards
>
> Alexander Kurtz
As Colin says, the {} construct is mostly useless and at least does not contribute to quoting.
On the same kind of things, the construct if test "x$foo" = "x" is pointless. It is a very strange
heritage from DOS, where IF x%A = x was a common construct, because DOS (command.com) lack quoting.
(Is wasn't possible to write IF "%a" = ""). In shell, "" is an empty string, but a real argument to
commands. The following construct is the good one : if test "$foo" = "". The test command will
receive three arguments: the value of $foo, the = sign and an empty argument and will return true if
$foo happens to be empty.
Writing solid code imply - in particular - knowing the exact behaviors of the programming language :-)
I agree of course that this is definitely cosmetic, and this doesn't means that your work to remove
unquoted variable is not good and necessary.
Nicolas.
next prev parent reply other threads:[~2011-04-05 20:07 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-05 12:55 [PATCH] add proper variable quoting to grub-mkconfig_lib (Debian bug #612417) Alexander Kurtz
2011-04-05 19:16 ` Nicolas de Pesloüan
2011-04-05 19:30 ` Colin Watson
2011-04-05 19:32 ` Alexander Kurtz
2011-04-05 19:47 ` Colin Watson
2011-04-05 20:07 ` Nicolas de Pesloüan [this message]
2011-04-05 20:53 ` Colin Watson
2011-04-05 21:27 ` Nicolas de Pesloüan
2011-04-06 15:31 ` Alexander Kurtz
2011-04-06 18:14 ` Nicolas de Pesloüan
2011-04-06 19:31 ` Colin Watson
2011-04-06 19:42 ` Nicolas de Pesloüan
2011-04-08 13:44 ` Vladimir 'φ-coder/phcoder' Serbinenko
2011-04-09 14:32 ` Alexander Kurtz
2011-04-10 13:33 ` Vladimir 'φ-coder/phcoder' Serbinenko
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