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To: Julian Elischer <julian@freebsd.org>
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Comments: In-reply-to Julian Elischer <julian@freebsd.org>
	message dated "Sat, 09 Oct 2010 22:32:05 -0700."
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Date: Sun, 10 Oct 2010 08:56:55 +0200
From: Daniel Braniss <danny@cs.huji.ac.il>
Message-ID: <E1P4pq3-000CSR-QS@kabab.cs.huji.ac.il>
Cc: Brandon Gooch <jamesbrandongooch@gmail.com>, freebsd-hackers@freebsd.org,
	Devin Teske <dteske@vicor.com>, Garrett Cooper <gcooper@freebsd.org>
Subject: Re: sysrc -- a sysctl(8)-like utility for managing /etc/rc.conf et.
 al.
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>   On 10/9/10 7:30 PM, Garrett Cooper wrote:
> >
> >> [ "..." ] is the same thing as [ -n "..." ] or test -n "..."
> >> [ ! "..." ] is the same things as [ -z "..." ] or test -z "..."
> >> I'll never understand why people have to throw an extra letter in there and
> >> then compare it to that letter.
> > I ran into issues using ! on Solaris ksh recently (not using test),
> > and I agree that your example below is more straightforward and
> > readable than the other examples I've dealt with in the past.
> 
> 
> Ah that reminds me for the reason for "X$foo" = "X"

but grasshopper, in Version 6 there was no test(1), hence the x$1 = x


> 
> it's in case $foo evaluates to "-n" or similar...
> 
> It's been a long time... but these days a data misevaluation leads to 
> such things ad  SQL injection attacks
> and I see no reason that a shell injection attack shouldn't be possible.