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Date: Tue, 3 Jun 1997 00:03:16 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199706021403.AAA31991@godzilla.zeta.org.au>
To: freebsd-bugs@hub.freebsd.org, Harlan.Stenn@pfcs.com
Subject: Re: conf/3751: Improvements to /etc/rc{,.network,.pccard}
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> J> That's not entirely confusing syntax.  It's normal habit to be on the
> J> safe side.  Although i agree, the quotes should always be there,
> 
> Agreed (obviously)

It's not obvious.  '[ X$foo_enable = XYES ]' is better than
'[ "X$foo_enable" = XYES ]' for boolean variables, since it detects some
bogus values.

> J> Prepending the X saves you from hidden gotchas like in:
> 
> J> foo="-ain't this weird?-"
> 
> J> if [ "$foo" = "bar" ] ; ...
> 
> Did you mean:
> 
>    if [ $foo = "bar" ] ; ... 
> 
> Shell metacharacters aren't expanded with "$foo".

I think he meant

    foo="!"

Some strings may be misinterpreted as options or operators.  There is no
problem in most cases because test's syntax gives precedence to the "="
operator, e.g., in

    [ -a = bar ]

Bruce