On Mon, 23 Jun 2008 10:18:32 -0700 (PDT) Roger Marquis wrote:
> David Korn wrote:
> > In my opinion, a better solution would be to adopt a mechanism
> > that was introduced by ksh93 is used by several other existing shells
> > such bash and zsh and is compatible with the current POSIX standard
> > so that no strictly conforming application could break.
> > The idea is to add literal string constants of the form $'...'
> A few real-world examples might help better define what this quote syntax
> will accomplish. Same with new escape sequences. I have not personally
> seen much call for either, though their potential for creating
> incompatibilities is clear. Accordingly, my question would be whether
> POSIX should be considering these features in the first place?
the "call" was introduced by the proposed solution for \x... in printf(3)
formats
the issue in this case is
(1) adding an incompatibility between printf(1) and printf(3) in the
way \x.. is parsed, and solves the problem only for one utility
vs.
(2) adding a sh(1) feature, already implemented in { bash ksh zsh },
that does not introduce the printf(3) incompatibility, and solved
the problem for all utilities
in particular, sh $'...'$'...' catenation mimics C "..." "..." catenation:
$'\xabc'$'def\n' vs "\xabc" "def\n"
-- Glenn Fowler -- AT&T Research, Florham Park NJ --
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