Re: Unexpected behavior of P parameter expansion flag inside arithmetic evaluation

[Peter Stephenson <Peter.Stephenson@xxxxxxx>]

On Wed, 17 Aug 2011 11:10:20 +0200
Nikolai Weibull <now@xxxxxxxx> wrote:
> % a=(abc)
> % (( r = $#a )); echo $r
> 1
> % b=a
> % (( r = ${#${(P)b}} )); echo $r
> 3
> % (( r = ${#${(P@)b}} )); echo $r
> 1
> 
> Why is the ‘@’ needed in this case?

(( ... ))

is equivalent to

let "..."

i.e. is in double-quoted context, so $b will interpolate $a as a
scalar.  See the documentation on arithmetic evaluation in the zshmisc
manual page.

-- 
Peter Stephenson <pws@xxxxxxx>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
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