Re: /dev/fd/63: line 21: ((: takes && kwsi += takes : attempted assignment to non-variable (error token is "+= takes ")

[Dennis Williamson]

On Wed, Feb 9, 2022, 1:52 PM Greg Wooledge <greg@wooledge.org> wrote:

> On Wed, Feb 09, 2022 at 08:20:29PM +0100, Alex fxmbsw7 Ratchev wrote:
> > bash-5.1# declare -A KWS ; code='echo foo' . ./+kw test ; . ./kws test
> > bash: ((: takes && kwsi += takes : attempted assignment to
> > non-variable (error token is "+= takes ")
>
> It would be *so* much simpler if you could take the time and effort to
> construct a minimal reproducing example.  One that people could simply
> run, without having to jump through *hoops*, to check your results.
>
> unicorn:~$ bash-5.1
> unicorn:~$ takes=
> unicorn:~$ kwsi=42
> unicorn:~$ (( takes && kwsi += takes ))
> bash-5.1: ((: takes && kwsi += takes : attempted assignment to
> non-variable (error token is "+= takes ")
>
> There.  Was that TRULY so difficult that you could not do it yourself?
>


Following up on Greg's excellent advice.

$ (( takes && kwsi += takes ))
bash-5.1: ((: takes && kwsi += takes : attempted assignment to non-variable
(error token is "+= takes ")

Hmmm. Something's wrong. What if I further simplify?

(( takes ))

Ok that works. What about

(( kwsi += takes ))

That works too. Maybe it's the &&

(( (takes && kwsi) += takes ))
...attempted assignment to non-variable ...

Aha!

(( takes && (kwsi += takes) ))

Bingo! You've solved the problem yourself.

>