Re: V+=1 doesn't work if V is a reference to an integer array element

[Léa Gris]

Le 13/01/2021 à 18:49, Greg Wooledge écrivait :
> On Wed, Jan 13, 2021 at 07:00:42PM +0200, Oğuz wrote:
> >      $ declare -n b=a[0]
>
> I can't see any documentation that supports the idea that this should
> be allowed in the first place.
>
>                -n     Give  each  name  the nameref attribute, making it a name
>                       reference to another variable.  That  other  variable  is
>                       defined  by  the  value of name.  All references, assign‐
>                       ments, and attribute modifications to name, except  those
>                       using  or changing the -n attribute itself, are performed
>                       on the variable referenced by name's value.
>
> In at least three places there, it says that that "target" of the
> name reference is a variable.  a[0] isn't a variable.

Even more weirdness:

echo $BASH_VERSION
> 5.0.17(1)-release

unset a b
declare -ai a=(1)
declare -in b="a[0]"
declare -p a b
> declare -ai a=([0]="1")
> declare -in b="a[0]"
b+=1
declare -p a
> declare -ai a=([0]="3")
b+=1
declare -p a
> declare -ai a=([0]="7")
b+=0
declare -p a
> declare -ai a=([0]="14")

--
Léa Gris