Re: test -v for array does not work as documented

[Greg Wooledge]

On Thu, Feb 20, 2020 at 04:05:01PM +0100, Ulrich Mueller wrote:
> >>>>> On Thu, 20 Feb 2020, pepa65 wrote:
> 
> > On 20/02/2020 19.48, Ulrich Mueller wrote:
> >> Still, I think it's sad that there isn't a command that can test for
> >> assigned vs void variable, without the need for parsing of declare -p
> >> output.
> 
> > There is no need to parse, the return value of `declare -p var` or
> > `typeset -p var` will tell you what you want.
> 
> Unfortunately, it doesn't:
> 
>    $ f() {
>    >   local var
>    >   var="foo"
>    >   declare -p var
>    >   echo $?
>    >   unset var
>    >   declare -p var
>    >   echo $?
>    > }
>    $ f
>    declare -- var="foo"
>    0
>    declare -- var
>    0

It appears to work very differently at the global scope, compared to
local scope.

wooledg:~$ unset var
wooledg:~$ declare -p var; echo $?
bash: declare: var: not found
1

wooledg:~$ f() { local var=x; unset var; declare -p var; echo $?; }
wooledg:~$ f
declare -- var
0

Intriguing, but everything about this still screams "stop doing this".
Whatever the actual goal is, this isn't the way to reach it.