On Tue, Apr 6, 2021 at 11:28 PM Robert Elz <k...@munnari.oz.au> wrote:
> | @ means everything or nothing. Unbound variable errors should not apply
> to it.
>
> I know nothing about namerefs and arrays and stuff like that,
> but did you consider the possibility that after
>
> array=()
>
> then
>
> array[@]
>
> is nothing, and so
>
> __ref=array[@]
>
> is just
>
> __ref=
>
> and consequently ${!__ref} is attempting to use '' as the name of a
> variable?
References are virtually like placeholders and don't expand the
referenced target themselves.
${!__ref} is synonymous to ${array[@]}, not ${${array[@]}}.
This is why you can do other parameter expansion features like
${!var+.} ${!var@a}.
--
konsolebox
