Re: [Help-bash] Is there a syntax to declare -p address@hidden

[Dennis Williamson]

On Thu, Dec 6, 2018, 10:23 PM Peng Yu <address@hidden wrote:

> On Thu, Dec 6, 2018 at 10:20 PM Dennis Williamson
> <address@hidden> wrote:
> >
> >
> >
> > On Thu, Dec 6, 2018, 10:13 PM Peng Yu <address@hidden wrote:
> >>
> >> On Wed, Dec 5, 2018 at 8:40 AM Tadeus Prastowo <
> address@hidden> wrote:
> >> >
> >> > On Wed, Dec 5, 2018 at 12:31 AM Peng Yu <address@hidden> wrote:
> >> >
> >> > [...]
> >> >
> >> > > $ ./main.sh
> >> > > set -- 1 '2     3'
> >> > > echo ${@@A}
> >> > > set -- '1' '2 3'
> >> > > echo "${@@A}"
> >> > > set -- '1' '2     3'
> >> > >
> >> > >
> >> > > Where is it documented?
> >> >
> >> >
> https://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion
> ,
> >> > particularly as quoted below:
> >> >
> >> > address@hidden
> >> >    The expansion is either a transformation of the value of parameter
> >> > or information about parameter itself, depending on the value of
> >> > operator. Each operator is a single letter:
> >> >    [...]
> >> >    A
> >> >       The expansion is a string in the form of an assignment statement
> >> > or declare command that, if evaluated, will recreate parameter with
> >> > its attributes and value.
> >> >    [...]
> >> >    If parameter is address@hidden or ‘*’, the operation is applied to 
> >> > each
> >> > positional parameter in turn, and the expansion is the resultant list.
> >> > [...]
> >> >    The result of the expansion is subject to word splitting and
> >> > pathname expansion as described below.
> >>
> >> How to understand why `echo address@hidden only print an empty line?
> >>
> >> $ echo "address@hidden"
> >>
> >> $ echo "${$}"
> >> 613
> >> $ echo address@hidden
> >>
> >> $ echo address@hidden
> >> declare -ir BASHPID='440'
> >>
> >> --
> >> Regards,
> >> Peng
> >
> >
> > You have too many dollar signs and not enough at signs. Try ${@@A} as
> Tadeus posted.
>
> No. I am referring to a different variable $$ insead of address@hidden
>
> --
> Regards,
> Peng
>

Why don't you ask about all the special parameters at once. Perhaps the
answer is that only some of them are user settable.

>