Re: [feature request] parameter transformation to safely add strings to PS1, &c.

[Emanuele Torre]

Emanuele Torre <torreemanuele6@gmail.com> wrote:
>   ~ --${@Q}-> '~' --${#\'}-> ~' --${%\'}-> ~

Sorry, that was a bad example. Still, it does not accomplish anything:

  \w --${@Q}-> '\w' --${#\'}-> \w' --${%\'}-> \w

On Sun, 22 Aug 2021 at 23:56, Emanuele Torre <torreemanuele6@gmail.com> wrote:
>
> Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com> wrote:
> > and renoving the beginning and ending ' s
>
> even if you remove the first and last ':
> 1) that is 3 PEs as the solution i described (${a//\\/\\\\}
> ${a//\`/\\\`} ${a//$/\\$} vs ${a@Q} ${a#\'} ${a%\'} )
> 2) it doesn't actually accomplish anything:
>
>   ~ --${@Q}-> '~' --${#\'}-> ~' --${%\'}-> ~
>
> On Sun, 22 Aug 2021 at 23:14, Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com> wrote:
> >
> > what about @Q
> > and renoving the beginning and ending ' s
> >
> >
> > On Sun, Aug 22, 2021, 23:13 Emanuele Torre <torreemanuele6@gmail.com> wrote:
> >>
> >> It would be nice to have a parameter transformation (e.g. "${par@p}")
> >> that expands $par to a string that will not be expanded by PS1, PS2, &c.
> >>
> >> example:
> >>
> >>   tmp_var=$(blabla) # this variable will not exist when PS1 is expanded
> >>   PS1="blabla ${tmp_var@p} blabla"
> >>
> >> I think a valid way to achieve the same behaviour in the currenct
> >> version of bash:
> >>
> >>   tmp_var=$(blabla)
> >>   tmp_var=${tmp_var//\\/\\\\}
> >>   tmp_var=${tmp_var//\`/\\\`}
> >>   tmp_var=${tmp_var//$/\\$}
> >>   PS1="blabla $tmp_var blabla"
> >>
> >> But a parameter transformation would be nicer.
> >>
> >> This parameter transformation should also make sure to not cause an
> >> expansion when concatenated.
> >>
> >>   var='$'
> >>   printf '%s\n' "${var@p}" # should not expand to `$'.
> >>   PS1="${var@P}(date)" # because this should expand to `$(date)'
> >>                        # and not to the output of `date'.
> >>
> >> Cheers,
> >>   emanuele6
> >>