Re: PS0 vs. \[ \] followup

2026=E5=B9=B46=E6=9C=8812=E6=97=A5(=E9=87=91) 4:24 Chet Ramey <chet.ramey@c=
ase.edu>:
> On 6/9/26 6:07 PM, Koichi Murase wrote:
>
> > Yes, we agree that they should simply vanish. We are talking about the
> > details of when they should vanish. Actually, the current behavior of
> > the devel branch fails to properly remove \x01 and \x02 embedded in a
> > command substitution, such as `$(prompt-framework git-status)'. In
> > fact, prompt frameworks such as Starship embed \x01 and \x02 in their
> > output to change colors and styles in the middle of their output. To
> > remove \x01 and \x02 properly, they should be removed at the very last
> > step, as we are requesting in the present thread.
>
> Are you saying that bash should remove 0x01 and 0x02 anywhere they appear
> in a prompt string, even if they are not added behind the scenes as part
> of processing \[ and \] before passing the prompt to readline?

Yes? But isn't that the behavior of PS1? As far as I test the behavior,

  PS1=3D$'\1\e[1m\2foo\1\e[m\2 '

has the same effect as

  PS1=3D$'\[\e[1m\]foo\[\e[m\] '

which implies that \1\2 that didn't originate from \[\] are treated
the same as the ones originating from \[\]. Also, in y.tab.c
(decode_prompt_string), I don't seem to find any special handling of
\1\2 to make it distinguishable from \1\2 originating from \[\].

> Why would it do that?

For consistency with PS1.

> > We are talking about the detailed behavior of `what it should be
> > doing'. Both removing \[\] from the beginning and removing \x01\0x02
> > at the final step satisfy what you seem to request. You haven't
> > explained why they should be removed before the `promptvars'
> > processing instead of after `promptvars'.
>
> There is no `removing'. They are simply not added if bash can't tell that
> the prompt will be passed to readline.

As already replied to kre's reply, that's just terminology. Could you
please interpret that =C2=ABremoving=C2=BB means that =C2=ABthe correspondi=
ng
substring is not included in the string passed to the next step of the
processing=C2=BB?

--
Koichi