Re: Doc: typo in config.sgml

On Tue, 1 Oct 2024 22:20:55 +0900
Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp> wrote:

> On Tue, 1 Oct 2024 15:16:52 +0900
> Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp> wrote:
>
> > On Tue, 01 Oct 2024 10:33:50 +0900 (JST)
> > Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:
> >
> > > >> That's because non-breaking space (nbsp) is not encoded as 0xa0 in
> > > >> UTF-8. nbsp in UTF-8 is "0xc2 0xa0" (2 bytes) (A 0xa0 is a nbsp's code
> > > >> point in Unicode. i.e. U+00A0).
> > > >> So grep -P "[\xC2\xA0]" should work to detect nbsp.
> > > >
> > > > `LC_ALL=C grep -P "\xC2\xA0"` works for my environment.
> > > > ([ and ] were not necessary.)
> > > >
> > > > When LC_ALL is null, `grep -P "\xA0"` could not detect any characters in charset.sgml,
> > > > but I think it is better to specify both LC_ALL=C and "\xC2\xA0" for making sure detecting
> > > > nbsp.
> > > >
> > > > One problem is that -P option can be used in only GNU grep, and grep in mac doesn't support it.
> > > >
> > > > On bash, we can also use `grep $'\xc2\xa0'`, but I am not sure we can assume the shell is bash.
> > > >
> > > > Maybe, better way is use perl itself rather than grep as following.
> > > >
> > > > `perl -ne '/\xC2\xA0/ and print' `
> > > >
> > > > I attached a patch fixed in this way.
> > >
> > > GNU sed can also be used without setting LC_ALL:
> > >
> > > sed -n /"\xC2\xA0"/p
> > >
> > > However I am not sure if non-GNU sed can do this too...
> >
> > Although I've not check it myself, BSD sed doesn't support \x escape according to [1].
> >
> > [1] https://stackoverflow.com/questions/24275070/sed-not-giving-me-correct-substitute-operation-for-newline-with-mac-difference
> >
> > By the way, I've attached a patch a bit modified to use the plural form statement
> > as same as check-tabs.
> >
> > Non-breaking **spaces** appear in SGML/XML files
>
> The previous patch was broken because the perl command failed to return the correct result.
> I've attached an updated patch to fix the return value. In passing, I added line breaks
> for long lines.

I've attached a updated patch.
I added the comment to explain why Perl is used instead of grep or sed.

Regards,
Yugo Nagata

--
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>