RE: Need multibyte advice - Shift-JIS

["Randall S. Becker" <rsbecker@nexbridge.com>]

On February 27, 2019 11:52, Michal Suchánek wrote:
> To: Randall S. Becker <rsbecker@nexbridge.com>
> Cc: git@vger.kernel.org
> Subject: Re: Need multibyte advice - Shift-JIS
> 
> On Wed, 27 Feb 2019 11:33:47 -0500
> "Randall S. Becker" <rsbecker@nexbridge.com> wrote:
> 
> > On February 27, 2019 11:29 Michal Suchánek wrote:
> > > On Wed, 27 Feb 2019 11:19:33 -0500
> > > "Randall S. Becker" <rsbecker@nexbridge.com> wrote:
> > >
> > > > On February 27, 2019 11:11, Michal Suchánek wrote:
> > > > > On Wed, 27 Feb 2019 10:54:23 -0500 "Randall S. Becker"
> > > > > <rsbecker@nexbridge.com> wrote:
> > > > >
> > > > > > On February 27, 2019 9:09, Michal Suchánek wrote:
> > > > > > > On Wed, 27 Feb 2019 08:04:08 -0500 "Randall S. Becker"
> > > > > > > <rsbecker@nexbridge.com> wrote:
> > > > > > >
> > > > > > > > Hi Git Team,
> > > > > > > >
> > > > > > > > I have to admit being perplexed by this one. I have been
> > > > > > > > asked to support the Shift-JIS character set in file
> > > > > > > > contents, comments, and logs, for a partner of mine. I
> > > > > > > > know there are a few ways to do this, but I'm looking for
> > > > > > > > the official non-hacky way
> > > to do this.
> > > > > > > > This is CLI only, and our pager, less, does not support
> > > > > > > > multi-byte, so I'm looking
> > > > > > for
> > > > > > > options there also.
> > > > > > >
> > > > > > > SJIS is about as much multibyte as UTF-8.
> > > > > > >
> > > > > > > Why do you think less does not support it?
> > > > > > >
> > > > > > > Last time I looked there was SJIS locale for libc so it is
> > > > > > > only matter of generating the correct locales and using
> > > > > > > them. Of course, if you are
> > > > > > running
> > > > > > > in UTF-8 SJIS will look like garbage.
> > > > > >
> > > > > > Sadly, I did not personally build less on this platform, and
> > > > > > the libc used did not include UTF-16, on the platform vendor
> > > > > > supplied less. cat works fine, but the usual
> > > > > > LESSCHARSET=utf-16 is unsupported, so I am looking for an
> > > > > > alternative. THAT is why I think less does not support it.
> > > > > > Sorry, I should have made that more
> > > clear.
> > > > > >
> > > > > > cat works fine, so if I set GIT_PAGER=cat, I can at least see
> > > > > > the diffs cleanly in SJIS, but this partner wants a pager that is usable.
> > > > > >
> > > > >
> > > > > So you want to use SJIS because UTF-16 is not supported. So what
> > > > > is the problem with SJIS (or UTF-8 for that matter)?
> > > >
> > > > The partner I am working with is using multi-byte SJIS, which is
> > > > also not
> > > supported by this incarnation of less. As a result, UTF-8 does not
> > > work either in this situation. The content is definitely multi-byte.
> > > I know this was fixed in RedHat's Less in 2016, but did not make this
> platform.
> > > >
> > >
> > > Both UTF-8 and SJIS is multibyte and both is supported by less in
> > > general. If your particular less cannot support it then it is broken
> > > and you should fix it or get it fixed.
> >
> > To be more specific, the implementation of less' UTF-8 on this platform will
> present the data as unusable junk as expected. SJIS is multi-byte, but is not
> one of the allowed encodings in less. I am not empowered to "get it fixed".
> Thanks for your advice.
> >
> 
> How is this 'allowed encodings in less' defined?

When you run less with LESSCHARSET=encoding, if the encoding is not known, you get the error:
invalid charset name

Doing the due diligence, I actually read the man page on the platform before asking the question, which listed the following as the only allowed encodings: ascii, iso8859, latin1, latin9, dos, IBM-1047, koi8-r, next, utf-8, windows. The utf-8 variant does not know how to display its multi-byte forms in SJIS, as with other platforms. Does that make sense now?