Re: Is it possible to detect `grotty -i` at runtime?

[John Gardner]

>
> `-i` is a _postprocessor_ option here.  Recall the basic *roff pipeline.
>

Ugh, *obviously.* For fuck sake, this is why I shouldn't be allowed to send
e-mails at 4am.

Somehow I got my wires crossed whilst preparing that e-mail, because I
vaguely recall having both grotty(1) and groff(1) open at the same time.
groffy(1), if you will.

Apologies for the retarded e-mail. This hasn't been one of my finer moments.
— J

On Fri, 22 Jul 2022 at 11:09, G. Branden Robinson <
g.branden.robinson@gmail.com> wrote:

> Hi John,
>
> At 2022-07-22T07:29:48+1000, John Gardner wrote:
> > I'm looking for a way to harden my .UL
> > <
> https://github.com/Alhadis/Mono/blob/25765171fbf676b623a4bcbf3d9f93384ef83040/ono.tmac#L171-L233
> >
> > (underline) macro against grotty(1) v1.23's new -i switch,
>
> This command-line option is not forthcoming.  It was introduced in groff
> 1.18 (July 2002).[1]  So it's a 20 year-old feature.
>
> What groff 1.23 does do is add a `-P` option to nroff so that arbitrary
> options can be passed to the postprocessor via that command.[2]
>
> > which causes italicised text to be rendered with actual italics (in
> > TTYs that support SGR 3, at least). My intended workaround involves
> > something like
> >
> > \l'\w,\$1,u\(ul'\h'-\w,\$1,u'\$1
> >
> > or some similarly atrocious hack. Unfortunately, there doesn't appear
> > to be any predefined register to report the status of grotty(1)'s -i
> > and -r switches (both of which change how italic fonts are rendered in
> > the terminal).
> >
> > Can anybody confirm that what I'm seeking to do is even possible?
>
> As I understand *roff architecture, this is indeed impossible.
>
> `-i` is a _postprocessor_ option here.  Recall the basic *roff pipeline.
>
> preprocessor | troff | postprocessor
>
> The most your macro can know about postprocessor-specific information is
> what was given as the -T argument to troff, what's in the corresponding
> `DESC` file (only if a mechanism for exposing that information via the
> roff language has been implemented), and, in groff, what the
> postprocessor-specific macro file (like tty.tmac) chooses to declare.
>
> Further, the pipeline can always be broken up such that a "grout" file
> (the output of the troff command itself) is stored and then processed
> with a different output driver (this is how gxditview works) or with
> different options to the intended output driver.
>
> What are you trying to do?  Avoid underlining text that the output
> device is already underlining itself?
>
> Regards,
> Branden
>
> [1] https://git.savannah.gnu.org/cgit/groff.git/tree/NEWS#n1694
>     https://git.savannah.gnu.org/cgit/groff.git/tree/NEWS#n2083
> [2] https://git.savannah.gnu.org/cgit/groff.git/tree/NEWS#n77
>