On 14/02/2022 13:52, Mario Blättermann wrote:
> Hello Pádraig,
> 
> Am Mo., 14. Feb. 2022 um 13:15 Uhr schrieb Pádraig Brady <P@draigbrady.com>:
>>
>> On 13/02/2022 13:19, Mario Blättermann wrote:
>>> Hello,
>>>
>>> the SEE ALSO sections in the man pages contain links which will be
>>> pulled in from *.x files by help2man. While help2man evaluates the
>>> Groff markup from --help and --version output, it doesn't bother with
>>> the markup in the *.x files. See the attached patch. The bold
>>> formatting of the links is especially useful in HTML output (but also
>>> in terminal output); the links become clickable and point to the
>>> respective man page in online collections [1]. You can test the
>>> behavior in the German version, where the links are already properly
>>> formatted [2].
>>>
>>> [1] https://man.archlinux.org/man/cat.1
>>> [2] https://man.archlinux.org/man/cat.1.de
>>
>> Sorry. I'm still not convinced on this.
>> It seems like a layering violation to stipulate a style here.
>> The renderer should have enough context to highlight appropriately.
>> See for example:
>>
>> https://man7.org/linux/man-pages/man1/sort.1.html
>>
> 
> Maybe some renderers are smart enough to highlight this. But it
> shouldn't be up to the developers of such renderers to apply missing
> formattings virtually.

Thanks for the consideration on this.
I'm not strongly against hardcoding the formatting,
but I do think it's worth discussing the need.

Note we discussed this previously at:
https://lists.gnu.org/archive/html/coreutils/2021-01/msg00008.html

The summary there was things have trended over time
from a mixture of none,italic,bold style references
to mostly bold.

>> Note the man7.org renderer only highlights the SEE ALSO references,
>> when ideally it would highlight all instances of this pattern.
>> Anyway handling references outside of the SEE ALSO section,
>> is another reason to have the renderer do this consistently.
>> See for example all the appropriately highlighted references in:
>>
>> http://man.he.net/?topic=sort&section=all
>> https://man.cx/sort
>>
> Yes, but this doesn't work in all imaginable cases, because the
> renderer needs to be able to evaluate if it is a link or not. In your
> example, "shuf" is a link because it is tagged with the section
> number, but this wouldn't, then "shuf" would be as plain as other
> words. See the "diff3.1" man page [1]: > > -e, --ed
> output ed script incorporating changes from OLDFILE to YOURFILE into MYFILE
> 
> If "ed" would be "ed(1)" then it would be detected as a command name
> here, but it isn't.

But it isn't bold either.
I suggest this page should be updated to use "ed(1)".

> Well, the best solution would be to dig in the
> Help2man code and try to improve the detection of parts worth to be
> formatted - provided solid Perl skills. But this would be outside of
> the topic of this bug report;

Yes a `help2man --bold-refs` option seems useful.
It give the option to apply the formatting,
and more centrally, rather than inconsistently sprinkled
through all man pages.
Also this would be the only way to consistently
style all references in coreutils, since some are output
to the terminal through --help.

> let's go back to the SEE ALSO links. The
> man page man-pages(7) says [2]:
> 
> »The name of the command, and its options, should always be formatted in bold.«
>  
> In fact, the SEE ALSO links are also command names, although not the
> command the current man page describes. 

The bold here is pertaining to styling of the headers of the page,
rather than to any command references in general IMHO.
In general bold text interspersed in other text on the terminal
can be quite distracting to read. Some terminals can make it
bigger, brighter, blurrier, ...

> Let's have a look at other projects [that hardcode bold references]
 > grub, grep, kernel.

I see Paul added the grep markup recently in a seemingly unrelated change:
https://git.savannah.gnu.org/gitweb/?p=grep.git;a=commit;h=fe630c9f

> I could mention lots of similar examples, but just open an arbitrary
> man page in your terminal with "man", not in Vim; you will see that
> (almost …) all SEE ALSO links are formatted bold.

I did check also, and see lots of inconsistencies.
BTW re vim, the match for references is:
   syn match manReference "\f\+([1-9][a-z]\=)"

> With the bold
> formatting (and correct placing of the section number), you make sure
> that *all* renderers, both the simple ones like "man" in the terminal
> and the advanced HTML/DVI/PDF/whatever renderers, format the links
> correctly.

"correctly" is a strong word here.

> [1] https://man.cx/diff3#heading3
> [2] https://man.archlinux.org/man/man-pages.7.en#Formatting_conventions_for_manual_pages_describing_commands
> [3] https://git.savannah.gnu.org/cgit/grub.git/tree/docs/man/grub-editenv.h2m
> [4] https://git.savannah.gnu.org/cgit/grep.git/tree/doc/grep.in.1#n1359
> [5] https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man1/mtrace.1#n64
> [6] https://github.com/freebsd/freebsd-src/blob/main/usr.bin/sort/sort.1.in#L580

I've attached a patch to implement help2man --bold-refs.
Brendan is that something that might be added to official help2man?

coreutils enables this by default for generated man pages,
and it can be disabled if needed with:
   ./configure --disable-bold-man-page-references

Also attached is an ancillary patch I noticed with wrong section for exec(3p)

Marking this bug as done.

cheers,
Pádraig