Re: [PATCH v4] help: colorize man pages

From: Jeff King <peff@peff.net>
Date: May 21, 2021, 08:44 UTC
Message-ID: <YKdy5jhHgG2who27@coredump.intra.peff.net>
In-Reply-To: <xmqqbl94smjb.fsf@gitster.g>

On Fri, May 21, 2021 at 02:06:48PM +0900, Junio C Hamano wrote:

Show 26 quoted lines

> Phillip Wood <phillip.wood123@gmail.com> writes:
> 
> > On 20/05/2021 05:07, Felipe Contreras wrote:
> >> We already colorize tools traditionally not colorized by default, like
> >> diff and grep. Let's do the same for man.
> >
> > I think there is a distinction between 'diff' and 'grep' where we are
> > generating the content and help where we are running man - I would 
> > expect a man page to look the same whether it is displayed by 'man git
> > foo' or 'git help foo'
> 
> ... as long as the user chooses "man" backend, that is.  And I tend
> to agree, but that is our expectation.
> 
> If we added this new mode of driving the same "man" but with
> different environment variables exported to tweak how "less"
> behaves, and taught it to builtin/help.c::exec_viewer() and
> builtin/help.c::man_viewer_list, that might become more palatable in
> the sense that we can view it as feeding the same manual page to
> this another "man" that behaves differently from the plain "man",
> just like we can feed it to "woman" or "konqueror" to get a different
> view.  So those (like you and I) who expect a man page to look the
> same in "man git foo" and "git help -m foo" can keep using our current
> configuration, while those who want yet another variant of "man" output
> in addition to the current "man", "woman", and "konqueror" can choose
> it and get "colorized" output.

I still don't understand what we gain by making this a Git feature, as all of the changed behavior is totally within the program we are calling. Imagine that konqueror (or an html viewer like firefox) had an option to set its color scheme from the command line. Should we introduce a new baked-in fancy-konqueror backend that is "run the tool with a tweaked color scheme"?

Why would we do that versus saying: if you want to change the colors in the tool that Git calls, then configure the tool?

If you like to see colors in manpages, why not configure "man" (either by setting these environment variables all the time, or by triggering them in MANPAGER)? And then Git doesn't have to care either way; it is calling "man" which does what the user wants, colors or no. If you really for some reason only want colorized man pages when called via "git help", then why not set man.fancy.cmd to invoke your preferred config?

If those configurations are awkward to trigger via man (e.g., putting escapes into termcap variables), isn't that something that could be improved in man? And then it would benefit everyone who uses man, not just Git.

-Peff