Re: [RFC PATCH 4/4] color.ui config: add "isatty" setting

From: Junio C Hamano <gitster@pobox.com>
Date: May 30, 2018, 22:57 UTC
Message-ID: <xmqqmuwgda5k.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180530210641.19771-5-avarab@gmail.com>

Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:

Show 10 quoted lines

> A co-worker of mine who was using UNIX systems when dinosaurs roamed
> the earth was lamenting that kids these days were using tools like
> "git" that thought they knew better than isatty(3) when deciding
> whether or not something was a terminal, and the state of the
> documentation fixed earlier in this series certainly didn't help.
>
> So this setting is a small gift to all the UNIX graybeards out
> there. Now they can set color.ui=isatty and only emit fancy colors in
> situations when the gods of old intended, not whatever heuristic we've
> decided to set "auto" to.

Re-read the above again, and notice that you are *only* hinting that you consider difference between "auto" and "isatty" is important, and that your "isatty" is better, without telling what the difference is, let alone why you think "isatty" is better.

Show 7 quoted lines

>
> As noted here this is *currently* the same as setting color.ui=auto &
> color.pager=false, but I think it's good to explicitly have this
> setting for any future changes. The reason, as now noted in the
> documentation is that the "auto" setting may become even smarter in
> the future and learn even deeper heuristics for when to turn itself on
> even if isatty(3) were returning true.

Do you mean s/true/false/ in the last part?

> At that point the fans of plain isatty(3) will become even more upset
> at what we're doing, so let's give them a simple future-proof opt-out.

You still haven't explained why "auto" that does more than "isatty" is and will be irritating.

That's not a good way to sell a patch.

Also even "isatty" still needs to do more than isatty(1) call. The process that is trying to do color.ui=isatty may be talking to an outgoing pipe due to the use of "git -p cmd", by that time, it is too late to call isatty(1) and obtain the info the caller wishes to.