Re: fatal output from git-show really wants a terminal

From: Jeff King <peff@peff.net>
Date: Dec 11, 2008, 21:55 UTC
Message-ID: <20081211215554.GA11565@sigill.intra.peff.net>
In-Reply-To: <200812111051.20322.bss03@volumehost.net>

On Thu, Dec 11, 2008 at 10:51:15AM -0600, Boyd Stephen Smith Jr. wrote:

> Initially, I was looking for 'stdout' or 'stderr', and found many unrelated 
> commits.  I then figured it was part of the PAGER support, and began

Try looking for isatty, which takes the numeric fd. I think the behavior you asked about would be this:

diff --git a/pager.c b/pager.c
index aa0966c..19f8856 100644
--- a/pager.c
+++ b/pager.c
@@ -42,7 +42,7 @@ void setup_pager(void)
 {
 	const char *pager = getenv("GIT_PAGER");
 
-	if (!isatty(1))
+	if (!isatty(0) || !isatty(2))
 		return;
 	if (!pager) {
 		if (!pager_program)

which is what is mentioned in POSIX:

  http://www.opengroup.org/onlinepubs/009695399/utilities/sh.html

But I don't think that makes sense here. We are not talking about
interactivity, but rather about where the output is going. So your test
would consider this interactive:

  $ git log >foo.out

and start a pager, which makes no sense.

Now if you proposed checking stderr and stdin _in addition_ to stdout,
that might make more sense, but I haven't thought too hard about any
implications.

And FWIW, I don't recall this ever being discussed before, but then I
have not been involved with git since the very beginning.

-Peff