Re: [PATCH] shortlog: prompt when reading from terminal by mistake

From: Junio C Hamano <junkio@cox.net>
Date: Mar 10, 2007, 00:39 UTC
Message-ID: <7vwt1q2apf.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.64.0703080827170.10832@woody.linux-foundation.org>

Linus Torvalds <torvalds@linux-foundation.org> writes:

Show 10 quoted lines

> Sure, this probably gets some cases (and the one you tried in particular), 
> but if you pipe the output to a pager, I doubt it's actually all that 
> useful.
>
> To simulate a "wait a long time without output" case, try this:
>
> 	( echo "Important warning" >&2 ; sleep 10) | less -S
>
> and at least for me, I don't see squat _in_case_I'm_at_the_top_ of the 
> window, simply because "less" will clear the screen for me.

> In other words, putting warnings on stderr usually isn't all that useful 
> when you have something like a pager that will do tty stuff - it will 
> easily overwrite the warning so quickly that you'll never see it at all.

That is correct in general, but you are being unfair.

You know git-shortlog has built-in pager _and_ you know _you_ added select(2) before spawning less, so that when that warning is emitted, less hasn't even started running --- it cannot clear the display.