Re: [RFC/PATCH] pager: do not fork a pager if environment variable PAGER is set to NONE

From: Junio C Hamano <junkio@cox.net>
Date: Apr 16, 2006, 02:20 UTC
Message-ID: <7v4q0udzwg.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.63.0604160357460.31461@wbgn013.biozentrum.uni-wuerzburg.de>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 22 quoted lines

> Hi,
>
> On Sat, 15 Apr 2006, Junio C Hamano wrote:
>
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>> 
>> > This helps debugging tremendously.
>> >
>> > Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
>> 
>> I like what this wants to do.  I am not so sure PAGER=NONE is a
>> good convention, however.
>
> I am sure it is not.
>
> One solution would be to introduce yet another command line option 
> "--no-pager", but I find that ugly.
>
> Another solution would be to check if the environment variable NO_PAGER is 
> set.
>
> Wishes?

Honestly, undecided. Not that I think people would do PAGER=NONE to mean a program /usr/bin/NONE.

Right now, the following does not say anything:

	$ PAGER= git log

but I do not think that is a reasonably behaviour, either. So detecting PAGER is set to an empty string (not "nonexistence" - the current behaviour of defaulting to "less" in such a case is reasonable) is probably a better alternative.

A somewhat related topic; I often set PAGER=cat when I do not want the --[More]-- prompt and I thing many Emacs users do this. It might also be good to detect it and omit piping in such a case, but that is independent, so if you are going to do this as well, please make it a separate patch.