Re: "Read my lips: no more merges" - aka Linux 2.6.14-rc1

On Wed, 14 Sep 2005, Alejandro Bonilla Beeche wrote:

A very strange Linux installation that doesn't come with "less"...

What a strange box. Anyway, that does point out that maybe the git RPM spec should have "less" as a dependency.

		Linus

Linus Torvalds wrote:

Generally you want to honour $PAGER if it is defined.

	-hpa

"H. Peter Anvin" <hpa@zytor.com> writes:

We do, in the form of "something | ${PAGER:-less}".

On Debian, "less" is Priority "standard" and my understanding is that the only thing we can (and should if I recall correctly) omit from the dependency list is the packages of Priority "essential", so technically we are required to list "less" as our dependency. I do not know about RPM/Fedora.

Junio C Hamano <junkio@cox.net> writes:

On my Debian system, there is a "sensible-pager" which does a ${PAGER:-pager}, and "pager" which is a symlink to an installed pager (using the 'alternatives' system). So a Debian package should probably use one of those.

On Thu, 15 Sep 2005, David Kågedal wrote:

Ok, this is now indisputable proof that Debian people are insane.

They have "sensible-pager", but not "less"?

Guys, somebody should visit a few Debian people with a baseball bat that is painted bright neon yellow, and has "CLUEBAT" written in big purple letters on it. And beat them to a quivering pulp.

There's "being flexible", and there's "being a total ass". Debian is being a total ass.

		Linus

Linus Torvalds <torvalds@osdl.org> writes:

No, you read my message wrong, or I failed to describe it properly.

sensible-pager is just an indirection that uses your preferred pager. This will usually be less, but if a user prefers to use e.g. "w3m" (or "more") that can be done by reconfiguring a symlink (using the update-alternatives program, or even a GUI such as galternatives).

So no, they haven't replaced less with sensible-pager. They just provided another way to select which pager you want. Setting $PAGER will still work the trick.

Running "sensible-pager" will check $PAGER an run that if set, otherwise run the pager selected via the alternatives sytem, which will usually be "less". The alternatives selection is done with a symlink called "/usr/bin/pager".

The advantage is, I guess, consistency. Different programs don't have to encode their own default pager.

To summarize: on a Debian system with "less" as the preferred pager, these four invokations are equal:

  $ ${PAGER:-less}
  $ sensible-pager
  $ pager
  $ less

If you set $PAGER to something else, the first two variants will run $PAGER, while the last two will still run "less".

On Thu, 15 Sep 2005, David Kågedal wrote:

No, I did get it.

It's the Debian people who don't get it.

Expecting other software projects to make cludges for Debian-specific packages is _insane_.

In other word, no sane package will ever use "sensible-pager", because it's not a sensible thing to do. Once Debian maintainers are "Big Poo-Bah And OverLord of the KnownUniverse" and can force everybody else to have "sensible-pager" too, maybe -then- it might make sense, but until then it's just an odd-ball Debian thing that makes Debian maintainers either (a) maintain stupid patches to teach other programs about it or (b) have normal programs that use the _standard_ pagers in the absense of $PAGER.

And like it or not, there are two standard pages: "more" and "less". In the immortal words: "To two shall you count. You shall not count to one, except on your way to two. And you shall definitely NOT count to three, not call it 'sensible-pager'".

The fact is, we HAVE a sensible-pager, and it is called "less".

And for old programs that assume that sensible-pager is "more", we either install that _too_, or we make a symlink that points to "less".

And for people who want something else, everybody already supports the STANDARD way of saying so: "$PAGER".

In other words, "sensible-pager" buys you absolutely _nothing_. Except for confusion and extra work.

No. That's NOT an advantage. It's a disadvantage. Different programs sure as hell will not do silly Debian-only things, so it just means that if Debian tries to enforce this, they're only causing more work for their own maintainers.

They're also causing more work and discomfort for their users, since now their users will have to live with the fact that they are used to non-standard behaviour.

And it has _zero_ upsides. Exactly because it's not standard. There's a lot to be said for "do it like others do it".

			Linus

On Thu, 2005-09-15 at 11:15 -0700, Linus Torvalds wrote:

Actually according to Debian policy, sensible-pager is a cludge which should be used _only_ in the case that the upstream program is hard to adapt to a PAGER environment approach. Only in this case the upstream package should be patched to at least use sensible-pager.

Debian prefers to call the symlink "pager" and let the sysadmin decide where it should point: less, more, whatever. The e2fsprogs upstream package for instance supports PAGER->/usr/bin/pager->/usr/bin/less. Granted /usr/bin/pager is probably Debian only but every upstream author deciding whether to use PAGER:more or PAGER:less is not _that_ much better.

Just wanted to nitpick. Now you can reignite your flamethrower ;-) 

				Christian

On Fri, Sep 16, 2005 at 12:08:12AM +0200, Christian Meder wrote:

Actually, debugfs uses $DEBUGFS_PAGER:$PAGER:pager:more:less as its search path, where it looks for each executable in /usr/bin, /bin, and the current directory.

Overkill, yes; but it was the best way to shut up the whiny debian users who kept on filing bug reports. (Yes, yes, I'm softie. Besides, it's userspace, and compared to GNOME, KDE, or Mozilla, the bloat involved isn't even measurable. :-)

							- Ted

On Wed, 14 Sep 2005, H. Peter Anvin wrote:

We do. But it falls back to "less" by default.

I realize that UNIX tradition is to fall back to "more", but let's face it, that's just old and broken. There's "tradition" and there's "being stupid and unable to change".

Of course, if RPM supports the notion of "suggest", maybe we can make "less" a suggestion rather than a requirement, since you can still use git without it as long as you set PAGER.

		Linus