doc: Remove claim that "more" can't move backward

[pehjota]

As suggested by a Debian user in 2012.

POSIX specifies that "more" can scroll backward.

util-linux's "more", added in version 1.6, was copied from system-0.98.tar.Z, where "CREDITS" says it came from BSD Net/2. "more" source code was released in 386BSD version 0.1, upon which NetBSD and FreeBSD were later based.

Both the Net/2-based version in system-0.98.tar.Z and 386BSD 0.1's "more" supported [N]b or [N]^B to skip backward N pages. In other words, apparently all versions of "more" since its first source code releases allow backward movement.

[gwsw]

all versions of "more" since its first source code releases allow backward movement.

The version of more that I was using in 1983 did not allow backwards movement. That's the reason that I wrote less in the first place; see the FAQ. I think that was on a BSD release but I'm not positive. The BSD code you linked to seems to implement backwards movement by calling fseek, which wouldn't work on a pipe, so perhaps that's the confusion. In any case, I accept that the claim that more does not support backwards movement is now antiquated at best.

[pehjota]

more was originally written by Eric Shienbrood at UCB in 1980. It was freely licensed first within Net/1 in June 1989 and wasn't standardized until Single Unix Specification, Issue 4 in 1994 (page 4 a.k.a. page 26: "The utilities first introduced in Issue 4 are as follows: [...] more"). Therefore it's unlikely that versions of more appeared outside BSD before 1989, so in 1983 you probably used it on BSD. I did a bit more digging to narrow down some interesting history:

more in 4.2BSD from 1983 (sccsid "@(#)more.c 4.16 (Berkeley) 83/08/26") lacks case 'b':/case ctrl('B'): in command(). This or an earlier version of BSD must be what you used.

more in 4.3BSD from 1986 (sccsid "@(#)more.c 5.4 (Berkeley) 4/3/86") has case 'b':/case ctrl('B'):. So 4.3BSD was the first release to include a version of more that supported backward movement on files (which is how your FAQ describes you using it – on log files, not pipes).

Given that 4.3BSD's more and early versions of less very coincidentally both use the same b/^B command keys, I'm guessing that UCB copied the feature from less. I see less appeared in 1994's post-USL-lawsuit 4.4BSD (or perhaps somewhere earlier in 1988?).

Anyway, on a related note, congratulations on (and thank you for) 40 years of maintaining less!

[avih]

ongratulations on (and thank you for) 40 years of maintaining less!

+1024

Many thanks from me as well. This has to be the most used command I use on any system.

[gwsw]

It's interesting that in those two early versions of less, the copyright notice has my name spelled incorrectly. So someone other than I must have added those copyright notices. I vaguely remember that when I first gave Berkeley permission to add less to BSD, there was some discussion about licensing (probably because I didn't understand the BSD license) but I don't remember when or how the first copyright notice was added to the files.