col is used to display troff documents in ttys, removing the reverse
line feeds generated by .2C in ms. This implementation keeps the limit
of 256 lines of 800 characteres of the original implementation.
Not quite necessary to have this in sbase at the moment. We can do
a clean implementation when required.
This implementation also has some bugs that they have been fixed
in OpenBSD -current but I am too lazy to backport (we also had local
changes to col(1)).
printf(1) as imported from OpenBSD will stay for now because I need
it for booting my system.
patch taken from openbsd.
Ingo Schwarze says:
If you call the col(1) utility with the -f option, permitting forward
half-line feeds in the output stream, and the input stream actually
contains half-line feeds in either direction, you end up with corrupt
output, containing meaningless escape-digitnine sequences instead of
the required escape-tab sequences.
$ hexdump -C half.txt
00000000 61 1b 09 62 1b 09 63 0a |a..b..c.|
00000008
$ col -f < half.txt | hexdump -C
00000000 61 1b 39 0d 20 62 1b 39 0d 20 20 63 0a |a.9. b.9. c.|
0000000d
Note how the third character changes from 0x09 to 0x39.
OK to commit the following fix? Don't worry, it isn't dangerous,
it only changes two *bits*, only a quarter of a byte.
The bug was introduced by the original author, Michael Rendell,
and committed by Keith Bostic on May 22, 1990 (SCCS rev. 5.1).
The following operating systems are affected:
* 4.3BSD Reno, BSD Net/2, 4.4BSD, 4.4BSD Lite1, 4.4BSD Lite2
* All versions of 386BSD, NetBSD, OpenBSD, FreeBSD and DragonFly
* All versions of Debian GNU/Linux and probably many other Linuxes
