etcupdate(8): consistent -h and -? text

Match verb forms.

etcupdate: add -? for help. improve option errors

Support -? to show help.
Implemented using getopts "leading colon optstring" feature.
Improve error messages for unknown options and missing arguments.
Change usage-related errors from stdout to stderr.
Keep all other errors to stdout for now.

etcupdate: -h to stdout. improve help

Send -h help to stdout not stderr, and exit 0 not 1.
Show options alphabetically.
Use UPPER_CASE instead of lowercase as the convention for argument names.

A few hints that sets may come in .tar.xz format (instead of .tgz)

branches: 1.22.22; 1.22.24;
Update date for previous, and fix some small errors.

Add "-d destdir" option to etcupdate.
This has been only lightly tested.

branches: 1.20.2; 1.20.8;
Remove the ability to specify multiple colon-separated file names with
a single "-s" option. Multiple "-s" options must now be used instead.
We have been printing a warning about this since 2008-09-14.

branches: 1.19.6;
s/the the/the/

In both postinstall and etcupdate, in modes where the -s argument
refers to tgz files or to a directory in which tgz files have already
been extracted, make it an error for the files that should have come
from etc.tgz to be missing. This is intended to prevent users from
accidentally deleting necessary files when they run "postinstall -s
xetc.tgz fix".

Use the absence of .../etc/mtree/set.etc in the extracted directory
as a test for the error case.

Remove options deprecated in NetBSD-4.0:
* Remove "-b binarydir" option (use "-s binarydir" instead).
* Remove "-s srcdir/etc" option (use "-s srcdir" instead).

Also document that "-s tgz1:tgz2" is merely deprecated, not removed
(use "-s tgz1 -s tgz2" instead).

Document the change in meaning of "-s foo:bar". It now means a single
file or directory nmed "foo:bar". If you want the old meaning,
use "-s foo -s bar" instead.

branches: 1.15.2;
Convert TNF licenses to new 2 clause variant

branches: 1.14.2;
Document some about being able to view differences and
toggling the different diff formats/tools.

branches: 1.13.4; 1.13.8;
* Make etcupdate's -s option accept a colon-separated list of tgz
files. (It was already possible to use several -s options.)
* Change man page to refer to "-s tgzdir" instead of "-s tempdir",
to reduce confusion between tempdir and temproot.
* Always use a temproot directory, even if passed "-s tgzdir".
* Always invoke "postinstall check", even when not using a source dir.
* Add a BUGS section saying that using -s srcdir is not recommended.

Reviewed by lukem and martti.

branches: 1.12.2;
Xref etcupdate from postinstall, and vice versa.

branches: 1.11.2;
Give etcupdate the ability to use etc.tgz and xetc.tgz.

* Expand the "-s" flag to -s {srcdir|tgzfile|tempdir}.
* Deprecate the "-b" flag. It is replaced by "-s tempdir".
* Change "-s srcdir" to refer to the top of the source tree (e.g.
/usr/src) instead of the etc subdirectory.

In etcupdate's interactive phase, enhance the "s" command to be able
to invoke alternative diff commands.

Also some style changes.

Approved by christos

branches: 1.10.4; 1.10.6; 1.10.10;
Some Bl improvements; drop trailing whitespace; don't comma-separate
"a, and b"; mention arguments in option listing; list options in SYNOPSIS
in default order (those without arguments first).

Massive cleanup of the document, although there is a lot more work to
do still.

Add a -l option telling etcupdate to skip any file who's RCS id has
not been changed.
(-l means "skip local modifications".)
Code and documentation from Christopher Richards in PR bin/20200

New sentence, new line; bump date for recent changes.

Checksum files produced by "etcupdate -a" should not be stored in /etc
as / might be a read-only filesystem (PR#20201).

allow /etc/etcupdate.conf (and ~/.etcupdate.conf) to set IGNOREFILES to a list
of files that etcupdate will ignore; never considering them for updating.

The correct capitalisation of 'NetBSD.org' is (you
guessed it) 'NetBSD.org'.

some mdoc fixes.

grammar fix.

Add a new -a flag (automatically update files which have not been
locally modified). Patch provided by Sverre Froyen in a private mail,
slightly modified by me.

branches: 1.1.2;
Added etcupdate (etcupdate-20020321 in pkgsrc)