Bring shutdown(8) into the 21st century.

I found this juxtaposition in the shutdown man page kind of
interesting:

time Time is the time at which shutdown will bring the system down
and may be the word now or a future time in one of two formats:
... [2nd format:] [[[[[cc]yy]mm]dd]hh]mm, ...
If the century [cc] is not specified, it defaults to 1900 for
years [yy] between 69 and 99, ...

In that, all the "[text]" except the one "[[[[["(etc) sequence are my
interjections, The ellipses ("...") represent where I omitted irrelevant
(for here) text.

Interesting yes, bizarre also. Requiring a future time, and then
defaulting to the (long gone) 20th century (for any random year)
makes no sense at all. So I fixed it.

In another hundred years or so, anytime from 2100 onwards, but best
left at least a decade into the new century, it will need altering again.
[One could write the code to automate this adjustment, but the man
page would still need updating.] More significant changes will be
needed as the 101st century approaches (years 10000 and beyond), as
then a 2 digit century will no longer be adequate. Call me then, and
if I'm able, I'll fix it.

If someone really has a need to schedule a shutdown for sometime
between 1969 and 1999 that can still be done by explicitly giving
the "19" cc value. It is just no longer ever the default.

Otherwise, now, years 20..90 mean the 21st century (2020..2099)
(the first 2 of those are already unusable, but, IMO, that's OK)
and years 00..19 mean the 22nd century (2100..2119) (except that
00, 2100, is still technically the final year of the 21st century).

This is advance planning for near the end of the 21st century when
someone wants to schedule a shutdown for early in the following
century, and can't be bothered typing the 2 century digits.

Use NULL instead of 0 for null pointer.

When the third arg to fwrite() is a size in bytes, then the second arg
should be 1. sizeof(*mbuf) happens to equal 1, but it's better not
to rely on that.

branches: 1.55.2; 1.55.8;
statc + __dead

Add -b and -vxz to usage.

Add flags -v, -x, and -z for verbose, debug, and silent shutdowns,
respectively, by passing flags AB_VERBOSE, AB_DEBUG, and/or AB_SILENT to
reboot(2).

branches: 1.52.2;
Remove _PATH_NOLOGIN before reboot, as well as before exit(), to prevent
a root file system which has been marked read-only in fstab from continuing
to prevent logins after reboot. From Ian D. Leroux in PR#43390.

Remove the \n and tabs from the __COPYRIGHT() strings.
(Tweak some to use a consistent format.)

branches: 1.50.4; 1.50.8;
Improvements and clarifications to log messages and also to the man page.
Partially cherry-picked from or inspired by PR bin/36551 by Greg A. Woods,
plus some additional grammar/usage/clarity adjustments while I was passing
through. Any mistakes are mine.

convert __attribute__s to applicable cdefs.h macros

branches: 1.48.4; 1.48.6;
PR/36626 - Jukka Salmi -- fails to compile if DEBUG is defined

- sprinkle static
- pass WARNS=4 and lint
- use size_t/time_t where appropriate
- get/setprogname()
- before executing rc.shutdown, set the real user id to 0, because shutdown
scripts may depend on it (for example su depends on being root).
- use warn instead of perror, and make sure we use the right errno.

branches: 1.46.4; 1.46.6;
PR/31531: Takahiro Kambe: shutdown(8) quietly exit if execed from login shell

Move WARNS=3 to the Makefile.inc, and add a little const to the remaining
programs that did not compile before.

branches: 1.44.2;
Finish previous (use ANSI function declarations) this time.

Kill __P(), use ANSI function declarations.

Add (unsigned char) cast to ctype functions

Comment typo: unecessary->unnecessary

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22308, verified by myself.

Add "-b bootstr" for shutdown to pass to reboot(8), so that shutdown
(which runs rc.shutdown, which might do stuff like, say, save your
ipnat or ipf state for restoration on reboot) can tell machines (sparc
and sun3 machines presently) how to boot.

__CONCAT does token pasting, not string concatnation. if something like:
__CONCAT("foo","bar");
actually works to concantate strings, it's because the preprocessor expands
it into "foo""bar" as separate strings, and then ANSI string concatenation
is performed on that. It's more straightforward to just use ANSI string
concatenation directly, and newer GCCs complain (rightly) about misuse
of token pasting.

backoff rev 1.36 - it's made obsolete by last rc.d changes and using
arbitrary hard time limit for /etc/rc.shutdown is not right anyway

when running /etc/rc.shutdown, don't want on it until it completes
indefinitely - by default, wait maximum of 300 seconds only
the timeout is settable via new -T flag
Adjust history to mention addition of shutdown hooks and -T option on manpage

This fixes bin/10637.

branches: 1.35.6;
exect->execve.
During my investigation, no reason could be found to enable tracing.
Fixes PR 7782 by Christoph Martin.

branches: 1.34.4;
testo. We want to source /etc/rc.shutdown.

Fixes PR #6474.

Run /etc/rc.shutdown when the final shutdown time has come.

Thanks to Ted Lemon for helping with my English.

Initialize the global variable `shuttime' with current time when
user requested to shutdown now, so that correct time is written in
/etc/nologin.

Add -p option in usage.

from Erik Bertelsen <erik@mediator.uni-c.dk>
{ put } { in } { lots } { of } { these } { to } { shut } { up } { egcs }

const poisoning.

KNF. ensure hostname is nul-terminated

Add a -p option, to power down the system at the specified time.

Need <time.h> for ctime(), time(), localtime() and mktime() prototypes.

add -D (no detach) option, per PR#4810

Oops; remove DEBUG.

Slight code rearrangement.

Document previous changes.

Recognize `-' only if it is the only argument after the time.

Allow `-dh'. Rearrange a bit.

Use err*(3) and warn*(3). Fix reading of the message from stdin.

Allow a century to be specified.
Don't validate the mmddhhmm values; mktime(3) does it.

make Y2K compliant and document as such.

branches: 1.16.2;
Don't delcare optind.

resolve conflicts from lite-2 merge

* cleanup for WARNS=1
* deprecate register
* fix .Nm usage

cleanup for gcc -Wall

add -d option to shutdown, as companion to reboot's -d flag (force crash dump)

eliminate possibility that execle() will be called with one too many
arguments.

After passing the terminating NULL for the argv list to execle(),
don't forget the (NULL) envp.
From Lennart Augustsson <augustss@cs.chalmers.se>, PR #2737.

convert to new RCS Id conventions; reduce my headache

Eliminate uses of some obsolete functions.

Merge with 4.4-Lite version.

Don't remove /etc/nologin if `-k' was used.

when warning, actually warn about the correct thing!

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

Use NULL instead of 0 for null pointer.

When the third arg to fwrite() is a size in bytes, then the second arg
should be 1. sizeof(*mbuf) happens to equal 1, but it's better not
to rely on that.

branches: 1.55.2; 1.55.8;
statc + __dead

Add -b and -vxz to usage.

Add flags -v, -x, and -z for verbose, debug, and silent shutdowns,
respectively, by passing flags AB_VERBOSE, AB_DEBUG, and/or AB_SILENT to
reboot(2).

branches: 1.52.2;
Remove _PATH_NOLOGIN before reboot, as well as before exit(), to prevent
a root file system which has been marked read-only in fstab from continuing
to prevent logins after reboot. From Ian D. Leroux in PR#43390.

Remove the \n and tabs from the __COPYRIGHT() strings.
(Tweak some to use a consistent format.)

branches: 1.50.4; 1.50.8;
Improvements and clarifications to log messages and also to the man page.
Partially cherry-picked from or inspired by PR bin/36551 by Greg A. Woods,
plus some additional grammar/usage/clarity adjustments while I was passing
through. Any mistakes are mine.

convert __attribute__s to applicable cdefs.h macros

branches: 1.48.4; 1.48.6;
PR/36626 - Jukka Salmi -- fails to compile if DEBUG is defined

- sprinkle static
- pass WARNS=4 and lint
- use size_t/time_t where appropriate
- get/setprogname()
- before executing rc.shutdown, set the real user id to 0, because shutdown
scripts may depend on it (for example su depends on being root).
- use warn instead of perror, and make sure we use the right errno.

branches: 1.46.4; 1.46.6;
PR/31531: Takahiro Kambe: shutdown(8) quietly exit if execed from login shell

Move WARNS=3 to the Makefile.inc, and add a little const to the remaining
programs that did not compile before.

branches: 1.44.2;
Finish previous (use ANSI function declarations) this time.

Kill __P(), use ANSI function declarations.

Add (unsigned char) cast to ctype functions

Comment typo: unecessary->unnecessary

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22308, verified by myself.

Add "-b bootstr" for shutdown to pass to reboot(8), so that shutdown
(which runs rc.shutdown, which might do stuff like, say, save your
ipnat or ipf state for restoration on reboot) can tell machines (sparc
and sun3 machines presently) how to boot.

__CONCAT does token pasting, not string concatnation. if something like:
__CONCAT("foo","bar");
actually works to concantate strings, it's because the preprocessor expands
it into "foo""bar" as separate strings, and then ANSI string concatenation
is performed on that. It's more straightforward to just use ANSI string
concatenation directly, and newer GCCs complain (rightly) about misuse
of token pasting.

backoff rev 1.36 - it's made obsolete by last rc.d changes and using
arbitrary hard time limit for /etc/rc.shutdown is not right anyway

when running /etc/rc.shutdown, don't want on it until it completes
indefinitely - by default, wait maximum of 300 seconds only
the timeout is settable via new -T flag
Adjust history to mention addition of shutdown hooks and -T option on manpage

This fixes bin/10637.

branches: 1.35.6;
exect->execve.
During my investigation, no reason could be found to enable tracing.
Fixes PR 7782 by Christoph Martin.

branches: 1.34.4;
testo. We want to source /etc/rc.shutdown.

Fixes PR #6474.

Run /etc/rc.shutdown when the final shutdown time has come.

Thanks to Ted Lemon for helping with my English.

Initialize the global variable `shuttime' with current time when
user requested to shutdown now, so that correct time is written in
/etc/nologin.

Add -p option in usage.

from Erik Bertelsen <erik@mediator.uni-c.dk>
{ put } { in } { lots } { of } { these } { to } { shut } { up } { egcs }

const poisoning.

KNF. ensure hostname is nul-terminated

Add a -p option, to power down the system at the specified time.

Need <time.h> for ctime(), time(), localtime() and mktime() prototypes.

add -D (no detach) option, per PR#4810

Oops; remove DEBUG.

Slight code rearrangement.

Document previous changes.

Recognize `-' only if it is the only argument after the time.

Allow `-dh'. Rearrange a bit.

Use err*(3) and warn*(3). Fix reading of the message from stdin.

Allow a century to be specified.
Don't validate the mmddhhmm values; mktime(3) does it.

make Y2K compliant and document as such.

branches: 1.16.2;
Don't delcare optind.

resolve conflicts from lite-2 merge

* cleanup for WARNS=1
* deprecate register
* fix .Nm usage

cleanup for gcc -Wall

add -d option to shutdown, as companion to reboot's -d flag (force crash dump)

eliminate possibility that execle() will be called with one too many
arguments.

After passing the terminating NULL for the argv list to execle(),
don't forget the (NULL) envp.
From Lennart Augustsson <augustss@cs.chalmers.se>, PR #2737.

convert to new RCS Id conventions; reduce my headache

Eliminate uses of some obsolete functions.

Merge with 4.4-Lite version.

Don't remove /etc/nologin if `-k' was used.

when warning, actually warn about the correct thing!

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision