Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Restrict locale settings to the file they occur in

This prevents LANG= in an included file from affecting the interpretation
of month and day names in the including file.

Make the internal pre-processor accept white space between the "#" at
the start of the line and the keyword for better compatibility with cpp.

Add support for the cpp keywords #warning and #error.

MFC after: 3 days

Add regression tests for conditions and comments

Fix one case where #else was not corerctly processed and simplify the
conditions logic.

Fix parsing of day and month names in the locale specified in the calendar
file. The previous version would expect those names to match the locale of
the user.

Mention that comments are now correctly processed and that // is supported
in addition to /* ... */.

MFC after: 3 days

Add extremely useful calendar(1) application to FreeBSD

It does extremely useful things like execute sendmail and spew dubiously
accurate factoids.

From the feedback, it seems like it is an essential utility in a modern unix
and not at all a useless bikeshed. How do those Linux people live without it?
Reverts r358561.

Fix typo in r278616

FreeBSD isn't an encyclopedia.

calendar: use iconv to respect the output encoding

calendar(1) can have input in various encoding, specifying
LANG=<locale_name> to enable calendar(1) to determine which one to use.

The problem is the content of the calendar itself is exposed as is making it
unreadable in many cases. For example french calendar which is encoded
ISO8859-1 is rendered badly in a fr_FR.UTF-8 environment.

Using iconv allows to solve this issue.
This will also allow to keep only 1 encoding in base for those files without
breaking user existing setup

Reported by: many
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D19221

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Rework calendar(1) parser

Support includes surrounded by '"' or '<' '>'
Print warnings about bad syntax
Correctly navigate through include directories to find calendar files
Correctly support multiple includes

Tested by: gjb
MFC after: 1 week

- calendar uses cpp internally, this diff removes this usage and
substitutes a limited subset cpp processor internally.

PR: src/178463
Approved by: re (gjb)

Handle some expression regressions.
Explicitly use GNU cpp for preprocessing.
Remove explicit debugging code.
Change some variable names to be less confusing.
Improve some comments.
Improve indentation.

PR: 162211
168785
MFC after: 2 weeks

Replace hard-coded value by Julian2Gregorian converter function.

Fix typo (Pashka -> Paskha).

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

For calendars which don't match the solar-based Gregorian calendar,
be able to specify a year string in an entry.

On request of joel@:

- Remove the 3rd clause of the UC Berkeley copyrighted files.
- For the files added copyrighted by me, move the "All rights
reserved" to the next line.

Long awaited update to the calendar system:

- Repeating events which span multiple years (because of -A, -B or
just the three days before the end of the year).

- Support for lunar events (full moon, new moon) and solar events
(equinox and solstice, chinese new year). Because of this, the
options -U (UTC offset) and -l (longitude) are available to
compensate if reality doesn't match the calculated values.

MFC after: 1 month

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Move functions which are only locally used into their C files and
make them static.

usage() in calendar.c
event_*() in io.c

PR: bin/118644
Approved by: bde@ (mentor)

style(9)ify usr.bin/calendar

PR: bin/118644
Approved by: bde@ (mentor)
MFC after: 1 week

Sort events by date.
Correct long-standing off-by-one error in -W option.

Submitted by: edwin@

Shorten some long lines. These files are still not completely
style(9) compliant.

ANSIfy function definitions.
Move some extern declarations to a header file.
Remove an unneeded extern declaration for optarg.

Include <sys/uio.h> for the complete type of struct iovec.

Approved by: das (mentor)

Add two new options:

-W is like -A (number of days in the future to consider, but also
specifies that we don't want special treatment at weekends.
-F changes our notion of "Friday" (the day before the weekend).

Arguably, calendar(1) is broken to have special treatment of weekends
by default, but this method maintains POLA.

remove __P

WARNS=2 fixup (mostly. Some are Hard To Fix(tm), so NO_WERROR is set)
Use __FBSDID().
Sort some headers.

Add missing $FreeBSD$ tags

More egcs warning fixes:
o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int
o #ifdef 0 -> #if 0

Reviewed by: obrien and chuckr

Allow to configure national Easter names.
Speedup my national months/days handling code.

Localize it
Handle Orthodox Eastern
-Wall cleanup

Change calendar to report the actual date for variable day events.
E.g. for Easter, and entries like "04/SunFirst" calendar will
now report:

04/05* Good Friday (2 days before easter)
04/07* First Sunday...

instead of:

Easter-2 Good Friday...
04/SunFirst First Sunday...

I also modified the calendar files to use the variable day format
for a lot of events so that they will be reported correctly.
E.g. U.S. daylight savings time is now listed as:

04/SunFirst Daylight savings time...

There are still a lot of wrong dates in there for some events
that move from year to year, but I don't have a good calendar handy
right now that I can use for reference.

Submitted by: pst
add forgotten file calendar.h. Sorry.