Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Replace strcat, strcpy and snprintf with bounds checking versions

Add file names and line numbers to calendar format error messages

Without file name and line number it is very cumbersum to identify the
locations of errors in calendar files.

MFC after: 3 days

Fix calculation of the recurring weekdays

Both the result of the first_dayofweek_of_year and the target
weekday are zero-based (0 fo sunday) while the target month-day
or year-day is 1-based. Adjust logic accordingly.

Also add testcase for this PR to the kyua test suite

PR: 201062
Submitted by: Richard Narron <comet.berkeley@gmail.com>
MFC after: 1 week

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.

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.

Fix a ton of speelling errors

arc lint is helpful

Reviewed By: allanjude, wblock, #manpages, chris@bsdjunk.com
Differential Revision: https://reviews.freebsd.org/D3337

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

Use even more conventional conversion routines.

Reported by: peterj@

Reluctantly remove one of the most extraordinary numeric conversion
routines I have ever seen and replace with something far more boring.

Tidy up command line processing:
- Add ? option to optstring.
- Sort options alphabetically.
- Vertical space.

Tidy up usage() function.

Bring man page in sync with source.

Ensure that debug code is only executed with the -d option.

Submitted by: Christiane Yeardley

Fix run-time breakage when encoutering invalid input-data.

PR: bin/157718

Fix the interpreter for:

Jul/Sat+3 Every third saturday of July - Jul/Sat+3

which was able to be done via:

Jul/SatThird Every third saturday of July - Jul/SatThird

Add interpreters for:

SatFourth Every third saturday of each month - SatFourth
Sat+4 Every third saturday of each month - Sat+4
Sat Every saturday of each month - Sat

MFC after: 2 weeks

Fix Paskha and Paskha-specific holidays.

Fix typo (Pashka -> Paskha).

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

Remove extra ;

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

While I am here, add more missing (unsigned char) casts to ctype() macros

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.

size_t is not equivalent to int on 64-bit platforms.

Pointy hat to: edwin@

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