Without `-y`, to show the current full year you'd have to specify which
one: `cal 2023`. Adding `-y` makes it possible to see the full current
year without remembering what year we are in.
This option is also stolen from FreeBSD :^)
Additionally, validate args: prevent passing both -3 and -y at the
same time. Passing both `--three-month-mode` and `--year` to `cal`
doesn't make sense. You'd either want the one or the other.
Making it configurable in system settings :^)
The --start-day option can still overwrite this global default.
This change makes it no longer possible to use unveil: as we have
to load the Calendar config file, which might be in a dynamic location.
It's also neccessary to add `cpath` to the pledge, as opening a
nonexistent config file with Core::ConfigFile::open_for_app creates it.
Making all the other parts of the world happier :^)
Add a `--starting-day` (`-s`) option to be compatible with GNU cal,
which has a similar option. The GNU option takes allows passing either
an int or a day name. Let's do something similar using weekdays we
already have in AK/DateConstants.h.
Also add myself to the copyright header, as by now I've modified most of
the lines in this file.
...instead of putting a star `*` next to it. This makes `cal`s output
much prettier, and gets rid of one FIXME. :^)
Don't use the escape sequence from the deleted FIXME - \e[30;47m would
set the background to white and foreground to black - which presumably
wouldn't do much on a light-theme terminal. Instead use \e[7m which sets
the color as "inverted".
Every other cal implementation just highlights the current day instead
of letting you specify a custom one to highlight. It doesn't seem to be
that useful, and is currently broken - no day gets highlighted at all,
because the `target_day` global is never written to.
Moreover, this complicates parsing the arguments. This commit also fixes
parsing a case where just a year is provided to `cal` - for example `cal
2023`.
