nnfc: no-nonsense FreeCell game in under 300 SLOC of POSIX AWK
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This is a simple and straightforward FreeCell implementation that adheres
to the POSIX AWK standard. Within <300 SLOC, it features:

* simple line-oriented command prompt compatible with standard move notation;
* Unicode/ASCII card suit signs (Unicode by default);
* color/monochrome display selection (color by default);
* M$-FreeCell-compatible deal seeding by the game number;
* FreeCell Pro-compatible supermoves to move stacks of cards between columns;
* FreeCell Pro-compatible card autohoming ("safe autoplay" strategy);
* internal help screen.

== How to run ==

The game is run as a usual AWK script:

awk -f nnfc.awk [-v ASCII=1] [-v MONOCHROME=1] [-v SEED=xxxxx]

Available parameters to pass to the script:

* `-v ASCII=1`: display Latin letters (c, d, h, s) instead of UTF-8 suits
* `-v MONOCHROME=1`: disable colors when displaying cards (e.g. on e-ink)
* `-v SEED=xxxxx`: set the PRNG seed (game number) to start a predefined game

== How to play ==

Once run, the game shows the current seed (game) number, the playfield with
all the cards in the traditional columnar layout and a command prompt.
Press Enter/Return after every command entry.

Move commands are entered with two characters without any separator:

* 0 or h is foundation/home cell (can be omitted and can only be the second)
* 1 to 8 are column (tableau) numbers
* a to d are freecell IDs

Examples:

* 7a: move from column 7 to freecell a
* 63: move (as many cards as possible) from column 6 to column 3
* d1: move from freecell d to column 1
* 4 (or 40, or 4h): move from column 4 to the foundation/home cell
* c (or c0, or ch): move from freecell c to the foundation/home cell

Besides moves, the following commands are available:

* h: display a help screen
* u: undo the last move (the history is saved from the beginning)
* r: restart (undo to the starting playfield)
* q: quit the game

== Compatibility ==

Primary testing was done on nawk and busybox awk, but the game should work
correctly on mawk, gawk and any other POSIX-compliant AWK implementation.
Particularly, additional tweaking had been done to make sure the game works
correctly with gawk --posix and mawk -W posix flags.

== Credits ==

Created by Luxferre in 2024. Released into public domain.