This code is based on:
Mines ver. 1.0
Minesweeper game written for Plan 9 Third Edition.
Original Copyright (C) 2001 Antonin Vecera
email: antonin.vecera@gmail.com
Controls
Left mouse button - uncover the current location
Middle mouse button - uncover all adjacent squares that are known to be safe
Right mouse button - mark a square as known to contain a mine
n - start a new game
q, DEL - quit the game
b, a, e - select game level (beginner, advanced, expert)
This code is licensed under the GNU General Public License, Version 2,
reproduced in the file /lib/legal/gpl.