readme

一款运行在linux上的象棋游戏。用GTK/GNOME环境下用GLADE开发。

hashsize command.

Typically middle-game searches are sped up by 25%-50% by the general
hash table and by much more in endgames where there are few pieces
(because so many of the positions turn out to be cached already in
the hash table.)

Pawn evaluation is traditionally expensive because there are so many 
things to evaluate. The pawn hash table remembers all the different
pawn structures in the search. Typically pawn structure evaluation
(without reference to pieces) may be calculated by simple table
lookup this way 90-99% of the time. Hence, any amount of pawn logic
that is pure-pawn and not related to pieces may be added without guilt.
On the other hand, pawn structure that relates to pieces must be
recalculated for every position. See ScoreP() in eval.c


AUXILLARY FILE FORMATS

.dat - binary book format, simply a 64-bit position hash and a 32-bit score
.pgn - game listing like 1. e4 e5 2. Nf3 etc.
.epd - epd-style format using FEN notation. See tests subdirectory for example.
log.nnn - record of an entire game from computer's viewpoint (thinking, etc.)
game.nnn - record of an entire game, similar to .pgn but auto-generated

The .dat file format is a simple binary format for the compiled book
which is read by the program when it is using book. See the section BOOK
for more detail.

EPD and PGN require little introduction. These are the uniformly accepted
standards for position recording and game recording.

Note that log.nnn and game.nnn files are written at the end of a game
when you use the "name" command to give the computer your name. It is
highly recommended to do this since the resulting two files that match
in a monotonically-increasing extension numbered suffix may be used for
reporting bugs and keeping track of your games.


COMPILERS

  We like GNU C in all its various forms. For Unix and Linux, use GNU C.

  For Microsoft Windows platforms we compile and test using Cygwin,
  which is a port of many GNU packages, including GCC.

  Cygwin may require specific run time DLL's to provide the interface, 
  these should be provided with any executable you receive.

  Whilst GCC is the supported compiler, a key goal is portability. If
  you experience problems compiling GNU Chess with a modern C compiler
  please let the developers know.

INTERNET

  GNU CHESS 5 has been tested substantially on the Free Internet Chess
  Servers (freechess.org) with Xboard (See Zippy documentation in the
  Xboard/Winboard distribution http://www.tim-mann.org/).

  GNU Chess 5.06 and later should also operate with icsDrone. Testing
  5.06 with icsDrone 1.5.0 showed no immediate issues.

XBOARD/WINBOARD

  Running the program with the "--xboard" command line parameter sets it
  to produce output acceptable to and accept input suitable for xboard
  and winboard, the graphical display front-ends with mouse interface.

  For historical reasons the option "xboard" does not need to be 
  preceeded by "--", however we would encourage the new syntax.

COMMAND LIST

  ^C
	Typically the interrupt key stops a search in progress,
	makes the move last considered best and returns to the
	command prompt

  quit
	Quit the program.
  exit
	In analysis mode this stops analysis, otherwise it quits the program.

  help
	Produces a help blurb corresponding to this list of commands.

  usage
	Produce blurb on command line options.
	(Same as "gnuchess --help")

  book
	add - compiles book.dat from book.pgn
	on - enables use of book
	off - disables use of book
	best - play best move from book
	worst - play worst move from book
	random - play any move from book
	
	prefer (default) - choose a good move from book
	(Method subject to variation)

  version
	prints out the version of this program
	(Same as "gnuchess --version")

  pgnsave FILENAME
	saves the game so far to the file from memory

  pgnload FILENAME
	loads the game in the file into memory

  force
  manual
	Makes the program stop moving. You may now enter moves
	to reach some position in the future.
	(Same as "gnuchess --manual")
   
  white
	Program plays black, set white to move.

  black
	Program plays white, set black to move.

	(White and black commands are mainly for icsDrone
	 and will cause the current en-passant capture
	 square to be forgotten).

  go
	Computer takes whichever side is on move and begins its
	thinking immediately

  easy 
	Disables thinking on opponent's time
	(Same as "gnuchess --easy").

  hard
	Enables thinking on opponent's time

  post
	Arranges for verbose thinking output showing variation, score,
	time, depth, etc.

	If pondering (see hard) is on, the program will output
	it's thinking whilst the opponent is thinking.

	(Also "gnuchess --post")

  nopost
	Turns off verbose thinking output

  name NAME
	Lets you input your name. Also writes the log.nnn and a
	corresponding game.nnn file. For details please see
	auxillary file format sections.

  result
	Mostly used by Internet Chess server.

  activate

	This command reactivates a game that has been terminated automatically
	due to checkmate or no more time on the clock. However, it does not
	alter those conditions. You would have to undo a move or two or
	add time to the clock with level or time in that case.

  rating COMPUTERRATING OPPONENTRATING
	Inputs the estimated rating for computer and for its opponent

  new
	Sets up new game (i.e. positions in original positions)

  time
	Inputs time left in game for computer in hundredths of a second.
	Mostly used by Internet Chess server.

  otim (NOT IMPLEMENTED)
	Mostly used by Internet Chess server.

  random (NOT IMPLEMENTED)
	Randomizes play by perturbing the evaluation score slightly.
	The degree of perturbation is adjustable.

  hash
	on - enables using the memory hash table to speed search
	off - disables the memory hash table

  hashsize N
	Sets the hash table to permit storage of N positions
	N is rounded down to nearest power of 2.
	(Also "gnuchess --hashsize=N")

  null
	on - enables using the null move heuristic to speed search
	off - disables using the null move heuristic

  xboard
	on - enables use of xboard/winboard
	off - disables use of xboard/winboard
	(Also "gnuchess --xboard")

  depth N
	Sets the program to look N ply (half-moves) deep for every
	search it performs. If there is a checkmate or other condition
	that does not allow that depth, then it will not be 

  level MOVES MINUTES INCREMENT
	Sets time control to be MOVES in MINUTES with each move giving
	an INCREMENT (in seconds, i.e. Fischer-style clock).

  load
  epdload
	Loads a position in EPD format from disk into memory.

  save
  epdsave
	Saves game position into EPD format from memory to disk.

  switch
	Switches side to move

  solve FILENAME
  solveepd FILENAME
	Solves the positions in FILENAME

  remove
	Backs up two moves in game history

  undo
	Backs up one move in game history

  show
	board - displays the current board
	time - displays the time settings
	moves - shows all moves using one call to routine
	escape - shows moves that escape from check using one call to routine
	noncapture - shows non-capture moves
	capture - shows capture moves
	eval [or score] - shows the evaluation per piece and overall
	game - shows moves in game history
	pin - shows pinned pieces

  test
	movelist - reads in an epd file and shows legal moves for its entries
	capture - reads in an epd file and shows legal captures for its entries
	movegenspeed - tests speed of move generator
	capturespeed - tests speed of capture move generator
	eval - reads in an epd file and shows evaluation for its entries
	evalspeed tests speed of the evaluator

  analyze
	Switches program into analysis mode, this is primarily intended for
	communicating analysis to an external interface using the Xboard 
	chess engine protocol. It enables "force", "post", and
	"hard", at the same time, whilst altering the
	output format of post to conform with the engine protocol.