crafty(6) crafty(6)

crafty - chess engine

crafty [bookpath=<directory>] [logpath=<directory>]
[tbpath=<directory-list>]











Crafty is a chess "engine". That is, the program
    concerns itself with playing chess and not with providing a graphic user
    interface. Thus Crafty is commonly invoked indirectly via
    XBoard, and current versions of these programs generally work very
    well together. Some noteworthy features of Crafty are:









In the command line arguments, <directory-spec> is a
    path to a directory, whereas <directory-list> is a non-empty
    sequence of paths to directories. For portability, several different
    characters are taken as path separators: the colon (:), the semicolon (;),
    and the comma (,).




There are actually four of these: bookpath is where Crafty
    seeks its opening books and writes learned knowledge; logpath is
    where Crafty normally writes a pair of files "game.nnn" and
    "log.nnn" for each game it plays; rcpath is where Crafty
    looks for a run control file to be read only; and tbpath is where
    Crafty looks for endgame tablebase files to be read only.




The four path specifications have a number of things in common:
    each has a default value set when Crafty is compiled, which can then
    be modified by the appropriate environment variable, and can then again be
    modified by an invocation argument, but can not be modified after the
    engine has been initialized (thus, in particular, it is not possible to
    modify the paths by editing a run control file). Possibly the best procedure
    is to avoid the invocation options, experiment with the environment
    variables, and then perhaps recompile the program with different defaults.
    Note that if the program is compiled "out of the box" then all
    four values default to "./" (the directory in which Crafty
    has been launched).




Crafty can be invoked with other arguments (such as
    "xboard" to indicate that Crafty is being invoked through
    xboard(6)) which would not usually be used directly.
  














Crafty's extensive command-line interface is defined in
    "option.c", discussed in "crafty.doc", and briefly
    described by the command "help".












Crafty tries to read a run control file rcpath/.craftyrc.
    (On a non-Unix system, ".craftyrc" changes to
    "crafty.rc".) Such a file should contain a sequence of valid
    Crafty commands, terminated by the command "exit" to restore
    standard input to the keyboard. See craftyrc(5) for a skeletal
    example.








When a game is played, Crafty normally writes
    "logpath/game.<nnn>" and
    "logpath/log.<nnn>". Details of what is written are
    modifiable by the `log' command. Because $CRAFTY_LOG_DIR defaults to
    "./" (the directory in which Crafty is launched), trouble can
    occur if the program is launched in a directory to which it is unable to
    write. Note that the "log.<nnn>" file normally contains all
    output that would be visible if Crafty were run from the command line
    but is usually hidden when it is run from a GUI.








Crafty is designed to maintain its chess opening knowledge in a
    file "book.bin", and to modify this file as it learns from its
    mistakes. Refer to the documentation for the "book" command for
    information on generating and customizing usage of "book.bin".


Further, files "books.bin" and "bookc.bin"
    allow easy customization of Crafty's opening play (against humans and
    computer, respectively). See the documentation for the "books"
    command.


Finally, there are several files "*.lrn" for synopses of
    what Crafty has been learning. See the documentation for the
    "learn" command.








When normally configured, Crafty reads late endgame knowledge from
    "*.emd" files, which are distance-to-mate tablebases. See the
    documentation for the "egtb" command.
  




















If $CRAFTY_BOOK_PATH is set, it overrides the compiled
    value of bookpath, the path to directory containing
    "book.bin" and friends. Unless learning has been disabled, Crafty
    will be writing in this directory.
  














If $CRAFTY_LOG_PATH is set, it overrides the compiled value
    of logpath, the path to directory for writing, but not reading, the
    log files.








If $CRAFTY_RC_PATH is set, it overrides the compiled value
    of rcpath, the path to directory for reading, but not writing, a run
    control file (".craftyrc" or "crafty.rc").








If $CRAFTY_TB_PATH is set, it overrides the compiled value
    of tbpath, the sequence of paths to directories for reading, but not
    writing, endgame tablebase files.
  
















craftyrc(5), xboard(6), /usr/share/doc/crafty








Crafty is the son of Cray Blitz, also written by Bob
    Hyatt. The subsequent history of Crafty is detailed in the source
    file "main.c". Opening books appeared in version 1.9. log files in
    1.11, endgame tablebases in 8.24, run control files in 9.22, and environment
    variables in 16.5.








In the interests of portability, Crafty deals with files in
    a simple manner, at the cost of robustness. Very long or incorrect paths may
    result in a "segmentation fault" when a file writing operation
    fails.


This manual page itself will probably always be flagrantly
    incomplete in that many essential, powerful, and interesting aspects of
    Crafty are not even mentioned.












Robert Hyatt (hyatt@cis.uab.edu).







  

    December 22, 2003
    Crafty 19.8