Provided by: crafty_23.4-6_amd64 bug

NAME

       crafty - chess engine

SYNOPSIS

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

DESCRIPTION

       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:

       *  Source code, provided, is unusually deserving of  study.   The  author  has  sought  to
          provide  a  starting  point for others writing chess-playing programs, leading to clean
          and portable code.  Another objective has been to  maintain  a  state-of-the-art  chess
          engine,  with  the  result  that  some  parts  of the source code may be challenging to
          understand.

       *  Flexible and powerful command-line interface.  About the only thing  that  can  not  be
          done within the CLI is changing various paths determining where Crafty reads and writes
          various files.  This manual page focuses on explaining these paths.

       *  Easy graphic user interface via xboard(6).

       *  Informative log files.  Writes "game.nnn" file storing current game in PGN format,  and
          also writes "log.nnn" file recording what the engine was "thinking".

       *  Intelligent  opening  play.   Crafty  learns  from  experience,  and  makes appropriate
          modifications to its opening book.  The "book" command allows generation of an  opening
          book  (from  PGN  data),  and customization of how it is used.  The learning facilities
          synthesize several different approaches,  and  allow  various  ways  for  the  user  to
          customize  and follow what is being learned. Additional commands allow easy creation of
          files to customize how Crafty plays  the  opening  against  humans  and  against  other
          computer programs.

       *  Uses  endgame  tablebases.  Precompiled tablebases in the appropriate format are freely
          downloadable from ftp://ftp.cis.uab.edu/hyatt/TB.

       *  Polished and powerful facilities for Internet play (for which the program continues  to
          be  extensively used).  Note that the licencing forbids concealing Crafty under another
          name, or unauthorized entry of it in a tournament in which other computer programs have
          been invited to compete.

       *  Annotation.   Generates  either  PGN  or  HTML files, in a manner made very flexible by
          choosing appropriate aptions to the "annotate | annotateh" command.

OPTIONS

       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.

COMMANDS

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

FILES

   Run control
       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.

   Logging
       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.

   Opening books
       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.

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

ENVIRONMENT VARIABLES

   CRAFTY_BOOK_PATH
       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.

   CRAFTY_LOG_PATH
       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.

   CRAFTY_RC_PATH
       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").

   CRAFTY_TB_PATH
       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.

SEE ALSO

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

HISTORY

       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.

BUGS

       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.

AUTHOR

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