🚀 go-pugleaf

Ed Suominen wrote:
> 
> I would like to use GNUchess (or something else) to generate a list of legal
> moves for a given position. I plan to use TCL to interface with the program
> via STDIN and STDOUT. The GNUchess command "test movelist" looks promising,
> but I don't see how I can call GNUchess from the command line to execute
> that one command, send the result to STDOUT, and return to TCL.
> 
> Is there a simple change to the source I could make to have GNUchess do
> this? Does anyone have any suggestions?

If you use gnuchess, use version 5 and read cmd.c - it isn't so
painful - I will document it better soon.

You shouldn't try to restart GNUchess each time, you can use
pipes, redirecting the stdin and stdout of GNUchess to you own
program like xboard does. TCL is good at that sort of thing I
believe.

"new" to restart a game, "epd" to set a position, "show moves"
to get a list of moves, there are various other commands. The
"test" commands are mostly aimed at developers, and some are
bust or require additional files. Since legal moves in a
position requires history (enpassant and legality of castling)
it is better to feed the moves in as they are played in most
cases, although a correct EPD record can handle these cases it's
easier just to use a program to supply all the chess brain.

If you do decide to go with GNUchess, I suggest working with the
CVS version on Savannah, so you get the benefits of current
developments, indeed 5.03Beta has a legal move correction in the
code be it ever so obscure.

xboard is open source for a reason ;), although xboard does not
do strict legal move detection as it plays variants, and will
play back games with illegal moves in. There was one in the GNU
chess 5.02 book.pgn where a player took enpassant when the pawn
had moved one square! (Indeed a Bishop on the second rank made
it clear that it couldn't have gone 2 squares....). Somehow
Xboard knew just what was meant!