Interfacing With External Program

I am making a chess playing robot which will be controlled online by matlab through serial interface. Currently, I need to interface with a chess engine. It should go like this. The chess engine is running separately. I send it string queries such as "move e2-e4" It returns string answers such as "bestmove g2-g4" I don't see where I can start. Can someone please link me to some example communication with external programs. I don't have C-source code of the program. Just an exe.

Answer 1

[Daniel Shub]

If you were not in MATLAB how would you call the chess engine? You can call external exe files with system.

doc system

[Rajendra]

The chess engine is called from dos window by simply writing its name for eg.

engine.exe

then the program starts in the same dos window and waits for input with a blinking cursor.

If I write engine.exe at matlab after CD to the directory, it issues unknown function error.

[Daniel Shub]

Did you look at the documentation for system?

try:

[status, result] = system('c:\ChessEnginePath\engine.exe move e2-e4')

[Rajendra]

I Tried this

[status, result] = system('c:\ChessEnginePath\engine.exe')

(trying

[status, result] = system('c:\ChessEnginePath\engine.exe move e2-e4') will issue error, becasue the engine don't accept arguments during starting)

Then the program runs in matlab command window itself with a blinking cursor!

I can input commands to it, but no output shows up. Finally after I quit the engine ('quit' command), all of its outputs now show-up in result variable

I want the program to run separately and I want to send it commands only occasionally since I need to do other tasks meanwhile.

Thanks for your help.

Answer 2

[Clemens]

On a similar problem I used the program expect to talk to the "bad" program for me. Say as mediator. (manual is at eg http://www.tcl.tk/man/expect5.31/expect.1.html and there are many samples online )

In your case the comand should look like:

[status,result] = system(...
   'expect -c ''spawn engine; send "move e2-e4\r"; close;''')

It can be installed on windows via cygwin (as I did) or mingw.