Extract evaluation data from Stockfish in Cpp

Question

I am working on a chess player-rating system based on engine evaluations. As part of this I would like to extract evaluation data from Stockfish for the top 10 moves in a given set of positions.

Ideally I would like to be able to loop this from my program, so something like:

while i < 1000:
#'evaluate' returns a list of top moves with their centipawn evaluations.
choices = evaluate(positions[i]); 
...do stuff...
i++;
end while

In the above 'positions' would be a vector of chess positions in FEN format. I have looked around and there are some solutions for this using the chess library in Python, but I would really like to do this from within cpp. Is there any relatively trouble-free way to do this?

Answer 1

The Python solutions are nothing but wrapper for sending UCI commands to the Stockfish engine. I'm not aware there is a C++ equivalent but you can code it yourself.

I don't have a copy-and-paste ready code for you. To do what you want you will need:

• Start Stockfish as a child process (or as a thread). https://www.reddit.com/r/learnprogramming/comments/q8sra3/how_do_i_make_a_uci_connect_to_my_c_gui/
• Communicate with your engine appropriately (lot's of materials on Stackoverflow)
• Learn the UCI commands
• Start a MultiPV analysis of 10
• Parse the results. Use a bitboard implementation to generate a FEN for each move.