-/// execute_uci_command() takes a string as input, uses a UCIParser
-/// object to parse this text string as a UCI command, and calls
-/// the appropriate functions. In addition to the UCI commands,
-/// the function also supports a few debug commands.
-
-bool execute_uci_command(const string& cmd) {
-
- static Position pos(StartPositionFEN, false, 0); // The root position
-
- UCIParser up(cmd);
- string token;
-
- up >> token; // operator>>() skips any whitespace
-
- if (token == "quit")
- return false;
-
- if (token == "go")
- return go(pos, up);
-
- if (token == "ucinewgame")
- pos.from_fen(StartPositionFEN, false);
-
- else if (token == "isready")
- cout << "readyok" << endl;
-
- else if (token == "position")
- set_position(pos, up);
-
- else if (token == "setoption")
- set_option(up);
-
- else if (token == "perft")
- perft(pos, up);
-
- else if (token == "d")
- pos.print();
-
- else if (token == "flip")
- pos.flip();
-
- else if (token == "eval")
- {
- read_evaluation_uci_options(pos.side_to_move());
- cout << trace_evaluate(pos) << endl;
- }
-
- else if (token == "key")
- cout << "key: " << hex << pos.get_key()
- << "\nmaterial key: " << pos.get_material_key()
- << "\npawn key: " << pos.get_pawn_key() << endl;
-
- else if (token == "uci")
- cout << "id name " << engine_name()
- << "\nid author " << engine_authors()
- << "\n" << Options.print_all()
- << "\nuciok" << endl;
- else
- cout << "Unknown command: " << cmd << endl;
-
- return true;
+/// Wait for a command from the user, parse this text string as an UCI command,
+/// and call the appropriate functions. Also intercepts EOF from stdin to ensure
+/// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
+/// commands, the function also supports a few debug commands.
+
+void UCI::loop(const string& args) {
+
+ Position pos(StartFEN, false, Threads.main()); // The root position
+ string token, cmd = args;
+
+ do {
+ if (args.empty() && !getline(cin, cmd)) // Block here waiting for input
+ cmd = "quit";
+
+ istringstream is(cmd);
+
+ is >> skipws >> token;
+
+ if (token == "quit" || token == "stop" || token == "ponderhit")
+ {
+ // The GUI sends 'ponderhit' to tell us to ponder on the same move the
+ // opponent has played. In case Signals.stopOnPonderhit is set we are
+ // waiting for 'ponderhit' to stop the search (for instance because we
+ // already ran out of time), otherwise we should continue searching but
+ // switch from pondering to normal search.
+ if (token != "ponderhit" || Search::Signals.stopOnPonderhit)
+ {
+ Search::Signals.stop = true;
+ Threads.main()->notify_one(); // Could be sleeping
+ }
+ else
+ Search::Limits.ponder = false;
+ }
+ else if (token == "perft" && (is >> token)) // Read perft depth
+ {
+ stringstream ss;
+
+ ss << Options["Hash"] << " "
+ << Options["Threads"] << " " << token << " current perft";
+
+ benchmark(pos, ss);
+ }
+ else if (token == "key")
+ sync_cout << hex << uppercase << setfill('0')
+ << "position key: " << setw(16) << pos.key()
+ << "\nmaterial key: " << setw(16) << pos.material_key()
+ << "\npawn key: " << setw(16) << pos.pawn_key()
+ << dec << sync_endl;
+
+ else if (token == "uci")
+ sync_cout << "id name " << engine_info(true)
+ << "\n" << Options
+ << "\nuciok" << sync_endl;
+
+ else if (token == "eval")
+ {
+ Search::RootColor = pos.side_to_move(); // Ensure it is set
+ sync_cout << Eval::trace(pos) << sync_endl;
+ }
+ else if (token == "ucinewgame") TT.clear();
+ else if (token == "go") go(pos, is);
+ else if (token == "position") position(pos, is);
+ else if (token == "setoption") setoption(is);
+ else if (token == "flip") pos.flip();
+ else if (token == "bench") benchmark(pos, is);
+ else if (token == "d") sync_cout << pos.pretty() << sync_endl;
+ else if (token == "isready") sync_cout << "readyok" << sync_endl;
+ else
+ sync_cout << "Unknown command: " << cmd << sync_endl;
+
+ } while (token != "quit" && args.empty()); // Args have one-shot behaviour
+
+ Threads.wait_for_think_finished(); // Cannot quit whilst the search is running