2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
30 #include "ucioption.h"
36 // FEN string of the initial position, normal chess
37 const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
39 // Keep track of position keys along the setup moves (from start position to the
40 // position just before to start searching). This is needed by draw detection
41 // where, due to 50 moves rule, we need to check at most 100 plies back.
42 StateInfo StateRingBuf[102], *SetupState = StateRingBuf;
44 void set_option(istringstream& up);
45 void set_position(Position& pos, istringstream& up);
46 void go(Position& pos, istringstream& up);
47 void perft(Position& pos, istringstream& up);
51 /// Wait for a command from the user, parse this text string as an UCI command,
52 /// and call the appropriate functions. Also intercepts EOF from stdin to ensure
53 /// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
54 /// commands, the function also supports a few debug commands.
58 Position pos(StartFEN, false, 0); // The root position
61 while (token != "quit")
63 if (!getline(cin, cmd)) // Block here waiting for input
66 istringstream is(cmd);
68 is >> skipws >> token;
70 if (token == "quit" || token == "stop")
71 Threads.stop_thinking();
73 else if (token == "ponderhit")
75 // The opponent has played the expected move. GUI sends "ponderhit" if
76 // we were told to ponder on the same move the opponent has played. We
77 // should continue searching but switching from pondering to normal search.
78 Search::Limits.ponder = false;
80 if (Search::Signals.stopOnPonderhit)
81 Threads.stop_thinking();
84 else if (token == "go")
87 else if (token == "ucinewgame")
88 pos.from_fen(StartFEN, false);
90 else if (token == "isready")
91 cout << "readyok" << endl;
93 else if (token == "position")
94 set_position(pos, is);
96 else if (token == "setoption")
99 else if (token == "perft")
102 else if (token == "d")
105 else if (token == "flip")
108 else if (token == "eval")
110 read_evaluation_uci_options(pos.side_to_move());
111 cout << trace_evaluate(pos) << endl;
114 else if (token == "key")
115 cout << "key: " << hex << pos.key()
116 << "\nmaterial key: " << pos.material_key()
117 << "\npawn key: " << pos.pawn_key() << endl;
119 else if (token == "uci")
120 cout << "id name " << engine_info(true)
122 << "\nuciok" << endl;
124 cout << "Unknown command: " << cmd << endl;
131 // set_position() is called when engine receives the "position" UCI
132 // command. The function sets up the position described in the given
133 // fen string ("fen") or the starting position ("startpos") and then
134 // makes the moves given in the following move list ("moves").
136 void set_position(Position& pos, istringstream& is) {
143 if (token == "startpos")
146 is >> token; // Consume "moves" token if any
148 else if (token == "fen")
149 while (is >> token && token != "moves")
154 pos.from_fen(fen, Options["UCI_Chess960"]);
156 // Parse move list (if any)
157 while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
159 pos.do_move(m, *SetupState);
161 // Increment pointer to StateRingBuf circular buffer
162 if (++SetupState - StateRingBuf >= 102)
163 SetupState = StateRingBuf;
168 // set_option() is called when engine receives the "setoption" UCI command. The
169 // function updates the UCI option ("name") to the given value ("value").
171 void set_option(istringstream& is) {
173 string token, name, value;
175 is >> token; // Consume "name" token
177 // Read option name (can contain spaces)
178 while (is >> token && token != "value")
179 name += string(" ", !name.empty()) + token;
181 // Read option value (can contain spaces)
183 value += string(" ", !value.empty()) + token;
185 if (!Options.count(name))
186 cout << "No such option: " << name << endl;
188 else if (value.empty()) // UCI buttons don't have a value
189 Options[name] = true;
192 Options[name] = value;
196 // go() is called when engine receives the "go" UCI command. The function sets
197 // the thinking time and other parameters from the input string, and then starts
198 // the main searching thread.
200 void go(Position& pos, istringstream& is) {
203 Search::LimitsType limits;
204 std::set<Move> searchMoves;
205 int time[] = { 0, 0 }, inc[] = { 0, 0 };
209 if (token == "infinite")
210 limits.infinite = true;
211 else if (token == "ponder")
212 limits.ponder = true;
213 else if (token == "wtime")
215 else if (token == "btime")
217 else if (token == "winc")
219 else if (token == "binc")
221 else if (token == "movestogo")
222 is >> limits.movesToGo;
223 else if (token == "depth")
224 is >> limits.maxDepth;
225 else if (token == "nodes")
226 is >> limits.maxNodes;
227 else if (token == "movetime")
228 is >> limits.maxTime;
229 else if (token == "searchmoves")
231 searchMoves.insert(move_from_uci(pos, token));
234 limits.time = time[pos.side_to_move()];
235 limits.increment = inc[pos.side_to_move()];
237 Threads.start_thinking(pos, limits, searchMoves, true);
241 // perft() is called when engine receives the "perft" command. The function
242 // calls perft() with the required search depth then prints counted leaf nodes
245 void perft(Position& pos, istringstream& is) {
252 time = system_time();
254 int64_t n = Search::perft(pos, depth * ONE_PLY);
256 time = system_time() - time;
258 std::cout << "\nNodes " << n
259 << "\nTime (ms) " << time
260 << "\nNodes/second " << int(n / (time / 1000.0)) << std::endl;