2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 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/>.
31 #include "ucioption.h"
37 // FEN string of the initial position, normal chess
38 const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
40 // Keep track of position keys along the setup moves (from start position to the
41 // position just before to start searching). This is needed by draw detection
42 // where, due to 50 moves rule, we need to check at most 100 plies back.
43 StateInfo StateRingBuf[102], *SetupState = StateRingBuf;
45 void set_option(istringstream& up);
46 void set_position(Position& pos, istringstream& up);
47 void go(Position& pos, istringstream& up);
48 void perft(Position& pos, istringstream& up);
52 /// Wait for a command from the user, parse this text string as an UCI command,
53 /// and call the appropriate functions. Also intercepts EOF from stdin to ensure
54 /// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
55 /// commands, the function also supports a few debug commands.
59 Position pos(StartFEN, false, 0); // The root position
62 while (token != "quit")
64 if (!getline(cin, cmd)) // Block here waiting for input
67 istringstream is(cmd);
69 is >> skipws >> token;
71 if (token == "quit" || token == "stop")
73 Search::Signals.stop = true;
74 Threads[0].wake_up(); // In case is waiting for stop or ponderhit
77 else if (token == "ponderhit")
79 // The opponent has played the expected move. GUI sends "ponderhit" if
80 // we were told to ponder on the same move the opponent has played. We
81 // should continue searching but switching from pondering to normal search.
82 Search::Limits.ponder = false;
84 if (Search::Signals.stopOnPonderhit)
85 Search::Signals.stop = true;
87 Threads[0].wake_up(); // In case is waiting for stop or ponderhit
90 else if (token == "go")
93 else if (token == "ucinewgame")
94 pos.from_fen(StartFEN, false);
96 else if (token == "isready")
97 cout << "readyok" << endl;
99 else if (token == "position")
100 set_position(pos, is);
102 else if (token == "setoption")
105 else if (token == "perft")
108 else if (token == "d")
111 else if (token == "flip")
114 else if (token == "eval")
116 read_evaluation_uci_options(pos.side_to_move());
117 cout << trace_evaluate(pos) << endl;
120 else if (token == "key")
121 cout << "key: " << hex << pos.get_key()
122 << "\nmaterial key: " << pos.get_material_key()
123 << "\npawn key: " << pos.get_pawn_key() << endl;
125 else if (token == "uci")
126 cout << "id name " << engine_name()
127 << "\nid author " << engine_authors()
128 << "\n" << Options.print_all()
129 << "\nuciok" << endl;
131 cout << "Unknown command: " << cmd << endl;
138 // set_position() is called when engine receives the "position" UCI
139 // command. The function sets up the position described in the given
140 // fen string ("fen") or the starting position ("startpos") and then
141 // makes the moves given in the following move list ("moves").
143 void set_position(Position& pos, istringstream& is) {
150 if (token == "startpos")
153 is >> token; // Consume "moves" token if any
155 else if (token == "fen")
156 while (is >> token && token != "moves")
161 pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
163 // Parse move list (if any)
164 while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
166 pos.do_move(m, *SetupState);
168 // Increment pointer to StateRingBuf circular buffer
169 if (++SetupState - StateRingBuf >= 102)
170 SetupState = StateRingBuf;
175 // set_option() is called when engine receives the "setoption" UCI command. The
176 // function updates the UCI option ("name") to the given value ("value").
178 void set_option(istringstream& is) {
180 string token, name, value;
182 is >> token; // Consume "name" token
184 // Read option name (can contain spaces)
185 while (is >> token && token != "value")
186 name += string(" ", !name.empty()) + token;
188 // Read option value (can contain spaces)
190 value += string(" ", !value.empty()) + token;
192 if (Options.find(name) != Options.end())
193 Options[name].set_value(value.empty() ? "true" : value); // UCI buttons don't have "value"
195 cout << "No such option: " << name << endl;
199 // go() is called when engine receives the "go" UCI command. The function sets
200 // the thinking time and other parameters from the input string, and then starts
201 // the main searching thread.
203 void go(Position& pos, istringstream& is) {
206 Search::LimitsType limits;
207 std::vector<Move> searchMoves;
208 int time[] = { 0, 0 }, inc[] = { 0, 0 };
212 if (token == "infinite")
213 limits.infinite = true;
214 else if (token == "ponder")
215 limits.ponder = true;
216 else if (token == "wtime")
218 else if (token == "btime")
220 else if (token == "winc")
222 else if (token == "binc")
224 else if (token == "movestogo")
225 is >> limits.movesToGo;
226 else if (token == "depth")
227 is >> limits.maxDepth;
228 else if (token == "nodes")
229 is >> limits.maxNodes;
230 else if (token == "movetime")
231 is >> limits.maxTime;
232 else if (token == "searchmoves")
234 searchMoves.push_back(move_from_uci(pos, token));
237 searchMoves.push_back(MOVE_NONE);
238 limits.time = time[pos.side_to_move()];
239 limits.increment = inc[pos.side_to_move()];
241 Threads.start_thinking(pos, limits, searchMoves, true);
245 // perft() is called when engine receives the "perft" command. The function
246 // calls perft() with the required search depth then prints counted leaf nodes
249 void perft(Position& pos, istringstream& is) {
256 time = get_system_time();
258 int64_t n = Search::perft(pos, depth * ONE_PLY);
260 time = get_system_time() - time;
262 std::cout << "\nNodes " << n
263 << "\nTime (ms) " << time
264 << "\nNodes/second " << int(n / (time / 1000.0)) << std::endl;