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/>.
32 #include "ucioption.h"
38 // FEN string for the initial position
39 const char* StarFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
41 // Keep track of position keys along the setup moves (from start position to the
42 // position just before to start searching). This is needed by draw detection
43 // where, due to 50 moves rule, we need to check at most 100 plies back.
44 StateInfo StateRingBuf[102], *SetupState = StateRingBuf;
46 void set_option(istringstream& up);
47 void set_position(Position& pos, istringstream& up);
48 bool go(Position& pos, istringstream& up);
49 void perft(Position& pos, istringstream& up);
53 /// Wait for a command from the user, parse this text string as an UCI command,
54 /// and calls the appropriate functions. Also intercepts EOF from stdin to
55 /// ensure that we exit gracefully if the GUI dies unexpectedly. In addition to
56 /// the UCI commands, the function also supports a few debug commands.
60 Position pos(StarFEN, false, 0); // The root position
68 istringstream is(cmd);
70 is >> skipws >> token;
75 else if (token == "stop")
76 { /* avoid to reply "Unknown command: stop" */ }
78 else if (token == "go")
81 else if (token == "ucinewgame")
82 pos.from_fen(StarFEN, false);
84 else if (token == "isready")
85 cout << "readyok" << endl;
87 else if (token == "position")
88 set_position(pos, is);
90 else if (token == "setoption")
93 else if (token == "perft")
96 else if (token == "d")
99 else if (token == "flip")
102 else if (token == "eval")
104 read_evaluation_uci_options(pos.side_to_move());
105 cout << trace_evaluate(pos) << endl;
108 else if (token == "key")
109 cout << "key: " << hex << pos.get_key()
110 << "\nmaterial key: " << pos.get_material_key()
111 << "\npawn key: " << pos.get_pawn_key() << endl;
113 else if (token == "uci")
114 cout << "id name " << engine_name()
115 << "\nid author " << engine_authors()
116 << "\n" << Options.print_all()
117 << "\nuciok" << endl;
119 cout << "Unknown command: " << cmd << endl;
126 // set_position() is called when engine receives the "position" UCI
127 // command. The function sets up the position described in the given
128 // fen string ("fen") or the starting position ("startpos") and then
129 // makes the moves given in the following move list ("moves").
131 void set_position(Position& pos, istringstream& is) {
138 if (token == "startpos")
141 is >> token; // Consume "moves" token if any
143 else if (token == "fen")
144 while (is >> token && token != "moves")
149 pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
151 // Parse move list (if any)
152 while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
154 pos.do_move(m, *SetupState);
156 // Increment pointer to StateRingBuf circular buffer
157 if (++SetupState - StateRingBuf >= 102)
158 SetupState = StateRingBuf;
163 // set_option() is called when engine receives the "setoption" UCI
164 // command. The function updates the corresponding UCI option ("name")
165 // to the given value ("value").
167 void set_option(istringstream& is) {
169 string token, name, value;
171 is >> token; // Consume "name" token
173 // Read option name (can contain spaces)
174 while (is >> token && token != "value")
175 name += string(" ", !name.empty()) + token;
177 // Read option value (can contain spaces)
179 value += string(" ", !value.empty()) + token;
181 if (Options.find(name) != Options.end())
182 Options[name].set_value(value.empty() ? "true" : value); // UCI buttons don't have "value"
184 cout << "No such option: " << name << endl;
188 // go() is called when engine receives the "go" UCI command. The
189 // function sets the thinking time and other parameters from the input
190 // string, and then calls think(). Returns false if a quit command
191 // is received while thinking, true otherwise.
193 bool go(Position& pos, istringstream& is) {
197 std::vector<Move> searchMoves;
198 int time[] = { 0, 0 }, inc[] = { 0, 0 };
202 if (token == "infinite")
203 limits.infinite = true;
204 else if (token == "ponder")
205 limits.ponder = true;
206 else if (token == "wtime")
208 else if (token == "btime")
210 else if (token == "winc")
212 else if (token == "binc")
214 else if (token == "movestogo")
215 is >> limits.movesToGo;
216 else if (token == "depth")
217 is >> limits.maxDepth;
218 else if (token == "nodes")
219 is >> limits.maxNodes;
220 else if (token == "movetime")
221 is >> limits.maxTime;
222 else if (token == "searchmoves")
224 searchMoves.push_back(move_from_uci(pos, token));
227 searchMoves.push_back(MOVE_NONE);
228 limits.time = time[pos.side_to_move()];
229 limits.increment = inc[pos.side_to_move()];
231 return think(pos, limits, &searchMoves[0]);
235 // perft() is called when engine receives the "perft" command.
236 // The function calls perft() passing the required search depth
237 // then prints counted leaf nodes and elapsed time.
239 void perft(Position& pos, istringstream& is) {
247 time = get_system_time();
249 n = perft(pos, depth * ONE_PLY);
251 time = get_system_time() - time;
253 std::cout << "\nNodes " << n
254 << "\nTime (ms) " << time
255 << "\nNodes/second " << int(n / (time / 1000.0)) << std::endl;