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 for the initial position
38 const char* StarFEN = "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 bool 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 calls the appropriate functions. Also intercepts EOF from stdin to
54 /// ensure that we exit gracefully if the GUI dies unexpectedly. In addition to
55 /// the UCI commands, the function also supports a few debug commands.
59 Position pos(StarFEN, false, 0); // The root position
62 while (getline(cin, cmd))
64 istringstream is(cmd);
66 is >> skipws >> token;
71 if (token == "go" && !go(pos, is))
74 if (token == "ucinewgame")
75 pos.from_fen(StarFEN, false);
77 else if (token == "isready")
78 cout << "readyok" << endl;
80 else if (token == "position")
81 set_position(pos, is);
83 else if (token == "setoption")
86 else if (token == "perft")
89 else if (token == "d")
92 else if (token == "flip")
95 else if (token == "eval")
97 read_evaluation_uci_options(pos.side_to_move());
98 cout << trace_evaluate(pos) << endl;
101 else if (token == "key")
102 cout << "key: " << hex << pos.get_key()
103 << "\nmaterial key: " << pos.get_material_key()
104 << "\npawn key: " << pos.get_pawn_key() << endl;
106 else if (token == "uci")
107 cout << "id name " << engine_name()
108 << "\nid author " << engine_authors()
109 << "\n" << Options.print_all()
110 << "\nuciok" << endl;
112 cout << "Unknown command: " << cmd << endl;
119 // set_position() is called when engine receives the "position" UCI
120 // command. The function sets up the position described in the given
121 // fen string ("fen") or the starting position ("startpos") and then
122 // makes the moves given in the following move list ("moves").
124 void set_position(Position& pos, istringstream& is) {
131 if (token == "startpos")
134 is >> token; // Consume "moves" token if any
136 else if (token == "fen")
137 while (is >> token && token != "moves")
142 pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
144 // Parse move list (if any)
145 while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
147 pos.do_move(m, *SetupState);
149 // Increment pointer to StateRingBuf circular buffer
150 if (++SetupState - StateRingBuf >= 102)
151 SetupState = StateRingBuf;
156 // set_option() is called when engine receives the "setoption" UCI
157 // command. The function updates the corresponding UCI option ("name")
158 // to the given value ("value").
160 void set_option(istringstream& is) {
162 string token, name, value;
164 is >> token; // Consume "name" token
166 // Read option name (can contain spaces)
167 while (is >> token && token != "value")
168 name += string(" ", !name.empty()) + token;
170 // Read option value (can contain spaces)
172 value += string(" ", !value.empty()) + token;
174 if (Options.find(name) != Options.end())
175 Options[name].set_value(value.empty() ? "true" : value); // UCI buttons don't have "value"
177 cout << "No such option: " << name << endl;
181 // go() is called when engine receives the "go" UCI command. The
182 // function sets the thinking time and other parameters from the input
183 // string, and then calls think(). Returns false if a quit command
184 // is received while thinking, true otherwise.
186 bool go(Position& pos, istringstream& is) {
190 std::vector<Move> searchMoves;
191 int time[] = { 0, 0 }, inc[] = { 0, 0 };
195 if (token == "infinite")
196 limits.infinite = true;
197 else if (token == "ponder")
198 limits.ponder = true;
199 else if (token == "wtime")
201 else if (token == "btime")
203 else if (token == "winc")
205 else if (token == "binc")
207 else if (token == "movestogo")
208 is >> limits.movesToGo;
209 else if (token == "depth")
210 is >> limits.maxDepth;
211 else if (token == "nodes")
212 is >> limits.maxNodes;
213 else if (token == "movetime")
214 is >> limits.maxTime;
215 else if (token == "searchmoves")
217 searchMoves.push_back(move_from_uci(pos, token));
220 searchMoves.push_back(MOVE_NONE);
221 limits.time = time[pos.side_to_move()];
222 limits.increment = inc[pos.side_to_move()];
224 return think(pos, limits, &searchMoves[0]);
228 // perft() is called when engine receives the "perft" command.
229 // The function calls perft() passing the required search depth
230 // then prints counted leaf nodes and elapsed time.
232 void perft(Position& pos, istringstream& is) {
240 time = get_system_time();
242 n = perft(pos, depth * ONE_PLY);
244 time = get_system_time() - time;
246 std::cout << "\nNodes " << n
247 << "\nTime (ms) " << time
248 << "\nNodes/second " << int(n / (time / 1000.0)) << std::endl;