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 string StartPositionFEN = "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 // UCIParser is a class for parsing UCI input. The class
46 // is actually a string stream built on a given input string.
47 typedef istringstream UCIParser;
49 void set_option(UCIParser& up);
50 void set_position(Position& pos, UCIParser& up);
51 bool go(Position& pos, UCIParser& up);
52 void perft(Position& pos, UCIParser& up);
56 /// execute_uci_command() takes a string as input, uses a UCIParser
57 /// object to parse this text string as a UCI command, and calls
58 /// the appropriate functions. In addition to the UCI commands,
59 /// the function also supports a few debug commands.
61 bool execute_uci_command(const string& cmd) {
63 static Position pos(StartPositionFEN, false, 0); // The root position
68 up >> skipws >> token;
76 if (token == "ucinewgame")
77 pos.from_fen(StartPositionFEN, false);
79 else if (token == "isready")
80 cout << "readyok" << endl;
82 else if (token == "position")
83 set_position(pos, up);
85 else if (token == "setoption")
88 else if (token == "perft")
91 else if (token == "d")
94 else if (token == "flip")
97 else if (token == "eval")
99 read_evaluation_uci_options(pos.side_to_move());
100 cout << trace_evaluate(pos) << endl;
103 else if (token == "key")
104 cout << "key: " << hex << pos.get_key()
105 << "\nmaterial key: " << pos.get_material_key()
106 << "\npawn key: " << pos.get_pawn_key() << endl;
108 else if (token == "uci")
109 cout << "id name " << engine_name()
110 << "\nid author " << engine_authors()
111 << "\n" << Options.print_all()
112 << "\nuciok" << endl;
114 cout << "Unknown command: " << cmd << endl;
122 // set_position() is called when engine receives the "position" UCI
123 // command. The function sets up the position described in the given
124 // fen string ("fen") or the starting position ("startpos") and then
125 // makes the moves given in the following move list ("moves").
127 void set_position(Position& pos, UCIParser& up) {
134 if (token == "startpos")
136 pos.from_fen(StartPositionFEN, false);
137 up >> token; // Consume "moves" token if any
139 else if (token == "fen")
141 while (up >> token && token != "moves")
144 pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
148 // Parse move list (if any)
149 while (up >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
151 pos.do_move(m, *SetupState);
153 // Increment pointer to StateRingBuf circular buffer
154 if (++SetupState - StateRingBuf >= 102)
155 SetupState = StateRingBuf;
160 // set_option() is called when engine receives the "setoption" UCI
161 // command. The function updates the corresponding UCI option ("name")
162 // to the given value ("value").
164 void set_option(UCIParser& up) {
166 string token, name, value;
168 up >> token; // Consume "name" token
170 // Read option name (can contain spaces)
171 while (up >> token && token != "value")
172 name += string(" ", !name.empty()) + token;
174 // Read option value (can contain spaces)
176 value += string(" ", !value.empty()) + token;
178 if (Options.find(name) != Options.end())
179 Options[name].set_value(value.empty() ? "true" : value); // UCI buttons don't have "value"
181 cout << "No such option: " << name << endl;
185 // go() is called when engine receives the "go" UCI command. The
186 // function sets the thinking time and other parameters from the input
187 // string, and then calls think(). Returns false if a quit command
188 // is received while thinking, true otherwise.
190 bool go(Position& pos, UCIParser& up) {
194 std::vector<Move> searchMoves;
195 int time[] = { 0, 0 }, inc[] = { 0, 0 };
199 if (token == "infinite")
200 limits.infinite = true;
201 else if (token == "ponder")
202 limits.ponder = true;
203 else if (token == "wtime")
205 else if (token == "btime")
207 else if (token == "winc")
209 else if (token == "binc")
211 else if (token == "movestogo")
212 up >> limits.movesToGo;
213 else if (token == "depth")
214 up >> limits.maxDepth;
215 else if (token == "nodes")
216 up >> limits.maxNodes;
217 else if (token == "movetime")
218 up >> limits.maxTime;
219 else if (token == "searchmoves")
221 searchMoves.push_back(move_from_uci(pos, token));
224 searchMoves.push_back(MOVE_NONE);
225 limits.time = time[pos.side_to_move()];
226 limits.increment = inc[pos.side_to_move()];
228 return think(pos, limits, &searchMoves[0]);
232 // perft() is called when engine receives the "perft" command.
233 // The function calls perft() passing the required search depth
234 // then prints counted leaf nodes and elapsed time.
236 void perft(Position& pos, UCIParser& up) {
244 time = get_system_time();
246 n = perft(pos, depth * ONE_PLY);
248 time = get_system_time() - time;
250 std::cout << "\nNodes " << n
251 << "\nTime (ms) " << time
252 << "\nNodes/second " << int(n / (time / 1000.0)) << std::endl;