How I tell the UCI engine to show less info during search?

Question

Is there a UCI command to output only selected info? For example if my input is

setoption name MultiPV value 3 go depth 8

I get info for every depth itineration in the search:

info depth 1 seldepth 1 multipv 1 score cp 74 nodes 63 nps 31500 tbhits 0 time 2 pv e2e4
info depth 1 seldepth 1 multipv 2 score cp 70 nodes 63 nps 31500 tbhits 0 time 2 pv d2d4
info depth 1 seldepth 1 multipv 3 score cp 68 nodes 63 nps 31500 tbhits 0 time 2 pv e2e3
info depth 2 seldepth 2 multipv 1 score cp 79 nodes 158 nps 52666 tbhits 0 time 3 pv e2e4 b7b6
info depth 2 seldepth 2 multipv 2 score cp 73 nodes 158 nps 52666 tbhits 0 time 3 pv e2e3 b7b6
info depth 2 seldepth 2 multipv 3 score cp 63 nodes 158 nps 52666 tbhits 0 time 3 pv d2d4 b7b6
info depth 3 seldepth 3 multipv 1 score cp 94 nodes 294 nps 98000 tbhits 0 time 3 pv e2e4 d7d6 d2d4
info depth 3 seldepth 3 multipv 2 score cp 94 nodes 294 nps 98000 tbhits 0 time 3 pv d2d4 d7d6 e2e4
info depth 3 seldepth 3 multipv 3 score cp 53 nodes 294 nps 98000 tbhits 0 time 3 pv e2e3 d7d6 d2d4
info depth 4 seldepth 4 multipv 1 score cp 92 nodes 642 nps 160500 tbhits 0 time 4 pv e2e4 e7e6 d2d4 b7b6
info depth 4 seldepth 4 multipv 2 score cp 89 nodes 642 nps 160500 tbhits 0 time 4 pv d2d4 e7e6 e2e4 d7d6
info depth 4 seldepth 4 multipv 3 score cp 7 nodes 642 nps 160500 tbhits 0 time 4 pv e2e3 d7d5 d2d4 e7e6
info depth 5 seldepth 5 multipv 1 score cp 50 nodes 2484 nps 310500 tbhits 0 time 8 pv b1c3 f7f5 d2d4 e7e6 d4d5
info depth 5 seldepth 5 multipv 2 score cp 28 nodes 2484 nps 310500 tbhits 0 time 8 pv e2e3 d7d5 d2d4 g8f6 b1c3
info depth 5 seldepth 5 multipv 3 score cp 22 nodes 2484 nps 310500 tbhits 0 time 8 pv e2e4 e7e6 d1e2 d7d5 d2d4
info depth 6 seldepth 6 multipv 1 score cp 13 nodes 4812 nps 401000 tbhits 0 time 12 pv e2e4 d7d5 d1e2 e7e6 d2d4 g8f6
info depth 6 seldepth 6 multipv 2 score cp 0 nodes 4812 nps 401000 tbhits 0 time 12 pv b1c3 d7d5 d2d4 g8f6 e2e3 e7e6
info depth 6 seldepth 6 multipv 3 score cp 0 nodes 4812 nps 401000 tbhits 0 time 12 pv e2e3 d7d5 d2d4 g8f6 b1c3 e7e6
info depth 7 seldepth 7 multipv 1 score cp 22 nodes 7301 nps 429470 tbhits 0 time 17 pv e2e4 d7d5 d1e2 e7e6 d2d4 d5e4 e2e4
info depth 7 seldepth 7 multipv 2 score cp 8 nodes 7301 nps 429470 tbhits 0 time 17 pv d2d4 d7d5 d1d3 g8f6 b1c3 e7e6 e2e4 f6e4 c3e4 d5e4 d3e4
info depth 7 seldepth 7 multipv 3 score cp 8 nodes 7301 nps 429470 tbhits 0 time 17 pv b1c3 d7d5 d2d4 g8f6 d1d3 e7e6 e2e4
info depth 8 seldepth 8 multipv 1 score cp 31 nodes 13100 nps 485185 tbhits 0 time 27 pv e2e4 d7d5 e4d5 d8d5 b1c3 d5a5 d1e2 e7e6
info depth 8 seldepth 8 multipv 2 score cp 4 nodes 13100 nps 485185 tbhits 0 time 27 pv b1c3 d7d5 e2e4 d5d4 c3b5 e7e6 e4e5 b7b6
info depth 8 seldepth 8 multipv 3 score cp -11 nodes 13100 nps 485185 tbhits 0 time 27 pv d2d3 d7d5 e2e4 b8c6 e4d5 d8d5 b1c3 d5a5
bestmove e2e4 ponder d7d5

---

Instead the output I want is only the last depth reached:

info depth 8 seldepth 8 multipv 1 score cp 31 nodes 13100 nps 485185 tbhits 0 time 27 pv e2e4 d7d5 e4d5 d8d5 b1c3 d5a5 d1e2 e7e6
info depth 8 seldepth 8 multipv 2 score cp 4 nodes 13100 nps 485185 tbhits 0 time 27 pv b1c3 d7d5 e2e4 d5d4 c3b5 e7e6 e4e5 b7b6
info depth 8 seldepth 8 multipv 3 score cp -11 nodes 13100 nps 485185 tbhits 0 time 27 pv d2d3 d7d5 e2e4 b8c6 e4d5 d8d5 b1c3 d5a5
bestmove e2e4 ponder d7d5

Any ideas on how to do this?

Answer 1

I don't think it's possible unless you recompile the source code. It's very easy to do it at the source code; you'll just need to add an if-statement just before the PV is printed.

Otherwise, you can pipe the outputs to a text file and do a grep like this:

grep 'depth 8' output.txt