+
+my %book_cache = ();
+sub book_info {
+ my ($fen, $board, $toplay) = @_;
+
+ if (exists($book_cache{$fen})) {
+ return $book_cache{$fen};
+ }
+
+ my $ret = `./booklook $fen`;
+ return '' if ($ret =~ /Not found/ || $ret eq '');
+
+ my @moves = ();
+
+ for my $m (split /\n/, $ret) {
+ my ($move, $annotation, $win, $draw, $lose, $rating, $rating_div) = split /,/, $m;
+
+ my $pmove;
+ if ($move eq '') {
+ $pmove = '(current)';
+ } else {
+ ($pmove) = prettyprint_pv($board, $move);
+ $pmove .= $annotation;
+ }
+
+ my $score;
+ if ($toplay eq 'W') {
+ $score = 1.0 * $win + 0.5 * $draw + 0.0 * $lose;
+ } else {
+ $score = 0.0 * $win + 0.5 * $draw + 1.0 * $lose;
+ }
+ my $n = $win + $draw + $lose;
+
+ my $percent;
+ if ($n == 0) {
+ $percent = " ";
+ } else {
+ $percent = sprintf "%4u%%", int(100.0 * $score / $n + 0.5);
+ }
+
+ push @moves, [ $pmove, $n, $percent, $rating ];
+ }
+
+ @moves[1..$#moves] = sort { $b->[2] cmp $a->[2] } @moves[1..$#moves];
+
+ my $text = "Book moves:\n\n Perf. N Rating\n\n";
+ for my $m (@moves) {
+ $text .= sprintf " %-10s %s %6u %4s\n", $m->[0], $m->[2], $m->[1], $m->[3]
+ }
+
+ return $text;
+}