command-line parsing for formats, add OpenBSD pledge - chess-puzzles - chess puzzle book generator
 (HTM) git clone git://git.codemadness.org/chess-puzzles
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       ---
 (DIR) commit b50c708ac5b44591b62aaa443022625c3fdd44cb
 (DIR) parent 3d921c8e0e2011ae994e508e89fc71086fffd598
 (HTM) Author: Hiltjo Posthuma <hiltjo@codemadness.org>
       Date:   Wed, 20 Dec 2023 22:31:43 +0100
       
       command-line parsing for formats, add OpenBSD pledge
       
       Diffstat:
         M Makefile                            |       7 ++-----
         A fen.c                               |     730 +++++++++++++++++++++++++++++++
         D fen_to_svg.c                        |     700 -------------------------------
       
       3 files changed, 732 insertions(+), 705 deletions(-)
       ---
 (DIR) diff --git a/Makefile b/Makefile
       @@ -1,8 +1,5 @@
        build: clean
       -        ${CC} -o fen_to_svg fen_to_svg.c ${CFLAGS} ${LDFLAGS}
       -        ln -s fen_to_svg fen_to_ascii
       -        ln -s fen_to_svg fen_to_tty
       -        ln -s fen_to_svg fen_to_fen
       +        ${CC} -o fen fen.c ${CFLAGS} ${LDFLAGS}
        
        db:
                rm -f lichess_db_puzzle.csv.zst lichess_db_puzzle.csv
       @@ -10,4 +7,4 @@ db:
                zstd -d < lichess_db_puzzle.csv.zst > lichess_db_puzzle.csv
        
        clean:
       -        rm -f fen_to_ascii fen_to_fen fen_to_svg fen_to_tty
       +        rm -f fen
 (DIR) diff --git a/fen.c b/fen.c
       @@ -0,0 +1,730 @@
       +#include <ctype.h>
       +#include <stdio.h>
       +#include <stdlib.h>
       +#include <string.h>
       +
       +#ifdef __OpenBSD__
       +#include <err.h>
       +#include <unistd.h>
       +#endif
       +
       +/* macro for truecolor RGB output to tty */
       +#define SETFGCOLOR(r,g,b)    printf("\x1b[38;2;%d;%d;%dm", r, g, b)
       +#define SETBGCOLOR(r,g,b)    printf("\x1b[48;2;%d;%d;%dm", r, g, b)
       +
       +static char board[8][8];
       +static char highlight[8][8];
       +
       +static int side_to_move = 'w'; /* default: white to move */
       +static int white_can_castle[2] = { 0, 0 }; /* allow king side, allow queen side? */
       +static int black_can_castle[2] = { 0, 0 }; /* allow king side, allow queen side? */
       +static int enpassantsquare[2] = { -1, -1 };
       +static int movenumber = 1;
       +static int halfmove = 0;
       +
       +/* lichess default theme colors */
       +static const int border[] = { 0x70, 0x49, 0x2d };
       +static const int darksquare[] = { 0xb5, 0x88, 0x63 };
       +static const int lightsquare[] = { 0xf0, 0xd9, 0xb5 };
       +static const int darksquarehi[] = { 0xaa, 0xa2, 0x3a };
       +static const int lightsquarehi[] = { 0xcd, 0xd2, 0x6a };
       +
       +static int showcoords = 1; /* config: show board coordinates? */
       +static int flipboard = 0; /* config: flip board ? */
       +
       +int
       +isvalidsquare(int x, int y)
       +{
       +        return !(x < 0 || x >= 8 || y < 0 || y >= 8);
       +}
       +
       +int
       +isvalidpiece(int c)
       +{
       +        static char pieces[] = "PNBRQKpnbrqk";
       +
       +        return strchr(pieces, c) ? 1 : 0;
       +}
       +
       +/* place a piece, if possible */
       +void
       +place(int piece, int x, int y)
       +{
       +        if (!isvalidsquare(x, y))
       +                return;
       +
       +        board[y][x] = piece;
       +}
       +
       +/* get piece, if possible */
       +int
       +getpiece(int x, int y)
       +{
       +        if (!isvalidsquare(x, y))
       +                return 0;
       +        return board[y][x];
       +}
       +
       +int
       +squaretoxy(const char *s, int *x, int *y)
       +{
       +        if (*s >= 'a' && *s <= 'h' &&
       +            *(s + 1) >= '1' && *(s + 1) <= '8') {
       +                *x = *s - 'a';
       +                *y = '8' - *(s + 1);
       +                return 1;
       +        }
       +        return 0;
       +}
       +
       +void
       +highlightmove(int x1, int y1, int x2, int y2)
       +{
       +        if (isvalidsquare(x1, y1))
       +                highlight[y1][x1] = 1;
       +
       +        if (isvalidsquare(x2, y2))
       +                highlight[y2][x2] = 1;
       +}
       +
       +void
       +showboardfen(void)
       +{
       +        int x, y, piece, skip = 0;
       +
       +        for (y = 0; y < 8; y++) {
       +                if (y > 0)
       +                        putchar('/');
       +                skip = 0;
       +                for (x = 0; x < 8; x++) {
       +                        piece = getpiece(x, y);
       +                        if (piece) {
       +                                if (skip)
       +                                        putchar(skip + '0');
       +                                putchar(piece);
       +                                skip = 0;
       +                        } else {
       +                                skip++;
       +                        }
       +                }
       +                if (skip)
       +                        putchar(skip + '0');
       +        }
       +        printf(" %c ", side_to_move);
       +        if (white_can_castle[0])
       +                putchar('K');
       +        if (white_can_castle[1])
       +                putchar('Q');
       +        if (black_can_castle[0])
       +                putchar('k');
       +        if (black_can_castle[1])
       +                putchar('q');
       +        if ((white_can_castle[0] + white_can_castle[1] +
       +            black_can_castle[0] + black_can_castle[1]) == 0)
       +                putchar('-'); /* no castling for either side */
       +        putchar(' ');
       +
       +        if (enpassantsquare[0] != -1 && enpassantsquare[1] != -1) {
       +                putchar('a' + enpassantsquare[0]);
       +                putchar('8' - enpassantsquare[1]);
       +        } else {
       +                putchar('-');
       +        }
       +        printf(" %d %d", halfmove, movenumber);
       +}
       +
       +void
       +showpiece_svg(int c)
       +{
       +        const char *s = "";
       +
       +        /* lichess default set,
       +           extracted from https://github.com/lichess-org/lila/tree/master/public/piece/cburnett */
       +        switch (c) {
       +        case 'K': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22.5 11.63V6M20 8h5\" stroke-linejoin=\"miter\"/><path d=\"M22.5 25s4.5-7.5 3-10.5c0 0-1-2.5-3-2.5s-3 2.5-3 2.5c-1.5 3 3 10.5 3 10.5\" fill=\"#fff\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M11.5 37c5.5 3.5 15.5 3.5 21 0v-7s9-4.5 6-10.5c-4-6.5-13.5-3.5-16 4V27v-3.5c-3.5-7.5-13-10.5-16-4-3 6 5 10 5 10V37z\" fill=\"#fff\"/><path d=\"M11.5 30c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0\"/></g>"; break;
       +        case 'Q': s = "<g fill=\"#fff\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M8 12a2 2 0 1 1-4 0 2 2 0 1 1 4 0zm16.5-4.5a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM41 12a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM16 8.5a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM33 9a2 2 0 1 1-4 0 2 2 0 1 1 4 0z\"/><path d=\"M9 26c8.5-1.5 21-1.5 27 0l2-12-7 11V11l-5.5 13.5-3-15-3 15-5.5-14V25L7 14l2 12z\" stroke-linecap=\"butt\"/><path d=\"M9 26c0 2 1.5 2 2.5 4 1 1.5 1 1 .5 3.5-1.5 1-1.5 2.5-1.5 2.5-1.5 1.5.5 2.5.5 2.5 6.5 1 16.5 1 23 0 0 0 1.5-1 0-2.5 0 0 .5-1.5-1-2.5-.5-2.5-.5-2 .5-3.5 1-2 2.5-2 2.5-4-8.5-1.5-18.5-1.5-27 0z\" stroke-linecap=\"butt\"/><path d=\"M11.5 30c3.5-1 18.5-1 22 0M12 33.5c6-1 15-1 21 0\" fill=\"none\"/></g>"; break;
       +        case 'R': s = "<g fill=\"#fff\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M9 39h27v-3H9v3zm3-3v-4h21v4H12zm-1-22V9h4v2h5V9h5v2h5V9h4v5\" stroke-linecap=\"butt\"/><path d=\"M34 14l-3 3H14l-3-3\"/><path d=\"M31 17v12.5H14V17\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M31 29.5l1.5 2.5h-20l1.5-2.5\"/><path d=\"M11 14h23\" fill=\"none\" stroke-linejoin=\"miter\"/></g>"; break;
       +        case 'B': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g fill=\"#fff\" stroke-linecap=\"butt\"><path d=\"M9 36c3.39-.97 10.11.43 13.5-2 3.39 2.43 10.11 1.03 13.5 2 0 0 1.65.54 3 2-.68.97-1.65.99-3 .5-3.39-.97-10.11.46-13.5-1-3.39 1.46-10.11.03-13.5 1-1.354.49-2.323.47-3-.5 1.354-1.94 3-2 3-2z\"/><path d=\"M15 32c2.5 2.5 12.5 2.5 15 0 .5-1.5 0-2 0-2 0-2.5-2.5-4-2.5-4 5.5-1.5 6-11.5-5-15.5-11 4-10.5 14-5 15.5 0 0-2.5 1.5-2.5 4 0 0-.5.5 0 2z\"/><path d=\"M25 8a2.5 2.5 0 1 1-5 0 2.5 2.5 0 1 1 5 0z\"/></g><path d=\"M17.5 26h10M15 30h15m-7.5-14.5v5M20 18h5\" stroke-linejoin=\"miter\"/></g>"; break;
       +        case 'N': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22 10c10.5 1 16.5 8 16 29H15c0-9 10-6.5 8-21\" fill=\"#fff\"/><path d=\"M24 18c.38 2.91-5.55 7.37-8 9-3 2-2.82 4.34-5 4-1.042-.94 1.41-3.04 0-3-1 0 .19 1.23-1 2-1 0-4.003 1-4-4 0-2 6-12 6-12s1.89-1.9 2-3.5c-.73-.994-.5-2-.5-3 1-1 3 2.5 3 2.5h2s.78-1.992 2.5-3c1 0 1 3 1 3\" fill=\"#fff\"/><path d=\"M9.5 25.5a.5.5 0 1 1-1 0 .5.5 0 1 1 1 0zm5.433-9.75a.5 1.5 30 1 1-.866-.5.5 1.5 30 1 1 .866.5z\" fill=\"#000\"/></g>"; break;
       +        case 'P': s = "<path d=\"M22.5 9c-2.21 0-4 1.79-4 4 0 .89.29 1.71.78 2.38C17.33 16.5 16 18.59 16 21c0 2.03.94 3.84 2.41 5.03-3 1.06-7.41 5.55-7.41 13.47h23c0-7.92-4.41-12.41-7.41-13.47 1.47-1.19 2.41-3 2.41-5.03 0-2.41-1.33-4.5-3.28-5.62.49-.67.78-1.49.78-2.38 0-2.21-1.79-4-4-4z\" fill=\"#fff\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>"; break;
       +        case 'k': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22.5 11.63V6\" stroke-linejoin=\"miter\"/><path d=\"M22.5 25s4.5-7.5 3-10.5c0 0-1-2.5-3-2.5s-3 2.5-3 2.5c-1.5 3 3 10.5 3 10.5\" fill=\"#000\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M11.5 37c5.5 3.5 15.5 3.5 21 0v-7s9-4.5 6-10.5c-4-6.5-13.5-3.5-16 4V27v-3.5c-3.5-7.5-13-10.5-16-4-3 6 5 10 5 10V37z\" fill=\"#000\"/><path d=\"M20 8h5\" stroke-linejoin=\"miter\"/><path d=\"M32 29.5s8.5-4 6.03-9.65C34.15 14 25 18 22.5 24.5l.01 2.1-.01-2.1C20 18 9.906 14 6.997 19.85c-2.497 5.65 4.853 9 4.853 9\" stroke=\"#ececec\"/><path d=\"M11.5 30c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0\" stroke=\"#ececec\"/></g>"; break;
       +        case 'q': s = "<g fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g stroke=\"none\"><circle cx=\"6\" cy=\"12\" r=\"2.75\"/><circle cx=\"14\" cy=\"9\" r=\"2.75\"/><circle cx=\"22.5\" cy=\"8\" r=\"2.75\"/><circle cx=\"31\" cy=\"9\" r=\"2.75\"/><circle cx=\"39\" cy=\"12\" r=\"2.75\"/></g><path d=\"M9 26c8.5-1.5 21-1.5 27 0l2.5-12.5L31 25l-.3-14.1-5.2 13.6-3-14.5-3 14.5-5.2-13.6L14 25 6.5 13.5 9 26z\" stroke-linecap=\"butt\"/><path d=\"M9 26c0 2 1.5 2 2.5 4 1 1.5 1 1 .5 3.5-1.5 1-1.5 2.5-1.5 2.5-1.5 1.5.5 2.5.5 2.5 6.5 1 16.5 1 23 0 0 0 1.5-1 0-2.5 0 0 .5-1.5-1-2.5-.5-2.5-.5-2 .5-3.5 1-2 2.5-2 2.5-4-8.5-1.5-18.5-1.5-27 0z\" stroke-linecap=\"butt\"/><path d=\"M11 38.5a35 35 1 0 0 23 0\" fill=\"none\" stroke-linecap=\"butt\"/><path d=\"M11 29a35 35 1 0 1 23 0m-21.5 2.5h20m-21 3a35 35 1 0 0 22 0m-23 3a35 35 1 0 0 24 0\" fill=\"none\" stroke=\"#ececec\"/></g>"; break;
       +        case 'r': s = "<g fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M9 39h27v-3H9v3zm3.5-7l1.5-2.5h17l1.5 2.5h-20zm-.5 4v-4h21v4H12z\" stroke-linecap=\"butt\"/><path d=\"M14 29.5v-13h17v13H14z\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M14 16.5L11 14h23l-3 2.5H14zM11 14V9h4v2h5V9h5v2h5V9h4v5H11z\" stroke-linecap=\"butt\"/><path d=\"M12 35.5h21m-20-4h19m-18-2h17m-17-13h17M11 14h23\" fill=\"none\" stroke=\"#ececec\" stroke-width=\"1\" stroke-linejoin=\"miter\"/></g>"; break;
       +        case 'b': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g fill=\"#000\" stroke-linecap=\"butt\"><path d=\"M9 36c3.39-.97 10.11.43 13.5-2 3.39 2.43 10.11 1.03 13.5 2 0 0 1.65.54 3 2-.68.97-1.65.99-3 .5-3.39-.97-10.11.46-13.5-1-3.39 1.46-10.11.03-13.5 1-1.354.49-2.323.47-3-.5 1.354-1.94 3-2 3-2z\"/><path d=\"M15 32c2.5 2.5 12.5 2.5 15 0 .5-1.5 0-2 0-2 0-2.5-2.5-4-2.5-4 5.5-1.5 6-11.5-5-15.5-11 4-10.5 14-5 15.5 0 0-2.5 1.5-2.5 4 0 0-.5.5 0 2z\"/><path d=\"M25 8a2.5 2.5 0 1 1-5 0 2.5 2.5 0 1 1 5 0z\"/></g><path d=\"M17.5 26h10M15 30h15m-7.5-14.5v5M20 18h5\" stroke=\"#ececec\" stroke-linejoin=\"miter\"/></g>"; break;
       +        case 'n': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22 10c10.5 1 16.5 8 16 29H15c0-9 10-6.5 8-21\" fill=\"#000\"/><path d=\"M24 18c.38 2.91-5.55 7.37-8 9-3 2-2.82 4.34-5 4-1.042-.94 1.41-3.04 0-3-1 0 .19 1.23-1 2-1 0-4.003 1-4-4 0-2 6-12 6-12s1.89-1.9 2-3.5c-.73-.994-.5-2-.5-3 1-1 3 2.5 3 2.5h2s.78-1.992 2.5-3c1 0 1 3 1 3\" fill=\"#000\"/><path d=\"M9.5 25.5a.5.5 0 1 1-1 0 .5.5 0 1 1 1 0zm5.433-9.75a.5 1.5 30 1 1-.866-.5.5 1.5 30 1 1 .866.5z\" fill=\"#ececec\" stroke=\"#ececec\"/><path d=\"M24.55 10.4l-.45 1.45.5.15c3.15 1 5.65 2.49 7.9 6.75S35.75 29.06 35.25 39l-.05.5h2.25l.05-.5c.5-10.06-.88-16.85-3.25-21.34-2.37-4.49-5.79-6.64-9.19-7.16l-.51-.1z\" fill=\"#ececec\" stroke=\"none\"/></g>"; break;
       +        case 'p': s = "<path d=\"M22.5 9c-2.21 0-4 1.79-4 4 0 .89.29 1.71.78 2.38C17.33 16.5 16 18.59 16 21c0 2.03.94 3.84 2.41 5.03-3 1.06-7.41 5.55-7.41 13.47h23c0-7.92-4.41-12.41-7.41-13.47 1.47-1.19 2.41-3 2.41-5.03 0-2.41-1.33-4.5-3.28-5.62.49-.67.78-1.49.78-2.38 0-2.21-1.79-4-4-4z\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>"; break;
       +        }
       +
       +        if (*s)
       +                fputs(s, stdout);
       +}
       +
       +void
       +showboard_svg(void)
       +{
       +        const int *color;
       +        int ix, iy, x, y, piece;
       +
       +        fputs("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n"
       +                "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n"
       +                "<svg width=\"360\" height=\"360\" viewBox=\"0 0 360 360\" xmlns=\"http://www.w3.org/2000/svg\">\n"
       +                "<rect fill=\"#fff\" stroke=\"#000\" x=\"0\" y=\"0\" width=\"360\" height=\"360\"/>\n", stdout);
       +
       +        fputs("<!-- Board FEN: ", stdout);
       +        showboardfen();
       +        fputs(" -->\n", stdout);
       +
       +        for (iy = 0; iy < 8; iy++) {
       +                y = flipboard ? 7 - iy : iy;
       +
       +                for (ix = 0; ix < 8; ix++) {
       +                        x = flipboard ? 7 - ix : ix;
       +
       +                        if (x % 2 == 0) {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                                else
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                        } else {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                                else
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                        }
       +
       +                        printf("<g><rect x=\"%d\" y=\"%d\" width=\"45\" height=\"45\" fill=\"#%02x%02x%02x\"/></g>\n",
       +                                ix * 45, iy * 45, color[0], color[1], color[2]);
       +
       +                        piece = getpiece(x, y);
       +                        if (piece) {
       +                                printf("<g transform=\"translate(%d %d)\">", ix * 45, iy * 45);
       +                                showpiece_svg(piece);
       +                                fputs("</g>\n", stdout);
       +                        }
       +                }
       +        }
       +
       +        if (showcoords) {
       +                ix = 7;
       +                x = flipboard ? 0 : 7;
       +                for (iy = 0; iy < 8; iy++) {
       +                        y = flipboard ? 7 - iy : iy;
       +
       +                        /* inverse square color for text */
       +                        if (x % 2 == 0) {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                                else
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                        } else {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                                else
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                        }
       +
       +                        printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"end\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
       +                                (ix + 1) * 45 - 2, (iy * 45) + 10, color[0], color[1], color[2], '8' - y);
       +                }
       +                iy = 7;
       +                y = flipboard ? 0 : 7;
       +                for (ix = 0; ix < 8; ix++) {
       +                        x = flipboard ? 7 - ix : ix;
       +
       +                        /* inverse square color for text */
       +                        if (x % 2 == 0) {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                                else
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                        } else {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                                else
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                        }
       +
       +                        printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"start\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
       +                                (ix * 45) + 2, (iy + 1) * 45 - 3, color[0], color[1], color[2], x + 'a');
       +                }
       +        }
       +
       +        fputs("</svg>\n", stdout);
       +}
       +
       +void
       +showpiece_tty(int c)
       +{
       +        const char *s = "";
       +
       +        /* simple or use unicode character */
       +#if 0
       +        putchar(c);
       +        return;
       +#endif
       +
       +        switch (c) {
       +        case 'K': s = "♔"; break;
       +        case 'Q': s = "♕"; break;
       +        case 'R': s = "♖"; break;
       +        case 'B': s = "♗"; break;
       +        case 'N': s = "♘"; break;
       +        case 'P': s = "♙"; break;
       +        case 'k': s = "♚"; break;
       +        case 'q': s = "♛"; break;
       +        case 'r': s = "♜"; break;
       +        case 'b': s = "♝"; break;
       +        case 'n': s = "♞"; break;
       +        case 'p': s = "♟"; break;
       +        }
       +
       +        if (*s)
       +                fputs(s, stdout);
       +}
       +
       +/* show board */
       +void
       +showboard_tty(void)
       +{
       +        const int *color;
       +        int ix, iy, x, y, piece;
       +
       +        printf("Board FEN:\n");
       +        showboardfen();
       +        printf("\n\n");
       +
       +        SETFGCOLOR(0x00, 0x00, 0x00);
       +
       +        color = border;
       +        SETBGCOLOR(color[0], color[1], color[2]);
       +        SETFGCOLOR(0xff, 0xff, 0xff);
       +        fputs("                             ", stdout);
       +        printf("\x1b[0m"); /* reset */
       +        SETFGCOLOR(0x00, 0x00, 0x00);
       +        putchar('\n');
       +
       +        for (iy = 0; iy < 8; iy++) {
       +                y = flipboard ? 7 - iy : iy;
       +
       +                color = border;
       +                SETBGCOLOR(color[0], color[1], color[2]);
       +                SETFGCOLOR(0xff, 0xff, 0xff);
       +                fputs("  ", stdout);
       +
       +                for (ix = 0; ix < 8; ix++) {
       +                        x = flipboard ? 7 - ix : ix;
       +
       +                        if (x % 2 == 0) {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                                else
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                        } else {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? darksquarehi : darksquare;
       +                                else
       +                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       +                        }
       +                        SETBGCOLOR(color[0], color[1], color[2]);
       +
       +                        fputs(" ", stdout);
       +                        piece = getpiece(x, y);
       +                        if (piece) {
       +                                if (piece >= 'A' && piece <= 'Z')
       +                                        SETFGCOLOR(0xff, 0xff, 0xff);
       +                                else
       +                                        SETFGCOLOR(0x00, 0x00, 0x00);
       +                                /* workaround: use black chess symbol, because the color
       +                                   is filled and better visible */
       +                                showpiece_tty(tolower(piece));
       +                        } else {
       +                                fputs(" ", stdout);
       +                        }
       +                        fputs(" ", stdout);
       +                }
       +                printf("\x1b[0m"); /* reset */
       +
       +                color = border;
       +                SETBGCOLOR(color[0], color[1], color[2]);
       +                SETFGCOLOR(0xff, 0xff, 0xff);
       +                if (showcoords) {
       +                        putchar(' ');
       +                        putchar('8' - y);
       +                        putchar(' ');
       +                } else {
       +                        fputs("   ", stdout);
       +                }
       +
       +                printf("\x1b[0m"); /* reset */
       +                SETFGCOLOR(0x00, 0x00, 0x00);
       +                putchar('\n');
       +        }
       +        color = border;
       +        SETBGCOLOR(color[0], color[1], color[2]);
       +        SETFGCOLOR(0xff, 0xff, 0xff);
       +        if (showcoords) {
       +                if (flipboard)
       +                        fputs("   h  g  f  e  d  c  b  a    ", stdout);
       +                else
       +                        fputs("   a  b  c  d  e  f  g  h    ", stdout);
       +        } else {
       +                fputs("                             ", stdout);
       +        }
       +        printf("\x1b[0m"); /* reset */
       +        printf("\n");
       +}
       +
       +void
       +showpiece_ascii(int c)
       +{
       +        putchar(c);
       +}
       +
       +/* OnlyFENs */
       +void
       +showboard_fen(void)
       +{
       +        showboardfen();
       +        printf("\n");
       +}
       +
       +/* show board */
       +void
       +showboard_ascii(void)
       +{
       +        int hi[3] = { '>', ' ', '<' };
       +        int dark[3] = { '.', '.', '.' };
       +        int light[3] = { ' ', ' ', ' ' };
       +        int *color, ix, iy, x, y, piece;
       +
       +        printf("Board FEN:\n");
       +        showboardfen();
       +        printf("\n\n");
       +
       +        for (iy = 0; iy < 8; iy++) {
       +                y = flipboard ? 7 - iy : iy;
       +
       +                fputs("+---+---+---+---+---+---+---+---+\n", stdout);
       +                for (ix = 0; ix < 8; ix++) {
       +                        x = flipboard ? 7 - ix : ix;
       +
       +                        if (x % 2 == 0) {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? hi : light;
       +                                else
       +                                        color = highlight[y][x] ? hi : dark;
       +                        } else {
       +                                if (y % 2 == 0)
       +                                        color = highlight[y][x] ? hi : dark;
       +                                else
       +                                        color = highlight[y][x] ? hi : light;
       +                        }
       +
       +                        if (ix == 0)
       +                                putchar('|');
       +                        putchar(color[0]);
       +                        piece = getpiece(x, y);
       +                        if (piece)
       +                                showpiece_ascii(piece);
       +                        else
       +                                putchar(color[1]);
       +                        putchar(color[2]);
       +                        putchar('|');
       +                }
       +                if (showcoords) {
       +                        putchar(' ');
       +                        putchar('8' - y);
       +                }
       +                putchar('\n');
       +        }
       +        fputs("+---+---+---+---+---+---+---+---+\n", stdout);
       +        if (showcoords) {
       +                if (flipboard)
       +                        printf("  h | g | f | e | d | c | b | a |\n");
       +                else
       +                        printf("  a | b | c | d | e | f | g | h |\n");
       +        }
       +
       +        fputs("\n", stdout);
       +}
       +
       +void
       +usage(char *argv0)
       +{
       +        fprintf(stderr, "usage: %s [-cCfF] [-o ascii|fen|tty|svg] [FEN] [moves]\n", argv0);
       +        exit(1);
       +}
       +
       +int
       +main(int argc, char *argv[])
       +{
       +        const char *fen, *moves, *s, *output = "svg";
       +        int x, y, x2, y2, field, piece, takepiece;
       +        int i, j;
       +        char square[3];
       +        long l;
       +
       +#ifdef __OpenBSD__
       +        if (pledge("stdio", NULL) = -1)
       +                err(1, "pledge");
       +#endif
       +
       +        fen = "startpos";
       +        moves = "";
       +
       +        for (i = 1; i < argc; i++) {
       +                if (argv[i][0] != '-')
       +                        break;
       +
       +                for (j = 1; argv[i][j]; j++) {
       +                        switch (argv[i][j]) {
       +                        case 'c': showcoords = 1; break;
       +                        case 'C': showcoords = 0; break;
       +                        case 'f': flipboard = 1; break;
       +                        case 'F': flipboard = 0; break;
       +                        case 'o':
       +                                if (i + 1 >= argc)
       +                                        usage(argv[0]);
       +                                output = argv[++i];
       +                                goto next;
       +                        default:
       +                                usage(argv[0]);
       +                                break;
       +                        }
       +                }
       +next:
       +        }
       +        if (i < argc) {
       +                fen = argv[i];
       +                i++;
       +        }
       +        if (i < argc) {
       +                moves = argv[i];
       +                i++;
       +        }
       +
       +        if (!strcmp(fen, "startpos"))
       +                fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
       +
       +        /* initial board state, FEN format */
       +        x = y = field = 0;
       +        for (s = fen; *s && field < 6; s++) {
       +                switch (field) {
       +                case 0: /* piece placement data */
       +                        /* skip square */
       +                        if (*s >= '1' && *s <= '9') {
       +                                x += (*s - '0');
       +                                continue;
       +                        }
       +                        /* next rank */
       +                        if (*s == '/') {
       +                                x = 0;
       +                                y++;
       +                                continue;
       +                        }
       +                        /* is piece? place it */
       +                        if (isvalidpiece(*s))
       +                                place(*s, x++, y);
       +                        break;
       +                case 1: /* active color */
       +                        if (*s == 'w' || *s == 'b')
       +                                side_to_move = *s;
       +                        break;
       +                case 2: /* castling availability */
       +                        if (*s == '-') {
       +                                white_can_castle[0] = 0;
       +                                white_can_castle[1] = 0;
       +                                black_can_castle[0] = 0;
       +                                black_can_castle[1] = 0;
       +                        } else if (*s == 'K') {
       +                                white_can_castle[0] = 1;
       +                        } else if (*s == 'Q') {
       +                                white_can_castle[1] = 1;
       +                        } else if (*s == 'k') {
       +                                black_can_castle[0] = 1;
       +                        } else if (*s == 'q') {
       +                                black_can_castle[1] = 1;
       +                        }
       +                        break;
       +                case 3: /* en passant square */
       +                        if (*s >= 'a' && *s <= 'h' &&
       +                                *(s + 1) >= '1' && *(s + 1) >= '6') {
       +
       +                                square[0] = *s;
       +                                square[1] = *(s + 1);
       +                                square[2] = '\0';
       +                                squaretoxy(square, &x, &y);
       +
       +                                enpassantsquare[0] = x;
       +                                enpassantsquare[1] = y;
       +                        }
       +                        break;
       +                case 4: /* halfmove */
       +                        if (!(*s >= '0' && *s <= '9'))
       +                                continue;
       +
       +                        l = strtol(s, NULL, 10);
       +                        if (l >= 0 && l < 32767) {
       +                                halfmove = l;
       +
       +                                for (; *s && isdigit((unsigned char)*s); s++)
       +                                        ;
       +                        }
       +                        break;
       +                case 5: /* move number */
       +                        if (!(*s >= '0' && *s <= '9'))
       +                                continue;
       +
       +                        l = strtol(s, NULL, 10);
       +                        if (l >= 0 && l < 32767) {
       +                                movenumber = (int)l;
       +                                for (; *s && isdigit((unsigned char)*s); s++)
       +                                        ;
       +                        }
       +                        break;
       +                }
       +                if (!*s)
       +                        break;
       +
       +                /* next field, fields are: piece placement data, active color,
       +                   Castling availability, En passant target square,
       +                   Halfmove clock, Fullmove number */
       +                if (*s == ' ') {
       +                        field++;
       +                        continue;
       +                }
       +        }
       +
       +        /* process moves */
       +        square[2] = '\0';
       +        x = y = x2 = y2 = -1;
       +        for (s = moves; *s; s++) {
       +                if (*s == ' ')
       +                        continue;
       +                if ((*s >= 'a' && *s <= 'h') &&
       +                    (*(s + 1) >= '1' && *(s + 1) <= '8') &&
       +                    (*(s + 2) >= 'a' && *(s + 2) <= 'h') &&
       +                    (*(s + 3) >= '1' && *(s + 3) <= '8')) {
       +                        square[0] = *s;
       +                        square[1] = *(s + 1);
       +
       +                        s += 2;
       +                        squaretoxy(square, &x, &y);
       +                        piece = getpiece(x, y);
       +
       +                        place(0, x, y); /* clear square */
       +
       +                        /* place piece at new location */
       +                        square[0] = *s;
       +                        square[1] = *(s + 1);
       +                        squaretoxy(square, &x2, &y2);
       +                        takepiece = getpiece(x2, y2);
       +                        place(piece, x2, y2);
       +                        s += 2;
       +
       +                        /* if pawn move or taken a piece increase halfmove counter */
       +                        if (piece == 'p' || piece == 'P' || takepiece != 0)
       +                                halfmove = 0;
       +                        else
       +                                halfmove++;
       +
       +                        /* castling */
       +                        if (piece == 'K' && y == 7 && y2 == 7 && x == 4) {
       +                                /* white: kingside castling: "e1g1" */
       +                                if (x2 == 6) {
       +                                        place('R', x2 - 1, y2);
       +                                        x2 = 7;
       +                                        y2 = 7;
       +                                        place(0, x2, y2); /* clear rook square */
       +                                } else if (x2 == 2) {
       +                                        /* white: queenside castling: "e1c1" */
       +                                        place('R', x2 + 1, y2);
       +                                        x2 = 0;
       +                                        y2 = 7;
       +                                        place(0, x2, y2);
       +                                }
       +                        } else if (piece == 'k' && y == 0 && y2 == 0 && x == 4) {
       +                                /* black: kingside castling: "e8g8" */
       +                                if (x2 == 6) {
       +                                        place('r', x2 - 1, y2);
       +                                        x2 = 7;
       +                                        y2 = 0;
       +                                        place(0, x2, y2); /* clear rook square */
       +                                } else if (x2 == 2) {
       +                                        /* black: queenside castling: "e8c8" */
       +                                        place('r', x2 + 1, y2);
       +                                        x2 = 0;
       +                                        y2 = 0;
       +                                        place(0, x2, y2); /* clear rook square */
       +                                }
       +                        }
       +
       +                        /* remove the ability to castle */
       +                        if (piece == 'K') {
       +                                white_can_castle[0] = white_can_castle[1] = 0;
       +                        } else if (piece == 'k') {
       +                                black_can_castle[0] = black_can_castle[1] = 0;
       +                        } else if (piece == 'R') {
       +                                if (x == 7 && y == 7)
       +                                        white_can_castle[0] = 0;
       +                                else if (x == 0 && y == 7)
       +                                        white_can_castle[1] = 0;
       +                        } else if (piece == 'r') {
       +                                if (x == 0 && y == 0)
       +                                        black_can_castle[1] = 0;
       +                                else if (x == 7 && y == 0)
       +                                        black_can_castle[0] = 0;
       +                        }
       +
       +                        /* the en passant square resets after a move */
       +                        enpassantsquare[0] = -1;
       +                        enpassantsquare[1] = -1;
       +                        /* moved 2 squares and there is an opponent pawn next to it */
       +                        if (piece == 'P' && y == 6 && y2 == 4) {
       +                                if (getpiece(x - 1, y2) == 'p' ||
       +                                    getpiece(x + 1, y2) == 'p') {
       +                                        enpassantsquare[0] = x;
       +                                        enpassantsquare[1] = 5;
       +                                }
       +                        } else if (piece == 'p' && y == 1 && y2 == 3) {
       +                                if (getpiece(x - 1, y2) == 'P' ||
       +                                    getpiece(x + 1, y2) == 'P') {
       +                                        enpassantsquare[0] = x;
       +                                        enpassantsquare[1] = 2;
       +                                }
       +                        }
       +
       +                        /* possible promotion: queen, knight, bishop */
       +                        if (*s == 'q' || *s == 'n' || *s == 'b') {
       +                                if (side_to_move == 'w')
       +                                        piece = toupper((unsigned char)*s);
       +                                else
       +                                        piece = *s;
       +                                place(piece, x2, y2);
       +                                s++;
       +                        }
       +
       +                        /* a move by black increases the move number */
       +                        if (side_to_move == 'b')
       +                                movenumber++;
       +
       +                        /* switch which side it is to move */
       +                        side_to_move = side_to_move == 'b' ? 'w' : 'b';
       +                }
       +        }
       +        /* highlight last move */
       +        highlightmove(x, y, x2, y2);
       +
       +        if (!strcmp(output, "ascii"))
       +                showboard_ascii();
       +        else if (!strcmp(output, "fen"))
       +                showboard_fen();
       +        else if (!strcmp(output, "svg"))
       +                showboard_svg();
       +        else if (!strcmp(output, "tty"))
       +                showboard_tty();
       +        else
       +                usage(argv[0]);
       +
       +        return 0;
       +}
 (DIR) diff --git a/fen_to_svg.c b/fen_to_svg.c
       @@ -1,700 +0,0 @@
       -/* TODO: output for PGN notation for moves */
       -
       -#include <ctype.h>
       -#include <stdio.h>
       -#include <stdlib.h>
       -#include <string.h>
       -
       -/* macro for truecolor RGB output to tty */
       -#define SETFGCOLOR(r,g,b)    printf("\x1b[38;2;%d;%d;%dm", r, g, b)
       -#define SETBGCOLOR(r,g,b)    printf("\x1b[48;2;%d;%d;%dm", r, g, b)
       -
       -static char board[8][8];
       -static char highlight[8][8];
       -
       -static int side_to_move = 'w'; /* default: white to move */
       -static int white_can_castle[2] = { 0, 0 }; /* allow king side, allow queen side? */
       -static int black_can_castle[2] = { 0, 0 }; /* allow king side, allow queen side? */
       -static int enpassantsquare[2] = { -1, -1 };
       -static int movenumber = 1;
       -static int halfmove = 0;
       -
       -/* lichess default theme colors */
       -static const int border[] = { 0x70, 0x49, 0x2d };
       -static const int darksquare[] = { 0xb5, 0x88, 0x63 };
       -static const int lightsquare[] = { 0xf0, 0xd9, 0xb5 };
       -static const int darksquarehi[] = { 0xaa, 0xa2, 0x3a };
       -static const int lightsquarehi[] = { 0xcd, 0xd2, 0x6a };
       -
       -static int showcoords = 1; /* config: show board coordinates? */
       -static int flipboard = 0; /* config: flip board ? */
       -
       -int
       -isvalidsquare(int x, int y)
       -{
       -        return !(x < 0 || x >= 8 || y < 0 || y >= 8);
       -}
       -
       -int
       -isvalidpiece(int c)
       -{
       -        static char pieces[] = "PNBRQKpnbrqk";
       -
       -        return strchr(pieces, c) ? 1 : 0;
       -}
       -
       -/* place a piece, if possible */
       -void
       -place(int piece, int x, int y)
       -{
       -        if (!isvalidsquare(x, y))
       -                return;
       -
       -        board[y][x] = piece;
       -}
       -
       -/* get piece, if possible */
       -int
       -getpiece(int x, int y)
       -{
       -        if (!isvalidsquare(x, y))
       -                return 0;
       -        return board[y][x];
       -}
       -
       -int
       -squaretoxy(const char *s, int *x, int *y)
       -{
       -        if (*s >= 'a' && *s <= 'h' &&
       -            *(s + 1) >= '1' && *(s + 1) <= '8') {
       -                *x = *s - 'a';
       -                *y = '8' - *(s + 1);
       -                return 1;
       -        }
       -        return 0;
       -}
       -
       -void
       -highlightmove(int x1, int y1, int x2, int y2)
       -{
       -        if (isvalidsquare(x1, y1))
       -                highlight[y1][x1] = 1;
       -
       -        if (isvalidsquare(x2, y2))
       -                highlight[y2][x2] = 1;
       -}
       -
       -void
       -showboardfen(void)
       -{
       -        int x, y, piece, skip = 0;
       -
       -        for (y = 0; y < 8; y++) {
       -                if (y > 0)
       -                        putchar('/');
       -                skip = 0;
       -                for (x = 0; x < 8; x++) {
       -                        piece = getpiece(x, y);
       -                        if (piece) {
       -                                if (skip)
       -                                        putchar(skip + '0');
       -                                putchar(piece);
       -                                skip = 0;
       -                        } else {
       -                                skip++;
       -                        }
       -                }
       -                if (skip)
       -                        putchar(skip + '0');
       -        }
       -        printf(" %c ", side_to_move);
       -        if (white_can_castle[0])
       -                putchar('K');
       -        if (white_can_castle[1])
       -                putchar('Q');
       -        if (black_can_castle[0])
       -                putchar('k');
       -        if (black_can_castle[1])
       -                putchar('q');
       -        if ((white_can_castle[0] + white_can_castle[1] +
       -            black_can_castle[0] + black_can_castle[1]) == 0)
       -                putchar('-'); /* no castling for either side */
       -        putchar(' ');
       -
       -        if (enpassantsquare[0] != -1 && enpassantsquare[1] != -1) {
       -                putchar('a' + enpassantsquare[0]);
       -                putchar('8' - enpassantsquare[1]);
       -        } else {
       -                putchar('-');
       -        }
       -        printf(" %d %d", halfmove, movenumber);
       -}
       -
       -void
       -svg_showpiece(int c)
       -{
       -        const char *s = "";
       -
       -        /* lichess default set,
       -           extracted from https://github.com/lichess-org/lila/tree/master/public/piece/cburnett */
       -        switch (c) {
       -        case 'K': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22.5 11.63V6M20 8h5\" stroke-linejoin=\"miter\"/><path d=\"M22.5 25s4.5-7.5 3-10.5c0 0-1-2.5-3-2.5s-3 2.5-3 2.5c-1.5 3 3 10.5 3 10.5\" fill=\"#fff\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M11.5 37c5.5 3.5 15.5 3.5 21 0v-7s9-4.5 6-10.5c-4-6.5-13.5-3.5-16 4V27v-3.5c-3.5-7.5-13-10.5-16-4-3 6 5 10 5 10V37z\" fill=\"#fff\"/><path d=\"M11.5 30c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0\"/></g>"; break;
       -        case 'Q': s = "<g fill=\"#fff\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M8 12a2 2 0 1 1-4 0 2 2 0 1 1 4 0zm16.5-4.5a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM41 12a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM16 8.5a2 2 0 1 1-4 0 2 2 0 1 1 4 0zM33 9a2 2 0 1 1-4 0 2 2 0 1 1 4 0z\"/><path d=\"M9 26c8.5-1.5 21-1.5 27 0l2-12-7 11V11l-5.5 13.5-3-15-3 15-5.5-14V25L7 14l2 12z\" stroke-linecap=\"butt\"/><path d=\"M9 26c0 2 1.5 2 2.5 4 1 1.5 1 1 .5 3.5-1.5 1-1.5 2.5-1.5 2.5-1.5 1.5.5 2.5.5 2.5 6.5 1 16.5 1 23 0 0 0 1.5-1 0-2.5 0 0 .5-1.5-1-2.5-.5-2.5-.5-2 .5-3.5 1-2 2.5-2 2.5-4-8.5-1.5-18.5-1.5-27 0z\" stroke-linecap=\"butt\"/><path d=\"M11.5 30c3.5-1 18.5-1 22 0M12 33.5c6-1 15-1 21 0\" fill=\"none\"/></g>"; break;
       -        case 'R': s = "<g fill=\"#fff\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M9 39h27v-3H9v3zm3-3v-4h21v4H12zm-1-22V9h4v2h5V9h5v2h5V9h4v5\" stroke-linecap=\"butt\"/><path d=\"M34 14l-3 3H14l-3-3\"/><path d=\"M31 17v12.5H14V17\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M31 29.5l1.5 2.5h-20l1.5-2.5\"/><path d=\"M11 14h23\" fill=\"none\" stroke-linejoin=\"miter\"/></g>"; break;
       -        case 'B': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g fill=\"#fff\" stroke-linecap=\"butt\"><path d=\"M9 36c3.39-.97 10.11.43 13.5-2 3.39 2.43 10.11 1.03 13.5 2 0 0 1.65.54 3 2-.68.97-1.65.99-3 .5-3.39-.97-10.11.46-13.5-1-3.39 1.46-10.11.03-13.5 1-1.354.49-2.323.47-3-.5 1.354-1.94 3-2 3-2z\"/><path d=\"M15 32c2.5 2.5 12.5 2.5 15 0 .5-1.5 0-2 0-2 0-2.5-2.5-4-2.5-4 5.5-1.5 6-11.5-5-15.5-11 4-10.5 14-5 15.5 0 0-2.5 1.5-2.5 4 0 0-.5.5 0 2z\"/><path d=\"M25 8a2.5 2.5 0 1 1-5 0 2.5 2.5 0 1 1 5 0z\"/></g><path d=\"M17.5 26h10M15 30h15m-7.5-14.5v5M20 18h5\" stroke-linejoin=\"miter\"/></g>"; break;
       -        case 'N': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22 10c10.5 1 16.5 8 16 29H15c0-9 10-6.5 8-21\" fill=\"#fff\"/><path d=\"M24 18c.38 2.91-5.55 7.37-8 9-3 2-2.82 4.34-5 4-1.042-.94 1.41-3.04 0-3-1 0 .19 1.23-1 2-1 0-4.003 1-4-4 0-2 6-12 6-12s1.89-1.9 2-3.5c-.73-.994-.5-2-.5-3 1-1 3 2.5 3 2.5h2s.78-1.992 2.5-3c1 0 1 3 1 3\" fill=\"#fff\"/><path d=\"M9.5 25.5a.5.5 0 1 1-1 0 .5.5 0 1 1 1 0zm5.433-9.75a.5 1.5 30 1 1-.866-.5.5 1.5 30 1 1 .866.5z\" fill=\"#000\"/></g>"; break;
       -        case 'P': s = "<path d=\"M22.5 9c-2.21 0-4 1.79-4 4 0 .89.29 1.71.78 2.38C17.33 16.5 16 18.59 16 21c0 2.03.94 3.84 2.41 5.03-3 1.06-7.41 5.55-7.41 13.47h23c0-7.92-4.41-12.41-7.41-13.47 1.47-1.19 2.41-3 2.41-5.03 0-2.41-1.33-4.5-3.28-5.62.49-.67.78-1.49.78-2.38 0-2.21-1.79-4-4-4z\" fill=\"#fff\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>"; break;
       -        case 'k': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22.5 11.63V6\" stroke-linejoin=\"miter\"/><path d=\"M22.5 25s4.5-7.5 3-10.5c0 0-1-2.5-3-2.5s-3 2.5-3 2.5c-1.5 3 3 10.5 3 10.5\" fill=\"#000\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M11.5 37c5.5 3.5 15.5 3.5 21 0v-7s9-4.5 6-10.5c-4-6.5-13.5-3.5-16 4V27v-3.5c-3.5-7.5-13-10.5-16-4-3 6 5 10 5 10V37z\" fill=\"#000\"/><path d=\"M20 8h5\" stroke-linejoin=\"miter\"/><path d=\"M32 29.5s8.5-4 6.03-9.65C34.15 14 25 18 22.5 24.5l.01 2.1-.01-2.1C20 18 9.906 14 6.997 19.85c-2.497 5.65 4.853 9 4.853 9\" stroke=\"#ececec\"/><path d=\"M11.5 30c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0m-21 3.5c5.5-3 15.5-3 21 0\" stroke=\"#ececec\"/></g>"; break;
       -        case 'q': s = "<g fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g stroke=\"none\"><circle cx=\"6\" cy=\"12\" r=\"2.75\"/><circle cx=\"14\" cy=\"9\" r=\"2.75\"/><circle cx=\"22.5\" cy=\"8\" r=\"2.75\"/><circle cx=\"31\" cy=\"9\" r=\"2.75\"/><circle cx=\"39\" cy=\"12\" r=\"2.75\"/></g><path d=\"M9 26c8.5-1.5 21-1.5 27 0l2.5-12.5L31 25l-.3-14.1-5.2 13.6-3-14.5-3 14.5-5.2-13.6L14 25 6.5 13.5 9 26z\" stroke-linecap=\"butt\"/><path d=\"M9 26c0 2 1.5 2 2.5 4 1 1.5 1 1 .5 3.5-1.5 1-1.5 2.5-1.5 2.5-1.5 1.5.5 2.5.5 2.5 6.5 1 16.5 1 23 0 0 0 1.5-1 0-2.5 0 0 .5-1.5-1-2.5-.5-2.5-.5-2 .5-3.5 1-2 2.5-2 2.5-4-8.5-1.5-18.5-1.5-27 0z\" stroke-linecap=\"butt\"/><path d=\"M11 38.5a35 35 1 0 0 23 0\" fill=\"none\" stroke-linecap=\"butt\"/><path d=\"M11 29a35 35 1 0 1 23 0m-21.5 2.5h20m-21 3a35 35 1 0 0 22 0m-23 3a35 35 1 0 0 24 0\" fill=\"none\" stroke=\"#ececec\"/></g>"; break;
       -        case 'r': s = "<g fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M9 39h27v-3H9v3zm3.5-7l1.5-2.5h17l1.5 2.5h-20zm-.5 4v-4h21v4H12z\" stroke-linecap=\"butt\"/><path d=\"M14 29.5v-13h17v13H14z\" stroke-linecap=\"butt\" stroke-linejoin=\"miter\"/><path d=\"M14 16.5L11 14h23l-3 2.5H14zM11 14V9h4v2h5V9h5v2h5V9h4v5H11z\" stroke-linecap=\"butt\"/><path d=\"M12 35.5h21m-20-4h19m-18-2h17m-17-13h17M11 14h23\" fill=\"none\" stroke=\"#ececec\" stroke-width=\"1\" stroke-linejoin=\"miter\"/></g>"; break;
       -        case 'b': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><g fill=\"#000\" stroke-linecap=\"butt\"><path d=\"M9 36c3.39-.97 10.11.43 13.5-2 3.39 2.43 10.11 1.03 13.5 2 0 0 1.65.54 3 2-.68.97-1.65.99-3 .5-3.39-.97-10.11.46-13.5-1-3.39 1.46-10.11.03-13.5 1-1.354.49-2.323.47-3-.5 1.354-1.94 3-2 3-2z\"/><path d=\"M15 32c2.5 2.5 12.5 2.5 15 0 .5-1.5 0-2 0-2 0-2.5-2.5-4-2.5-4 5.5-1.5 6-11.5-5-15.5-11 4-10.5 14-5 15.5 0 0-2.5 1.5-2.5 4 0 0-.5.5 0 2z\"/><path d=\"M25 8a2.5 2.5 0 1 1-5 0 2.5 2.5 0 1 1 5 0z\"/></g><path d=\"M17.5 26h10M15 30h15m-7.5-14.5v5M20 18h5\" stroke=\"#ececec\" stroke-linejoin=\"miter\"/></g>"; break;
       -        case 'n': s = "<g fill=\"none\" fill-rule=\"evenodd\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M22 10c10.5 1 16.5 8 16 29H15c0-9 10-6.5 8-21\" fill=\"#000\"/><path d=\"M24 18c.38 2.91-5.55 7.37-8 9-3 2-2.82 4.34-5 4-1.042-.94 1.41-3.04 0-3-1 0 .19 1.23-1 2-1 0-4.003 1-4-4 0-2 6-12 6-12s1.89-1.9 2-3.5c-.73-.994-.5-2-.5-3 1-1 3 2.5 3 2.5h2s.78-1.992 2.5-3c1 0 1 3 1 3\" fill=\"#000\"/><path d=\"M9.5 25.5a.5.5 0 1 1-1 0 .5.5 0 1 1 1 0zm5.433-9.75a.5 1.5 30 1 1-.866-.5.5 1.5 30 1 1 .866.5z\" fill=\"#ececec\" stroke=\"#ececec\"/><path d=\"M24.55 10.4l-.45 1.45.5.15c3.15 1 5.65 2.49 7.9 6.75S35.75 29.06 35.25 39l-.05.5h2.25l.05-.5c.5-10.06-.88-16.85-3.25-21.34-2.37-4.49-5.79-6.64-9.19-7.16l-.51-.1z\" fill=\"#ececec\" stroke=\"none\"/></g>"; break;
       -        case 'p': s = "<path d=\"M22.5 9c-2.21 0-4 1.79-4 4 0 .89.29 1.71.78 2.38C17.33 16.5 16 18.59 16 21c0 2.03.94 3.84 2.41 5.03-3 1.06-7.41 5.55-7.41 13.47h23c0-7.92-4.41-12.41-7.41-13.47 1.47-1.19 2.41-3 2.41-5.03 0-2.41-1.33-4.5-3.28-5.62.49-.67.78-1.49.78-2.38 0-2.21-1.79-4-4-4z\" stroke=\"#000\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>"; break;
       -        }
       -
       -        if (*s)
       -                fputs(s, stdout);
       -}
       -
       -void
       -svg_showboard(void)
       -{
       -        const int *color;
       -        int ix, iy, x, y, piece;
       -
       -        fputs("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n"
       -                "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n"
       -                "<svg width=\"360\" height=\"360\" viewBox=\"0 0 360 360\" xmlns=\"http://www.w3.org/2000/svg\">\n"
       -                "<rect fill=\"#fff\" stroke=\"#000\" x=\"0\" y=\"0\" width=\"360\" height=\"360\"/>\n", stdout);
       -
       -        fputs("<!-- Board FEN: ", stdout);
       -        showboardfen();
       -        fputs(" -->\n", stdout);
       -
       -        for (iy = 0; iy < 8; iy++) {
       -                y = flipboard ? 7 - iy : iy;
       -
       -                for (ix = 0; ix < 8; ix++) {
       -                        x = flipboard ? 7 - ix : ix;
       -
       -                        if (x % 2 == 0) {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                                else
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                        } else {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                                else
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                        }
       -
       -                        printf("<g><rect x=\"%d\" y=\"%d\" width=\"45\" height=\"45\" fill=\"#%02x%02x%02x\"/></g>\n",
       -                                ix * 45, iy * 45, color[0], color[1], color[2]);
       -
       -                        piece = getpiece(x, y);
       -                        if (piece) {
       -                                printf("<g transform=\"translate(%d %d)\">", ix * 45, iy * 45);
       -                                svg_showpiece(piece);
       -                                fputs("</g>\n", stdout);
       -                        }
       -                }
       -        }
       -
       -        if (showcoords) {
       -                ix = 7;
       -                x = flipboard ? 0 : 7;
       -                for (iy = 0; iy < 8; iy++) {
       -                        y = flipboard ? 7 - iy : iy;
       -
       -                        /* inverse square color for text */
       -                        if (x % 2 == 0) {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                                else
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                        } else {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                                else
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                        }
       -
       -                        printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"end\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
       -                                (ix + 1) * 45 - 2, (iy * 45) + 10, color[0], color[1], color[2], '8' - y);
       -                }
       -                iy = 7;
       -                y = flipboard ? 0 : 7;
       -                for (ix = 0; ix < 8; ix++) {
       -                        x = flipboard ? 7 - ix : ix;
       -
       -                        /* inverse square color for text */
       -                        if (x % 2 == 0) {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                                else
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                        } else {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                                else
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                        }
       -
       -                        printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"start\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
       -                                (ix * 45) + 2, (iy + 1) * 45 - 3, color[0], color[1], color[2], x + 'a');
       -                }
       -        }
       -
       -        fputs("</svg>\n", stdout);
       -}
       -
       -void
       -tty_showpiece(int c)
       -{
       -        const char *s = "";
       -
       -        /* simple or use unicode character */
       -#if 0
       -        putchar(c);
       -        return;
       -#endif
       -
       -        switch (c) {
       -        case 'K': s = "♔"; break;
       -        case 'Q': s = "♕"; break;
       -        case 'R': s = "♖"; break;
       -        case 'B': s = "♗"; break;
       -        case 'N': s = "♘"; break;
       -        case 'P': s = "♙"; break;
       -        case 'k': s = "♚"; break;
       -        case 'q': s = "♛"; break;
       -        case 'r': s = "♜"; break;
       -        case 'b': s = "♝"; break;
       -        case 'n': s = "♞"; break;
       -        case 'p': s = "♟"; break;
       -        }
       -
       -        if (*s)
       -                fputs(s, stdout);
       -}
       -
       -/* show board */
       -void
       -tty_showboard(void)
       -{
       -        const int *color;
       -        int ix, iy, x, y, piece;
       -
       -        printf("Board FEN:\n");
       -        showboardfen();
       -        printf("\n\n");
       -
       -        SETFGCOLOR(0x00, 0x00, 0x00);
       -
       -        color = border;
       -        SETBGCOLOR(color[0], color[1], color[2]);
       -        SETFGCOLOR(0xff, 0xff, 0xff);
       -        fputs("                             ", stdout);
       -        printf("\x1b[0m"); /* reset */
       -        SETFGCOLOR(0x00, 0x00, 0x00);
       -        putchar('\n');
       -
       -        for (iy = 0; iy < 8; iy++) {
       -                y = flipboard ? 7 - iy : iy;
       -
       -                color = border;
       -                SETBGCOLOR(color[0], color[1], color[2]);
       -                SETFGCOLOR(0xff, 0xff, 0xff);
       -                fputs("  ", stdout);
       -
       -                for (ix = 0; ix < 8; ix++) {
       -                        x = flipboard ? 7 - ix : ix;
       -
       -                        if (x % 2 == 0) {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                                else
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                        } else {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? darksquarehi : darksquare;
       -                                else
       -                                        color = highlight[y][x] ? lightsquarehi : lightsquare;
       -                        }
       -                        SETBGCOLOR(color[0], color[1], color[2]);
       -
       -                        fputs(" ", stdout);
       -                        piece = getpiece(x, y);
       -                        if (piece) {
       -                                if (piece >= 'A' && piece <= 'Z')
       -                                        SETFGCOLOR(0xff, 0xff, 0xff);
       -                                else
       -                                        SETFGCOLOR(0x00, 0x00, 0x00);
       -                                /* workaround: use black chess symbol, because the color
       -                                   is filled and better visible */
       -                                tty_showpiece(tolower(piece));
       -                        } else {
       -                                fputs(" ", stdout);
       -                        }
       -                        fputs(" ", stdout);
       -                }
       -                printf("\x1b[0m"); /* reset */
       -
       -                color = border;
       -                SETBGCOLOR(color[0], color[1], color[2]);
       -                SETFGCOLOR(0xff, 0xff, 0xff);
       -                if (showcoords) {
       -                        putchar(' ');
       -                        putchar('8' - y);
       -                        putchar(' ');
       -                } else {
       -                        fputs("   ", stdout);
       -                }
       -
       -                printf("\x1b[0m"); /* reset */
       -                SETFGCOLOR(0x00, 0x00, 0x00);
       -                putchar('\n');
       -        }
       -        color = border;
       -        SETBGCOLOR(color[0], color[1], color[2]);
       -        SETFGCOLOR(0xff, 0xff, 0xff);
       -        if (showcoords) {
       -                if (flipboard)
       -                        fputs("   h  g  f  e  d  c  b  a    ", stdout);
       -                else
       -                        fputs("   a  b  c  d  e  f  g  h    ", stdout);
       -        } else {
       -                fputs("                             ", stdout);
       -        }
       -        printf("\x1b[0m"); /* reset */
       -        printf("\n");
       -}
       -
       -void
       -ascii_showpiece(int c)
       -{
       -        putchar(c);
       -}
       -
       -/* OnlyFENs */
       -void
       -fen_showboard(void)
       -{
       -        showboardfen();
       -        printf("\n");
       -}
       -
       -/* show board */
       -void
       -ascii_showboard(void)
       -{
       -        int hi[3] = { '>', ' ', '<' };
       -        int dark[3] = { '.', '.', '.' };
       -        int light[3] = { ' ', ' ', ' ' };
       -        int *color, ix, iy, x, y, piece;
       -
       -        printf("Board FEN:\n");
       -        showboardfen();
       -        printf("\n\n");
       -
       -        for (iy = 0; iy < 8; iy++) {
       -                y = flipboard ? 7 - iy : iy;
       -
       -                fputs("+---+---+---+---+---+---+---+---+\n", stdout);
       -                for (ix = 0; ix < 8; ix++) {
       -                        x = flipboard ? 7 - ix : ix;
       -
       -                        if (x % 2 == 0) {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? hi : light;
       -                                else
       -                                        color = highlight[y][x] ? hi : dark;
       -                        } else {
       -                                if (y % 2 == 0)
       -                                        color = highlight[y][x] ? hi : dark;
       -                                else
       -                                        color = highlight[y][x] ? hi : light;
       -                        }
       -
       -                        if (ix == 0)
       -                                putchar('|');
       -                        putchar(color[0]);
       -                        piece = getpiece(x, y);
       -                        if (piece)
       -                                ascii_showpiece(piece);
       -                        else
       -                                putchar(color[1]);
       -                        putchar(color[2]);
       -                        putchar('|');
       -                }
       -                if (showcoords) {
       -                        putchar(' ');
       -                        putchar('8' - y);
       -                }
       -                putchar('\n');
       -        }
       -        fputs("+---+---+---+---+---+---+---+---+\n", stdout);
       -        if (showcoords) {
       -                if (flipboard)
       -                        printf("  h | g | f | e | d | c | b | a |\n");
       -                else
       -                        printf("  a | b | c | d | e | f | g | h |\n");
       -        }
       -
       -        fputs("\n", stdout);
       -}
       -
       -int
       -main(int argc, char *argv[])
       -{
       -        const char *progname, *fen, *moves, *s;
       -        int x, y, x2, y2, field, piece, takepiece;
       -        char square[3];
       -        long l;
       -
       -        if (argc > 3) {
       -                fprintf(stderr, "usage: %s <FEN> [moves] or\n", argv[0]);
       -                fprintf(stderr, "       %s <FEN> or\n", argv[0]);
       -                fprintf(stderr, "       %s\n", argv[0]);
       -                return 1;
       -        }
       -        if (argc > 1)
       -                fen = argv[1];
       -        else
       -                fen = "startpos";
       -
       -        if (argc > 2)
       -                moves = argv[2];
       -        else
       -                moves = "";
       -
       -        if (!strcmp(fen, "startpos"))
       -                fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
       -
       -        /* initial board state, FEN format */
       -        x = y = field = 0;
       -        for (s = fen; *s && field < 6; s++) {
       -                switch (field) {
       -                case 0: /* piece placement data */
       -                        /* skip square */
       -                        if (*s >= '1' && *s <= '9') {
       -                                x += (*s - '0');
       -                                continue;
       -                        }
       -                        /* next rank */
       -                        if (*s == '/') {
       -                                x = 0;
       -                                y++;
       -                                continue;
       -                        }
       -                        /* is piece? place it */
       -                        if (isvalidpiece(*s))
       -                                place(*s, x++, y);
       -                        break;
       -                case 1: /* active color */
       -                        if (*s == 'w' || *s == 'b')
       -                                side_to_move = *s;
       -                        break;
       -                case 2: /* castling availability */
       -                        if (*s == '-') {
       -                                white_can_castle[0] = 0;
       -                                white_can_castle[1] = 0;
       -                                black_can_castle[0] = 0;
       -                                black_can_castle[1] = 0;
       -                        } else if (*s == 'K') {
       -                                white_can_castle[0] = 1;
       -                        } else if (*s == 'Q') {
       -                                white_can_castle[1] = 1;
       -                        } else if (*s == 'k') {
       -                                black_can_castle[0] = 1;
       -                        } else if (*s == 'q') {
       -                                black_can_castle[1] = 1;
       -                        }
       -                        break;
       -                case 3: /* en passant square */
       -                        if (*s >= 'a' && *s <= 'h' &&
       -                                *(s + 1) >= '1' && *(s + 1) >= '6') {
       -
       -                                square[0] = *s;
       -                                square[1] = *(s + 1);
       -                                square[2] = '\0';
       -                                squaretoxy(square, &x, &y);
       -
       -                                enpassantsquare[0] = x;
       -                                enpassantsquare[1] = y;
       -                        }
       -                        break;
       -                case 4: /* halfmove */
       -                        if (!(*s >= '0' && *s <= '9'))
       -                                continue;
       -
       -                        l = strtol(s, NULL, 10);
       -                        if (l >= 0 && l < 32767) {
       -                                halfmove = l;
       -
       -                                for (; *s && isdigit((unsigned char)*s); s++)
       -                                        ;
       -                        }
       -                        break;
       -                case 5: /* move number */
       -                        if (!(*s >= '0' && *s <= '9'))
       -                                continue;
       -
       -                        l = strtol(s, NULL, 10);
       -                        if (l >= 0 && l < 32767) {
       -                                movenumber = (int)l;
       -                                for (; *s && isdigit((unsigned char)*s); s++)
       -                                        ;
       -                        }
       -                        break;
       -                }
       -                if (!*s)
       -                        break;
       -
       -                /* next field, fields are: piece placement data, active color,
       -                   Castling availability, En passant target square,
       -                   Halfmove clock, Fullmove number */
       -                if (*s == ' ') {
       -                        field++;
       -                        continue;
       -                }
       -        }
       -
       -        /* process moves */
       -        square[2] = '\0';
       -        x = y = x2 = y2 = -1;
       -        for (s = moves; *s; s++) {
       -                if (*s == ' ')
       -                        continue;
       -                if ((*s >= 'a' && *s <= 'h') &&
       -                    (*(s + 1) >= '1' && *(s + 1) <= '8') &&
       -                    (*(s + 2) >= 'a' && *(s + 2) <= 'h') &&
       -                    (*(s + 3) >= '1' && *(s + 3) <= '8')) {
       -                        square[0] = *s;
       -                        square[1] = *(s + 1);
       -
       -                        s += 2;
       -                        squaretoxy(square, &x, &y);
       -                        piece = getpiece(x, y);
       -
       -                        place(0, x, y); /* clear square */
       -
       -                        /* place piece at new location */
       -                        square[0] = *s;
       -                        square[1] = *(s + 1);
       -                        squaretoxy(square, &x2, &y2);
       -                        takepiece = getpiece(x2, y2);
       -                        place(piece, x2, y2);
       -                        s += 2;
       -
       -                        /* if pawn move or taken a piece increase halfmove counter */
       -                        /* TODO: taking enpassant should reset halfmove too */
       -                        if (piece == 'p' || piece == 'P' || takepiece != 0)
       -                                halfmove = 0;
       -                        else
       -                                halfmove++;
       -
       -                        /* castling */
       -                        if (piece == 'K' && y == 7 && y2 == 7 && x == 4) {
       -                                /* white: kingside castling: "e1g1" */
       -                                if (x2 == 6) {
       -                                        place('R', x2 - 1, y2);
       -                                        x2 = 7;
       -                                        y2 = 7;
       -                                        place(0, x2, y2); /* clear rook square */
       -                                } else if (x2 == 2) {
       -                                        /* white: queenside castling: "e1c1" */
       -                                        place('R', x2 + 1, y2);
       -                                        x2 = 0;
       -                                        y2 = 7;
       -                                        place(0, x2, y2);
       -                                }
       -                        } else if (piece == 'k' && y == 0 && y2 == 0 && x == 4) {
       -                                /* black: kingside castling: "e8g8" */
       -                                if (x2 == 6) {
       -                                        place('r', x2 - 1, y2);
       -                                        x2 = 7;
       -                                        y2 = 0;
       -                                        place(0, x2, y2); /* clear rook square */
       -                                } else if (x2 == 2) {
       -                                        /* black: queenside castling: "e8c8" */
       -                                        place('r', x2 + 1, y2);
       -                                        x2 = 0;
       -                                        y2 = 0;
       -                                        place(0, x2, y2); /* clear rook square */
       -                                }
       -                        }
       -
       -                        /* remove the ability to castle */
       -                        if (piece == 'K') {
       -                                white_can_castle[0] = white_can_castle[1] = 0;
       -                        } else if (piece == 'k') {
       -                                black_can_castle[0] = black_can_castle[1] = 0;
       -                        } else if (piece == 'R') {
       -                                if (x == 7 && y == 7)
       -                                        white_can_castle[0] = 0;
       -                                else if (x == 0 && y == 7)
       -                                        white_can_castle[1] = 0;
       -                        } else if (piece == 'r') {
       -                                if (x == 0 && y == 0)
       -                                        black_can_castle[1] = 0;
       -                                else if (x == 7 && y == 0)
       -                                        black_can_castle[0] = 0;
       -                        }
       -
       -                        /* the en passant square resets after a move */
       -                        enpassantsquare[0] = -1;
       -                        enpassantsquare[1] = -1;
       -                        /* moved 2 squares and there is an opponent pawn next to it */
       -                        if (piece == 'P' && y == 6 && y2 == 4) {
       -                                if (getpiece(x - 1, y2) == 'p' ||
       -                                    getpiece(x + 1, y2) == 'p') {
       -                                        enpassantsquare[0] = x;
       -                                        enpassantsquare[1] = 5;
       -                                }
       -                        } else if (piece == 'p' && y == 1 && y2 == 3) {
       -                                if (getpiece(x - 1, y2) == 'P' ||
       -                                    getpiece(x + 1, y2) == 'P') {
       -                                        enpassantsquare[0] = x;
       -                                        enpassantsquare[1] = 2;
       -                                }
       -                        }
       -
       -                        /* possible promotion: queen, knight, bishop */
       -                        if (*s == 'q' || *s == 'n' || *s == 'b') {
       -                                if (side_to_move == 'w')
       -                                        piece = toupper((unsigned char)*s);
       -                                else
       -                                        piece = *s;
       -                                place(piece, x2, y2);
       -                                s++;
       -                        }
       -
       -                        /* a move by black increases the move number */
       -                        if (side_to_move == 'b')
       -                                movenumber++;
       -
       -                        /* switch which side it is to move */
       -                        side_to_move = side_to_move == 'b' ? 'w' : 'b';
       -
       -                        /* TODO: reset enpassant square if applicable */
       -                }
       -        }
       -        /* highlight last move */
       -        highlightmove(x, y, x2, y2);
       -
       -        progname = argv[0] ? argv[0] : "fen_to_svg";
       -        if ((s = strrchr(progname, '/')))
       -                progname = s + 1;
       -        if (!strcmp(progname, "fen_to_ascii"))
       -                ascii_showboard();
       -        else if (!strcmp(progname, "fen_to_tty"))
       -                tty_showboard();
       -        else if (!strcmp(progname, "fen_to_fen"))
       -                fen_showboard();
       -        else
       -                svg_showboard();
       -
       -        return 0;
       -}