--- a/src/chess/pgn.c Mon Aug 17 12:22:08 2026 +0200
+++ b/src/chess/pgn.c Fri Aug 21 16:08:50 2026 +0200
@@ -58,7 +58,7 @@
return pgn_error_pos;
}
-static const char *pgn_result(GameState *gamestate) {
+static const char *pgn_result(const GameState *gamestate) {
if (is_game_drawn(gamestate)) {
return "1/2-1/2";
} else if (gamestate->wresign) {
@@ -269,7 +269,7 @@
}
}
-static const char *pgn_date(GameState *gamestate) {
+static const char *pgn_date(const GameState *gamestate) {
static char date[16];
time_t dateseconds;
if (gamestate->movecount == 0) {
@@ -301,98 +301,101 @@
return date;
}
-const char *pgn_player_name(GameState *gamestate, uint8_t color) {
+const char *pgn_player_name(const GameState *gamestate, uint8_t color) {
const char *name = color == WHITE ? gamestate->wname : gamestate->bname;
return name[0] != '\0' ? name : "Anonymous";
}
-void write_pgn(FILE* stream, GameState *gamestate, bool export_comments) {
+int write_pgn(FILE* stream, const GameState *gamestate, bool export_comments) {
+ char *pgn = create_pgn(gamestate, export_comments);
+ if (pgn == NULL) return 1;
+ fputs(pgn, stream);
+ free(pgn);
+ return 0;
+}
+
+char *create_pgn(const GameState *gamestate, bool export_comments) {
+ size_t resultcap = 4096;
+ char *result = malloc(resultcap);
+ if (result == NULL) return NULL;
+ char *resp = result;
+
/* STR tag pairs */
- fprintf(stream, "[Event \"%s\"]\n", "terminal-chess game");
- fprintf(stream, "[Site \"%s\"]\n", "Somewhere on Earth");
- fprintf(stream, "[Date \"%s\"]\n", pgn_date(gamestate));
- fprintf(stream, "[Round \"%s\"]\n", "-");
- fprintf(stream, "[White \"%s\"]\n", pgn_player_name(gamestate, WHITE));
- fprintf(stream, "[Black \"%s\"]\n", pgn_player_name(gamestate, BLACK));
- const char *result = pgn_result(gamestate);
- fprintf(stream, "[Result \"%s\"]\n\n", result);
+ resp += sprintf(resp, "[Event \"%s\"]\n", "terminal-chess game");
+ resp += sprintf(resp, "[Site \"%s\"]\n", "Somewhere on Earth");
+ resp += sprintf(resp, "[Date \"%s\"]\n", pgn_date(gamestate));
+ resp += sprintf(resp, "[Round \"%s\"]\n", "-");
+ resp += sprintf(resp, "[White \"%s\"]\n", pgn_player_name(gamestate, WHITE));
+ resp += sprintf(resp, "[Black \"%s\"]\n", pgn_player_name(gamestate, BLACK));
+ const char *gameresult = pgn_result(gamestate);
+ resp += sprintf(resp, "[Result \"%s\"]\n\n", gameresult);
// TODO: add optional clock info
/* moves */
- size_t moveblkcap = 4096;
- char *moveblk = malloc(moveblkcap);
- char *moveblkptr = moveblk;
- if (moveblk == NULL) {
- // TODO: error handling (for the entire function actually)
- abort();
- }
+ char *moveblk = resp; /* remember where the move block starts */
+
for (unsigned i = 0 ; i < gamestate->movecount ; i++) {
- /* reallocate move block buffer if needed */
+ /* reallocate buffer if needed */
{
- size_t moveblksize = moveblkptr - moveblk;
- if (moveblksize + 128 > moveblkcap) {
- moveblkcap *= 2;
- char *newmoveblk = realloc(moveblk, moveblkcap);
- if (newmoveblk == NULL) {
- free(moveblk);
- abort();
+ size_t rsize = resp - result;
+ if (rsize + 128 > resultcap) {
+ resultcap *= 2;
+ char *newresult = realloc(result, resultcap);
+ if (newresult == NULL) {
+ free(result);
+ return NULL;
}
- moveblk = newmoveblk;
- moveblkptr = moveblk + moveblksize;
+ result = newresult;
+ resp = result + rsize;
}
}
- int snpr; /* return value of printf calls */
-
if (i % 2 == 0) {
- snpr = snprintf(moveblkptr, 16, "%d.\x1f%s",
+ resp += snprintf(resp, 16, "%d.\x1f%s",
1+i/2, gamestate->moves[i].string);
} else {
- snpr = snprintf(moveblkptr, 16, "%s",
+ resp += snprintf(resp, 16, "%s",
gamestate->moves[i].string);
}
- moveblkptr += snpr;
if (!export_comments) {
- *(moveblkptr++) = ' ';
+ *(resp++) = ' ';
continue;
}
/* add clock times when the game was under time control */
if (gamestate->info.timecontrol) {
- memcpy(moveblkptr, " {[%clk ", 8);
- moveblkptr += 8;
+ memcpy(resp, " {[%clk ", 8);
+ resp += 8;
unsigned clkmv = i + 2; /* time for the next move! */
uint16_t clk = remaining_movetime2(gamestate, clkmv);
- snpr = print_clk(clk, moveblkptr, true);
- moveblkptr += snpr;
- *(moveblkptr++) = ']';
- *(moveblkptr++) = '}';
+ resp += print_clk(clk, resp, true);
+ *(resp++) = ']';
+ *(resp++) = '}';
/* elapsed move time */
- memcpy(moveblkptr, " {[%emt ", 8);
- moveblkptr += 8;
+ memcpy(resp, " {[%emt ", 8);
+ resp += 8;
uint16_t emt = gamestate->moves[i].movetime.tv_sec;
- snpr = print_clk(emt, moveblkptr, true);
- moveblkptr += snpr;
- *(moveblkptr++) = ']';
- *(moveblkptr++) = '}';
+ resp += print_clk(emt, resp, true);
+ *(resp++) = ']';
+ *(resp++) = '}';
}
- *(moveblkptr++) = ' ';
+ *(resp++) = ' ';
}
- if (result[0] != '*') {
- size_t rlen = strlen(result);
- memcpy(moveblkptr, result, rlen);
- moveblkptr += rlen;
+ if (gameresult[0] != '*') {
+ size_t rlen = strlen(gameresult);
+ memcpy(resp, gameresult, rlen);
+ resp += rlen;
}
- *(moveblkptr++) = '\n';
- *moveblkptr = 0;
+ *(resp++) = '\n';
+ *resp = 0;
+ /* post-process move block and format it nicely */
pgn_insert_newlines(moveblk);
- fputs(moveblk, stream);
- free(moveblk);
+ return result;
}