i forgot about goto until gemini reshowed me

CMakeLists.txt

@@ -1,5 +1,4 @@
 cmake_minimum_required(VERSION 3.16)
-set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_C_STANDARD 23)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -10,5 +9,3 @@ set(SOURCES
 )
 
 add_executable(tic_tac_toe ${SOURCES})
-
-target_include_directories(tic_tac_toe PRIVATE include)

src/main.c

@@ -1,118 +1,101 @@
-#include <stdio.h>
 #include <string.h>
 #include <termios.h>
 #include <time.h>
 #include <unistd.h>
 
 const char p1 = 'x', p2 = 'o';
-char temp = p1;
+char temp = 'x';
-char status[32];
+char buf[9] = { "         " };
-char buf[9];
+static const unsigned char wins[8][3] = { { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 },
+					  { 0, 3, 6 }, { 1, 4, 7 }, { 2, 5, 8 },
+					  { 0, 4, 8 }, { 2, 4, 6 } };
 
-bool
+int
 check_line(const char id)
 {
-	const int wins[8][3] = { { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 },
-				 { 0, 3, 6 }, { 1, 4, 7 }, { 2, 5, 8 },
-				 { 0, 4, 8 }, { 2, 4, 6 } };
 	for (int i = 0; i < sizeof(wins) / sizeof(wins[0]); i++)
 	{
 		if ((buf[wins[i][0]] == id && buf[wins[i][1]] == id &&
 		     buf[wins[i][2]] == id))
 		{
-			return true;
+			return 1;
 		}
 	}
-	return false;
+	return 0;
 }
 
 void
-set_raw_mode(bool enable)
+draw_board()
 {
-	static struct termios oldt, newt;
+	char divider[] = " - + - + -\n";
-	if (enable)
+	write(1, "\033[H\033[J", sizeof("\033[H\033[J") - 1);
+	for (int i = 0; i < 9; i += 3)
 	{
-		tcgetattr(STDIN_FILENO, &oldt);
+		char row[] = " 0 | 0 | 0\n";
-		newt = oldt;
+		row[1] = buf[i];
-		newt.c_lflag &= ~(ICANON | ECHO);
+		row[5] = buf[i + 1];
-		tcsetattr(STDIN_FILENO, TCSANOW, &newt);
+		row[9] = buf[i + 2];
+		write(1, row, sizeof(row) - 1);
+		if (i < 6) write(1, divider, sizeof(divider) - 1);
 	}
-	else
+	write(1, "Current Player: ", 16);
-	{
+	write(1, &temp, 1);
-		tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
+	write(1, "\n", 1);
-	}
-}
-
-bool
-update_status()
-{
-	auto p1_check = check_line(p1);
-	auto p2_check = check_line(p2);
-	if (p1_check || p2_check)
-	{
-		(p1_check ? (void)strncpy(status, "Game Over! Player 1 wins!\n",
-					  sizeof(status))
-			  : (void)strncpy(status, "Game Over! Player 2 wins!\n",
-					  sizeof(status)));
-		return true;
-	}
-	int count = 0;
-	for (int i = 0; i < sizeof(buf) / sizeof(buf[0]); i++)
-	{
-		if (buf[i] != ' ') count++;
-	}
-	if (count == sizeof(buf) / sizeof(buf[0]))
-	{
-		(void)strncpy(status, "Game Over! It's a tie!\n",
-			      sizeof(status));
-		return true;
-	}
-	snprintf(status, sizeof(status), "Current Player: %c\n", temp);
-
-	return false;
-}
-
-bool
-process_input()
-{
-	char ch;
-	while (read(STDIN_FILENO, &ch, 1))
-	{
-		if (ch == 'q') return false;
-		if (ch < '1' || ch > '9') continue;
-		int index = ch - '1';
-		if (buf[index] != ' ') continue;
-		buf[index] = temp;
-		temp = (temp == p1) ? p2 : p1;
-		return true;
-	}
-	return true;
 }
 
 int
 main()
 {
-	bool game_over;
+	static struct termios oldt, newt;
-	for (int i = 0; i < sizeof(buf) / sizeof(buf[0]); i++) buf[i] = ' ';
+	tcgetattr(STDIN_FILENO, &oldt);
-
+	newt = oldt;
-	set_raw_mode(true);
+	newt.c_lflag &= ~(ICANON | ECHO);
-	printf("\033[?25l");
+	tcsetattr(STDIN_FILENO, TCSANOW, &newt);
-	do
+	write(1, "\033[?25l", sizeof("\033[?25l") - 1);
+	while (1)
 	{
-		game_over = update_status();
+		if (check_line(p1))
-		printf("\033[H\033[J");
+		{
-		printf(" %c | %c | %c\n", buf[0], buf[1], buf[2]);
+			break;
-		printf(" - + - + -\n");
+		}
-		printf(" %c | %c | %c\n", buf[3], buf[4], buf[5]);
+		if (check_line(p2))
-		printf(" - + - + -\n");
+		{
-		printf(" %c | %c | %c\n", buf[6], buf[7], buf[8]);
+			write(1, "P2 wins!\n", sizeof("P2 wins!\n") - 1);
-		printf("%s", status);
+			break;
-		fflush(stdout);
+		}
-	} while (!game_over && process_input());
+		int filled = 0;
-	printf("Press any key to quit.\n");
+		while (filled < 9)
+		{
+			draw_board();
+			char ch;
+			read(0, &ch, 1);
+			if (ch == 'q') break;
+			int idx = ch - '1';
+			if (ch >= '1' && ch <= '9' && buf[idx] == ' ')
+			{
+				buf[idx] = temp;
+				if (check_line(temp))
+				{
+					draw_board();
+					write(1, &temp, 1);
+					write(1, " wins!\n",
+					      sizeof(" wins!\n") - 1);
+					goto end;
+				}
+				temp = (temp == p1) ? p2 : p1;
+				filled++;
+			}
+		}
+		write(1, "It's a tie!\n", sizeof("It's a tie!\n") - 1);
+		break;
+	}
+end:
+	write(1, "Press any key to quit.\n",
+	      sizeof("Press any key to quit.\n") - 1);
 
 	char dummy;
 	read(STDIN_FILENO, &dummy, 1);
-	printf("\033[?25h");
+	write(1, "\033[?25h", 5);
-	set_raw_mode(false);
+	tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
+	return 0;
 }