Better error handling, no zombie process on failure.

include/editing_area/level.h

@@ -9,6 +9,8 @@ struct Level {
 	tile_t *data;
 };
 
-void level_read(struct Level *, char *path);
+/* return -1 if error */
+int level_read(struct Level *, char *path);
 void level_free(struct Level *);
-void level_write(struct Level level, char *path);
+/* return -1 if error */
+int level_write(struct Level level, char *path);

src/editing_area/level.c

@@ -8,12 +8,12 @@
 
 static const int kble_fmt_version = 0;
 
-static char read_byte(FILE *file);
+static int read_byte(FILE *file);
 static tile_t read_byte_group(FILE *file, int size);
-static void write_byte(FILE *file, char byte);
-static void write_byte_group(FILE *file, tile_t value, int size);
+static int write_byte(FILE *file, char byte);
+static int write_byte_group(FILE *file, tile_t value, int size);
 
-void level_read(struct Level *level, char *path)
+int level_read(struct Level *level, char *path)
 {
 	FILE *file = NULL;
 	char byte = 0;
@@ -27,7 +27,7 @@ void level_read(struct Level *level, char *path)
 	if (file == NULL) {
 		fprintf(stderr, "ERROR: cannot open input file %s\n",
 		        path);
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 
 	/* check KBLE format version */
@@ -37,23 +37,26 @@ void level_read(struct Level *level, char *path)
 		        "ERROR: KBLE format version doesn't match ; "
 		        "expected %d, got %d\n",
 		        kble_fmt_version, byte);
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 
 	/* get tile size (in bytes) */
 	tile_size = read_byte(file);
+	if (tile_size < 0) return -1;
 	/* check than tile size is in boundaries */
 	if (tile_size > sizeof(tile_t) / sizeof(char)) {
 		fprintf(stderr,
 		        "ERROR: tile size is too big ; "
 		        "maximum is %ld, found %d",
 		        sizeof(tile_t), tile_size);
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 	/* get width */
 	level->width = read_byte_group(file, 2);
+	if (level->width == (tile_t)-1) return -1;
 	/* get height */
 	level->height = read_byte_group(file, 2);
+	if (level->height == (tile_t)-1) return -1;
 
 	/* allocate memory for data */
 	level_size = level->width * level->height;
@@ -66,7 +69,7 @@ void level_read(struct Level *level, char *path)
 	/* check for allocation failure */
 	if (level->data == NULL) {
 		fprintf(stderr, "ERROR: memory allocation failure\n");
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 
 	/* read file content */
@@ -77,11 +80,13 @@ void level_read(struct Level *level, char *path)
 
 	/* close file */
 	fclose(file);
+
+	return 0;
 }
 
 void level_free(struct Level *level) { free(level->data); }
 
-void level_write(struct Level level, char *path)
+int level_write(struct Level level, char *path)
 {
 	FILE *file = NULL;
 	int tile = 0;
@@ -95,7 +100,7 @@ void level_write(struct Level level, char *path)
 	if (file == NULL) {
 		fprintf(stderr, "ERROR: cannot open output file %s\n",
 		        path);
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 
 	/* find longest value in data (in bytes) */
@@ -124,50 +129,60 @@ void level_write(struct Level level, char *path)
 
 	/* close file */
 	fclose(file);
+
+	return 0;
 }
 
-/* Read a single byte safely (handle EOF). */
-static char read_byte(FILE *file)
+/* Read a single byte safely (handle EOF). Return -1 if error. */
+static int read_byte(FILE *file)
 {
 	const int byte = fgetc(file);
 	if (byte == EOF) {
 		fprintf(stderr, "ERROR: unexpected EOF\n");
-		exit(EXIT_FAILURE);
+		return -1;
 	}
 	return (char)byte;
 }
 
-/* Read multiple bytes and "merge" them into one integer. */
+/* Read multiple bytes and "merge" them into one integer. Return -1 if error. */
 static tile_t read_byte_group(FILE *file, int size)
 {
 	int group = 0;
 	char *byte_ptr = (char *)&group;
+	int value = 0;
 	int i = 0;
 	byte_ptr += size;
 	for (i = 0; i < size; i += 1) {
-		byte_ptr -= 1, *byte_ptr = read_byte(file);
+		value = read_byte(file);
+		if (value < 0)
+			return -1;
+		byte_ptr -= 1, *byte_ptr = value;
 	}
 	return group;
 }
 
-/* Write a single byte safely (handle EOF). */
-static void write_byte(FILE *file, char byte)
+/* Write a single byte safely (handle EOF). Return -1 if error. */
+static int write_byte(FILE *file, char byte)
 {
 	const int result = fputc(byte, file);
 	if (result == EOF) {
 		fprintf(stderr, "ERROR: file write error\n");
-		exit(EXIT_FAILURE);
+		return -1;
 	}
+	return 0;
 }
 
-/* Write an integer as multiple bytes. */
-static void write_byte_group(FILE *file, tile_t value, int size)
+/* Write an integer as multiple bytes. Return -1 if error. */
+static int write_byte_group(FILE *file, tile_t value, int size)
 {
 	char *value_ptr = (char *)&value;
 	value_ptr += size;
+	int error;
 	int i = 0;
 	for (i = 0; i < size; i += 1) {
 		value_ptr -= 1;
-		write_byte(file, *value_ptr);
+		error = write_byte(file, *value_ptr);
+		if (error < 0) return -1;
 	}
+	return 0;
 }

src/editing_area/main.c

@@ -21,6 +21,7 @@ int editing_area_main(int argc, char **argv,
 {
 	int mouse_x;
 	int mouse_y;
+	int error;
 	struct Level level;
 	level.data = NULL;
 
@@ -36,9 +37,10 @@ int editing_area_main(int argc, char **argv,
 	if (tileset.width >= TILESET_MIN_WIDTH_PX &&
 	    tileset.height >= TILESET_MIN_HEIGHT_PX) {
 		/* load level */
-		level_read(&level, argv[2]);
+		error = level_read(&level, argv[2]);
+		printf("%d\n", error);
 
-		while (!WindowShouldClose()) {
+		while ((!WindowShouldClose()) && (error >= 0)) {
 			/* update */
 			update_mouse(&mouse_x, &mouse_y, level,
 			             shared_data);
@@ -53,8 +55,10 @@ int editing_area_main(int argc, char **argv,
 			EndDrawing();
 		}
 
-		/* save level */
-		level_write(level, argv[2]);
+		if (error >= 0) {
+			/* save level */
+			error = level_write(level, argv[2]);
+		}
 	} else
 		fprintf(stderr,
 		        "ERROR: tileset size is invalid, expected at "