keymap: add --interactive mode

Add -i/--interactive mode to keymap tool, for easy debugging of unknown and
wrong keymaps. Use like

  sudo /lib/udev/keymap -i input/event4

and note down the wrong/missing keys.

1 files changed, 62 insertions, 7 deletions

diff --git a/keymap/keymap.c b/keymap/keymap.c
index 516dbc0..c48d934 100644
--- a/keymap/keymap.c
+++ b/keymap/keymap.c
@@ -228,18 +228,65 @@ static const char* default_keymap_path(const char* path)
 	return path;
 }
 
+static void print_key(struct input_event *event)
+{
+	static int cur_scancode = 0;
+
+	/* save scan code for next EV_KEY event */
+	if (event->type == EV_MSC && event->code == MSC_SCAN)
+	    cur_scancode = event->value;
+
+	/* key press */
+	if (event->type == EV_KEY && event->value)
+	    printf("scan code: 0x%02X   key code: %s\n", cur_scancode,
+		    format_keyname(key_names[event->code]));
+}
+
+static void interactive(int fd)
+{
+	struct input_event ev;
+	int run = 1;
+
+	/* grab input device */
+	ioctl(fd, EVIOCGRAB, 1);
+
+	puts("Press ESC to finish");
+	while (run) {
+		switch (read(fd, &ev, sizeof(ev))) {
+		case -1:
+			perror("read");
+			run = 0;
+			break;
+		case 0:
+			run = 0;
+			break;
+		default:
+			print_key(&ev);
+			/* stop on Escape key release */
+			if (ev.type == EV_KEY && ev.code == KEY_ESC && ev.value == 0)
+				run = 0;
+			break;
+		}
+	}
+
+	/* release input device */
+	ioctl(fd, EVIOCGRAB, 0);
+}
+
 int main(int argc, char **argv)
 {
 	static const struct option options[] = {
 		{ "help", no_argument, NULL, 'h' },
+		{ "interactive", no_argument, NULL, 'i' },
 		{}
 	};
 	int fd = -1;
+	int opt_interactive = 0;
 
 	while (1) {
 		int option;
 
-		option = getopt_long(argc, argv, "h", options, NULL);
+		option = getopt_long(argc, argv, "hi", options, NULL);
 		if (option == -1)
 			break;
 
@@ -247,22 +294,30 @@ int main(int argc, char **argv)
 		case 'h':
 			printf("Usage: keymap <event device> [<map file>]\n\n");
 			return 0;
+
+		case 'i':
+			opt_interactive = 1;
+			break;
 		default:
 			return 1;
 		}
 	}
 
-	if (argc < 2 || argc > 3) {
+	if (argc < optind+1 || argc > optind+2) {
 		fprintf(stderr, "Usage: keymap <event device> [<map file>]\n\n");
 		return 2;
 	}
 
-	if ((fd = evdev_open(argv[1])) < 0)
+	if ((fd = evdev_open(argv[optind])) < 0)
 		return 3;
 
-	if (argc == 3)
-		merge_table(fd, default_keymap_path(argv[2]));
-	else
-		dump_table(fd);
+	if (argc == optind+2)
+		merge_table(fd, default_keymap_path(argv[optind+1]));
+	else {
+		if (opt_interactive)
+			interactive(fd);
+		else
+			dump_table(fd);
+	}
 	return 0;
 }