Add help text for simple-yuv

1 files changed, 25 insertions, 4 deletions

diff --git a/simple-yuv.c b/simple-yuv.c
index 4051b85..28a1bcc 100644
--- a/simple-yuv.c
+++ b/simple-yuv.c
@@ -662,6 +662,22 @@ fullscreen_window(struct window *window)
 					0, NULL);
 }
 
+static void
+usage(const char *p, int exit_code)
+{
+	if (p)
+		printf("%s\n\n", p);
+
+	printf("usage:\n\n"
+	       "  --yuyv\tinput format is YUYV\n"
+	       "  --yuv\t\tinput format is YUV420\n"
+	       "  --nv12\tinput format is NV12\n"
+	       "  -f\t\tfullscreen\n"
+	       "  -\t\ttake input from stdin\n\n");
+
+	exit(exit_code);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -674,14 +690,19 @@ main(int argc, char **argv)
 	for (i = 1; i < argc; i++) {
 		if (strcmp(argv[i], "--yuyv") == 0)
 			format = WL_DRM_FORMAT_YUYV;
-		if (strcmp(argv[i], "--yuv") == 0)
+		else if (strcmp(argv[i], "--yuv") == 0)
 			format = WL_DRM_FORMAT_YUV420;
-		if (strcmp(argv[i], "--nv12") == 0)
+		else if (strcmp(argv[i], "--nv12") == 0)
 			format = WL_DRM_FORMAT_NV12;
-		if (strcmp(argv[i], "-") == 0)
+		else if (strcmp(argv[i], "-") == 0)
 			source = stdin;
-		if (strcmp(argv[i], "-f") == 0)
+		else if (strcmp(argv[i], "-f") == 0)
 			fullscreen = 1;
+		else if (strcmp(argv[i], "-h") == 0 ||
+			 strcmp(argv[i], "--help") == 0)
+			usage(NULL, EXIT_SUCCESS);
+		else
+			usage("unrecognized option", EXIT_FAILURE);
 	}
 
 	display = create_display();