feat: add -h/--help with full option descriptions to fpack/funpack

tools/fpack.c

@@ -34,6 +34,7 @@ static struct option long_opts[] = {
 	{"progress", no_argument,       NULL, 'p'},
 	{"quiet",    no_argument,       NULL, 'q'},
 	{"verbose",  no_argument,       NULL, 'v'},
+	{"help",     no_argument,       NULL, 'h'},
 	{NULL, 0, NULL, 0}
 };
 
@@ -230,9 +231,25 @@ static int add_dir(struct fpk_writer *w, const char *dir, size_t base_len)
 static void usage(void)
 {
 	fprintf(stderr, "usage: %s [-o output.fpk] [-p] [-q] [-v] input_dir\n", PROGRAM_NAME);
+	fprintf(stderr, "try '%s --help' for more information\n", PROGRAM_NAME);
 	exit(1);
 }
 
+static void help(void)
+{
+	printf("usage: %s [options] input_dir\n", PROGRAM_NAME);
+	printf("\n");
+	printf("Pack a directory tree into an fpk archive.\n");
+	printf("\n");
+	printf("options:\n");
+	printf("  -o, --output=FILE  write the archive to FILE instead of the derived name\n");
+	printf("  -p, --progress     print packing progress\n");
+	printf("  -q, --quiet        suppress the final summary line\n");
+	printf("  -v, --verbose      print each packed entry\n");
+	printf("  -h, --help         show this help and exit\n");
+	exit(0);
+}
+
 int main(int argc, char **argv)
 {
 	const char *output_arg = NULL;
@@ -242,7 +259,7 @@ int main(int argc, char **argv)
 	struct fpk_writer *w;
 	int c;
 
-	while ((c = getopt_long(argc, argv, "o:pqv", long_opts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "o:pqvh", long_opts, NULL)) != -1) {
 		switch (c) {
 		case 'o':
 			output_arg = optarg;
@@ -256,6 +273,9 @@ int main(int argc, char **argv)
 		case 'v':
 			flags |= FPACK_VERBOSE;
 			break;
+		case 'h':
+			help();
+			break;
 		default:
 			usage();
 		}