Add extraopts to our usage

src/_usage.c

@@ -10,8 +10,11 @@
 static void usage (int exit_status)
 {
 	int i;
-	printf ("Usage: " APPLET " [options]\n\n");
-	printf ("Options: [" getoptstring "]\n");
+	printf ("Usage: " APPLET " [options] ");
+#ifdef extraopts
+	printf (extraopts);
+#endif
+	printf ("\n\nOptions: [" getoptstring "]\n");
 	for (i = 0; longopts[i].name; ++i)
 		printf ("  -%c, --%s\n", longopts[i].val, longopts[i].name);
 	exit (exit_status);

src/checkown.c

@@ -132,6 +132,7 @@ static struct group *get_group (const char *name)
 }
 
 #include "_usage.h"
+#define extraopts "dir1 dir2 ..."
 #define getoptstring "fm:g:u:" getoptstring_COMMON
 static struct option longopts[] = {
 	{ "directory",      0, NULL, 'd'},
@@ -190,6 +191,9 @@ int checkown (int argc, char **argv)
 		}
 	}
 
+	if (optind >= argc)
+		usage (EXIT_FAILURE);
+
 	if (pw) {
 		uid = pw->pw_uid;
 		gid = pw->pw_gid;

src/mountinfo.c

@@ -246,6 +246,7 @@ static regex_t *get_regex (char *string)
 }
 
 #include "_usage.h"
+#define extraopts "[mount1] [mount2] ..."
 #define getoptstring "f:F:n:N:o:O:p:P:iqst" getoptstring_COMMON
 static struct option longopts[] = {
 	{ "fstype-regex",        1, NULL, 'f'},

src/rc-status.c

@@ -55,6 +55,7 @@ static void print_service (char *service)
 }
 
 #include "_usage.h"
+#define extraopts "[runlevel1] [runlevel2] ..."
 #define getoptstring "alsu" getoptstring_COMMON
 static const struct option longopts[] = {
 	{"all",         0, NULL, 'a'},