if (argc == -1)
if (argc <= 1)
watch (argc, argv)    int argc;    char **argv;{    if (argc == -1)	usage (watch_usage);    if (strcmp (argv[1], "on") == 0)    {	--argc;	++argv;	return watch_on (argc, argv);    }    else if (strcmp (argv[1], "off") == 0)    {	--argc;	++argv;	return watch_off (argc, argv);    }    else if (strcmp (argv[1], "add") == 0)    {	--argc;	++argv;	return watch_add (argc, argv);    }    else if (strcmp (argv[1], "remove") == 0)    {	--argc;	++argv;	return watch_remove (argc, argv);    }    else	usage (watch_usage);    return 0;}