diff -urN slock-1.0/slock.c slock-1.0-getopt//slock.c
--- slock-1.0/slock.c	2009-11-26 20:53:26.000000000 +0800
+++ slock-1.0-getopt//slock.c	2010-09-18 12:34:56.761712744 +0800
@@ -74,9 +74,9 @@
 
 static void
 #ifdef HAVE_BSD_AUTH
-read_password(Display *dpy)
+read_password(Display *dpy, Bool silent)
 #else
-read_password(Display *dpy, const char *pws)
+read_password(Display *dpy, const char *pws, Bool silent)
 #endif
 {
 	char buf[32], passwd[256];
@@ -117,7 +117,7 @@
 #else
 				running = strcmp(crypt(passwd, pws), pws);
 #endif
-				if (running != 0)
+				if (running != 0 && silent == False)
 					XBell(dpy, 100);
 				len = 0;
 				break;
@@ -209,7 +209,13 @@
 
 static void
 usage(void) {
-	fprintf(stderr, "usage: %s -v", __progname);
+	fprintf(stderr, "slock-%s, © 2006-2008 Anselm R Garbe\n"
+		"usage: %s [-h|-s|-v]\n"
+		"\t-h show this message\n"
+		"\t-s silent (don't ring bell on password failure)\n"
+		"\t-v show this message\n"
+		, VERSION, __progname
+	);
 	exit(EXIT_FAILURE);
 }
 
@@ -219,14 +225,19 @@
 	const char *pws;
 #endif
 	Display *dpy;
-	int nscreens, screen;
+	int nscreens, screen, opt;
+	Bool silent = False;
 
 	struct st_lock **locks;
 
-	if((argc == 2) && !strcmp("-v", argv[1]))
-		die("slock-%s, © 2006-2008 Anselm R Garbe", VERSION);
-	else if(argc != 1)
-		usage();
+	while ( (opt = getopt(argc, argv, "hsv")) != -1) {
+		switch (opt) {
+			case 's': 
+				silent = True; break;
+			default:
+				usage();
+		}
+	}
 
 #ifndef HAVE_BSD_AUTH
 	pws = get_password();
@@ -248,9 +259,9 @@
 
 	/* Everything is now blank. Now wait for the correct password. */
 #ifdef HAVE_BSD_AUTH
-	read_password(dpy);
+	read_password(dpy, silent);
 #else
-	read_password(dpy, pws);
+	read_password(dpy, pws, silent);
 #endif
 
 	/* Password ok, unlock everything and quit. */