No need for usage()

There are 2 arguments why -v and -h are broken:

	1) if you are running off git, -v will show the last stable
           release, effectively making this option useless.
           people running stable versions leave open an attack surface
           this way in case there are vulnerabilities found.
           99% of the people are also using package managers to keep
           their software up to date, instead of running $TOOL -v to
           check how old it is.
        2) -h is a sad excuse for not just looking at the manual page
           (man 1 slock). Given we accept a post_lock_command, we can't
           be as liberal and just intercept certain flags.

I changed the manpage to reflect this change.

slock.1

@@ -1,29 +1,19 @@
 .TH SLOCK 1 slock\-VERSION
 .SH NAME
-slock \- simple X display locker
+slock \- simple X screen locker
 .SH SYNOPSIS
 .B slock
-.RB [ \-v
+.RB [
-|
+.IR cmd
-.IR post_lock_command ]
+]
 .SH DESCRIPTION
 .B slock
-is a screen locker for X. If provided, the
+is an X screen locker. If provided,
-.IR post_lock_command
+.IR cmd
-will be executed when the screen is locked.
+is executed after the screen has been locked.
-.SH OPTIONS
-.TP
-.B \-v
-prints version information to stdout, then exits.
 .SH EXAMPLES
 $ slock /usr/sbin/s2ram
 .SH CUSTOMIZATION
 .B slock
 can be customized by creating a custom config.h and (re)compiling the source
 code. This keeps it fast, secure and simple.
-.SH AUTHORS
-See the LICENSE file for the authors.
-.SH LICENSE
-See the LICENSE file for the terms of redistribution.
-.SH BUGS
-Please report them.

slock.c

@@ -272,27 +272,15 @@ lockscreen(Display *dpy, int screen)
 	return NULL;
 }
 
-static void
-usage(void)
-{
-	fprintf(stderr, "usage: slock [-v|POST_LOCK_CMD]\n");
-	exit(1);
-}
-
 int
-main(int argc, char **argv) {
+main(int argc, char **argv)
+{
 #ifndef HAVE_BSD_AUTH
 	const char *pws;
 #endif
 	Display *dpy;
 	int screen;
 
-	if ((argc == 2) && !strcmp("-v", argv[1]))
-		die("slock-%s, © 2006-2016 slock engineers\n", VERSION);
-
-	if ((argc == 2) && !strcmp("-h", argv[1]))
-		usage();
-
 #ifdef __linux__
 	dontkillme();
 #endif