Add a new rc_usercheck variable (default to YES). When set to no, root

privilege is needed to run rc_check.
In effect this means /etc/rc.d/foobar check can now be run as a regular
user.
Discussed with robert@ during g2k12.
ok todd@

src/etc/rc.d/rc.subr

@@ -1,4 +1,4 @@
-#	$OpenBSD: rc.subr,v 1.58 2012/07/07 10:28:07 ajacoutot Exp $
+#	$OpenBSD: rc.subr,v 1.59 2012/08/04 15:30:25 ajacoutot Exp $
 #
 # Copyright (c) 2010, 2011 Antoine Jacoutot <ajacoutot@openbsd.org>
 # Copyright (c) 2010, 2011 Ingo Schwarze <schwarze@openbsd.org>
@@ -48,7 +48,7 @@ rc_start() {
 }
 
 rc_check() {
-	pkill -0 -f "^${pexp}"
+	pgrep -f "^${pexp}" >/dev/null
 }
 
 rc_reload() {
@@ -96,6 +96,10 @@ rc_wait() {
 rc_cmd() {
 	local _bg _n
 
+	[ "$(id -u)" -eq 0 ] || \
+		[ X"${rc_usercheck}" != X"NO" -a X"$1" = "Xcheck" ] || \
+		rc_err "$0: need root privileges"
+
 	if [ -z "${_RC_FORCE}" ] && [ X"${daemon_flags}" = X"NO" ]
 	then
 		if [ -n "${_RC_DEBUG}" ]
@@ -167,8 +171,6 @@ rc_cmd() {
 	esac
 }
 
-[ $(id -u) -eq 0 ] || rc_err "$0: need root privileges"
-
 [ -z "${local_rcconf}" ] && . /etc/rc.conf
 
 [ -n "${daemon}" ] || rc_err "$0: daemon is not set"