periodic: set _localbase for periodic scripts from within periodic.conf

Set _localbase variable from within /etc/defaults/periodic.conf
for use by periodic scripts.

This fixes e5d7100c09, no other functional changes intended.

Reported by:		gahr, otis
Reviewed by:		markj, gahr
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D47486

usr.sbin/periodic/periodic.conf

@@ -15,6 +15,15 @@
 #
 #
 
+_set_localbase() {
+	_localbase=`/sbin/sysctl -n user.localbase 2> /dev/null`
+	# Set default value of _localbase if not previously set
+	: ${_localbase:="/usr/local"}
+}
+
+# Set _localbase with fallback to /usr/local
+_set_localbase
+
 # What files override these defaults ?
 periodic_conf_files="/etc/periodic.conf /etc/periodic.conf.local ${_localbase}/etc/periodic.conf"
 

usr.sbin/periodic/periodic.sh

@@ -29,14 +29,6 @@ if [ $# -lt 1 ] ; then
     usage
 fi
 
-_localbase=`/sbin/sysctl -n user.localbase 2> /dev/null`
-# Set default value of _localbase if not previously set
-: ${_localbase:="/usr/local"}
-
-# Use a deterministic path to match the preset from /etc/crontab in case
-# periodic is run interactively.
-export PATH=/sbin:/bin:/usr/sbin:/usr/bin:${_localbase}/sbin:${_localbase}/bin
-
 # If possible, check the global system configuration file,
 # to see if there are additional dirs to check
 if [ -r /etc/defaults/periodic.conf ]; then
@@ -44,6 +36,10 @@ if [ -r /etc/defaults/periodic.conf ]; then
     source_periodic_confs
 fi
 
+# Use a deterministic path to match the preset from /etc/crontab in case
+# periodic is run interactively.
+export PATH=/sbin:/bin:/usr/sbin:/usr/bin:${_localbase}/sbin:${_localbase}/bin
+
 host=`hostname`
 export host