Managing unbound variables

scripts/lfirewall

@@ -18,6 +18,8 @@
 # description: Activates/Deactivates the firewall at boot time
 #
 
+set -euo pipefail
+
 PATH=/bin:/sbin:/usr/bin:/usr/sbin
 
 #Defautl network interface
@@ -41,7 +43,9 @@ SSH_PORT="22"
 
 CONFIGURATION_FILE=/etc/lfirewall/lfirewall.conf
 if [ -f $CONFIGURATION_FILE ] ; then
+	set +u
 	. $CONFIGURATION_FILE
+	set -u
 fi
 
 IP_TABLES="/sbin/iptables"
@@ -126,7 +130,7 @@ fw_start () {
 		done
 	fi
 	# Remote management
-	if [ -n "$NETWORK_MGMT" ] ; then
+	if [ "${NETWORK_MGMT:=UNBOUND_VARIABLE}" != "UNBOUND_VARIABLE" ] ; then
 		$do_action $IPTABLES_ADD INPUT -p tcp --src ${NETWORK_MGMT} --dport ${SSH_PORT} -j ACCEPT
 	else
 		$do_action $IPTABLES_ADD INPUT -p tcp --dport ${SSH_PORT}  -j ACCEPT