config file option

he-ddns

@@ -13,10 +13,11 @@ Update Hurricane Electric Dynamic DNS for DOMAIN with key in KEYFILE.
 Requires curl to be installed in \$PATH.
 
 Options:
+  -c, --config FILE     get configuration from FILE instead of $config
   -4, --ipv4            use IPv4
   -6, --ipv6            use IPv6
-  -u, --url     url to use, defaults to $url
-  -h, --help    Display this help.
+  -u, --url URL         update dns at URL instead of $url
+  -h, --help            Display this help
 
 https://gitlab.com/rascul/he-ddns
 "
@@ -28,9 +29,18 @@ show_help() {
 args=
 ipv4=
 ipv6=
+config=/etc/he-ddnsrc
 
 while (($#)); do
 	case $1 in
+		-c|--config)
+			if [[ -n "$2" ]]; then
+				config="$2"
+				shift
+			else
+				die $LINENO "$help_text"
+			fi
+			;;
 		-4)
 			ipv4=true
 			;;