-cat >$d1/tinc-up <<EOF
-#!/bin/sh
-ip netns add ping.test1
-ip link set dev \$INTERFACE netns ping.test1
-ip netns exec ping.test1 ip addr add 192.168.1.1/24 dev \$INTERFACE
-ip netns exec ping.test1 ip link set \$INTERFACE up
-EOF
+# shellcheck disable=SC2016
+create_script foo tinc-up "
+ ip link set dev \$INTERFACE netns ping.test1
+ ip netns exec ping.test1 ip addr add $ip_foo/$mask dev \$INTERFACE
+ ip netns exec ping.test1 ip link set \$INTERFACE up
+"