OpenVPN connect with DNS configuration

#!/bin/sh -e

script_dir="`dirname $0`"
vpnconfig="client.conf"
vpnlog="openvpn.log"
vpnpidfile="openvpn.pid"
vpnconnecttime="5" # seconds
vpnresolvconf="resolv.conf"
systemresolvconf="/etc/resolv.conf"

if ! cd $script_dir ; then
    echo "Cannot cd to $script_dir." 1>&2
    exit 1
fi

sudo echo "Launching OpenVPN..."

sudo openvpn $vpnconfig > $vpnlog &

sleep 1 # wait for sudo to launch command

vpnpid=$(ps --ppid $! -o pid=)

echo $vpnpid > $vpnpidfile

sleep $vpnconnecttime

sudo cp $vpnresolvconf $systemresolvconf