dynv6-osx.sh

#!/bin/sh -e
# based on https://gist.github.com/corny/7a07f5ac901844bd20c9
# updates the (public) IPv6 address and the (local?) IPv4 address

# cp ./dynv6.sh /usr/local/bin/
# chmod +x /usr/local/bin/dynv6.sh
# sudo touch /var/log/dynv6
# sudo chown $USER /var/log/dynv6
#
# ADD A CRONJOB (crontab -e)
# optional: add '   MAILTO=""   ' to crontab if you whish no eMail alert
# @reboot /usr/local/bin/dynv6.sh <public_dns> <token> [device] >/var/log/dynv6 2>&1
# */20 * * * * /usr/local/bin/dynv6.sh <public_dns> <token>  [device] >/var/log/dynv6 2>&1

PATH=/usr/local/bin:/usr/local/sbin:~/bin:/usr/bin:/bin:/usr/sbin:/sbin
hostname=$1
token=$2
device=$3
dynv6Path=$HOME/.dynv6
mkdir -p $dynv6Path
file6=$dynv6Path/addr6
file4=$dynv6Path/addr4

[ -e $file6 ] && old6=`cat $file6`
[ -e $file4 ] && old4=`cat $file4`

if [ -z "$hostname" -o -z "$token" ]; then
  echo "Usage:  $0 <your-name.dynv6.net> <your-authentication-token> [device]"
  exit 1
fi

if [ -z "$netmask" ]; then
  netmask=128
fi

address6=$(ifconfig $device | grep inet6 | awk -F " " '{print $2}'|tail -n 1)
address4=$(ifconfig $device | grep inet | awk -F " " '{print $2}'|tail -n 1)

if [ -e /usr/bin/curl ]; then
  bin="curl -fsS"
elif [ -e /usr/bin/wget ]; then
  bin="wget -O-"
else
  echo "$(date): neither curl nor wget found"
  exit 1
fi

if [ -z "$address6" ]; then
  echo "$(date): no IPv6 address found"
  exit 1
fi

# address with netmask
current6=$address6/$netmask
current4=$address4

if [ "$old6" = "$current6" ]; then
  echo "$(date): IPv6 address unchanged: $current6"
else
  $bin "http://dynv6.com/api/update?hostname=$hostname&ipv6=$current6&token=$token"
  echo "$(date): New IPv6 address: $current6"
fi

if [ "$old4" = "$current4" ]; then
  echo "$(date): IPv4 address unchanged: $current4"
 else
  $bin "http://ipv4.dynv6.com/api/update?hostname=$hostname&ipv4=$current4&token=$token"
  echo "$(date): New IPv4 address: $current4"
fi

# save current address
echo $current6 > $file6
echo $current4 > $file4