OSX Version of a script to update IPv4 and IPv6 on http://dynv6.com

dynv6.sh

#!/bin/sh -e

##
## 03/03/2015 
## Updates IPv4 and IPv6 on DynV6.com on OSX
## https://gist.github.com/smj10j/6730d6136eb206e9b9bc
## Original at https://gist.github.com/corny/7a07f5ac901844bd20c9
##
## Example call: 
## token=<token> ./dynv6.sh <your dynv6 hostname>
## 
## Read more: http://dynv6.com/hosts/1401/instructions
##

hostname=$1
device=$2
file=$HOME/.dynv6.addr6
[ -e $file ] && old=`cat $file`

if [ -z "$hostname" -o -z "$token" ]; then
  echo "Usage: token=<your-authentication-token> [netmask=64] $0 your-name.dynv6.net [device]"
  exit 1
fi

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

if [ -z "$device" ]; then
  device="en0"
fi
address=$(ifconfig $device inet6 | grep -v " fd" | sed -n 's/.*inet6 \([0-9a-f:]\+\).*/\1/p' | head -n 1)

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

if [ -z "$address" ]; then
  echo "no ipv6 address found"
  exit 1
fi

# address with netmask
current=$address/$netmask

if [ "$old" = "$current" ]; then
  echo "ipv6 address unchanged"
  echo "sending anyway in case ipv4 has changed"
  # exit
fi

# send addresses to dynv6
$bin "http://dynv6.com/api/update?hostname=$hostname&ipv6=$current&ipv4=auto&token=$token"

# save current address
echo $current > $file

Stephen, doesn't work here. Line 32, I guess. Here, DHCPv6-PD.

mine neither for, apparently a different reason:

/dynv6.sh: line 18: [: /Volumes/Macintosh: binary operator expected