A simple bash script that will update a host's IP address using the ZoneEdit DNS management service. Currently using on *and only tested on* my RaspberryPi Raspbian Apache2 web server

update_dynamic_ip

#!/bin/bash

# This file is intended to be used to update a host's IP address
#   that uses the ZoneEdit DNS management service.
# This script uses dig to obtain the network's current public IP
#   address which means it should be executed on a machine running
#   on the same network as your server.

USERNAME=username
PASSWORD=password
HOST=examplehost.com
IP_ADDR="$(dig +short myip.opendns.com @resolver1.opendns.com)"
HTTP="https://dynamic.zoneedit.com/auth/dynamic.html?host=${HOST}&dnsto=${IP_ADDR}"

curl -u $USERNAME:$PASSWORD $HTTP

# To make this in to a cron job so this will run automatically,
#   open your crontab jobs file by running the following command:
#     sudo crontab -e
#   then input the following line at the bottom of the file and save changes.
#     */15 * * * * /path/to/update_ip.sh
#   Doing this will make this script execute every 15th
#   minute of every hour, keeping your domain up to date
#   with your dynamic IP address within 15 minutes.