Updated 2013-03-16
Script stopped working due to changes in
html2text this was resolved by adding
curl as a dependency.
For my DSL line I get a dynamic IP address. On the inside it's quite easy to find out what the external IP is, but on the outside damn near impossible to find out what the IP might have changed to.
To get around that problem I wrote a little script that checks the external IP and sends me an e-mail if there has been any changes.
Dependencies:
curl, html2text and ssmtp.
Source formatted by
formatmysourcecode.blogspot.com and available for download on
github here.
# /bin/sh
# ipquery.sh
# IP checker and updater by Markus Ulfberg 2009-05-12
# Variables
# Path where ip.txt resides or will be created if it doesen't exist already
DIR=youdirhere
# E-mail address, both from and to
ADDRESS=your@emailadress.here
# E-mail Subject
SUBJECT="New IP number"
# Check for ip.txt and create if it doesn't exist.
if [ ! -s $DIR/ip.txt ]
then
# Create ip.txt
echo "ip.txt doesn't exist. Creating ip.txt ..."
echo "0.0.0.0" > $DIR/ip.txt
else
echo "ip.txt exists. Continuing ..."
fi
# Get current IP
currentIP=`curl http://checkip.dyndns.org | html2text | grep Current | awk '{print$4}'`
echo "Current IP: $IP"
# Read old IP from file
oldIP=`cat $DIR/ip.txt`
echo "Old IP: $oldIP"
# Compare current and old IP
if [ $oldIP != $currentIP ]
then
echo "IP has changed to: $currentIP"
# Write new IP to ip.txt
echo $currentIP > $DIR/ip.txt
# Set e-mail content to new IP
CONTENT=$currentIP
# Send the e-mail notification
echo -e "FROM:$ADDRESS\nTO:$ADDRESS\nSUBJECT:$SUBJECT\nContent-type:text/plain\n$CONTENT\n" | `/usr/sbin/ssmtp $ADDRESS`
else
echo "IP is still: $currentIP"
fi
exit 0
