This handy tool is a way to send an IP or Domain name from a remote site
when needing to set-up a VPN or SSH session to a network that doesn't
have a www address. This often happens when the target is connected
through an ISP with a dynamic IP address.
The target network is running a (SUSE) Linux box on their network, which
can be primarily MS windows or something, has someway of sending an
email from the command line, and optionally uses a cron table.
(see HowTo: Using the cron shell tool to automate procedures - Part 2 of 3 on how to
As the Linux box that grabs, processes and sends this information does
little else, I use the sleep option and run it continuously in the
background. It starts from rc.local, so will send an IP address as soon
as the network and its Internet connection comes online.
If you want to use it from crontab, leave out the while loop and sleep,
and export OLDIP so sendip.sh can compare it next time it runs. If
security is an issue, encrypt $NEWIP before sending it with mutt.
This shell script sends a line like 220.127.116.11 and
only sends another if it has changed after the sleep period.