Linux Blog

Automatically reconnecting to a host

Filed under: Shell Script Sundays — at 9:15 pm on Sunday, August 17, 2008

If you follow me on Twitter: then you may know that I regularly update a bunch of Linux PC’s and servers. Now, since I’m sort of lazy and don’t like manually doing anything I don’t have to I thought I’d post the one liner I use to automatically reconnect to a host.

while ! ping -W 1 -c 1 [hostname or IP] 2>&1 >/dev/null; do true; done && sleep 15; ssh [user]@[hostname or IP]

This script uses the ping command to ping the server once (-c 1) with the timeout of 1 second (-W 1) ping a host or IP with a timeout of one second. Once the ping loop is broken (ping returns true) I let it sleep for 15 seconds to enable SSH to come up. Then the inevitable happens. I use SSH to reconnect to the host.

There you have it, a quick way to reconnect to a host without typing the command or pressing the up arrow every time. Enjoy!