Ok, it’s not a full location detection as such.. I use my laptop (Ubuntu 9.04) both at home and work, as well as other places.  The problem that I had was related to how SAMBA was configured.  At home I have one workgroup name and at work I want the machine to appear in the company domain.  But also, while out and about in the big bad world I don’t want SAMBA on at all, no need to share anything with anyone.

So, to over come this and correct it at boot time I’ve come up with the simple script below.  The only other thing you need to do is prepare a couple of smb.conf files to suit the locations you’ll be in.   I have 2 smb.conf files, one for HOME and one for WORK.   I run the script from /etc/rc.local so it runs when I should have networking fully up and running. 

Here is the script:

#!/bin/bash

HOME=YOUR_HOME_GW_IP

WORK=YOUR_WORK_GW_IP

GW=`route -n | grep ^0.0.0.0| awk '{print $2}'`

if [ $GW = $WORK ]; then

    #echo "You're at work"

    cp /etc/samba/smb.conf.WORK /etc/samba/smb.conf

    /etc/init.d/samba restart

elif [ $GW = $HOME ]; then

    #echo "You're at home"

    cp /etc/samba/smb.conf.HOME /etc/samba/smb.conf

    /etc/init.d/samba restart

else

    #echo "You're somewhere else"

    /etc/init.d/samba stop

fi

Pretty simple really.  Hope others will find it useful.