checking I'm at home and online

Just for my own reference, and in case anyone else wants to do this:

I have jobs on my laptop that I want to run at home, but not automatically on someone else's network (might be bandwidth intensive, for instance). I also wanted the script to notify me that it's started running.

I have them in a bash script that I can run manually with ./script.bash or in a cron job as /path/to/script.bash cron

Within the scripts, the relevant lines are:

test "$1" != "cron" || (/sbin/iwconfig wlan1 | grep 'ESSID:"PSEUDOMONAS_ESSID"') || exit
DISPLAY=:0.0 XAUTHORITY=~/.Xauthority notify-send "Notification" "Starting jobs"

I had to fiddle and web-search a bit to work out how to get things working. /sbin/ not being in path for cron jobs was a bit of a gotcha. I run Xubuntu 11.04 FWIW.