A shell script to check the current AirPort/Wi-Fi SSID and take actions depending on which SSID it finds.
The airport command can be found at
/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport
It has been there at least since 10.6 and the syntax (AFAIK) has not changed.
I do this as part of my initial setup of a new Mac:
cd /usr/local/bin
ln -s /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport .
That way I have the airport command in my $PATH and if Apple updates it, I will still be using the current version.
At its core, this script is really built around one line:
airport -I | awk -F': ' '/ SSID/{print $NF}'
That will show you the current SSID that you are connected to. If you are not connected to any AirPort/Wi-Fi networks, it will not show anything.
If you want to be able to determine whether or not the AirPort card is turned off, use this:
airport -I | egrep 'AirPort: Off|^ *SSID: ' | sed 's#^ *SSID: ##g'
If you get an SSID of
AirPort: Off
then you know that it is off.
If you need to turn the AirPort card on, you can do that with this:
networksetup -setairportpower enX on
where "X" is probably either 0 or 1. You can probably find out by:
Hacky-but-shorter way:
networksetup -setairportpower enX off 2>&1 |\
awk -F' ' '/:/{print $NF}'
Cleaner way:
networksetup -listnetworkserviceorder |\
awk -F' ' '/(Wi-Fi|AirPort)/{print $NF}' |\
awk -F')' '/^en/{print $1}'