WiFiOrEth.sh

#!/bin/sh

#Verify your interfaces using "ifconfig" and disconnecting/reconnecting WiFi and Ethernet to find out which is which
# Works in mountain lion. Might need changes in DETECT_INET in other versions

# Default sound name "PC 3270 Beep" doesn't exist in standard installs. Sound name should be the file name,
# without extension, of .aif file placed in either /System/Library/Sounds or ~/Library/Sounds
# In this case I have /Users/eduo/Library/Sounds/PC 3270 Beep.aiff so name is "PC 3270B Beep"

# Remember to set permissions to execute on this script: chmod 755 WiFiOrEth.sh

ENET_INTERFACE="en2"
WLAN_INTERFACE="en0"
DETECT_ENET=$(ifconfig $ENET_INTERFACE 2>/dev/null| grep "status:" | tr -d '\t' | cut -d ' ' -f2 | tr -d '\n')
DETECT_WLAN=$(ifconfig $WLAN_INTERFACE 2>/dev/null| grep "status:" | tr -d '\t' | cut -d ' ' -f2 | tr -d '\n')

TITLE="Airport status changed"
SUBTITLE="${0}"
NOTIF="Airport as been modified due to Ethernet Status"

if [ "$DETECT_ENET" = "active" ] ; then
        /usr/sbin/networksetup -setairportpower $WLAN_INTERFACE off
        echo "$0 - Wired ethernet detected, turning off Airport."
TITLE="Airport Off"
NOTIF="Ethernet detected, Airport has been turned off"
osascript -e 'display notification "'"${NOTIF}"'" with title "'"${TITLE}"'" subtitle "'"${SUBTITLE}"'" sound name "PC 3270 Beep"'
        exit 0
elif [ "$DETECT_WLAN" = "inactive" ] ; then
        /usr/sbin/networksetup -setairportpower $WLAN_INTERFACE on
        echo "$0 - No wired ethernet, turning on Airport."
TITLE="Airport On"
NOTIF="Ethernet disconnected, Airport has been turned on"
osascript -e 'display notification "'"${NOTIF}"'" with title "'"${TITLE}"'" subtitle "'"${SUBTITLE}"'" sound name "PC 3270 Beep"'
        exit 1
fi