Toggle airport depending on wired network status. Works on Retina Macbooks using thunderbolt ethernet adapter (en3). Airport should be en0.

_toggle_macbook_wifi_when_ethernet_conected.md

1. sudo mv toggleAirport.sh /Library/Scripts/
2. sudo chmod 755 /Library/Scripts/toggleAirport.sh
3. sudo mv com.mine.toggleairport.plist /System/Library/LaunchAgents/
4. sudo chown root:wheel /System/Library/LaunchAgents/com.mine.toggleairport.plist
5. sudo launchctl load /System/Library/LaunchAgents/com.mine.toggleairport.plist

The script should run on startup and give you growl notifications when airport status is changed if you have GrowlNotify installed

Credit to www.georges.nu/blog/2011/06/how-to-automatically-turn-off-airport-when-ethernet-is-plugged-in/

com.mine.toggleairport.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.asb.toggleairport</string>
  <key>OnDemand</key>
  <true/>
  <key>ProgramArguments</key>
  <array>
    <string>/Library/Scripts/toggleAirport.sh</string>
  </array>
  <key>WatchPaths</key>
  <array>
    <string>/Library/Preferences/SystemConfiguration</string>
  </array>
</dict>
</plist>

toggleAirport.sh

#!/bin/bash

function set_airport {

    new_status=$1

    if [ $new_status = "On" ]; then
    /usr/sbin/networksetup -setairportpower en0 on
    touch /var/tmp/prev_air_on
    else
    /usr/sbin/networksetup -setairportpower en0 off
    if [ -f "/var/tmp/prev_air_on" ]; then
        rm /var/tmp/prev_air_on
    fi
    fi

}

function growl {

    # Checks whether Growl is installed
    if [ -f "/usr/local/bin/growlnotify" ]; then
    /usr/local/bin/growlnotify -m "$1" -a "AirPort Utility.app"
    fi

}

# Set default values
prev_eth_status="Off"
prev_air_status="Off"

eth_status="Off"

# Determine previous ethernet status
# If file prev_eth_on exists, ethernet was active last time we checked
if [ -f "/var/tmp/prev_eth_on" ]; then
    prev_eth_status="On"
fi

# Determine same for AirPort status
# File is prev_air_on
if [ -f "/var/tmp/prev_air_on" ]; then
    prev_air_status="On"
fi

# Check actual current ethernet status
if [ "`ifconfig en3 | grep \"status: active\"`" != "" ]; then
    eth_status="On"
fi

# And actual current AirPort status
air_status=`/usr/sbin/networksetup -getairportpower en0 | awk '{ print $4 }'`

# If any change has occured. Run external script (if it exists)
if [ "$prev_air_status" != "$air_status" ] || [ "$prev_eth_status" != "$eth_status" ]; then
    if [ -f "./statusChanged.sh" ]; then
    "./statusChanged.sh" "$eth_status" "$air_status" &
    fi
fi

# Determine whether ethernet status changed
if [ "$prev_eth_status" != "$eth_status" ]; then

    if [ "$eth_status" = "On" ]; then
    set_airport "Off"
    growl "Wired network detected. Turning AirPort off."
    else
    set_airport "On"
    growl "No wired network detected. Turning AirPort on."
    fi

# If ethernet did not change
else

    # Check whether AirPort status changed
    # If so it was done manually by user
    if [ "$prev_air_status" != "$air_status" ]; then
    set_airport $air_status

    if [ "$air_status" = "On" ]; then
        growl "AirPort manually turned on."
    else
        growl "AirPort manually turned off."
    fi

    fi

fi

# Update ethernet status
if [ "$eth_status" == "On" ]; then
    touch /var/tmp/prev_eth_on
else
    if [ -f "/var/tmp/prev_eth_on" ]; then
    rm /var/tmp/prev_eth_on
    fi
fi

exit 0