Automatically disable Wifi when an Ethernet connection (cable) is plugged in on a Mac

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>

Installation.md

Overview

This is a bash script that will automatically turn your wifi off if you connect your computer to an ethernet connection and turn wifi back on when you unplug your ethernet cable/adapter. If you decide to turn wifi on for whatever reason, it will remember that choice. This was improvised from this mac hint to work with Yosemite, and without hard-coding the adapter names. It's supposed to support growl, but I didn't check that part. I did, however, add OSX notification center support. Feel free to fork and fix any issues you encounter.

Most the credit for these changes go to Dave Holland.

This script was initially developed by Albert Bori. It was forked by Gary Mayden who added an automatic install script and modified the ethernet_names sed regular expression

My contribution is generalizing the ethernet_names sed regular expression to return any device that natches the pattern 'en.' and to handle the existence of duplicate Wi-Fi interfaces on the same device.

Requirements

• Mac OSX 10+
• Administrator privileges

Automated Installation Instructions ( per Gary Mayden )

• Copy installToggle.sh to a suitable local location such as (i.e. /tmp)
• Run sudo installToggle.sh

Manual Installation Instructions

• Copy toggleAirport.sh to /Library/Scripts/
• Run chmod 755 /Library/Scripts/toggleAirport.sh
• Copy com.mine.toggleairport.plist to /Library/LaunchAgents/
• Run chmod 600 /Library/LaunchAgents/com.mine.toggleairport.plist
• Run sudo launchctl load /Library/LaunchAgents/com.mine.toggleairport.plist to start the watcher

Uninstall Instructions

• Run sudo launchctl unload /Library/LaunchAgents/com.mine.toggleairport.plist to stop the watcher
• Delete /Library/Scripts/toggleAirport.sh
• Delete /Library/LaunchAgents/com.mine.toggleairport.plist
• Delete /private/var/tmp/prev_eth_on
• Delete /private/var/tmp/prev_air_on

Misc

To debug, just run: sudo /Library/Scripts/toggleAirport.sh and add echo's wherever you'd like

Bug

I do not receive an Apple Notification when a change is made. I suspect this is because the script is executed by the super-user and not as the logged in user. When I run the script sudoed to root (sudo -i), I do receive the notification. I am guessing that this is because of root being my effective UID while my login account is the actual UID. I do not have time at the present to investigate.

installToggle.sh

#!/bin/bash

sudo curl -o /Library/Scripts/toggleAirport.sh https://gist.githubusercontent.com/lbe/a0fd13b617c34bb1da08fe8e6d32638d/raw/e93b8b9a676e71ba4c6f3d2086024ca39068e13a/toggleAirport.sh
#https://gist.githubusercontent.com/gary-mayden/ebb6a64918009c88cb61/raw/53bf350f0f83dcd67ae320d4fa9a325d5b3b2354/toggleAirport.sh
sudo curl -o /Library/LaunchAgents/com.mine.toggleairport.plist https://gist.githubusercontent.com/lbe/a0fd13b617c34bb1da08fe8e6d32638d/raw/e93b8b9a676e71ba4c6f3d2086024ca39068e13a/com.mine.toggleairport.plist
#https://gist.githubusercontent.com/gary-mayden/ebb6a64918009c88cb61/raw/2af10cd69a5192366202e9df477fb356b8e2ea19/com.mine.toggleairport.plist

sudo chmod 755 /Library/Scripts/toggleAirport.sh
sudo chmod 600 /Library/LaunchAgents/com.mine.toggleairport.plist

sudo rm -R /var/tmp/prev_*

sudo launchctl load /Library/LaunchAgents/com.mine.toggleairport.plist

toggleAirport.sh

#!/bin/bash

function set_airport {

    new_status=$1

    if [ $new_status = "On" ]; then
        /usr/sbin/networksetup -setairportpower $air_name on
        touch /var/tmp/prev_air_on
    else
        /usr/sbin/networksetup -setairportpower $air_name 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"
    else
        osascript -e "display notification \"$1\" with title \"Wifi Toggle\" sound name \"Hero\""
    fi

}

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

# Grab the names of the adapters. We assume here that any ethernet connection name ends in "Ethernet"
eth_names=`networksetup -listnetworkserviceorder | sed -En '/Wi-Fi/! s/^\(Hardware Port: .*Device: (en.)\)$/\1/p'`
air_name=`networksetup -listnetworkserviceorder | sed -En 's/^\(Hardware Port: (Wi-Fi|AirPort), Device: (en.)\)$/\2/p' | sort -u`

# 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
for eth_name in ${eth_names}; do
    if ([ "$eth_name" != "" ] && [ "`ifconfig $eth_name | grep "status: active"`" != "" ]); then
        eth_status="On"
    fi
done

# And actual current AirPort status
air_status=`/usr/sbin/networksetup -getairportpower $air_name | 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