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

README.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.

Minimal changes to the script itself and addition of an install script by Jake Ireland, with suggestions from the community and with help from ShellCheck.

Requirements

• Mac OSX 10+
• Administrator privileges

Installation Instructions

Run

bash <(wget -q -O - "$(wget -q -O - 'https://gist.github.com/jakewilliami/b03e6eb61ce6a583860fd43a8befd3f9' | grep -E 'init.sh.*Raw' | awk -F'"' '{ print "https://gist.github.com/" $4 }')")

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

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>

init.sh

#! /bin/bash

case $EUID in
   *)  : ;; # not root so we are okay
   0)  echo -e "\u001b[1;31mYou are running this script as sudo; exiting.\u001b[0;38m" && exit 1 ;; # we are running script as root so we need to exit (otherwise the script will not show notifications)
esac

TEMP_DIR="/tmp/eth-init/"
SCRIPTS_DIR="/Library/Scripts/"
PLIST_DIR="/Library/LaunchAgents/"

notify_user() {
  echo -e "\u001b[1;34m===>\u001b[0;38m\t\u001b[1;38m${1}\u001b[0;38m"
}

mkdir -p "${TEMP_DIR}"

notify_user "Downloading script and property list files from GitHub."

cd "${TEMP_DIR}"
sudo wget 'https://gist.github.com/jakewilliami/b03e6eb61ce6a583860fd43a8befd3f9/raw/11d0be5033c30e8a0aeb4576a563a7b527857be3/toggleAirport.sh'
sudo wget 'https://gist.github.com/albertbori/1798d88a93175b9da00b/raw/21794addaf65ba3beae0600009c85ca072f6c335/com.mine.toggleairport.plist'

notify_user "Copying files to the appropriate directories in your root's Library."

sudo cp ./toggleAirport.sh "${SCRIPTS_DIR}"
sudo cp ./com.mine.toggleairport.plist "${PLIST_DIR}"

cd - > /dev/null

notify_user "Making these files executable for your user."

sudo chmod u+x "${SCRIPTS_DIR}"/toggleAirport.sh
sudo chown root "${PLIST_DIR}"/com.mine.toggleairport.plist
sudo chmod 644 "${PLIST_DIR}"/com.mine.toggleairport.plist

notify_user "Launching script daemon."

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

notify_user "Should be all up and running now :)"

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 command -v growlnotify; then
        growlnotify -m "$1" -a "AirPort Utility.app"
    else
        osascript -e "display notification \"$1\" with title \"WiFi Toggle\""
    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 's|^\(Hardware Port: .*(Slot 1\|Ethernet\|LAN).*, Device: (en.+)\)$|\2|p')
air_name=$(networksetup -listnetworkserviceorder | sed -En 's/^\(Hardware Port: (Wi-Fi|AirPort), Device: (en.)\)$/\2/p')

# 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