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.

Requirements

• Mac OSX 10+
• Administrator privileges

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

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 's|^\(Hardware Port: .*Ethernet, Device: (en.)\)$|\1|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

i recommend this repo, which seems to have been inspired by this gist: https://github.com/Calvin-LL/toggleairport
I can confirm it works ok on Sonoma.
Great work, many thanks!

Thanks to this thread for the ideas. I've just created a new version of this in case anyone is interested. Tested on macOS 14.3.

Download and save in your path as wifi-toggle.sh (any name will work).

You need to open the script and change the ETHERNET_REGEX variable to match the name of your ethernet device. You can find the name of your device by running networksetup -listnetworkserviceorder. Your ethernet device name is the text after number in parenthesis (eg. (2) CalDigit TS3).

Run wifi-toggle.sh on and it will install a launchd service in ~/Library/LaunchAgents.

Now ...

• If your ethernet is active, your wifi will automatically turn off
• If your ethernet is inactive, your wifi will automatically turn on.

If you want to stop the automatic toggle, run wifi-toggle.sh off.

❯ wifi-toggle.sh help
Automatically toggle macOS Wi-Fi based on ethernet status (uses launchd)

Usage: wifi-toggle.sh [ on | off | help ]
   on - start automatically toggling Wi-Fi (install launchd service)
  off - stop automatically toggling Wi-Fi (uninstall launchd service)
  run - Toggle Wi-Fi status (run by launchd)

Thanks @adamshand , that worked perfectly on MacOS 14.3.1. I love that it waits until both the ethernet AND the wifi is up. It's been bugging me for ages that sometimes the network doesn't switch properly, and this solves it!

Fantastic combined effort, love gists sometimes, was really hoping I didn't have to kludge with grep matching interfaces today :).

Nice, glad it's working!

@adamshand I will give it a try and have no doubt it will work. In that case, I think it deserves it proper repo or own page :-)

@adamshand , what is the recommended path to put this script in? Certainly when using an MDM? What is your experience?

@kMikaZu doesn't really matter where you put it. I put it in ~/bin/noarch on my laptop, if I was deploying via MDM I'd probably use /usr/local/bin.

I used the original script and I get the following errors:

DEBUG: is_launchd_loaded(): nz.haume.wifi-toggle not loaded
Creating launchd service: /var/root/Library/LaunchAgents/nz.haume.wifi-toggle.plist
/usr/local/bin/wifitoggle-original.sh: line 53: /var/root/Library/LaunchAgents/nz.haume.wifi-toggle.plist: No such file or directory
Enabling launchd service: nz.haume.wifi-toggle
Bootstrap failed: 125: Domain does not support specified action

Script is installed via Kandji with a Post Install script. The Bootstrap failed: 125 error has something to do with the fact that is has to be run as the current user. I tried some things but no luck so far.

I don't know anything about Kandji sorry, I can help with that.

However it looks like you are installing it as root. I haven't tested that at all, it's designed to be installed by a normal user account.

You have experience with adapting the code so it runs as the current user?

The script is written and tested running as the normal user (not root). If you follow the instructions and install the script as normal user, it should (hopefully) work as intended. If you want it to run as root or to be installed by MDM you will need to test that and possibly make changes to the code.