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

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.

I got an error when following these instructions. macOS Sonoma, M1 MacBook Air.

Warning: Expecting a LaunchDaemons path since the command was ran as root. Got LaunchAgents instead.
launchctl bootstrap is a recommended alternative.
Load failed: 5: Input/output error
Try running launchctl bootstrap as root for richer errors.

The script is written and tested running as the normal user (not root).

I am running it as normal user

The warning message you posted suggests otherwise?

Warning: Expecting a LaunchDaemons path since the command was ran as root.

Well I’m definitely not logged in as root… I guess ill investage that side of thing

I had the same experiences.

Not sure what's going on sorry. The error message indicates that macOS thinks you are running the command as root.

Can you show me the entire terminal session and exactly how you are installing it?

I got an error when following these instructions. macOS Sonoma, M1 MacBook Air.

Warning: Expecting a LaunchDaemons path since the command was ran as root. Got LaunchAgents instead. launchctl bootstrap is a recommended alternative. Load failed: 5: Input/output error Try running launchctl bootstrap as root for richer errors.

I just got a similar thing on Sequoia, @adamshand

/wifi-toggle.sh: line 53: /Users/john/Library/LaunchAgents/nz.haume.wifi-toggle.plist: Permission denied
Enabling launchd service: nz.haume.wifi-toggle
Bootstrap failed: 5: Input/output error
Try re-running the command as root for richer errors.
john@Johns-M1 Downloads % chmod +x wifi-toggle.sh 
john@Johns-M1 Downloads % ./wifi-toggle.sh on    
DEBUG: is_launchd_loaded(): nz.haume.wifi-toggle not loaded
Creating launchd service: /Users/john/Library/LaunchAgents/nz.haume.wifi-toggle.plist
./wifi-toggle.sh: line 53: /Users/john/Library/LaunchAgents/nz.haume.wifi-toggle.plist: Permission denied
Enabling launchd service: nz.haume.wifi-toggle
Bootstrap failed: 5: Input/output error
Try re-running the command as root for richer errors.

It's not working because you don't have permission to write to the LaunchAgents directory;

/wifi-toggle.sh: line 53: /Users/john/Library/LaunchAgents/nz.haume.wifi-toggle.plist: Permission denied

It's not working because you don't have permission to write to the LaunchAgents directory;

/wifi-toggle.sh: line 53: /Users/john/Library/LaunchAgents/nz.haume.wifi-toggle.plist: Permission denied

Yep - that did it. Now to see if this handled the move to Sequoia. Will let you know.

Thanks!

Works. For my case, I had to tweak the regex as follows to account for differences in naming:

eth_names=`networksetup -listnetworkserviceorder | sed -En 's|^\(Hardware Port: .*Ethernet.*, Device: (en.+)\)$|\1|p'`

. This is my network list:

% networksetup -listnetworkserviceorder
An asterisk (*) denotes that a network service is disabled.
(1) Thunderbolt Ethernet Slot 0
(Hardware Port: Thunderbolt Ethernet Slot 1, Device: en10)

(2) Thunderbolt Ethernet Slot 1
(Hardware Port: Thunderbolt Ethernet Slot 1, Device: en12)

(3) USB 10/100/1G/2.5G LAN
(Hardware Port: USB 10/100/1G/2.5G LAN, Device: en8)

(4) Thunderbolt Bridge
(Hardware Port: Thunderbolt Bridge, Device: bridge0)

(5) Targus USB3 DV4K DOCK w PD60W
(Hardware Port: Targus USB3 DV4K DOCK w PD60W, Device: en7)

(6) USB 10/100/1000 LAN
(Hardware Port: USB 10/100/1000 LAN, Device: en6)

(7) Wi-Fi
(Hardware Port: Wi-Fi, Device: en0)

.