I wanted to turn off/disable my Wi-Fi adapter when I plug in an Ethernet cable.
Add this script as /etc/NetworkManager/dispatcher.d/99-disable-wifi-when-ethernet-connected.sh grant it executable permissions.
#!/bin/sh
myname=${0##*/}
log() { logger -p user.info -t "${myname}[$$]" "$*"; }
IFACE=$1
ACTION=$2
release=$(lsb_release -s -c)
case ${release} in
trusty | utopic) nmobj=nm ;;
*) nmobj=radio ;;
esac
case ${IFACE} in
eth* | usb* | en*)
case ${ACTION} in
up)
log "disabling wifi radio"
nmcli "${nmobj}" wifi off
;;
down)
log "enabling wifi radio"
nmcli "${nmobj}" wifi on
;;
esac
;;
esac
References
https://askubuntu.com/questions/112968/automatically-disable-wifi-wireless-when-wired#112969
