Plays an audio file when power is connected

power.sh

#!/bin/bash

# Please supply your own audio file...

audiofile="$1"

if [[ ! -f "$audiofile" ]]
then
    echo "USAGE: $(basename ${0}) audio_file"
    exit 1
fi

function getPowerState {
    pmset -g | grep "*" | grep AC
}

last=$(getPowerState)

while true
do
    next=$(getPowerState)

    if [[ -z "$last" && -n "$next" ]]
    then
    afplay $audiofile
    fi

    sleep 2
    last="$next"
done