show the battery pct & whether charging in ps1

laptop_battery_ps1.bash

function get_bat_msg() {
    BAT_PCT=$(cat /sys/class/power_supply/BAT1/capacity);
    if [ $BAT_PCT -le 40 ]; then
        BAT_PCT_COLOUR=31
    elif [ $BAT_PCT -le 80 ]; then
        BAT_PCT_COLOUR=93
    else
        BAT_PCT_COLOUR=32;
    fi;
    if [[ "$(cat /sys/class/power_supply/BAT1/status)" == "Discharging" ]]; then
        BAT_STATE="Battery"
        BAT_STATE_COLOUR=37
    else
        BAT_STATE="Powered"
        BAT_STATE_COLOUR=35
    fi;
    BAT_PCT_MSG="\e[38;5;${BAT_PCT_COLOUR}m${BAT_PCT}\e[0m%"
    BAT_STATE_MSG="\e[38;5;${BAT_STATE_COLOUR}m$BAT_STATE\e[0m"

    echo -e "($BAT_PCT_MSG [$BAT_STATE_MSG])"
}

PS1="\$(get_bat_msg) $PS1"