bluetooth_battery_status.sh

#!/bin/bash

#SCRIPTS_DIR=~/src/scripts

get_battery_status() {
	device_uuid=$1
	device_uuid_slug=$(echo "$device_uuid" | sed 's/:/_/g')
	device_upower_path=$(upower -e | grep "$device_uuid_slug")
	if [[ "$?" != 0 ]]; then
		return 1
	fi

	upower_out=$(upower -i "$device_upower_path")
	percentage=$(echo "$upower_out" | grep 'percentage:' | grep -oe '[0-9]*%')
	if [[ "$?" != 0 ]]; then
		return 1
	fi

	echo $percentage
}

# prepare devices to process
connected_devices=$1
if [[ "$connected_devices" == "" ]]; then
	connected_devices=$(bluetoothctl devices Connected | cut -f2 -d' ' | while read uuid; do bluetoothctl info $uuid | grep -B8 -e 'Connected: yes' | grep 'Device' | cut -f2 -d' '; done)
fi
if [[ "$connected_devices" == "" ]]; then
	echo "no bluetooth devices connected" >&2
	exit 1
fi

n=0
declare -A device_batteries
for device in ${connected_devices//\\n/ }; do
	device_battery_percentage=$(get_battery_status "$device")
	if [[ $? != 0 ]]; then
		continue
	fi

	n=$((n + 1))
	device_batteries[$device]=$device_battery_percentage
	# echo "$device: $device_battery_percentage"
done

if [[ $n -eq 0 ]]; then
	echo "cannot get battery status for any specified bluetooth device" >&2
	exit 1
fi

# TODO: do something else?
for device in ${!device_batteries[*]}; do
	echo "$device ${device_batteries[$device]}"
done