#!/bin/sh

convert_to_human_readable() {
	if [ "$1" -lt 1024 ]; then
		printf "%.1fK\n" "$1"
	elif [ "$1" -lt 1048576 ]; then
		printf "%.1fM\n" $(($1 / 1024))
	else
		printf "%.1fG\n" $(($1 / 1048576))
	fi
}

while read -r label size _; do
	case $label in
	MemTotal:) total_mem=$size ;;
	MemAvailable:) free_mem=$size ;;
	esac
done </proc/meminfo
used_mem=$((total_mem - free_mem))

printf '%s (%s%%)\n' "$(convert_to_human_readable "$used_mem")" $((used_mem * 100 / total_mem))