#!/bin/bash
input=$1
input=${input%\%}
re_num='^100$|(^[0-9]{1,2}$)' #100 nebo [0-9] jednou az dvakrat
[[ $input =~ $re_num ]] && val=$(($input*240)) || echo "NavN"
su -c "sudo brightnessctl s $val" bash >/dev/null
#echo "brightness set to $val"