Change screen brightness for the terminal

dimm.sh

#! /usr/bin/env bash

# Sets brightness to parameter level [0, max_brightness]
# Default: 10_000

default=10000
brightness=${1:-$default}
max="$(cat /sys/class/backlight/*/max_brightness)"

if test "$brightness" -eq "$brightness" 2>/dev/null; then # numeric value
  if [ "$brightness" -gt "$max" ]; then
    brightness="$max"
  elif [ "$brightness" -lt 0 ]; then
    brightness=0
  fi
else
  brightness="$default"
fi

echo "Setting brightness to $brightness"
echo "$brightness" | sudo tee /sys/class/backlight/*/brightness >/dev/null