home/bin/monitor-brightness

   1 #! /bin/bash
   2
   3 max() {
   4     if [[ "$1" -gt "$2" ]]; then echo "$1"; else echo "$2"; fi
   5 }
   6
   7 min() {
   8     if [[ "$1" -lt "$2" ]]; then echo "$1"; else echo "$2"; fi
   9 }
  10
  11 _get() {
  12     sudo ddcutil getvcp 10 | grep -o ' current value = \+[0-9]\+' | awk '{print $4}'
  13 }
  14
  15 _set() {
  16     sudo ddcutil setvcp 10 "$1"
  17 }
  18
  19 args="$*"
  20
  21 case "$args" in
  22     '') _get;;
  23     i | inc | increase) _set "$(min $(( $(_get) + 5)) 100)";;
  24     d | dec | decrease) _set "$(max $(( $(_get) - 5)) 0)";;
  25     *)
  26         if [[ "$args" =~ ^[0-9]+$ && "$args" -gt -1 && "$args" -lt 101 ]]; then
  27             _set "$args"
  28         else
  29             printf 'Error: expected a numeric argument between 0 and 100, but given "%s"\n' "$args" >&2
  30             exit 1
  31         fi
  32 esac