bright.py

#!/usr/bin/env python3

import subprocess
import sys
import re
from subprocess import Popen, PIPE, STDOUT

FILENAME = "/tmp/last_bright"
INC_ABS = 6

if len(sys.argv) < 2:
    print("usage: bright.py -u/-d")
    exit(-1)

if sys.argv[1] == "-u":
    inc = INC_ABS
elif sys.argv[1] == "-d":
    inc = -INC_ABS
else:
    print("usage: bright.py -u/-d")
    exit(-1)

try:
    with open(FILENAME, "r") as f:
        current_lvl = int(f.read())
except:
    current_lvl_str = subprocess.check_output(['ddcutil', '-d', '1', 'getvcp', '10']).decode()
    current_lvl = int(re.search(r'current value =\W+(\d+)', current_lvl_str).group(1))


next_lvl = current_lvl + inc

if next_lvl < 0:
    next_lvl = 0

Popen(['ddcutil', '-d', '1', 'setvcp', '10', str(next_lvl)], stdin=None, stdout=None, stderr=None, close_fds=True, shell=False)

with open(FILENAME, 'w') as f:
    f.write(str(next_lvl))