backlight.sh

#!/bin/bash

# backlight brightness controls. use freely
# and adjust sysfs directory if not on intel
# $author  praveen reddy gorla


#!/bin/bash
# backlight brightness controls. use freely
# and adjust sysfs directory if not on intel


#copyright (c) 2016 Author(s): Gorla Praven <gorlapraveen@gmail.com>
#This program is free software: you can redistribute it and/or modify
#it under the terms of the GNU General Public License as published by
#the Free Software Foundation, either version 3 of the License, or (at your option) any later version.This program is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#GNU General Public License for more details.
#You should have received a copy of the GNU General Public License  along with this program.  If not, see <https://www.gnu.org/licenses/>.
    

sysfs="/sys/class/backlight/intel_backlight"
max="$(cat ${sysfs}/max_brightness)"
level="$(cat ${sysfs}/brightness)"


usage()
{
script=${0##*/}
echo
echo "Invalid usage of ${script}!"
echo "  $1"
echo " "
echo "------- Hello $USER, use the folowing to control the brightness level --------"
echo "=============================================================================="
echo "run                : backlight [commands] [options] "
echo " "
echo "[command]"
echo "$script current    : Shows present brightness level with a max brightness level of  $max "
echo "$script increase   : increases brightness"
echo "$script decrease   : decreases brightness"
echo "$script set        : sets brightness to an Integer "
echo "$script nightmmode : Nightmode"
echo "$script daymode    : Daymode"
echo " "
echo "[options]          : input integers form 1 to $max"
echo "============================================================================="
echo "Example usage      :'backlight increase' to increase brightness by one level"
echo "Example usage      :'backlight set 300' to set brightness level to 300 in range of 1 to $max"
echo "-------------------------------------Try Again-------------------------------"


exit 1
}

set_brightness()
{

level="$1"

if [ "$level" -lt 1 ] ; then
 level=1
echo minimum  brightness level is $level
elif [ "$level" -gt "$max" ] ; then
 level="$max"
echo "maximum brightness level accepted is $level"
fi
 
echo "$level" > $sysfs/brightness 
}

case "$1" in
   current)
    (( level=level ))
 
    echo "current brightness level as of on $(date +\"%T\") is $level"
;; 
  increase)
    (( level++ ))
    set_brightness $level 
    echo brightness levelset to $level
    ;;
  decrease)
    (( level-- ))
    set_brightness $level
    echo brightness levelset to $level 
    ;;

 nightmode)
   (( level=65 ))
   set_brightness $level
   NM=1
   DM=0
   echo Working on Night Mode
   ;;
 daymode)
   (( level=712 ))
   set_brightness $level
   NM=0
   DM=1
  echo Working on Day Light Mode
 ;;

  set)
    if [[ ! $2 =~ ^[[:digit:]]+$ ]]; then
     usage " $USER please input an integer"
    fi

    set_brightness "$2"
    echo brightness levelset to $level
    ;;
  *)

    usage "invalid argument, Make a valid one among the following"

  usage "invalid argument, Make a valid one among the following"
esac