rafa-garcia / bashlight

Brightness control in bare bash

bashlight

Brightness control in bash.

This utility handles display brightness when backlight control is exposed to the user through a sysfs interface at /sys/class/backlight. By default, the brightness level is managed for every registered class device through its backlight sysfs entry.

Dependencies

• bash
• ACPI, graphic or platform driver controlling brightness and exposing a sysfs interface.
  • [ "$(ls -A /sys/class/backlight)" ] && echo "Yea" || echo "Nay"
• Installed by a sudoer

Installation

1. Clone the repository.

   • git clone https://github.com/rafa-garcia/bashlight

2. Change working directory to bashlight.

   • cd bashlight

3. Run sudo make install from the root directory to install the script, manpage and udev rule.

   • The 90-backlight.rules udev rule will be added to allow the video group to control backlight
   • The video group must have the user that runs the application as member

bashlight can also be uninstalled easily with sudo make uninstall.

Usage

usage: bashlight [options]
Where options are:
  -help                    Print out a summary of the usage and exit
  -version                 Print out the program version and exit
  -get                     Print out the current backlight brightness of each output
  -set <percentage>        Sets each backlight brightness to the specified level
  -inc <percentage>        Increases brightness by the specified amount
  -dec <percentage>        Decreases brightness by the specified amount
  -time <milliseconds>     Length of time to transition to new value. Default is 200
  -steps <steps>           Number of steps to take while transitioning. Default is 20

Why

After moving to Wayland, I struggled to find a portable (as in pure bash) X.Org's xbacklight-like utility that does not require X and handles similar CLI options.

License

The application is licensed under the MIT License.