backlight-dbus

backlight-dbus - a backlight controller using DBus

Synopsis

backlight-dbus [-h] [-v] [-d device_name] [-x session_id] [-t countdown] [brightness]

Description

backlight-dbus is a small utility to adjust the backlight brightness of a monitor using the DBus interface of systemd-logind. When called with no arguments, the current and maximum brightness levels are printed.

Building

Requirements:

• systemd header files (available in the package libsystemd-dev on Debian)
• gcc
• make

Once the requirements have been satisfied, you can simply run the following:

make
make install

Options

• -h Show help message.

• -v Enable verbose output (debug messages).

• -d device_name

  The device name to control. This is a folder (usually a symlink) in /sys/class/backlight/. If not specified, the first folder found will be used.

• -x session_id

  The systemd-logind session ID of the current user. If not specified, the environment variable XDG_SESSION_ID is first checked, and then a list of all sessions is checked.

• -t countdown

  The number of seconds over which the brightness should fade. This can be a floating point number.

• brightness

  This can be one of:

  • An absolute number, like the value in /sys/class/backlight/<device_name>/brightness.
  • A plus (+) or minus (-) sign followed by an absolute number. The number will be added/subtracted from the current brightness value.
  • A number followed by a percent sign (%). The brightness will be set to this percentage of the maximum value.

  The +/- signs and the % sign may be combined together.

Examples

backlight-dbus -d acpi_video0 15

backlight-dbus -200

backlight-dbus -t 3.5 75%

backlight-dbus -10%

Notes

Currently, the program will run for longer than the specified countdown because the time it takes to wait for a DBus method call to return is not accounted for.

See Also

• xbacklight(1)

Author

Max Erenberg