How to use the command xbacklight (with examples)

xbacklight is a utility command used to adjust the brightness of the screen using the RandR (Resize and Rotate) extension. It provides various options to set or modify the brightness level of the screen.

Use case 1: Get the current screen brightness as a percentage

Code:

xbacklight

Motivation: This use case is helpful when you want to know the current brightness level of your screen.

Explanation: The command xbacklight without any arguments returns the current screen brightness as a percentage.

Example output:

60.000000

Use case 2: Set the screen brightness to 40%

Code:

xbacklight -set 40

Motivation: When you want to manually set the brightness level of your screen, you can use this command.

Explanation: The -set option followed by a value sets the screen brightness to the specified percentage. In this case, it sets the brightness to 40%.

Example output: (No output is generated)

Use case 3: Increase current brightness by 25%

Code:

xbacklight -inc 25

Motivation: This use case comes in handy when you want to increment the brightness level by a certain percentage.

Explanation: The -inc option followed by a value increases the current screen brightness by the specified percentage. In this case, it increases the brightness by 25%.

Example output: (No output is generated)

Use case 4: Decrease current brightness by 75%

Code:

xbacklight -dec 75

Motivation: When you need to decrease the brightness level by a certain percentage, you can utilize this command.

Explanation: The -dec option followed by a value decreases the current screen brightness by the specified percentage. In this case, it decreases the brightness by 75%.

Example output: (No output is generated)

Use case 5: Increase backlight to 100%, over 60 seconds (value given in ms), using 60 steps

Code:

xbacklight -set 100 -time 60000 -steps 60

Motivation: This use case is useful when you want to gradually increase the brightness level over a specific duration with intermediate steps.

Explanation: The -set option followed by a value sets the screen brightness to the specified percentage. The -time option followed by a value specifies the duration in milliseconds for the transition. The -steps option followed by a value determines the number of intermediate steps between the current brightness and the target brightness.

Example output: (No output is generated)

Conclusion:

xbacklight is a versatile command that allows you to adjust the brightness level of your screen effortlessly. Whether you need to retrieve the current brightness or modify it, xbacklight provides various options and arguments to meet your requirements.