How to use the command 'picom' (with examples)

Picom is a standalone compositor for Xorg, a display server used on many Unix-like operating systems. It enhances the graphical experience by adding visual effects like shadows, transparency, and fading transitions. Picom is particularly advantageous for users who prefer lightweight systems but still desire a modern graphical interface. The following examples demonstrate how to utilize picom in different scenarios.

Use case 1: Enable picom during a session

Code:

picom &

Motivation:

Starting picom during a session allows users to enhance their current graphical environment without needing to restart or log out. Users who quickly want to activate compositing effects like shadows and transparency for an aesthetic or practical reason (e.g., reducing screen tearing) can do so with this command.

Explanation:

• picom: This is the main command, calling the standalone compositor to start processing.
• &: The ampersand allows the command to run in the background. This way, the terminal remains available for other tasks, rather than being tied up running picom interactively.

Example output:

Upon executing this command, you may not receive any output in the terminal, but the visual changes on the screen will be evident. Windows may appear with shadows and have smooth edge transitions when moved or resized. Checking running processes will reveal picom has been added to the list.

Use case 2: Start picom as a background process

Code:

picom -b

Motivation:

Running picom as a background process is essential for users who wish to ensure system resources management and avoid command-line display clutter. By daemonizing the process, users can start picom quietly without visible interface control, which is ideal for inclusion in startup scripts or during boot processes.

Explanation:

• picom: The command to initiate the compositor.
• -b: This flag runs picom in “daemon” mode, essentially telling it to be a background process, unbothered by terminal activity or closure. This approach enhances workflow efficiency by keeping the terminal responses clean.

Example output:

The command itself likely yields no terminal output. However, the stability of window transitions and fewer artifacts during screen updates evidence the background running of picom. The system monitor will show picom executing without it occupying the terminal foreground.

Use case 3: Use a custom configuration file

Code:

picom --config path/to/config_file

Motivation:

Using a custom configuration file is crucial for advanced users who require personalized settings tailored to their needs. Instead of relying on default settings, users can fine-tune a variety of parameters such as shadows, fading time, and exclusion rules for window effects. This approach ensures the graphical experience is precisely what the user desires.

Explanation:

• picom: Initiates the compositor.
• --config: This flag specifies using a custom configuration file rather than the default one. The user needs to provide an absolute or relative path to the intended configuration file.
• path/to/config_file: This represents the file path to the customized configuration settings. Users will create this file beforehand to hold their desired settings.

Example output:

When executed, this command utilizes the given configuration settings. You might observe distinct themes or behaviors compared to the default, such as different shadow lengths or fade speeds. The responsiveness and appearance of the desktop are directly tied to the directives in the configuration file.

Conclusion:

Learning to use picom effectively enhances your Xorg experience by providing aesthetic improvements and smoother screen rendering functionality. Whether launching picom for a single session, running it quietly in the background, or applying customized configurations, each method offers a unique advantage that caters to a user’s particular needs and preferences. These examples demonstrate how versatile and beneficial knowing specific picom commands can be in improving system usability and enjoyment.