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

Slurp is a command-line tool designed for selecting a region on a screen in Wayland compositors. Its primary purpose is to allow users to interact with the display by defining a specific area (or even a point) that can subsequently be used for various tasks, such as screenshots and recordings. The tool has several arguments, each providing a unique way to leverage the selected region. Below, we delve into multiple use cases for using the ‘slurp’ command effectively.

Use case 1: Select a region and print it to stdout

Code:

slurp

Motivation:

Selecting a specific region on the screen and outputting its details to standard output is immensely useful in scenarios where you want to quickly capture or identify a particular section of your display. For example, software developers or graphic designers may need precise measurements of a region for application testing or design accuracy.

Explanation:

• slurp: Simply using the slurp command, without any additional flags, will prompt the user to visually select a rectangle on their screen. The coordinates and dimensions of the selected area are then printed to the terminal’s standard output, providing a straightforward way to capture and display region information.

Example output:

100x100 500x300

Use case 2: Select a region and print it to stdout, while displaying the dimensions of the selection

Code:

slurp -d

Motivation:

When selecting a region on the screen, knowing its dimensions in real-time can help ensure accuracy in the selection process. This capability can be particularly valuable for professionals who require precision, such as user interface designers who need to compare selected regions against expected measurements.

Explanation:

• -d: This flag instructs slurp to display the dimensions of the current selection on the screen while you’re making it. It enables users to view size information in real-time, thereby aiding in more accurate and informed selections.

Example output:

[Dimensions: 640x480]

Use case 3: Select a single point instead of a region

Code:

slurp -p

Motivation:

In some cases, selecting just a single pixel on the screen is necessary. For example, determining the exact coordinates of a point where an element begins or diagnosing a single-pixel width error in a design can be quite important.

Explanation:

• -p: This flag changes the behavior of slurp to allow the selection of a single point rather than an entire region. Once selected, the coordinates of that point are displayed, offering precise pinpoint accuracy.

Example output:

300x400

Use case 4: Select an output and print its name

Code:

slurp -o -f '%o'

Motivation:

When working with systems featuring multiple outputs, such as dual monitors, determining which output is selected is crucial. This information can be used to script commands that target specific displays or automate configurations.

Explanation:

• -o: This flag switches slurp to select entire outputs (screens) rather than regions or points.
• -f '%o': This formatting option specifies that the output name should be printed, which typically helps in identifying the selected display.

Example output:

Monitor1

Use case 5: Select a specific region and take a borderless screenshot of it, using grim

Code:

grim -g "$(slurp -w 0)"

Motivation:

Capturing screenshots with exact regions is essential for documentation or tutorial preparation. Using grim along with slurp, you can ensure that only the relevant content is included in the snapshot, excluding any unnecessary borders or toolbar areas.

Explanation:

• grim: A screenshot tool that works within Wayland sessions.
• -g: This specifies the geometry for the screenshot, which is obtained from slurp.
• $(slurp -w 0): Invokes slurp to select a region, passing those precise coordinates to grim for capturing an image of that bounded area. The -w 0 flag ensures no window decorations are included.

Example output:

A borderless PNG image file of the selected region is created and saved.

Use case 6: Select a specific region and take a borderless video of it, using wf-recorder

Code:

wf-recorder --geometry "$(slurp -w 0)"

Motivation:

Recording videos of specific regions can be useful for creating software demonstrations, capturing video calls, or recording gameplay for tutorial purposes. Using wf-recorder alongside slurp, you can precisely define and record the necessary areas without capturing irrelevant screen space.

Explanation:

• wf-recorder: A tool for recording video on Wayland compositors.
• --geometry: Uses specified coordinates to determine what part of the screen to record.
• $(slurp -w 0): Calls slurp to define the recording area, with the -w 0 argument ensuring no border is included.

Example output:

A video file is generated, limited to the selected area of the screen, providing a focused recording.

Conclusion:

The slurp command offers a versatile toolset for precise screen region selection within a Wayland environment. Whether you are measuring dimensions, selecting outputs, or capturing visuals, slurp’s various flags and functional integration with other utilities like grim and wf-recorder provide powerful ways to manage and capture screen content. Each use case demonstrates how slurp caters to different needs, from simple coordinate capturing to more complex multimedia tasks.