xkbvleds

xkbvleds [options]

-display
    Specifies the X server to connect to.

-indicator
    Specifies which indicator name to display. If not specified, all indicators are shown.

-font
    Specifies the font to use for displaying the indicator names.

-size
    Specifies the size of the window and the font in pixels.

-delay
    Specifies the delay between updates of the indicator state in milliseconds. Default is 100 milliseconds.

-padding
    Specifies the padding around the indicator text in pixels.

xkbvleds is a utility for the X Window System that shows the current state of the keyboard LEDs (Caps Lock, Num Lock, Scroll Lock) for a specified XKB (X Keyboard Extension) keyboard.

It provides a visual representation of these indicators, which can be useful when physical keyboard LEDs are not available or visible, or for debugging XKB configurations. The command queries the X server to get the active state of the keyboard and then updates its display accordingly. It's often used as part of a desktop environment or a status bar to provide immediate feedback on keyboard mode.

Limitations:
xkbvleds requires an X server to run, as it's a graphical utility. It only displays XKB indicators, not direct hardware LED states. Its functionality is heavily dependent on proper XKB configuration; misconfiguration might lead to discrepancies between displayed and physical states. The output is a graphical window, not text to standard output, making it unsuitable for scripting where text parsing is required.

Unlike many command-line utilities, xkbvleds opens a small graphical window to display the LED states. This window is typically non-interactive and updates automatically to reflect changes in the keyboard's state.

When run without any options, xkbvleds connects to the default X display and shows the state of all standard indicators (e.g., Caps Lock, Num Lock, Scroll Lock) using default font and sizing, continuously updating its display.

xkbvleds is part of the xkbutils package, which provides various utilities for the X Keyboard Extension (XKB). XKB was introduced to provide a more flexible and powerful keyboard management system than the original X protocol. xkbvleds serves as a simple visual debugger and status display for this system. Its development likely tracks the evolution and maintenance of the XKB extension itself within the X.Org project, ensuring compatibility and functionality with modern X environments.

xkbcomp(1), setxkbmap(1), xset(1)