Technical Reference: Kernel and Subsystems, Volume 2

KSLED (Illuminate/Darken Keyboard LEDs)

Purpose

Illuminates and darkens LEDs on the keyboard.

Syntax

#include <sys/inputdd.h>

int ioctl (FileDescriptor, KSLED, Arg) int FileDescriptor, * Arg;

Description

The KSLED ioctl subroutine call illuminates and darkens the LEDs on the natively attached keyboard. The Arg parameter points to a bit mask (one bit per LED) that specifies the state of each keyboard LED.

The current state of the keyboard LEDs is returned in the input ring event report for the keyboard.

When keyboard diagnostics are enabled, the KSLED ioctl operation fails and sets the errno global variable to a value of EBUSY.

Parameters

Arg

Specifies the address of the LED bit mask. The bit mask can be any combination of the following values ORed together:

#define KSCROLLLOCK   0x01  /*Illuminates ScrollLock LED.*/
#define KSNUMLOCK     0x02  /*Illuminates NumLock LED.*/
#define KSCAPLOCK     0x04  /*Illuminates CapsLock LED.*/

FileDescriptor

Specifies the open file descriptor for the keyboard.