Abstraction functions to handle device capabilities, specifically device properties such as the name of the device and the bits representing the events supported by this device. More...

Functions
const char *	libevdev_get_name (const struct libevdev *dev)
	Retrieve the device's name, either as set by the caller or as read from the kernel.

const char *	libevdev_get_phys (const struct libevdev *dev)
	Retrieve the device's physical location, either as set by the caller or as read from the kernel.

const char *	libevdev_get_uniq (const struct libevdev *dev)
	Retrieve the device's unique identifier, either as set by the caller or as read from the kernel.

int	libevdev_get_id_product (const struct libevdev *dev)

int	libevdev_get_id_vendor (const struct libevdev *dev)

int	libevdev_get_id_bustype (const struct libevdev *dev)

int	libevdev_get_id_version (const struct libevdev *dev)

int	libevdev_get_driver_version (const struct libevdev *dev)

int	libevdev_has_property (const struct libevdev *dev, unsigned int prop)

int	libevdev_has_event_type (const struct libevdev *dev, unsigned int type)

int	libevdev_has_event_code (const struct libevdev *dev, unsigned int type, unsigned int code)

int	libevdev_get_abs_minimum (const struct libevdev *dev, unsigned int code)
	Get the minimum axis value for the given axis, as advertised by the kernel.

int	libevdev_get_abs_maximum (const struct libevdev *dev, unsigned int code)
	Get the maximum axis value for the given axis, as advertised by the kernel.

int	libevdev_get_abs_fuzz (const struct libevdev *dev, unsigned int code)
	Get the axis fuzz for the given axis, as advertised by the kernel.

int	libevdev_get_abs_flat (const struct libevdev *dev, unsigned int code)
	Get the axis flat for the given axis, as advertised by the kernel.

int	libevdev_get_abs_resolution (const struct libevdev *dev, unsigned int code)
	Get the axis resolution for the given axis, as advertised by the kernel.

const struct input_absinfo *	libevdev_get_abs_info (const struct libevdev *dev, unsigned int code)
	Get the axis info for the given axis, as advertised by the kernel.

int	libevdev_get_event_value (const struct libevdev *dev, unsigned int type, unsigned int code)
	Behaviour of this function is undefined if the device does not provide the event.

int	libevdev_fetch_event_value (const struct libevdev dev, unsigned int type, unsigned int code, int value)
	Fetch the current value of the event type.

int	libevdev_get_repeat (const struct libevdev dev, int delay, int *period)
	Get the repeat delay and repeat period values for this device.

Detailed Description

Abstraction functions to handle device capabilities, specifically device properties such as the name of the device and the bits representing the events supported by this device.

The logical state returned may lag behind the physical state of the device. libevdev queries the device state on libevdev_set_fd() and then relies on the caller to parse events through libevdev_next_event(). If a caller does not use libevdev_next_event(), libevdev will not update the internal state of the device and thus returns outdated values.

Function Documentation

◆ libevdev_fetch_event_value()

int libevdev_fetch_event_value	(	const struct libevdev *	dev,
		unsigned int	type,
		unsigned int	code,
		int *	value
	)

Fetch the current value of the event type.

This is a shortcut for

if (libevdev_has_event_type(dev, t) && libevdev_has_event_code(dev, t, c))

val = libevdev_get_event_value(dev, t, c);

libevdev_has_event_type

int libevdev_has_event_type(const struct libevdev *dev, unsigned int type)

libevdev_get_event_value

int libevdev_get_event_value(const struct libevdev *dev, unsigned int type, unsigned int code)

Behaviour of this function is undefined if the device does not provide the event.

libevdev_has_event_code

int libevdev_has_event_code(const struct libevdev *dev, unsigned int type, unsigned int code)

Parameters

	dev	The evdev device, already initialized with libevdev_set_fd()
	type	The event type for the code to query (EV_SYN, EV_REL, etc.)
	code	The event code to query for, one of ABS_X, REL_X, etc.
[out]	value	The current value of this axis returned.

Returns: If the device supports this event type and code, the return value is non-zero and value is set to the current value of this axis. Otherwise, 0 is returned and value is unmodified.

Note: This function is signal-safe.; The value for ABS_MT_ events is undefined, use libevdev_fetch_slot_value() instead

See also: libevdev_fetch_slot_value

◆ libevdev_get_abs_flat()

int libevdev_get_abs_flat	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the axis flat for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: axis flat for the given axis or 0 if the axis is invalid

Note: This function is signal-safe.

◆ libevdev_get_abs_fuzz()

int libevdev_get_abs_fuzz	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the axis fuzz for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: axis fuzz for the given axis or 0 if the axis is invalid

Note: This function is signal-safe.

◆ libevdev_get_abs_info()

const struct input_absinfo * libevdev_get_abs_info	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the axis info for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: The input_absinfo for the given code, or NULL if the device does not support this event code.

Note: This function is signal-safe.

◆ libevdev_get_abs_maximum()

int libevdev_get_abs_maximum	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the maximum axis value for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: axis maximum for the given axis or 0 if the axis is invalid

Note: This function is signal-safe.

◆ libevdev_get_abs_minimum()

int libevdev_get_abs_minimum	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the minimum axis value for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: axis minimum for the given axis or 0 if the axis is invalid

Note: This function is signal-safe.

◆ libevdev_get_abs_resolution()

int libevdev_get_abs_resolution	(	const struct libevdev *	dev,
		unsigned int	code
	)

Get the axis resolution for the given axis, as advertised by the kernel.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
code	The EV_ABS event code to query for, one of ABS_X, ABS_Y, etc.

Returns: axis resolution for the given axis or 0 if the axis is invalid

Note: This function is signal-safe.

◆ libevdev_get_driver_version()

int libevdev_get_driver_version ( const struct libevdev * dev )

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The driver version for this device

Note: This function is signal-safe.

◆ libevdev_get_event_value()

int libevdev_get_event_value	(	const struct libevdev *	dev,
		unsigned int	type,
		unsigned int	code
	)

Behaviour of this function is undefined if the device does not provide the event.

If the device supports ABS_MT_SLOT, the value returned for any ABS_MT_* event code is undefined. Use libevdev_get_slot_value() instead.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
type	The event type for the code to query (EV_SYN, EV_REL, etc.)
code	The event code to query for, one of ABS_X, REL_X, etc.

Returns: The current value of the event.

Note: This function is signal-safe.; The value for ABS_MT_ events is undefined, use libevdev_get_slot_value() instead

See also: libevdev_get_slot_value

◆ libevdev_get_id_bustype()

int libevdev_get_id_bustype ( const struct libevdev * dev )

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The device's bus type

Note: This function is signal-safe.

◆ libevdev_get_id_product()

int libevdev_get_id_product ( const struct libevdev * dev )

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The device's product ID

Note: This function is signal-safe.

◆ libevdev_get_id_vendor()

int libevdev_get_id_vendor ( const struct libevdev * dev )

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The device's vendor ID

Note: This function is signal-safe.

◆ libevdev_get_id_version()

int libevdev_get_id_version ( const struct libevdev * dev )

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The device's firmware version

Note: This function is signal-safe.

◆ libevdev_get_name()

const char * libevdev_get_name ( const struct libevdev * dev )

Retrieve the device's name, either as set by the caller or as read from the kernel.

The string returned is valid until libevdev_free() or until libevdev_set_name(), whichever comes earlier.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The device name as read off the kernel device. The name is never NULL but it may be the empty string.

Note: This function is signal-safe.

◆ libevdev_get_phys()

const char * libevdev_get_phys ( const struct libevdev * dev )

Retrieve the device's physical location, either as set by the caller or as read from the kernel.

The string returned is valid until libevdev_free() or until libevdev_set_phys(), whichever comes earlier.

Virtual devices such as uinput devices have no phys location.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The physical location of this device, or NULL if there is none

Note: This function is signal safe.

◆ libevdev_get_repeat()

int libevdev_get_repeat	(	const struct libevdev *	dev,
		int *	delay,
		int *	period
	)

Get the repeat delay and repeat period values for this device.

This function is a convenience function only, EV_REP is supported by libevdev_get_event_value().

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
delay	If not null, set to the repeat delay value
period	If not null, set to the repeat period value

Returns: 0 on success, -1 if this device does not have repeat settings.

Note: This function is signal-safe

See also: libevdev_get_event_value

◆ libevdev_get_uniq()

const char * libevdev_get_uniq ( const struct libevdev * dev )

Retrieve the device's unique identifier, either as set by the caller or as read from the kernel.

The string returned is valid until libevdev_free() or until libevdev_set_uniq(), whichever comes earlier.

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()

Returns: The unique identifier for this device, or NULL if there is none

Note: This function is signal safe.

◆ libevdev_has_event_code()

int libevdev_has_event_code	(	const struct libevdev *	dev,
		unsigned int	type,
		unsigned int	code
	)

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
type	The event type for the code to query (EV_SYN, EV_REL, etc.)
code	The event code to query for, one of ABS_X, REL_X, etc.

Returns: 1 if the device supports this event type and code, or 0 otherwise.

Note: This function is signal-safe.

◆ libevdev_has_event_type()

int libevdev_has_event_type	(	const struct libevdev *	dev,
		unsigned int	type
	)

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
type	The event type to query for, one of EV_SYN, EV_REL, etc.

Returns: 1 if the device supports this event type, or 0 otherwise.

Note: This function is signal-safe.

◆ libevdev_has_property()

int libevdev_has_property	(	const struct libevdev *	dev,
		unsigned int	prop
	)

Parameters

dev	The evdev device, already initialized with libevdev_set_fd()
prop	The input property to query for, one of INPUT_PROP_...

Returns: 1 if the device provides this input property, or 0 otherwise.

Note: This function is signal-safe

Functions

Detailed Description

Function Documentation

◆ libevdev_fetch_event_value()

◆ libevdev_get_abs_flat()

◆ libevdev_get_abs_fuzz()

◆ libevdev_get_abs_info()

◆ libevdev_get_abs_maximum()

◆ libevdev_get_abs_minimum()

◆ libevdev_get_abs_resolution()

◆ libevdev_get_driver_version()

◆ libevdev_get_event_value()

◆ libevdev_get_id_bustype()

◆ libevdev_get_id_product()

◆ libevdev_get_id_vendor()

◆ libevdev_get_id_version()

◆ libevdev_get_name()

◆ libevdev_get_phys()

◆ libevdev_get_repeat()

◆ libevdev_get_uniq()

◆ libevdev_has_event_code()

◆ libevdev_has_event_type()

◆ libevdev_has_property()