XGETDEVICEPROPERTY(3) |  | XGETDEVICEPROPERTY(3)

# NAME

XGetDeviceProperty, XChangeDeviceProperty, XDeleteDeviceProperty - Get, change or delete a device's property.

# SYNOPSIS

    #include <X11/extensions/XInput.h>

    int XGetDeviceProperty( Display *display,

                            XDevice *device,

                            Atom property,

                            long offset,

                            long length,

                            Bool delete,

                            Atom req_type,

                            Atom *actual_type_return,

                            int *actual_format_return,

                            unsigned long *nitems_return,

                            unsigned long *bytes_after_return,

                            unsigned char **prop_return)

    void XChangeDeviceProperty( Display *display,

                                XDevice *device,

                                Atom property,

                                Atom type,

                                int format,

                                int mode,

                                const unsigned char *data,

                                int nelements)

    void XDeleteDeviceProperty( Display *display,

                                XDevice *device,

                                Atom property)

    actual_type_return

           Returns an atom identifier that defines the actual type

           of the property.

    actual_format_return

           Returns the actual format of the property.

    bytes_after_return

           Returns the number of bytes remaining to be read in the

           property if a partial read was performed.

    data

           Specifies the property data.

    delete

           Specifies a Boolean value that determines whether the

           property is deleted.

    display

           Specifies the connection to the X server.

    device

           The device to grab.

    format

           Specifies whether the data should be viewed as a list of

           8-bit, 16-bit, or 32-bit quantities. Possible values are

           8, 16, and 32. This information allows the X server to

           correctly perform byte-swap operations as necessary. If

           the format is 16-bit or 32-bit, you must explicitly cast

           the data pointer to an (unsigned char*) in the call to

           XChangeDeviceProperty.

    length

           Specifies the length in 32-bit multiplies of the data to

           be retrieved.

    mode

           Specifies the mode of operation. You can pass

           PropModeReplace, PropModePrepend, or PropModeAppend.

    nelements

           Specifies the number of elements in data.

    nitems_return

           Returns the actual number of 8-bit, 16-bit, or 32-bit

           items stored in the prop_return array.

    num_values

           Specifies the number of elements in the values list.

    offset

           Specifies the offset in the specified property (in

           32-bit quantities) where the data is to be retrieved.

    property

           Specifies the property to modify or query.

    prop_return

           Returns the data in the specified format. If the

           returned format is 8, the returned data is represented

           as a char array. If the returned format is 16, the

           returned data is represented as an array of short int

           type and should be cast to that type to obtain the

           elements. If the returned format is 32, the property

           data will be stored as an array of longs (which in a

           64-bit application will be 64-bit values that are padded

           in the upper 4 bytes).

    req_type

           Specifies the atom identifier associated with the

           property type or AnyPropertyType.

# DESCRIPTION

The XGetDeviceProperty function returns the actual type of the property; the actual format of the property; the number of 8-bit, 16-bit, or 32-bit items transferred; the number of bytes remaining to be read in the property; and a pointer to the data actually returned. For a detailed description of this function, see the man page to XGetWindowProperty.

The XChangeDeviceProperty function alters the property for the specified device and causes the server to generate a XPropertyNotifyEvent event on that device. For a detailed description of this function, see the man page to XChangeProperty.

The XDeleteDeviceProperty function deletes the specified device property. Note that a client cannot delete a property created by a driver or the server. Attempting to do so will result in a BadAtom error.

XGetDeviceProperty can generate a BadAtom, BadDevice error.

XChangeDeviceProperty can generate a BadDevice, a BadMatch, a BadAtom, and a BadValue error.

XDeleteDeviceProperty can generate a BadDevice, and a BadAtom error.

# DIAGNOSIS

    BadAtom

           A value does not describe a valid named identifier or

           the client attempted to remove a driver-allocated

           property.

    BadDevice

           An invalid device was specified. The device does not

           exist.

# SEE ALSO

    XListDeviceProperties(3)

05/18/2026 |