struct udev_device

struct udev_device;

Opaque object representing one kernel sys device.

udev_device_ref ()

struct udev_device * udev_device_ref                    (struct udev_device *udev_device);

Take a reference of a udev device.

udev_device_unref ()

void                udev_device_unref                   (struct udev_device *udev_device);

Drop a reference of a udev device. If the refcount reaches zero, the resources of the device will be released.

udev_device_get_udev ()

struct udev *       udev_device_get_udev                (struct udev_device *udev_device);

Retrieve the udev library context the device was created with.

udev_device_new_from_syspath ()

struct udev_device * udev_device_new_from_syspath       (struct udev *udev,
                                                         const char *syspath);

Create new udev device, and fill in information from the sys device and the udev database entry. The syspath is the absolute path to the device, including the sys mount point.

The initial refcount is 1, and needs to be decremented to release the resources of the udev device.

udev_device_new_from_devnum ()

struct udev_device * udev_device_new_from_devnum        (struct udev *udev,
                                                         char type,
                                                         dev_t devnum);

Create new udev device, and fill in information from the sys device and the udev database entry. The device is looked up by its major/minor number. Character and block device numbers are not unique across the two types, they do not share the same range of numbers.

The initial refcount is 1, and needs to be decremented to release the resources of the udev device.

udev_device_new_from_subsystem_sysname ()

struct udev_device * udev_device_new_from_subsystem_sysname
                                                        (struct udev *udev,
                                                         const char *subsystem,
                                                         const char *sysname);

Create new udev device, and fill in information from the sys device and the udev database entry. The device is looked up by the subsystem and name string of the device, like "mem", "zero", or "block", "sda".

The initial refcount is 1, and needs to be decremented to release the resources of the udev device.

udev_device_get_parent ()

struct udev_device * udev_device_get_parent             (struct udev_device *udev_device);

Find the next parent device, and fill in information from the sys device and the udev database entry.

The returned the device is not referenced. It is attached to the child device, and will be cleaned up when the child device is cleaned up.

It is not necessarily just the upper level directory, empty or not recognized sys directories are ignored.

It can be called as many times as needed, without caring about references.

udev_device_get_parent_with_subsystem_devtype ()

struct udev_device * udev_device_get_parent_with_subsystem_devtype
                                                        (struct udev_device *udev_device,
                                                         const char *subsystem,
                                                         const char *devtype);

Find the next parent device, with a matching subsystem and devtype value, and fill in information from the sys device and the udev database entry.

The returned the device is not referenced. It is attached to the child device, and will be cleaned up when the child device is cleaned up.

It can be called as many times as needed, without caring about references.

udev_device_get_devpath ()

const char *        udev_device_get_devpath             (struct udev_device *udev_device);

Retrieve the kernel devpath value of the udev device. The path does not contain the sys mount point, and starts with a '/'.

udev_device_get_subsystem ()

const char *        udev_device_get_subsystem           (struct udev_device *udev_device);

Retrieve the subsystem string of the udev device. The string does not contain any "/".

udev_device_get_devtype ()

const char *        udev_device_get_devtype             (struct udev_device *udev_device);

Retrieve the devtype string of the udev device.

udev_device_get_syspath ()

const char *        udev_device_get_syspath             (struct udev_device *udev_device);

Retrieve the sys path of the udev device. The path is an absolute path and starts with the sys mount point.

udev_device_get_sysname ()

const char *        udev_device_get_sysname             (struct udev_device *udev_device);

udev_device_get_sysnum ()

const char *        udev_device_get_sysnum              (struct udev_device *udev_device);

udev_device_get_devnode ()

const char *        udev_device_get_devnode             (struct udev_device *udev_device);

Retrieve the device node file name belonging to the udev device. The path is an absolute path, and starts with the device directory.

udev_device_get_devlinks_list_entry ()

struct udev_list_entry * udev_device_get_devlinks_list_entry
                                                        (struct udev_device *udev_device);

Retrieve the list of device links pointing to the device file of the udev device. The next list entry can be retrieved with udev_list_entry_next(), which returns NULL if no more entries exist. The devlink path can be retrieved from the list entry by udev_list_entry_get_name(). The path is an absolute path, and starts with the device directory.

udev_device_get_properties_list_entry ()

struct udev_list_entry * udev_device_get_properties_list_entry
                                                        (struct udev_device *udev_device);

Retrieve the list of key/value device properties of the udev device. The next list entry can be retrieved with udev_list_entry_next(), which returns NULL if no more entries exist. The property name can be retrieved from the list entry by udev_list_get_name(), the property value by udev_list_get_value().

udev_device_get_property_value ()

const char *        udev_device_get_property_value      (struct udev_device *udev_device,
                                                         const char *key);

udev_device_get_driver ()

const char *        udev_device_get_driver              (struct udev_device *udev_device);

udev_device_get_devnum ()

dev_t               udev_device_get_devnum              (struct udev_device *udev_device);

This is only valid if the device was received through a monitor. Devices read from sys do not have a sequence number.

udev_device_get_action ()

const char *        udev_device_get_action              (struct udev_device *udev_device);

This is only valid if the device was received through a monitor. Devices read from sys do not have an action string. Usual actions are: add, remove, change, online, offline.

udev_device_get_sysattr_value ()

const char *        udev_device_get_sysattr_value       (struct udev_device *udev_device,
                                                         const char *sysattr);

The retrieved value is cached in the device. Repeated calls will return the same value and not open the attribute again.