динамическое управление устройством (Dynamic device management)
Описание (Description)
udev supplies the system software with device events, manages
permissions of device nodes and may create additional symlinks in
the /dev/ directory, or renames network interfaces. The kernel
usually just assigns unpredictable device names based on the
order of discovery. Meaningful symlinks or network device names
provide a way to reliably identify devices based on their
properties or current configuration.
The udev daemon, systemd-udevd.service(8), receives device
uevents directly from the kernel whenever a device is added or
removed from the system, or it changes its state. When udev
receives a device event, it matches its configured set of rules
against various device attributes to identify the device. Rules
that match may provide additional device information to be stored
in the udev database or to be used to create meaningful symlink
names.
All device information udev processes is stored in the udev
database and sent out to possible event subscribers. Access to
all stored data and the event sources is provided by the library
libudev.