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NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COLOPHON |
LIBUDEV(3) libudev LIBUDEV(3)
libudev - API for enumerating and introspecting local devices
#include <libudev.h>
pkg-config --cflags --libs libudev
libudev.h provides APIs to introspect and enumerate devices on the
local system.
All functions require a libudev context to operate. This context can
be create via udev_new(3). It is used to track library state and link
objects together. No global state is used by libudev, everything is
always linked to a udev context.
All functions listed here are thread-agnostic and only a single
specific thread may operate on a given object during its entire
lifetime. It's safe to allocate multiple independent objects and use
each from a specific thread in parallel. However, it's not safe to
allocate such an object in one thread, and operate or free it from
any other, even if locking is used to ensure these threads don't
operate on it at the very same time.
To introspect a local device on a system, a udev device object can be
created via udev_device_new_from_syspath(3) and friends. The device
object allows one to query current state, read and write attributes
and lookup properties of the device in question.
To enumerate local devices on the system, an enumeration object can
be created via udev_enumerate_new(3).
To monitor the local system for hotplugged or unplugged devices, a
monitor can be created via udev_monitor_new_from_netlink(3).
Whenever libudev returns a list of objects, the udev_list_entry(3)
API should be used to iterate, access and modify those lists.
Furthermore, libudev also exports legacy APIs that should not be used
by new software (and as such are not documented as part of this
manual). This includes the hardware database known as udev_hwdb
(please use the new sd-hwdb(3) API instead) and the udev_queue object
to query the udev daemon (which should not be used by new software at
all).
udev_new(3), udev_device_new_from_syspath(3), udev_enumerate_new(3),
udev_monitor_new_from_netlink(3), udev_list_entry(3), systemd(1),
sd-device(3), sd-hwdb(3), pkg-config(1)
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2020-08-13. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-08-11.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
systemd 246 LIBUDEV(3)
Pages that refer to this page: 30-systemd-environment-d-generator(7) , systemd.directives(7) , systemd.index(7)