libudev(3) — Linux manual page


LIBUDEV(3)                         libudev                        LIBUDEV(3)

NAME         top

       libudev - API for enumerating and introspecting local devices

SYNOPSIS         top

       #include <libudev.h>

       pkg-config --cflags --libs libudev

DESCRIPTION         top

       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

SEE ALSO         top

       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)

COLOPHON         top

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systemd 247                                                       LIBUDEV(3)

Pages that refer to this page: 30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)