UPower

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UPower
UPower logo: a battery cell of size AA
300px
GNOME Power Manager notification about switch to battery power
Developer(s) David Zeuthen, Richard Hughes a.o. (freedesktop.org)
Initial release 2008; 16 years ago (2008)
Stable release 0.99.1 / 18 August 2014; 9 years ago (2014-08-18)
Written in C
Operating system Linux
License GPL (free software)
Website upower.freedesktop.org

UPower (previously DeviceKit-power) is a piece of middleware (an abstraction layer) for power management on Linux systems.[1] It enumerates power sources, provides statistics and history data on them and notifies users of status changes. It consists of a daemon (upowerd), an application programming interface and a set of command line tools. The daemon provides applications with its functionality over the system bus (an instance of D-Bus, service org.freedesktop.UPower).[2] PolicyKit restricts access to the UPower functionality for inducing hibernate mode or shutting down the operating system (freedesktop.upower.policy).[3] Using the command-line client program upower, one can query and monitor information on the power devices in the system. Graphical user interfaces to the functionality of UPower are e.g. the GNOME Power Manager and the Xfce Power Manager.[4]

UPower is a product of the cross-desktop freedesktop.org project. As free software it is published with its source code under the terms of version 2 or later of the GNU General Public License (GPL).

It was conceived as a replacement for the corresponding parts of functionality of the deprecated HAL. 2008 David Zeuthen began a comprehensive rewrite of HAL. This produced a set of separate services under the new name "DeviceKit".[5] 2010 was contained therein DeviceKit-power was renamed. UPower was initially introduced and established as a standard in GNOME.[6] In January 2011 the desktop environment Xfce followed (version 4.8).

External links

Sources

  1. Michael Kofler (2011) (in German), Linux 2011
    Debian, Fedora, openSUSE, Ubuntu (10 ed.), München: Pearson Education Deutschland GmbH, pp. 504, ISBN 9783827330253 
  2. Oliver Diedrich (The H Open), 11 February 2013: D-Bus is coming to the Linux Kernel
  3. Richard Petersen (2010) (in German), Fedora 14
    Administration and Security, Alameda, CA: Surfing Turtle Press, ISBN 9781936280230 
  4. http://goodies.xfce.org/projects/applications/xfce4-power-manager
  5. David Zeuthen (7 May 2008), freedesktop.org, ed., "Update on DeviceKit" (in German), HAL-Mailingliste, http://lists.freedesktop.org/archives/hal/2008-May/011560.html 
  6. Thorsten Leemhuis (The H Open), 7 August 2012: Comment: Desktop Fragmentation