UPower Knowpia

UPower
	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
Stable release	1.90.4 / 8 April 2024; 2 days ago
Repository	gitlab.freedesktop.org/upower/upower.git ;
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.^[2] It enumerates power sources, maintains statistics and history data on them and notifies about status changes. It consists of a daemon (upowerd), an application programming interface and a set of command line tools. The daemon provides its functionality to applications over the system bus (an instance of D-Bus, service org.freedesktop.UPower).^[3] PolicyKit restricts access to the UPower functionality for initiating hibernate mode or shutting down the operating system (freedesktop.upower.policy).^[4] The command-line client program upower can be used to query and monitor information about the power supply devices in the system. Graphical user interfaces to the functionality of UPower include the GNOME Power Manager and the Xfce Power Manager.^[5]

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 features of the deprecated HAL. In 2008, David Zeuthen started a comprehensive rewrite of HAL. This resulted in a set of separate services under the new name "DeviceKit".^[6] In 2010 the included DeviceKit-power was renamed. UPower was first introduced and established as a standard in GNOME.^[7] In January 2011 the desktop environment Xfce followed (version 4.8).

Sources edit

^ "Release v1.90.4".
^ Michael Kofler (2011), Linux 2011 : Debian, Fedora, openSUSE, Ubuntu (in German) (10 ed.), München: Pearson Education Deutschland GmbH, p. 504, ISBN 9783827330253
^ Oliver Diedrich (The H Open), 11 February 2013: D-Bus is coming to the Linux Kernel
^ Richard Petersen (2010), Fedora 14 : Administration and Security (in German), Alameda, CA: Surfing Turtle Press, ISBN 9781936280230
^ "Xfce:xfce4-power-manager:start [Xfce Docs]".
^ David Zeuthen (7 May 2008), freedesktop.org (ed.), "Update on DeviceKit", HAL-Mailingliste (in German)
^ Thorsten Leemhuis (The H Open), 7 August 2012: Comment: Desktop Fragmentation^{[permanent dead link]}