Evdev
Encyclopedia
In computing
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...

, evdev (for event device) is a component of the Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

 for handling input (from keyboards, mice, joysticks, etc.) and a closely related input driver for the X.Org Server
X.Org Server
X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

. The kernel component is glue code
Glue code
In programming, glue code is code that does not contribute any functionality towards meeting the program's requirements, but instead serves solely to "glue together" different parts of code that would not otherwise be compatible...

 which translates input events from peripheral-specific drivers into a generic structure which the input driver can easily translate into X11
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

 events. Thus every input device with a Linux driver is compatible with the X.Org input driver, making X.Org much easier to configure.

Most recent Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

s install evdev by default.

Using evdev makes it easier for the X.Org server to support hotplugging of input devices and allows advanced input devices, like multi-button mice and multimedia keyboards, to work correctly. The previous approach involved a kernel-level sink device emulating a PS/2 mouse and an AT keyboard, which collected events from all input devices, while the X server was configured for one keyboard and one mouse.

External links

  • "Linux Input drivers v1.0" by Vojtech Pavlik, 2001 (Linux kernel document, now somewhat dated)
  • The evdev(4) man page at X.Org
    X.Org Foundation
    The X.Org Foundation is the organization holding the stewardship for the development of the X Window System. It was founded on 22 January 2004....

    's website
  • "linux input ecosystem" by Joe Shaw, 1 October 2010 (blog post)
  • Multiterminal with evdev
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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