Linux: Keyboard Software Guide
This page is a overview of how to create keyboard shortcuts, how to remap/swap keys, how to change keyboard layout.
In Linux, there are 2 steps to create keyboard shortcuts:
- Action: A shell command that does something, for example, switch/close window, simulate key press, mouse click, launch app, open file, empty trash.
- Bind Key: Make a key press run a shell command/script.
First, let's look at the easy way.
Basic of Keybinding Using Control Panel
The most easy way to add a new keyboard shortcut or keyboard layout, is the system control panel in a graphical user interface (available in any of the Gnome, KDE, Ubuntu, Xfce, LXDE). Under the system control panel (aka Setting Manager or System Preference), usually there are apps named Window Manager, or Keyboard, or Keyboard Layout.
The window manager typically lets you set keys related to manipulating windows, system-wide, such as switching windows, close window, max/min window, move window, show/hide/iconify window, switch workspace (aka virtual screen), etc.
The keyboard setting tool typically lets you set a key to launch app, or run a shell script. But it does not lets you swap keys, or set a key to send key combo such as 【Ctrl+s】
Swapping Keys, Remap Keys
xmodmap
xmodmap is a simple tool that lets you remap/swap keys for apps running under X11.
[see Linux: xmodmap Tutorial]
scancode, keycode, keysym
To work with keys in Linux X11, you must understand {scancode, keycode, keysym} because many key tools use their concept and syntax.
- Scancode → a number your keyboard send to computer. For USB keyboards, it's defined by the USB standard.
- Keycode → a number used by Linux kernel to represent key (or mouse button/wheel). The Linux kernel translate scancode to keycode.
- Keysym → a short string (usually descriptive) that are received by X11 applications.
How to find the scancode of a key?
[see Linux: Find Keyboard Key Scancode]
How to find the keycode / keysym of a key?
How to set system keyboard layout?
keybinding in linux can be divided into 2 layers: the X11 window system layer, or system level.
Many keybinding setup works in X11 layer only. i.e. when in Virtual Console or single user mode console or system startup console, your custome key setting won't kick in.
The letter layout, is usually in the system layer. (but it can also be X11 layer only too.)
[see Linux: Set System Keyboard Layout]
Tool to Bind Key
xbindkeys
if your desktop doesn't provide a way to bind a key to launch a script, then you can use xbindkeys.
[see Linux: xbindkeys Tutorial]
Tool for Key Actions
「wmctrl」 for Switch Windows
wmctrl is a command line tool to {switch, close, move, resize, set title, list, …} windows.
「xvkbd」 for Sending Keychords
xvkbd is a virtual keyboard for X window system. It is useful as a shell command to send keys.
Linux: Control Sound Level by Command Line
xdotool
xdotool. «programatically simulate keyboard input and mouse activity. It does this using X11's XTEST extension and other Xlib functions.»
(note: i tried xdotool under Ubuntu/xfce. Doesn't work in my first 30 min of looking into it.)
#Install xdotool sudo apt-get install xdotool
Example. Send 【Ctrl+w】 to close tab.
xdotool key --delay 40 Control_L+w
Example. Click on upper left corner, (90, 10) pixels.
xdotool mousemove 90 10 click 1
「autokey」 for Expanding Abbreviations
AutoKey. For expanding abbrev to full words/text.
Install:
sudo apt-get install autokey-gtk (for Gnome) or
sudo apt-get install autokey-qt (for KDE)
(note: i haven't used AutoKey, and the project seems dead as of 2017-06-06.)
Other Keyboard Tools
Mouse Extra Button Tools
- roccat mouse Linux drivers. http://sourceforge.net/projects/roccat/
- by Michael Speth http://sourceforge.net/projects/kbmaster/
How to set 5 buttons mouse?
apt-get install imwheel for config mouse buttons.
Emacs
See: Emacs Keybinding, Keyboard, Articles Index.
Space Bar as Dual Key
Linux utility to configure modifier keys to act as other keys when pressed and released on their own. https://github.com/alols/xcape
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