78 

    79 Keyboard's keys under X window.

    80 ===============================

    81 

    82   scancodes

    83                 hardware-dependent codes generated by keystrokes and received by

    84                 the X server.

    85   keycodes

    86                 Codes sent by the X server to the client indicating which key

    87                 was pressed. Keycodes by themselves do not indicate what the

    88                 keystroke means; the client must request that information from

    89                 the X server.

    90   modifiers

    91                 Flags, such as ``shift'' and ``control,'' that the server sends

    92                 with each keycode to the client. The client's interpretation of

    93                 the keycode may depend on the state of the modifiers. For

    94                 example, the state of the shift modifier determines whether an

    95                 alphabetic character should be lowercase or uppercase. Because

    96                 the X server encodes the states of the eight modifiers (shift,

    97                 lock, control, mod1, mod2, mod3, mod4, and mod5) in a single

    98                 byte of data, modifiers are often referred to as ``modifier

    99                 bits.''

   100   keysyms

   101                 codes that specify the glyphs appearing on the keys. The X

   102                 server also maintains a list of strings that describe the

   103                 keysyms, such as ``a'', ``B'', and ``Control.''

   104 

   105 Find the keycode.

   106 =================

   107 

   108 ::

   109 

   110   $ xev

   111   $ cat /usr/include/X11/keysymdef.h

   112 

   113 Don't run under X::

   114 

   115   $ showkey

   116 

   117 To do same under X::

   118 

   119   $ xev | sed -n 's=.*keycode \([0-9]*\).*=\1=p'

   120 

   121 List key modifier::

   122 

   123   $ xmodmap -pm

   124 

   125 Add keycode to modifier::

   126 

   127   $ xmodmap -e "add shift = Shift_R"

   128 

   129 Remove keycode from modifier::

   130 

   131   $ xmodmap -e "remove shift = Shift_L"

   132 

   133 Examining the current keymap table::

   134 

   135   $ xmodmap -pk

   136 

   137 Changing the keymap table::

   138 

   139   $ xmodmap -e "keycode 34 = bracketleft braceleft"

   140   $ xmodmap -e "keysym CapsLock = Control_L"

   141 

   142   https://wiki.ubuntu.com/LaptopTesting/Keycodes

   143                 Ubuntu Keycodes howto.

   144   http://en.gentoo-wiki.com/wiki/Multimedia_Keys

   145                 Gentoo Multimedia Keys howto.