NAME¶
keymaps - keyboard table descriptions for loadkeys and dumpkeys
DESCRIPTION¶
These files are used by
loadkeys(1) to modify the translation tables used
by the kernel keyboard driver and generated by
dumpkeys(1) from those
translation tables.
The format of these files is vaguely similar to the one accepted by
xmodmap(1). The file consists of charset or key or string definition
lines interspersed with comments.
Comments are introduced with
! or
# characters and continue to the
end of the line. Anything following one of these characters on that line is
ignored. Note that comments need not begin from column one as with
xmodmap(1).
The syntax of keymap files is line oriented; a complete definition must fit on a
single logical line. Logical lines can, however, be split into multiple
physical lines by ending each subline with the backslash character (\).
INCLUDE FILES¶
A keymap can include other keymaps using the syntax
include "pathname"
CHARSET DEFINITIONS¶
A character set definition line is of the form:
charset <charset>
Where
<charset> is one of the currently supported charsets, which
can be found using
dumpkeys --help. It defines how following keysyms
are to be interpreted. For example, in iso-8859-1 the symbol mu (or micro) has
code 0265, while in iso-8859-7 the letter mu has code 0354.
COMPLETE KEYCODE DEFINITIONS¶
Each complete key definition line is of the form:
keycode keynumber =
keysym keysym keysym...
keynumber is the internal identification number of the key, roughly
equivalent to the scan code of it.
keynumber can be given in decimal,
octal or hexadecimal notation. Octal is denoted by a leading zero and
hexadecimal by the prefix
0x.
Each of the
keysyms represent keyboard actions, of which up to 256 can be
bound to a single key. The actions available include outputting Latin1
character codes or character sequences, switching consoles or keymaps, booting
the machine etc. (The complete list can be obtained from
dumpkeys(1) by saying
dumpkeys -l).
Each
keysym may be prefixed by a '+' (plus sign), in which case this
keysym is treated as a "letter" and therefore affected by the
"CapsLock" the same way as by "Shift" (to be correct, the
CapsLock inverts the Shift state). The ASCII letters ('a'-'z' and 'A'-'Z') are
made CapsLock'able by default. If Shift+CapsLock should not produce a lower
case symbol, put lines like
keycode 30 = +a A
in the map file.
Which of the actions bound to a given key is taken when it is pressed depends on
what modifiers are in effect at that moment. The keyboard driver supports 8
modifiers. These modifiers are labeled (completely arbitrarily) Shift, AltGr,
Control, Alt, ShiftL, ShiftR, CtrlL and CtrlR. Each of these modifiers has an
associated weight of power of two according to the following table:
- modifier
- weight
- Shift
-
1
- AltGr
-
2
- Control
-
4
- Alt
-
8
- ShiftL
-
16
- ShiftR
-
32
- CtrlL
-
64
- CtrlR
- 128
The effective action of a key is found out by adding up the weights of all the
modifiers in effect. By default, no modifiers are in effect, so action number
zero, i.e. the one in the first column in a key definition line, is taken when
the key is pressed or released. When e.g. Shift and Alt modifiers are in
effect, action number nine (from the 10th column) is the effective one.
Changing the state of what modifiers are in effect can be achieved by binding
appropriate key actions to desired keys. For example, binding the symbol Shift
to a key sets the Shift modifier in effect when that key is pressed and
cancels the effect of that modifier when the key is released. Binding
AltGr_Lock to a key sets AltGr in effect when the key is pressed and cancels
the effect when the key is pressed again. (By default Shift, AltGr, Control
and Alt are bound to the keys that bear a similar label; AltGr may denote the
right Alt key.)
Note that you should be very careful when binding the modifier keys, otherwise
you can end up with an unusable keyboard mapping. If you for example define a
key to have Control in its first column and leave the rest of the columns to
be VoidSymbols, you're in trouble. This is because pressing the key puts
Control modifier in effect and the following actions are looked up from the
fifth column (see the table above). So, when you release the key, the action
from the fifth column is taken. It has VoidSymbol in it, so nothing happens.
This means that the Control modifier is still in effect, although you have
released the key. Re-pressing and releasing the key has no effect. To avoid
this, you should always define all the columns to have the same modifier
symbol. There is a handy short-hand notation for this, see below.
keysyms can be given in decimal, octal, hexadecimal or symbolic notation.
The numeric notations use the same format as with
keynumber. The
symbolic notation resembles that used by
xmodmap(1). Notable
differences are the number symbols. The numeric symbols '0', ..., '9' of
xmodmap(1) are replaced with the corresponding words 'zero', 'one', ...
'nine' to avoid confusion with the numeric notation.
It should be noted that using numeric notation for the
keysyms is highly
unportable as the key action numbers may vary from one kernel version to
another and the use of numeric notations is thus strongly discouraged. They
are intended to be used only when you know there is a supported keyboard
action in your kernel for which your current version of
loadkeys(1) has
no symbolic name.
If you do need to use numeric notations, comment those lines heavily and add a
comment at the top of the file. This will save your sanity (if any) later. If
this file should happen to get past your personal system, it may also save you
much pain and embarrassment. Also, please file a bug report against loadkeys
noting the need for a symbolic name.
There is a number of short-hand notations to add readability and reduce typing
work and the probability of typing-errors.
First of all, you can give a map specification line, of the form
keymaps 0-2,4-5,8,12
to indicate that the lines of the keymap will not specify all 256 columns, but
only the indicated ones. (In the example: only the plain, Shift, AltGr,
Control, Control+Shift, Alt and Control+Alt maps, that is, 7 columns instead
of 256.) When no such line is given, the keymaps 0-M will be defined, where
M+1 is the maximum number of entries found in any definition line.
Next, you can leave off any trailing VoidSymbol entries from a key definition
line. VoidSymbol denotes a keyboard action which produces no output and has no
other effects either. For example, to define key number 30 to output 'a'
unshifted, 'A' when pressed with Shift and do nothing when pressed with AltGr
or other modifiers, you can write
keycode 30 =
a A
instead of the more verbose
keycode 30 = a A VoidSymbol VoidSymbol \
VoidSymbol VoidSymbol VoidSymbol ...
For added convenience, you can usually get off with still more terse
definitions. If you enter a key definition line with only and exactly one
action code after the equals sign, it has a special meaning. If the code
(numeric or symbolic) is not an ASCII letter, it means the code is implicitly
replicated through all columns being defined. If, on the other hand, the
action code is an ASCII character in the range 'a', ..., 'z' or 'A', ..., 'Z'
in the ASCII collating sequence, the following definitions are made for the
different modifier combinations, provided these are actually being defined.
(The table lists the two possible cases: either the single action code is a
lower case letter, denoted by 'x' or an upper case letter, denoted by 'Y'.)
- modifier
- symbol
- none
- x Y
- Shift
- X y
- AltGr
- x Y
- Shift+AltGr
- X y
- Control
- Control_x Control_y
- Shift+Control
- Control_x Control_y
- AltGr+Control
- Control_x Control_y
- Shift+AltGr+Control
- Control_x Control_y
- Alt
- Meta_x Meta_Y
- Shift+Alt
- Meta_X Meta_y
- AltGr+Alt
- Meta_x Meta_Y
- Shift+AltGr+Alt
- Meta_X Meta_y
- Control+Alt
- Meta_Control_x Meta_Control_y
- Shift+Control+Alt
- Meta_Control_x Meta_Control_y
- AltGr+Control+Alt
- Meta_Control_x Meta_Control_y
- Shift+AltGr+Control+Alt
- Meta_Control_x Meta_Control_y
SINGLE MODIFIER DEFINITIONS¶
All the previous forms of key definition lines always define all the M+1
possible modifier combinations being defined, whether the line actually
contains that many action codes or not. There is, however, a variation of the
definition syntax for defining only single actions to a particular modifier
combination of a key. This is especially useful, if you load a keymap which
doesn't match your needs in only some modifier combinations, like
AltGr+function keys. You can then make a small local file redefining only
those modifier combinations and loading it after the main file. The syntax of
this form is:
{
plain | <modifier sequence> }
keycode
keynumber = keysym
e.g.,
plain keycode 14 = BackSpace
control alt keycode 83 = Boot
alt keycode 105 = Decr_Console
alt keycode 106 = Incr_Console
Using "plain" will define only the base entry of a key (i.e. the one
with no modifiers in effect) without affecting the bindings of other modifier
combinations of that key.
STRING DEFINITIONS¶
In addition to comments and key definition lines, the keymap files can contain
string definitions. These are used to define what each function key action
code sends. The syntax of string definitions is:
string keysym =
text
text can contain literal characters, octal character codes in the format
of backslash followed by up to three octal digits, and the three escape
sequences
\n,
\\, and
\", for newline, backslash and
quote, respectively.
COMPOSE DEFINITIONS¶
Then there may also be compose definitions. They have syntax
compose 'char'
'char' to 'char'
and describe how two bytes are combined to form a third one (when a dead accent
or compose key is used). This is used to get accented letters and the like on
a standard keyboard.
ABBREVIATIONS¶
Various abbreviations can be used with kbd-0.96 and later.
- strings as usual
- Defines the usual values of the strings (but not the keys
they are bound to).
- compose as usual for "iso-8859-1"
- Defines the usual compose combinations.
- alt_is_meta
- Whenever some combination is defined as an ASCII symbol,
and there is a corresponding Alt keymap, define by default the
corresponding Alt combination as Meta_value.
To find out what
keysyms there are available for use in keymaps files,
use the command
dumpkeys --long-info
Unfortunately, there is currently no description of what each symbol does. It
has to be guessed from the name or figured out from the kernel sources.
EXAMPLES¶
(Be careful to use a keymaps line, like the first line of `dumpkeys`, or
"keymaps 0-15" or so.)
The following entry exchanges the left Control key and the Caps Lock key on the
keyboard:
keycode 58 = Control
keycode 29 = Caps_Lock
Key number 58 is normally the Caps Lock key, and key number 29 is normally the
Control key.
The following entry sets the Shift and Caps Lock keys to behave more nicely,
like in older typewriters. That is, pressing Caps Lock key once or more sets
the keyboard in CapsLock state and pressing either of the Shift keys releases
it.
keycode 42 = Uncaps_Shift
keycode 54 = Uncaps_Shift
keycode 58 = Caps_On
The following entry sets the layout of the edit pad in the enhanced keyboard to
be more like that in the VT200 series terminals:
keycode 102 = Insert
keycode 104 = Remove
keycode 107 = Prior
shift keycode 107 = Scroll_Backward
keycode 110 = Find
keycode 111 = Select
control alt keycode 111 = Boot
control altgr keycode 111 = Boot
Here's an example to bind the string "du\ndf\n" to the key AltGr-D. We
use the "spare" action code F100 not normally bound to any key.
altgr keycode 32 = F100
string F100 = "du\ndf\n"
SEE ALSO¶
loadkeys(1),
dumpkeys(1),
showkey(1),
xmodmap(1).