keyboard - how to type characters
Keyboards are idiosyncratic. It should be obvious how to type ordinary
characters, backspace, tab, escape, and newline. In Plan
9, the key labeled Return
generates a newline
); if there is a key labeled Line Feed
, it generates
a carriage return (0x0D
); Plan 9 eschews CRLFs. All control characters
are typed in the usual way; in particular, control-J is a line feed and
control-M a carriage return.
The down arrow, used by 9term
(1), and sam
causes windows to scroll forward. The up arrow scrolls backward.
Characters in Plan 9 are runes (see utf
(7)). Any 16-bit rune can be typed
using a compose key followed by several other keys. The compose key is also
generally near the lower right of the main key area: the NUM PAD
the Gnot, the Alternate
key on the Next, the Compose
key on the
SLC, the Option
key on the Magnum, and either Alt
key on the PC.
After typing the compose key, type a capital and exactly four hexadecimal
characters (digits and to to type a single rune with the value represented by
the typed number. There are shorthands for many characters, comprising the
compose key followed by a two- or three-character sequence. The full list is
too long to repeat here, but is contained in the file in a format suitable for
(1) or look
(1). To add a sequence, edit that file and then
There are several rules guiding the design of the sequences, as illustrated by
the following examples.
- A repeated symbol gives a variant of that symbol, e.g., ?? yields
- ASCII digraphs for mathematical operators give the
corresponding operator, e.g., <= yields ≤.
- Two letters give the corresponding ligature, e.g., AE yields
- Mathematical and other symbols are given by abbreviations for their names,
e.g., pg yields ¶.
- Chess pieces are given by a w or b followed by a letter for
the piece (k for king, q for queen, r for rook,
n for knight, b for bishop, or p for pawn), e.g.,
wk for a white king.
- Greek letters are given by an asterisk followed by a corresponding latin
letter, e.g., *d yields δ.
- Cyrillic letters are given by an at sign followed by a corresponding latin
letter or letters, e.g., @ya yields я.
- Script letters are given by a dollar sign followed by the corresponding
regular letter, e.g., $F yields ℱ.
- A digraph of a symbol followed by a letter gives the letter with an accent
that looks like the symbol, e.g., ,c yields ç.
- Two digits give the fraction with that numerator and denominator, e.g.,
12 yields ½.
- The letter s followed by a character gives that character as a
superscript, e.g., s1 yields ⁱ. These characters are taken
from the Unicode block 0x2070; the 1, 2, and 3 superscripts in the Latin-1
block are available by using a capital S instead of s.
- Sometimes a pair of characters give a symbol related to the
superimposition of the characters, e.g., cO yields ©.
- A mnemonic letter followed by $ gives a currency symbol, e.g., l$
Note the difference between ß (ss) and µ (micron) and the Greek
β and μ.
Under X Windows, both the Alt key and the ``Multi key'' can begin a compose
sequence in a Plan 9 program.
It is also possible to configure X Windows to use the same keystroke mappings as
the Plan 9 programs. First, generate an XCompose sequence list by using
mklatinkbd -x $PLAN9/lib/keyboard >$HOME/.XCompose
Second, configure a ``Multi key'' by running
xmodmap -e 'keysym Super_L = Multi_key'
(The name typically denotes the Windows key on recent keyboards.)
Third, set these environment variables so that GTK- and QT-based programs will
use the compose sequences:
Finally, start a new GTK- or QT-based program:
In that terminal, typing the key sequence `Windows * a
should be interpreted as the Greek letter
If using the GNOME Window Manager, put the xmodmap
commands into the file $HOME/.gnomerc
to run them automatically at
- sorted table of characters and keyboard sequences