LESSKEY(1)
NAME
lesskey - specify key bindings for less
SYNOPSIS
lesskey [-o output] [input]
lesskey -V
DESCRIPTION
Lesskey is used to specify a set of key bindings to be
used by less. The input file is a text file which
describes the key bindings, If the input file is "-",
standard input is read. If no input file is specified, a
standard filename is used as the name of the input file,
which depends on the system being used: On Unix systems,
$HOME/.lesskey is used; on MS-DOS systems, $HOME/_lesskey
is used; and on OS/2 systems $HOME/lesskey.ini is used, or
$INIT/lesskey.ini if $HOME is undefined. The output file
is a binary file which is used by less. If no output file
is specified, and the environment variable LESSKEY is set,
the value of LESSKEY is used as the name of the output
file. Otherwise, a standard filename is used as the name
of the output file, which depends on the system being
used: On Unix and OS-9 systems, $HOME/.less is used; on
MS-DOS systems, $HOME/_less is used; and on OS/2 systems,
$HOME/less.ini is used, or $INIT/less.ini if $HOME is
undefined. If the output file already exists, lesskey
will overwrite it.
The -V option causes lesskey to print its version number
and immediately exit. If -V is present, other options and
arguments are ignored.
The input file consists of one or more sections. Each
section starts with a line that identifies the type of
section. Possible sections are:
#command
Defines new command keys.
#line-edit
Defines new line-editing keys.
#env Defines environment variables.
Blank lines and lines which start with a pound sign (#)
are ignored, except for the special section header lines.
COMMAND SECTION
The command section begins with the line
#command
If the command section is the first section in the file,
this line may be omitted. The command section consists of
lines of the form:
string <whitespace> action [extra-string] <newline>
Whitespace is any sequence of one or more spaces and/or
tabs. The string is the command key(s) which invoke the
action. The string may be a single command key, or a
sequence of up to 15 keys. The action is the name of the
less action, from the list below. The characters in the
string may appear literally, or be prefixed by a caret to
indicate a control key. A backslash followed by one to
three octal digits may be used to specify a character by
its octal value. A backslash followed by b, e, n, r or t
specifies BACKSPACE, ESCAPE, NEWLINE, RETURN or TAB,
respectively. A backslash followed by any other character
indicates that character is to be taken literally. Char-
acters which must be preceded by backslash include caret,
space, tab and the backslash itself.
An action may be followed by an "extra" string. When such
a command is entered while running less, the action is
performed, and then the extra string is parsed, just as if
it were typed in to less. This feature can be used in
certain cases to extend the functionality of a command.
For example, see the "{" and ":t" commands in the example
below. The extra string has a special meaning for the
"quit" action: when less quits, first character of the
extra string is used as its exit status.
EXAMPLE
The following input file describes the set of default com-
mand keys used by less:
#command
\r forw-line
\n forw-line
e forw-line
j forw-line
^E forw-line
^N forw-line
k back-line
y back-line
^Y back-line
^K back-line
^P back-line
J forw-line-force
K back-line-force
Y back-line-force
d forw-scroll
^D forw-scroll
u back-scroll
^U back-scroll
\40 forw-screen
f forw-screen
^F forw-screen
^V forw-screen
b back-screen
^B back-screen
\ev back-screen
\e\40 forw-screen-force
z forw-window
w back-window
F forw-forever
\e[ left-scroll
\e] right-scroll
R repaint-flush
r repaint
^R repaint
^L repaint
g goto-line
< goto-line
\e< goto-line
p percent
% percent
{ forw-bracket {}
} back-bracket {}
( forw-bracket ()
) back-bracket ()
[ forw-bracket []
] back-bracket []
\e^F forw-bracket
\e^B back-bracket
G goto-end
\e> goto-end
> goto-end
= status
^G status
:f status
/ forw-search
? back-search
\e/ forw-search *
\e? back-search *
n repeat-search
\en repeat-search-all
N reverse-search
\eN reverse-search-all
\eu undo-hilite
m set-mark
' goto-mark
^X^X goto-mark
E examine
:e examine
^X^V examine
:n next-file
:p prev-file
:x index-file
- toggle-option
:t toggle-option t
s toggle-option o
_ display-option
| pipe
v visual
! shell
+ firstcmd
H help
h help
V version
q quit
:q quit
:Q quit
ZZ quit
PRECEDENCE
Commands specified by lesskey take precedence over the
default commands. A default command key may be disabled
by including it in the input file with the action
"invalid". Alternatively, a key may be defined to do
nothing by using the action "noaction". "noaction" is
similar to "invalid", but less will give an error beep for
an "invalid" command, but not for a "noaction" command.
In addition, ALL default commands may be disabled by
adding this control line to the input file:
#stop
This will cause all default commands to be ignored. The
#stop line should be the last line in that section of the
file.
Be aware that #stop can be dangerous. Since all default
commands are disabled, you must provide sufficient com-
mands before the #stop line to enable all necessary
actions. For example, failure to provide a "quit" command
can lead to frustration.
LINE EDITING SECTION
The line-editing section begins with the line:
#line-edit
This section specifies new key bindings for the line edit-
ing commands, in a manner similar to the way key bindings
for ordinary commands are specified in the #command sec-
tion. The line-editing section consists of a list of keys
and actions, one per line as in the example below.
EXAMPLE
The following input file describes the set of default
line-editing keys used by less:
#line-edit
\t forw-complete
\17 back-complete
\e\t back-complete
\14 expand
^V literal
^A literal
\el right
\eh left
\eb word-left
\ew word-right
\ei insert
\ex delete
\e\b word-backspace
\e0 home
\e$ end
\ek up
\ej down
LESS ENVIRONMENT VARIABLES
The environment variable section begins with the line
#env
Following this line is a list of environment variable
assignments. Each line consists of an environment vari-
able name, an equals sign (=) and the value to be assigned
to the environment variable. White space before and after
the equals sign is ignored. Variables assigned in this
way are visible only to less. If a variable is specified
in the system environment and also in a lesskey file, the
value in the lesskey file takes precedence. Although the
lesskey file can be used to override variables set in the
environment, the main purpose of assigning variables in
the lesskey file is simply to have all less configuration
information stored in one file.
EXAMPLE
The following input file sets the -i option whenever less
is run, and specifies the character set to be "latin1":
#env
LESS = -i
LESSCHARSET = latin1
SEE ALSO
less(1)
WARNINGS
It is not possible to specify special keys, such as upar-
row, in a keyboard-independent manner. The only way to
specify such keys is to specify the escape sequence which
a particular keyboard sends when such a keys is pressed.
On MS-DOS and OS/2 systems, certain keys send a sequence
of characters which start with a NUL character (0). This
NUL character should be represented as \340 in a lesskey
file.
COPYRIGHT
Copyright (c) 1984,1985,1989,1994,1995 Mark Nudelman
Comments to: markn@fog.net