Provided by: less_590-2ubuntu2.1_amd64 
NAME
lesskey - specify key bindings for less
SYNOPSIS (deprecated)
lesskey [-o output] [--] [input]
lesskey [--output=output] [--] [input]
lesskey -V
lesskey --version
SCOPE
This document describes the format of the lesskey source file, which is used by less version 582 and
later. In previous versions of less, a separate program called lesskey was used to compile the lesskey
source file into a format understood by less. This compilation step is no longer required and the
lesskey program is therefore deprecated although the file format remains supported by less itself.
FILE FORMAT
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 certain characters
specifies input characters as follows:
\b BACKSPACE
\e ESCAPE
\n NEWLINE
\r RETURN
\t TAB
\ku UP ARROW
\kd DOWN ARROW
\kr RIGHT ARROW
\kl LEFT ARROW
\kU PAGE UP
\kD PAGE DOWN
\kh HOME
\ke END
\kx DELETE
A backslash followed by any other character indicates that character is to be taken literally.
Characters 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, the first character of the extra string is used as its exit status.
EXAMPLE
The following input file describes the set of default command keys used by less:
#command
\r forw-line
\n forw-line
e forw-line
j forw-line
\kd 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
\kD forw-screen
b back-screen
^B back-screen
\ev back-screen
\kU back-screen
z forw-window
w back-window
\e\40 forw-screen-force
F forw-forever
\eF forw-until-hilite
R repaint-flush
r repaint
^R repaint
^L repaint
\eu undo-hilite
\eU clear-search
g goto-line
\kh goto-line
< goto-line
\e< goto-line
p percent
% percent
\e[ left-scroll
\e] right-scroll
\e( left-scroll
\e) right-scroll
\kl left-scroll
\kr right-scroll
\e{ no-scroll
\e} end-scroll
{ 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
\ke goto-end
\eG goto-end-buffered
= 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
& filter
m set-mark
M set-mark-bottom
\em clear-mark
' goto-mark
^X^X goto-mark
E examine
:e examine
^X^V examine
:n next-file
:p prev-file
t next-tag
T prev-tag
:x index-file
:d remove-file
- toggle-option
:t toggle-option t
s toggle-option o
_ display-option
| pipe
v visual
! shell
+ firstcmd
H help
h help
V version
0 digit
1 digit
2 digit
3 digit
4 digit
5 digit
6 digit
7 digit
8 digit
9 digit
q quit
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 commands 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 editing commands, in a manner similar to the way key
bindings for ordinary commands are specified in the #command section. 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
^L expand
^V literal
^A literal
\el right
\kr right
\eh left
\kl left
\eb word-left
\e\kl word-left
\ew word-right
\e\kr word-right
\ei insert
\ex delete
\kx delete
\eX word-delete
\ekx word-delete
\e\b word-backspace
\e0 home
\kh home
\e$ end
\ke end
\ek up
\ku up
\ej down
^G abort
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
variable 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
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) 1984-2021 Mark Nudelman
less is part of the GNU project and is free software. You can redistribute it and/or modify it under the
terms of either (1) the GNU General Public License as published by the Free Software Foundation; or (2)
the Less License. See the file README in the less distribution for more details regarding
redistribution. You should have received a copy of the GNU General Public License along with the source
for less; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place, Suite
330, Boston, MA 02111-1307, USA. You should also have received a copy of the Less License; see the file
LICENSE.
less is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
AUTHOR
Mark Nudelman
Report bugs at https://github.com/gwsw/less/issues.
Version 590: 03 Jun 2021 LESSKEY(1)