lesskey - specify key bindings for less
(deprecated) lesskey [-o output] [--] [input] lesskey [--output=output] [--] [input] lesskey -V lesskey --version
LESSKEY(1) General Commands Manual LESSKEY(1)
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 fol-
lowed 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 sta-
tus.
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 com-
mands. 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 over-
ride 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
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | text/less |
+---------------+------------------+
|Stability | Volatile |
+---------------+------------------+
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 redis-
tribute it and/or modify it under the terms of either (1) the GNU Gen-
eral 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 FIT-
NESS 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.
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from http://www.greenwoodsoft-
ware.com/less/less-590.tar.gz.
Further information about this software can be found on the open source
community website at http://www.greenwoodsoftware.com/less/.
Version 590: 03 Jun 2021 LESSKEY(1)