LESSKEY(1) General Commands Manual LESSKEY(1)
NAME
lesskey - specify key bindings for less
SYNOPSIS
lesskey [-o output] [--] [input]
lesskey [--output=output] [--] [input]
lesskey -V
lesskey --version
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 or --version option causes lesskey to print its version number and immediately exit. If -V or --version 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 certain characters specifies input characters as follows:
BACKSPACE
e ESCAPE
NEWLINE
RETURN
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 back-
slash 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 command keys used by less:
#command
forw-line
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
e40 forw-screen-force
F forw-forever
R repaint-flush
r repaint
^R repaint
^L repaint
eu undo-hilite
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
{ 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
= 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
' 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
forw-complete
17 back-complete
e back-complete
^L expand
^V literal
^A literal
el right
kr right
eh left
kl left
eb word-left
ekl word-left
ew word-right
ekr word-right
ei insert
ex delete
kx delete
eX word-delete
ekx word-delete
e 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) 2000-2011 Mark Nudelman
lesskey is part of the GNU project and is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either version 2, or (at your option) any later version.
lesskey 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.
You should have received a copy of the GNU General Public License along with lesskey; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
AUTHOR
Mark Nudelman <markn@greenwoodsoftware.com>
Send bug reports or comments to the above address or to bug-less@gnu.org.
Version 444: 09 Jun 2011 LESSKEY(1)