lesskey —
specify key bindings for less
lesskey |
[ -o
output |
--output=output
]
[input ] |
lesskey is used to specify a set of key
bindings to be used by
less(1).
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; by
default
$HOME/.lesskey. The output file is
a binary file which is used by
less(1). 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;
by default
$HOME/.less is used. If the
output file already exists,
lesskey will
overwrite it.
A system-wide lesskey file may also be set up to provide key bindings. If a key
is defined in both a local lesskey file and in the system-wide file, key
bindings in the local file take precedence over those in the system-wide file.
If the environment variable
LESSKEY_SYSTEM
is set,
less(1) uses that as the
name of the system-wide lesskey file. Otherwise,
less(1) looks in a standard place
for the system-wide lesskey file: On
OpenBSD, the
system-wide lesskey file is
/etc/sysless.
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.
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, first character of the extra
string is used as its exit status.
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
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
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.
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.
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
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. Whitespace before
and after the equals sign is ignored. Variables assigned in this way are
visible only to less. If environment variables are defined in more than one
place, variables defined in a local lesskey file take precedence over
variables defined in the system environment, which take precedence over
variables defined in the system-wide lesskey file. 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.
The following input file sets the -i option whenever less is run:
LESSKEY- Name of the default
lesskey file.
LESSKEY_SYSTEM- Name of the default system-wide
lesskey
file.
- $HOME/.less
- Default
lesskey file.
- $HOME/.lesskey
- Default
lesskey input file.
- /etc/sysless
- Default system-wide
lesskey file.
less(1)
Mark Nudelman
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