The input file 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 carat 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. Characters which must be preceded by backslash include carat, space, tab and the backslash itself. Blank lines and lines which start with a pound sign (#) are ignored.
An action may be followed by an extra string. This string is parsed after the command is entered, just as if it were entered on the command line. This feature can be used in certain cases to extend the functionality of a command. For example, these entries would create a pair of commands to turn on/off line numbers using vi syntax:
:set\ nu toggle-option -N
:set\ nonu toggle-option +N
See also the ":ta" command in the example below.
\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
' back-scroll
\40 forw-screen
f forw-screen
^F forw-screen
^V forw-screen
b back-screen
^B back-screen
\ev back-screen
z forw-window
w back-window
F forw-forever
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
P 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
\u 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
Commands specified by lesskey take precedence over the default commands. A default command key may be disabled by including it in the key file with the action "invalid".