The input file consists of lines of the form:
string <whitespace> action <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 may be used to cause the following character to be taken literally. Characters which must be preceeded by backslash include carat, space, tab and the backslash itself. A backslash followed by one to three octal digits may be used to specify a character by its octal value. Blank lines and lines which start with a pound sign (#) are ignored.
As an example, the following input file describes the set of default command keys used by less:
k back-line
y back-line
^K back-line
^Y back-line
^P back-line
b back-screen
^B back-screen
\33v back-screen
u back-scroll
^U back-scroll
? back-search
E examine
^X^V examine
+ first-cmd
e forw-line
j forw-line
^E forw-line
^J forw-line
^M forw-line
^N forw-line
f forw-screen
^F forw-screen
\40 forw-screen
^V forw-screen
d forw-scroll
^D forw-scroll
/ forw-search
G goto-end
> goto-end
\33> goto-end
g goto-line
< goto-line
\33< goto-line
' goto-mark
^X^X goto-mark
H help
N next-file
% percent
p percent
P prev-file
q quit
ZZ quit
^L repaint
^R repaint
r repaint
R flush-repaint
n repeat-search
m set-mark
! shell
= status
^G status
- toggle-option
_ display-option
V version
v visual
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".