# phpman > man > lesskey(1) > **TLDR:** Customize keybindings for `less`. > - Compile key bindings from a source file: `lesskey {{path/to/lesskey_file}}` - Compile key bindings and write to a specific output file: `lesskey {{-o|--output}} {{path/to/output}} {{path/to/lesskey_file}}` - Display version: `lesskey {{-V|--version}}` *Source: tldr-pages* --- [LESSKEY(1)](https://www.chedong.com/phpMan.php/man/LESSKEY/1/markdown) General Commands Manual [LESSKEY(1)](https://www.chedong.com/phpMan.php/man/LESSKEY/1/markdown) ## 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 iden‐ tifies 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 com‐ mand section consists of lines of the form: _string_ _action_ [extra-string] 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 oc‐ tal 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 liter‐ ally. Characters which must be preceded by backslash include caret, space, tab and the back‐ slash 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 com‐ mand. 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 status. ## 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 commands. A default command key may be disabled by including it in the input file with the action "invalid". Alterna‐ tively, 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 con‐ trol 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 pro‐ vide 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 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)](https://www.chedong.com/phpMan.php/man/less/1/markdown) ## 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 redistribute it and/or modify it under the terms of either (1) the GNU General 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 Gen‐ eral 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 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. ## AUTHOR Mark Nudelman Report bugs at . Version 590: 03 Jun 2021 [LESSKEY(1)](https://www.chedong.com/phpMan.php/man/LESSKEY/1/markdown)