path: root/lesskey.man

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 speci-
       fied, 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 $HOME is unde-
       fined.  The output file is a binary file which is used by less.  If  no
       output  file is specified, and the environment variable LESSKEY is set,
       the value of LESSKEY is used as the name of the  output  file.   Other-
       wise, a standard filename is used as the name of the output file, which
       depends  on  the  system  being  used:  On  Unix  and   OS-9   systems,
       "$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  fol-
       lowed 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, the first character of the extra string is used as its exit sta-
       tus.

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 com-
       mands.  A default command key may be disabled by including  it  in  the
       input  file with the action "invalid".  Alternatively, a key may be de-
       fined to do nothing by using the action "noaction".  "noaction" is sim-
       ilar  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
            \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 over-
       ride 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) 1984-2021  Mark Nudelman

       less  is  part of the GNU project and is free software.  You can redis-
       tribute it and/or modify it under the terms of either (1) the GNU  Gen-
       eral  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 General 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  FIT-
       NESS  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
       more details.

AUTHOR
       Mark Nudelman
       Report bugs at https://github.com/gwsw/less/issues.



                           Version 581: 06 Apr 2021                 LESSKEY(1)