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 4mLESS24m(1)                          General       Commands       Manual
 4mLESS24m(1)

 1mNAME0m
        less - display the contents of a file in a terminal

 1mSYNOPSIS0m


        1mless                                                    22m[1m-
 22m[1m+22m]1maABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~22m]             [1m-b
 4m22msize24m] [1m-D 4m22mcolor24m]
               [1m-h  4m22mlines24m]  [1m-j   4m22mline24m]   [1m-k
 4m22mkeyfile24m]    [1m-22m{1mo22m|1mO22m}   4mlogfile24m]
 [1m-p 4m22mpattern0m
               4m]24m  [1m-P  4m22mprompt24m]  [1m-t  4m22mtag24m]
 [1m-T                    4m22mtagsfile24m]                    [1m-x
 4m22mtab24m[{1m,4m22mtab24m}...]]
               [1m-y  4m22mlines24m]  [1m-z   4m22mlines24m]   [1m-
 4m22mlines24m]     [1m-"4m22mcc24m]     [1m-#     4m22mshift24m]
 [1m+4m22mlesscommand24m]
               [1m--22m] [4mfile24m ...]

        1mless -?0m
        1mless --help0m

        1mless -V0m
        1mless --version0m

        (See  the  OPTIONS section for alternate  option  syntax  with  long
 option
        names.)

 1mDESCRIPTION0m
        1mLess 22mis a program similar to 1mmore22m(1), but it has  many
 more  features.
        1mLess  22mdoes  not  have to read the entire  input  file  before
 starting, so
        with large input files it starts  up  faster   than   text   editors
 like
        1mvi22m(1).    1mLess  22muses  termcap  (or  terminfo  on  some
 systems), so it can run
        on a variety of  terminals.   There  is  even  limited  support  for
 hardcopy
        terminals.   (On  a hardcopy terminal, lines which should be printed
 at
        the top of the screen are prefixed with a caret.)

 1mCOMMANDS0m
        Commands are based on both 1mmore 22mand 1mvi22m.  Commands  may
 be preceded by  a
        decimal number, called N in the descriptions below.  The  number  is
 used
        by some commands, as indicated.

        In  the following descriptions, ^X means  controlX.   ESC  stands
 for the
        ESCAPE key; for example ESCv means the  two  character   sequence
 "ES
        CAPE", then "v".

        h or H Help:  display  a  summary of these commands.  If you  forget
 all
               the other commands, remember this one.

        SPACE or ^V or f or ^F
               Scroll forward N  lines,  default  one  window  (see   option
 1m-z  22mbe
               low).  If N is more than the  screen  size,  only  the  final
 screen
               ful  is  displayed.   Warning:  some  systems  use  ^V  as  a
 special
               literalization character.

        z      Like SPACE, but if N is  specified,  it   becomes   the   new
 window
               size.

        ENTER or RETURN or ^N or e or ^E or j or ^J
               Scroll  forward N lines, default 1.  The entire N  lines  are
 dis
               played, even if N is more than the screen size.

        d or ^D
               Scroll forward N lines, default one half of the screen  size.
 If
               N is specified, it becomes the new default for  subsequent  d
 and
               u commands.

        b or ^B or ESCv
               Scroll  backward  N lines, default  one  window  (see  option
 1m-z 22mbe
               low).  If N is more than the  screen  size,  only  the  final
 screen
               ful is displayed.

        w      Like ESCv, but if N is specified, it   becomes   the   new
 window
               size.

        y or ^Y or ^P or k or ^K
               Scroll backward N lines, default 1.  The entire N  lines  are
 dis
               played,  even  if N is more than the screen  size.   Warning:
 some
               systems use ^Y as a special job control character.

        u or ^U
               Scroll backward N lines, default one  half  of   the   screen
 size.
               If   N   is  specified,  it  becomes  the  new  default   for
 subsequent d
               and u commands.

        J      Like j, but continues to scroll beyond the end of the file.

        K or Y Like k, but continues to scroll  beyond  the   beginning   of
 the
               file.

        ESCSPACE
               Like SPACE, but scrolls a full screenful, even if it  reaches
 the
               end of the file.

        ESCb  Like b, but scrolls a full screenful, even  if  it  reaches
 the be
               ginning of the file.

        ESCj  Scroll  forward  N file lines, default 1.  A file line is a
 com
               plete line in the file, terminated by a newline.

        ESCk  Scroll backwards N file lines, default 1.

        ESC) or RIGHTARROW
               Scroll horizontally right  N  characters,  default  half  the
 screen
               width  (see   the  1m-#  22moption).   If  a  number  N  is
 specified, it be
               comes  the  default  for  future  RIGHTARROW  and   LEFTARROW
 commands.
               While  the  text  is  scrolled,  it acts as though the  1m-S
 22moption
               (chop lines) were in effect.

        ESC( or LEFTARROW
               Scroll horizontally left  N  characters,  default  half   the
 screen
               width  (see   the  1m-#  22moption).   If  a  number  N  is
 specified, it be
               comes  the  default  for  future  RIGHTARROW  and   LEFTARROW
 commands.

        ESC} or ^RIGHTARROW or SHIFTRIGHTARROW
               Scroll horizontally right to show the end  of   the   longest
 dis
               played line.

        ESC{ or ^LEFTARROW or SHIFTLEFTARROW
               Scroll horizontally left back to the first column.

        ^END or SHIFTEND
               Go  to  line  N  in  the  file, default the end of the  file,
 and
               scroll horizontally right to show the end  of   the   longest
 dis
               played line.

        ^HOME or SHIFTHOME
               Go  to  line  N  in the file, default 1 (beginning of  file),
 and
               scroll horizontally left back to the first column.

        r or ^R or ^L
               Repaint the screen.

        R      Repaint the screen, discarding any buffered input.  That  is,
 re
               load the current file.  Useful if the file is changing  while
 it
               is being viewed.

        F      Scroll  forward, and keep trying to read when the end of file
 is
               reached.  Normally this command would be used  when   already
 at
               the  end of the file.  It is a way to monitor the tail  of  a
 file
               which is growing while it is being  viewed.   (The   behavior
 is
               similar  to  the  "tail  -f" command.)  To stop  waiting  for
 more
               data, enter  the  interrupt  character  (usually   ^C).    On
 systems
               which support 1mpoll22m(2) you  can  also  use  ^X  or  the
 character spec
               ified  by  the  1m--intr  22moption.   If the  input  is  a
 pipe and the
               1m--exit-follow-on-close 22moption is  in  effect,  1mless
 22mwill  automati
               cally  stop  waiting for data when the input side of the pipe
 is
               closed.

        ESCf  Like F, but each time a line is found  which  matches   the
 last
               search pattern, the terminal bell is rung.

        ESCF  Like  F,  but  as soon as a line is found which matches the
 last
               search  pattern,  the  terminal  bell  is  rung  and  forward
 scrolling
               stops.

        g or < or ESC< or HOME
               Go to line N in the file,  default  1  (beginning  of  file).
 (Warn
               ing: this may be slow if N is large.)

        G or > or ESC> or END
               Go  to  line N in the file, default  the  end  of  the  file.
 (Warn
               ing: this may be slow if  N  is  large,  or  if  N   is   not
 specified
               and standard input, rather than a file, is being read.)

        ESCG  Same  as  G, except if no number N  is  specified  and  the
 input is
               standard  input,   goes   to   the   last   line   which   is
 currently
               buffered.

        p or % Go to a position N  percent  into  the  file.   N  should  be
 between 0
               and 100, and may contain a decimal point.

        P      Go to the line containing byte offset N in the file.

        {      If a left curly bracket appears in the top line displayed  on
 the
               screen,  the  {  command  will  go  to   the  matching  right
 curly
               bracket.  The matching right curly bracket is  positioned  on
 the
               bottom line of the screen.  If there is more  than  one  left
 curly
               bracket  on  the top line, a number N may be used to  specify
 the
               Nth bracket on the line.

        }      If a right curly bracket appears in the bottom line displayed
 on
               the screen, the } command will go  to   the   matching   left
 curly
               bracket.   The  matching left curly bracket is positioned  on
 the
               top line of the screen.  If there is  more  than  one   right
 curly
               bracket  on  the  bottom line, a number  N  may  be  used  to
 specify
               the Nth bracket on the line.

        (       Like  {,  but  applies  to  parentheses  rather  than  curly
 brackets.

        )       Like  },  but  applies  to  parentheses  rather  than  curly
 brackets.

        [      Like {, but applies to  square  brackets  rather  than  curly
 brack
               ets.

        ]      Like  }, but applies to square  brackets  rather  than  curly
 brack
               ets.

        ESC^F Followed by two characters, acts like {, but uses  the  two
 char
               acters  as   open  and  close  brackets,  respectively.   For
 example,
               "ESC ^F < >" could be used to  go  forward  to  the  >  which
 matches
               the < in the top displayed line.

        ESC^B Followed  by two characters, acts like }, but uses the  two
 char
               acters  as  open  and  close  brackets,  respectively.    For
 example,
               "ESC ^B < >" could be used to go  backward  to  the  <  which
 matches
               the > in the bottom displayed line.

        m      Followed  by  any lowercase or uppercase  letter,  marks  the
 first
               displayed line with that letter.  If a number  N  is   given,
 line
               number N is marked instead.  If the status column is  enabled
 via
               the 1m-J 22moption, the  status  column  shows  the  marked
 line.

        M      Acts  like  m,  except  the last  displayed  line  is  marked
 rather
               than the first displayed line.  If a number   N   is   given,
 line
               number N is marked instead.

        '      (Single  quote.)  Followed  by  any  lowercase  or  uppercase
 letter,
               returns to the position which was  previously   marked   with
 that
               letter.   Followed by another single quote,  returns  to  the
 posi
               tion  at  which  the  last  "large"  movement   command   was
 executed.
               Followed  by a ^ or $, jumps to the beginning or end  of  the
 file
               respectively.  If a number N is given,  the  marked  line  is
 placed
               on the Nth line on the screen.  Otherwise, it is placed on
 the
               same  line  that it was on when it was marked (the first line
 on
               the screen if marked via  the  1mm  22mcommand,  the   last
 line  on  the
               screen if marked via the 1mM 22mcommand, or the  line  that
 was clicked
               if  marked  via the mouse).  Marks are preserved when  a  new
 file
               is examined within a single invocation of 1mless22m, so the
 ' command
               can be used to switch between input  files.   The  1m--save-
 marks 22mop
               tion  causes  marks  to  be   preserved   across    different
 invocations
               of 1mless22m.

        ^X^X   Same as single quote.

        ESCm  Followed  by  any lowercase or uppercase letter, clears the
 mark
               identified by that letter.

        /4mpattern0m
               Search forward in the file for the Nth line containing the
 pat
               tern.  N defaults to 1.  The pattern is a regular expression,
 as
               recognized by the regular expression  library   supplied   by
 your
               system.     By   default,   searching   is   casesensitive
 (uppercase and
               lowercase are considered different); the 1m-i 22moption can
 be  used
               to  change  this.   The  search  starts  at  the  first  line
 displayed
               (but see the 1m-a 22mand 1m-j  22moptions,  which  change
 this).

               Certain characters are special if entered at  the   beginning
 of
               the  pattern;  they modify the type  of  search  rather  than
 become
               part of the pattern:

               ^N or !
                      Search for lines which do NOT match the pattern.

               ^E or *
                      Search multiple  files.   That  is,  if   the   search
 reaches
                      the  END of the current file without finding a  match,
 the
                      search continues in the next file   in   the   command
 line
                      list.

               ^F or @
                      Begin  the  search at the first line of the FIRST file
 in
                      the  command  line  list,  regardless  of   what    is
 currently
                      displayed  on  the screen or the settings of the 1m-a
 22mor 1m-j0m
                      options.

               ^K     Highlight any text which matches the  pattern  on  the
 cur
                      rent screen, but dont move to the first match (KEEP
 cur
                      rent position).

               ^R     Dont  interpret  regular expression metacharacters;
 that
                      is, do a simple textual comparison.

               ^S     Followed by a digit N between 1  and  5.   Only   text
 which
                      has a nonempty match for the  Nth  parenthesized
 SUBPAT
                      TERN  will be considered to match  the  pattern.   For
 exam
                      ple, searching for  "(abc)|(def)"  modified  with  ^S1
 would
                      search  for  instances  of "abc", but would  highlight
 in
                      stances of both "abc" and "def".  (Supported  only  if
 1mless0m
                      is  built  with  one  of   the   regular    expression
 libraries
                      1mposix22m,    1mpcre22m,    or     1mpcre222m.)
 Multiple ^S modifiers can be
                      specified, to match more than one subpattern.

               ^W     WRAP around the current  file.   That   is,   if   the
 search
                      reaches   the   end   of   the  current  file  without
 finding a
                      match, the search continues from the first   line   of
 the
                      current  file up to the line where it started.  If the
 ^W
                      modifier is set, the ^E modifier is ignored.

               ^L     The next character is taken literally; that   is,   it
 be
                      comes  part of the pattern even if it is  one  of  the
 above
                      search modifier characters.

        ?4mpattern0m
               Search backward in the file for the  Nth  line  containing
 the
               pattern.   The search starts at the last line displayed  (but
 see
               the 1m-a 22mand 1m-j 22moptions, which change this).

               Certain characters are special as in the / command:

               ^N or !
                      Search for lines which do NOT match the pattern.

               ^E or *
                      Search multiple  files.   That  is,  if   the   search
 reaches
                      the   beginning   of   the   current   file    without
 finding a
                      match, the search continues in the previous  file   in
 the
                      command line list.

               ^F or @
                      Begin the search at the last line of the last file  in
 the
                      command  line  list, regardless of what  is  currently
 dis
                      played on the screen or  the  settings  of  the  1m-a
 22mor 1m-j  22mop
                      tions.

               ^K     As in forward searches.

               ^R     As in forward searches.

               ^S     As in forward searches.

               ^W     WRAP  around  the  current  file.   That  is,  if  the
 search
                      reaches the beginning  of  the  current  file  without
 finding
                      a match, the search continues from the last  line   of
 the
                      current file up to the line where it started.

               ^L     As in forward searches.

        ESC/4mpattern0m
               Same as "/*".

        ESC?4mpattern0m
               Same as "?*".

        n      Repeat  previous  search, for Nth line containing the last
 pat
               tern.  If the previous search was modified by ^N, the  search
 is
               made  for the Nth line NOT containing the pattern.  If the
 pre
               vious search was modified by ^E, the  search   continues   in
 the
               next  (or  previous)  file if not satisfied  in  the  current
 file.
               If the previous search was modified by ^R,  the   search   is
 done
               without  using  regular expressions.  If the previous  search
 was
               modified by ^W, the search wraps at the end  (or   beginning)
 of
               the  file.   There is no effect if the  previous  search  was
 modi
               fied by ^F or ^K.

        N      Repeat previous search, but in the reverse direction.

        ESCn  Repeat previous search, but crossing file boundaries.   The
 ef
               fect is as if the previous search were modified by *.

        ESCN  Repeat  previous search, but in the reverse  direction  and
 cross
               ing file boundaries.

        ESCu  Undo search highlighting.    Turn   off   highlighting   of
 strings
               matching the current  search  pattern.   If  highlighting  is
 already
               off  because of a previous ESCu command, turn highlighting
 back
               on.  Any search command will also  turn   highlighting   back
 on.
               Also  unselects   any  OSC  8  hyperlink  that  is  currently
 selected.
               (Highlighting can also be  disabled  by  toggling  the  1m-G
 22moption; in
               that case search commands do not turn highlighting back on.)

        ESCU  Like ESCu but also clears the  saved   search   pattern.
 If  the
               status  column  is  enabled  via  the 1m-J 22moption,  this
 clears all
               search matches marked in the status column.

        &4mpattern0m
               Display only lines which match the pattern; lines  which   do
 not
               match  the pattern are hidden.  If pattern is empty  (if  you
 type
               & immediately followed by ENTER), any  filtering  is   turned
 off,
               and  all  lines are displayed.  While filtering is in effect,
 an
               ampersand is displayed at the beginning of the prompt,  as  a
 re
               minder   that   some   lines  in  the  file  may  be  hidden.
 Multiple &
               commands may be entered, in which  case  only   lines   which
 match
               all of the patterns will be displayed.

               Certain characters are special as in the / command:

               ^N or !
                      Display only lines which do NOT match the pattern.

               ^R     Dont  interpret  regular expression metacharacters;
 that
                      is, do a simple textual comparison.

        :e [4mfilename24m]
               Examine a  new  file.   If  the  filename  is  missing,   the
 "current"
               file  (see  the :n and :p commands below) from  the  list  of
 files
               in the command line is reexamined.  A percent sign (%)  in
 the
               filename  is  replaced by the name of the  current  file.   A
 pound
               sign (#) is  replaced  by  the   name   of   the   previously
 examined
               file.   However,  two  consecutive  percent signs are  simply
 re
               placed with a single percent sign.  This allows you to  enter
 a
               filename   that   contains  a  percent  sign  in  the   name.
 Similarly,
               two consecutive pound signs are  replaced   with   a   single
 pound
               sign.   The  filename  is inserted into the command line list
 of
               files so that it  can  be  seen  by  subsequent  :n  and   :p
 commands.
               If the filename consists  of  several  files,  they  are  all
 inserted
               into  the  list  of files and the first one is examined.   If
 the
               filename contains one or more  spaces,  the  entire  filename
 should
               be enclosed in double quotes (also see the 1m-" 22moption).

        ^X^V or E
               Same as :e.  Warning:  some  systems  use  ^V  as  a  special
 literal
               ization  character.  On such systems, you may not be able  to
 use
               ^V.

        :n     Examine the next file (from the list of files  given  in  the
 com
               mand  line).   If a number N is specified,  the  Nth  next
 file is
               examined.

        :p     Examine the previous file in the command  line  list.   If  a
 number
               N is specified, the Nth previous file is examined.

        :x     Examine the first file in the command line list.  If a number
 N
               is specified, the Nth file in the list is examined.

        :d     Remove the current file from the list of files.

        t      Go  to the next tag, if there were more than one matches  for
 the
               current tag.  See the 1m-t 22moption for more details about
 tags.

        T      Go to the previous tag, if there were more than  one  matches
 for
               the current tag.

        ^O^N or ^On
               Search forward  in  the  file  for  the  Nth  next  OSC  8
 hyperlink.

        ^O^P or ^Op
               Search  backward  in the file for the Nth previous  OSC  8
 hyper
               link.

        ^O^L or ^Ol
               Jump to the currently selected OSC 8 hyperlink.

        = or ^G or :f
               Prints  some  information  about  the  file  being    viewed,
 including
               its  name and the line number and byte offset of  the  bottom
 line
               being displayed.  If possible, it also prints the  length  of
 the
               file,  the  number  of  lines in the file and the percent  of
 the
               file above the last displayed line.

        -      Followed by one of  the  command  line  option  letters  (see
 OPTIONS
               below),  this will change the  setting  of  that  option  and
 print a
               message describing the new setting.  If a ^P (CONTROLP) is
 en
               tered  immediately  after the dash, the setting of the option
 is
               changed but no message is printed.  If the option letter  has
 a
               numeric  value (such as 1m-b 22mor 1m-h22m), or a  string
 value (such as 1m-P0m
               or 1m-t22m), a new value may be entered  after  the  option
 letter.   If
               no  new  value is entered, a message describing  the  current
 set
               ting is printed and nothing is changed.

        --     Like the - command, but  takes  a  long  option   name   (see
 OPTIONS
               below)  rather  than a single option letter.  Press ENTER  or
 RE
               TURN after typing the option name to  change  it.   You   can
 enter
               just the beginning of an option name, then press TAB to  find
 all
               option names which begin with that string.  A ^P  immediately
 af
               ter   the  second  dash  suppresses  printing  of  a  message
 describing
               the new setting, as in the - command.

        -+     Followed by one of the command line option letters this  will
 re
               set the option to its default setting and print   a   message
 de
               scribing  the  new   setting.    (The   "-+4mX24m"  command
 does the same
               thing as "1m-+X22m" on the command line.)  This  does   not
 work  for
               stringvalued options.

        --+    Like  the -+ command, but takes a  long  option  name  rather
 than a
               single option letter.

        -!     Followed by one of the command line  option   letters,   this
 will
               reset  the  option  to the "opposite" of its default  setting
 and
               print a message describing the new setting.   This  does  not
 work
               for numeric or stringvalued options.

        --!    Like  the -! command, but takes a  long  option  name  rather
 than a
               single option letter.

        _      (Underscore.)  Followed by one of the  command  line   option
 let
               ters,  this  will print  a  message  describing  the  current
 setting
               of that option.  The setting of the option is not changed.

        __     (Double underscore.)  Like the _  (underscore)  command,  but
 takes
               a long option name rather than a single option  letter.   You
 must
               press ENTER or RETURN after typing the option name.

        +4mcmd24m   Causes the specified cmd to be executed  each  time  a
 new file  is
               examined.  For example, +G causes  1mless  22mto  initially
 display each
               file starting at the end rather than the beginning.

        V      Prints the version number of 1mless 22mbeing run.

        q or Q or :q or :Q or ZZ
               Exits 1mless22m.

        The following seven commands may or may not be valid,  depending  on
 your
        particular installation.

        v      Invokes  an  editor  to edit the current file  being  viewed.
 The
               editor is taken  from  the  environment  variable  VISUAL  if
 defined,
               or EDITOR if VISUAL is not defined, or defaults  to  "vi"  if
 nei
               ther  VISUAL  nor EDITOR is defined.  See also the discussion
 of
               LESSEDIT under the section on PROMPTS below.

        ! 4mshellcommand0m
               Invokes a shell to run the shellcommand given.  A  percent
 sign
               (%)  in the command is replaced by the name  of  the  current
 file.
               A pound sign (#) is replaced by the name  of  the  previously
 exam
               ined file.  "!!" repeats the last shell command.   "!"   with
 no
               shell  command  invokes  an  interactive  shell.   If  a   ^P
 (CONTROLP)
               is entered immediately after the  !,  no  "done"  message  is
 printed
               after the shell command is executed.  On  Unix  systems,  the
 shell
               is  taken  from  the  environment variable SHELL, or defaults
 to
               "sh".  On MSDOS, Windows, and OS/2 systems, the  shell  is
 the
               normal command processor.

        # 4mshellcommand0m
               Similar  to the "!"  command,  except  that  the  command  is
 expanded
               in the same way as prompt strings.  For example, the name  of
 the
               current file would be given as "%f".

        | <4mm24m> 4mshellcommand0m
               <m> represents any mark letter.  Pipes  a  section   of   the
 input
               file  to  the given shell command.  If  the  marked  line  is
 before
               the top line of the current screen, the section to be   piped
 is
               between  the  marked  line  and   the   bottom  line  of  the
 current
               screen, inclusive.  Otherwise (if the marked  line   is   the
 top
               line  of the current screen or after it) the section  of  the
 file
               to be piped is between the top line of the   current   screen
 and
               the  marked line, inclusive.  <m> may  also  be  ^  or  $  to
 indicate
               beginning or end of  file  respectively.   If  <m>  is  .  or
 newline,
               the current screen  is  piped.   If  a  ^P  (CONTROLP)  is
 entered im
               mediately  after  the  mark  letter,  no  "done"  message  is
 printed
               after the shell command is executed.

        s 4mfilename0m
               Save the input to a file.  This works only if  the  input  is
 a
               pipe, not an ordinary file.

        ^O^O
               Run  a shell command to open the URI in  the  current  OSC  8
 hyper
               link, selected by a previous ^O^N  or  ^O^P   command.    The
 shell
               command   is    given    by    the    environment    variable
 named
               "LESS_OSC8_OPEN_xxx" where "xxx" is the scheme from  the  URI
 (the
               part before the first colon),  converted  to  lowercase.   If
 there
               is    no    colon    in    the    URI,    the     environment
 variable
               LESS_OSC8_OPEN_NONE is used.  The URI from the  hyperlink  is
 then
               shellescaped and appended to the value of the  environment
 vari
               able after a space, and the resulting string is  executed  as
 a
               shell command.

               For  example, if you wish to open https links by  invoking  a
 pro
               gram called "mybrowser" with  a  "--new-window"  option,  you
 could
               set

               LESS_OSC8_OPEN_https="mybrowser --new-window"

               If  the handler command begins with "-", the command  is  not
 dis
               played before it is  executed.   If   the   handler   command
 begins
               with  ^P  (CONTROLP),  the  "link  done"  message  is  not
 displayed
               after it is executed.  If the handler  command  begins   with
 ^P
               followed by "-", neither the  command  nor  the  "link  done"
 message
               is displayed.

               If  you  attempt  to  open  a link with the "xxx" scheme  and
 the
               LESS_OSC8_OPEN_xxx    variable    is     not     set,     the
 variable
               LESS_OSC8_OPEN_ANY  is tried.  If neither  LESS_OSC8_OPEN_xxx
 nor
               LESS_OSC8_OPEN_ANY is set,  links  using  the  "xxx"   scheme
 cannot
               be   opened.    However,   there   is   a    default    value
 for
               LESS_OSC8_OPEN_ANY which invokes the  program   1mless-osc8-
 open22m(1).
               This  program will open links  with  the  schemes  "man"  (by
 running
               1mman22m(1)) or "file"  (by  running  another  instance  of
 1mless22m(1) if the
               file  is  local).   1mless-osc8-open  22mshould   work   on
 systems  which
               provide a POSIXcompatible shell.

               Any  shell  metacharacters such as semicolons, dollar  signs,
 am
               persands, etc.  in the URI will be shellescaped before the
 URI
               is  appended  to the handler command.  If the handler  passes
 the
               URI or any substring of it to a shell, it should  take   care
 to
               appropriately  quote such strings, to  prevent  execution  of
 unin
               tended shell commands when opening  a  URI   which   contains
 shell
               metacharacters.

               As  a special case, if the URI begins with "#", the remainder
 of
               the URI is taken to be the  value  of  the  id  parameter  in
 another
               OSC  8  link in the same file, and ^O^O will simply  jump  to
 that
               link rather than running a handler program.

        ^X     When the "Waiting for data" message  is  displayed,  such  as
 while
               in  the  F  command, pressing ^X will stop  1mless  22mfrom
 waiting and
               return to a prompt.  This may cause 1mless 22mto think that
 the  file
               ends  at the current position, so it may be necessary to  use
 the
               R or F command to see more data.   The  1m--intr  22moption
 can be  used
               to  specify  a  different  character to use  instead  of  ^X.
 This
               command works only on systems that support the 1mpoll22m(2)
 function.
               On systems without 1mpoll22m(2),  the  interrupt  character
 (usually ^C)
               can be used instead.

 1mOPTIONS0m
        Command line options are  described  below.   Most  options  may  be
 changed
        while 1mless 22mis running, via the "-" command.

        Some  options  may be given in one  of  two  forms:  either  a  dash
 followed
        by a single letter, or two dashes followed by a long  option   name.
 A
        long  option name may be abbreviated as long as the abbreviation  is
 un
        ambiguous.  For example, 1m--mouse 22mmay  be  abbreviated   1m--
 mou22m,  but  not
        1m--mo22m, since both 1m--mouse 22mand 1m--modelines  22mbegin
 with 1m--mo22m.

        Some long option names  are  in  uppercase,  such  as  1m--QUIT-AT-
 EOF22m, as dis
        tinct from 1m--quit-at-eof22m.  Such option names need  only  have
 their first
        letter  capitalized;  the  remainder of the name may  be  in  either
 case.
        For example, 1m--Quit-at-eof  22mis  equivalent  to  1m--QUIT-AT-
 EOF22m.

        Options are also taken from the environment  variable  "LESS".   For
 exam
        ple, to avoid typing "less -options ..." each  time  1mless  22mis
 invoked, you
        might tell 1mcsh22m:

        setenv LESS "-options"

        or if you use 1msh22m:

        LESS="-options"; export LESS

        On MSDOS and Windows, you dont  need  the  quotes,   but   you
 should  be
        careful  that  any  percent  signs in the  options  string  are  not
 inter
        preted as an environment variable expansion.

        The environment variable is  parsed  before  the  command  line,  so
 command
        line  options override the LESS environment variable.  If an  option
 ap
        pears in the LESS variable, it can be reset to its default value  on
 the
        command line by beginning the command line option with "1m-+22m".

        Some options like 1m-k 22mor 1m-D 22mrequire a string to  follow
 the  option  let
        ter.   The  string  for  that option is considered  to  end  when  a
 dollar
        sign ($) is found.  For example, you can set two  1m-D  22moptions
 like this:

        LESS="Dnwb$Dsbw"

        If  the  1m--use-backslash  22moption  appears  earlier   in   the
 options,  then  a
        dollar  sign or backslash may be included  literally  in  an  option
 string
        by  preceding  it  with  a  backslash.   If  the  1m--use-backslash
 22moption is not
        in effect, then backslashes are not treated specially, and there  is
 no
        way to include a dollar sign in the option string.

        1m-? 22mor 1m--help0m
               This  option displays a summary of the commands  accepted  by
 1mless0m
               (the same as the h command).  (Depending on how  your   shell
 in
               terprets  the  question  mark,  it may be necessary to  quote
 the
               question mark, thus: "1m-?22m".)

        1m-a 22mor 1m--search-skip-screen0m
               By default,  forward  searches  start  at  the  top  of   the
 displayed
               screen  and  backwards  searches start at the bottom  of  the
 dis
               played screen (except for repeated searches invoked by the  n
 or
               N  commands,  which  start after or before the "target"  line
 re
               spectively; see the  1m-j  22moption  for  more  about  the
 target  line).
               The  1m-a  22moption  causes forward  searches  to  instead
 start at the
               bottom of the screen and backward searches to start  at   the
 top
               of the screen, thus  skipping  all  lines  displayed  on  the
 screen.

        1m-A 22mor 1m--SEARCH-SKIP-SCREEN0m
               auses   all   forward  searches  (not   just   nonrepeated
 searches) to
               start just after the target line, and all backward   searches
 to
               start  just before the target line.  Thus,  forward  searches
 will
               skip part of the displayed screen (from the first line up  to
 and
               including the target line).   Similarly  backwards   searches
 will
               skip the displayed screen  from  the  last  line  up  to  and
 including
               the target line.  This  was  the  default  behavior  in  less
 versions
               prior to 441.

        1m-b4m22mn24m or 1m--buffers=4m22mn0m
               Specifies  the  amount  of  buffer   space  1mless  22mwill
 use for each
               file, in units of kilobytes (1024 bytes).  By default  64  KB
 of
               buffer  space  is used for each file (unless the  file  is  a
 pipe;
               see the 1m-B 22moption).  The 1m-b  22moption   specifies
 instead  that  4mn0m
               kilobytes of buffer space should be used for each  file.   If
 4mn24m is
               -1,  buffer  space is unlimited; that is, the entire file can
 be
               read into memory.

        1m-B 22mor 1m--auto-buffers0m
               By default, when data  is  read  from  a  pipe,  buffers  are
 allocated
               automatically as needed.  If a large amount of data  is  read
 from
               the pipe, this can cause a large amount  of  memory   to   be
 allo
               cated.   The  1m-B   22moption   disables   this  automatic
 allocation of
               buffers for pipes, so that only 64 KB  (or  the   amount   of
 space
               specified  by the 1m-b 22moption) is  used  for  the  pipe.
 Warning: use
               of 1m-B 22mcan result in erroneous display, since only  the
 most  re
               cently viewed part of the piped data is kept in  memory;  any
 ear
               lier  data  is   lost.   Lost  characters  are  displayed  as
 question
               marks.

        1m-c 22mor 1m--clear-screen0m
               Causes full screen repaints to be  painted   from   the   top
 line
               down.   By   default,   full  screen  repaints  are  done  by
 scrolling
               from the bottom of the screen.

        1m-C 22mor 1m--CLEAR-SCREEN0m
               Same as 1m-c22m, for compatibility with older  versions  of
 1mless22m.

        1m-d 22mor 1m--dumb0m
               The 1m-d 22moption suppresses the  error  message  normally
 displayed if
               the  terminal  is  dumb;  that  is,  lacks   some   important
 capability,
               such as the ability to clear the screen or  scroll  backward.
 The
               1m-d  22moption  does  not otherwise change the behavior of
 1mless 22mon a
               dumb terminal.

        1m-Dx4m22mcolor24m or 1m--color=x4m22mcolor0m
               Changes the color of different parts of the displayed   text.
 1mx0m
               is a single character which selects the type  of  text  whose
 color
               is being set:

               B      Binary characters.

               C      Control characters.

               E      Errors and informational messages.

               H      Header lines and  columns,  set  via  the  1m--header
 22moption.

               J      Target line when highlighted via --hilite-target.

               M      Mark letters in the status column.

               N      Line numbers enabled via the 1m-N 22moption.

               P      Prompts.

               R      The rscroll character.

               S      Search results.

               T      The  tilde  lines  displayed after the end of the file
 or
                      before the beginning of the file.

               W      The highlight enabled via the 1m-w 22moption.

               1-5    The text in a  search   result   which   matches   the
 first
                      through     fifth     parenthesized     subpattern.
 Subpattern
                      coloring works only if 1mless 22mis built  with  one
 of the reg
                      ular expression libraries  1mposix22m,  1mpcre22m,
 or 1mpcre222m.

               d      Bold text.

               k      Blinking text.

               s      Standout text.

               u      Underlined text.

               The uppercase letters and digits  can  be  used   only   when
 the
               1m--use-color  22moption is enabled.  When  text  color  is
 specified by
               both  an  uppercase  letter  and  a  lowercase  letter,   the
 uppercase
               letter  takes  precedence.  For example, error  messages  are
 nor
               mally displayed as standout text.  So if both "s"   and   "E"
 are
               given  a color, the "E" color applies to error messages,  and
 the
               "s" color applies to  other  standout  text.   The  lowercase
 letters
               refer to bold and underline text   formed   by   overstriking
 with
               backspaces  (see the 1m-U 22moption) and  to  noncontent
 text (such as
               line numbers and prompts), but not to  text  formatted  using
 ANSI
               escape  sequences with the 1m-R 22moption (but see the note
 below for
               different behavior on Windows and MSDOS).

               A lowercase letter may be followed by a + to  indicate   that
 the
               normal  format  change  and  the  specified color should both
 be
               used.  For example, 1m-Dug 22mdisplays underlined  text  as
 green with
               out underlining; the green  color  has  replaced  the   usual
 under
               line  formatting.   But   1m-Du+g   22mdisplays  underlined
 text as both
               green and in underlined format.

               4mcolor24m is either a 4bit color string or  an  8bit
 color string:

               A 4bit color string is one or two characters,  where   the
 first
               character  specifies  the foreground  color  and  the  second
 speci
               fies the background color as follows:

               b      Blue

               c      Cyan

               g      Green

               k      Black

               m      Magenta

               r      Red

               w      White

               y      Yellow

               The corresponding uppercase letter denotes a brighter   shade
 of
               the  color.   For example, 1m-DNGk 22mdisplays line numbers
 as bright
               green text on a black background, and  1m-DEbR  22mdisplays
 error  mes
               sages  as blue text on a bright red  background.   If  either
 char
               acter is a "-" or is omitted, the corresponding color is  set
 to
               that of normal text.

               An  8bit  color string is  one  or  two  decimal  integers
 separated
               by a dot, where the first integer  specifies  the  foreground
 color
               and the second specifies the background color.  Each  integer
 is
               a  value  between 0 and 255 inclusive which  selects  a  "CSI
 38;5"
               color                       value                        (see
 https://en.wikipedia.org/wiki/ANSI_escape_code
               #SGR).   If  either  integer  is a "-"  or  is  omitted,  the
 corre
               sponding color is set to that of normal text.

               A 4bit or 8bit color string may be followed by  one  or
 more  of
               the  following  characters to set text attributes in addition
 to
               the color.

               s or ~ Standout (reverse video)

               u or _ Underline

               d or * Bold

               l or & Blinking

               On MSDOS and Windows, the 1m--color  22moption   behaves
 differently
               from what is described above in these ways:

                     The bold (d and *)  and  blinking  (l  and  &)  text
 attributes
                      at the end of a color string are not supported.

                     Lowercase  color  selector  letters  refer  to  text
 formatted
                      by ANSI escape sequences with 1m-R22m, in   addition
 to  over
                      struck and noncontent text (but see 1m-Da22m).

                     For  historical  reasons,  when  a  lowercase  color
 selector
                      letter is followed by  a  numeric  color  value,   the
 number
                      is  not  interpreted  as an "CSI 38;5" color value  as
 de
                      scribed     above,     but     instead      as       a
 4bit
                      CHAR_INFO.Attributes   value,   between   0   and   15
 inclusive
                      (see                   https://learn.microsoft.com/en-
 us/windows/console/
                      char-info-str).

                      To  avoid  confusion,  it  is  recommended  that   the
 equivalent
                      letters   rather   than   numbers   be  used  after  a
 lowercase
                      color selector on MSDOS/Windows.

                     Numeric color values ("CSI 38;5" color) following an
 up
                      percase  color  selector letter are not  supported  on
 sys
                      tems earlier than Windows 10.

                     Only a limited set of ANSI escape sequences  to  set
 color
                      in  the   content   work   correctly.   4bit  color
 sequences
                      work, but "CSI 38;5" color sequences do not.

                     The 1m-Da 22moption makes the  behavior  of  1m--
 color 22mmore similar
                      to its behavior on nonMSDOS/Windows  systems  by
 (1) mak
                      ing lowercase color selector letters not  affect  text
 for
                      matted with ANSI escape sequences,  and  (2)  allowing
 "CSI
                      38;5" color sequences in the content work  by  passing
 them
                      to the terminal (only on  Windows  10  and  later;  on
 earlier
                      Windows systems, such sequences do not work regardless
 of
                      the setting of 1m-Da22m).

        1m-e 22mor 1m--quit-at-eof0m
               Causes  1mless  22mto  automatically  exit the second  time
 it reaches
               endoffile.  By default, the only way  to  exit  1mless
 22mis  via  the
               "q" command.

        1m-E 22mor 1m--QUIT-AT-EOF0m
               Causes 1mless 22mto automatically exit the  first  time  it
 reaches end
               offile.

        1m-f 22mor 1m--force0m
               Forces nonregular files to be  opened.   (A  nonregular
 file is a
               directory  or a device special file.)   Also  suppresses  the
 warn
               ing message when  a  binary  file  is  opened.   By  default,
 1mless 22mwill
               refuse to open nonregular files.  Note that some operating
 sys
               tems will not allow directories to be  read,  even  if  1m-f
 22mis set.

        1m-F 22mor 1m--quit-if-one-screen0m
               Causes 1mless 22mto automatically exit if the  entire  file
 can be dis
               played on the first screen.  Also see  the   description   of
 the
               LESS_SHELL_LINES environment variable below.

        1m-g 22mor 1m--hilite-search0m
               Normally,  1mless   22mwill  highlight  ALL  strings  which
 match the last
               search command.  The 1m-g 22moption changes this   behavior
 to  high
               light  only  the  particular  string which was found  by  the
 last
               search command.  This can cause 1mless 22mto  run  somewhat
 faster than
               the default.

        1m-G 22mor 1m--HILITE-SEARCH0m
               The -G option suppresses all highlighting of  strings   found
 by
               search commands.

        1m-h4m22mn24m or 1m--max-back-scroll=4m22mn0m
               Specifies  a  maximum number of lines to scroll backward.  If
 it
               is necessary to scroll backward more than 4mn24m lines, the
 screen is
               repainted in a forward direction instead.  (If  the  terminal
 does
               not have  the  ability  to  scroll  backward,  1m-h0  22mis
 implied.)

        1m-i 22mor 1m--ignore-case0m
               Causes searches  to  ignore  case;  that  is,  uppercase  and
 lowercase
               are considered identical.  This  option  is  ignored  if  any
 upper
               case  letters appear in the search pattern; in  other  words,
 if a
               pattern contains uppercase letters, then that   search   does
 not
               ignore case.

        1m-I 22mor 1m--IGNORE-CASE0m
               Like  1m-i22m,   but  searches  ignore  case  even  if  the
 pattern contains
               uppercase letters.

        1m-j4m22mn24m or 1m--jump-target=4m22mn0m
               Specifies a line on the screen where the "target" line is  to
 be
               positioned.   The  target line is the line specified  by  any
 com
               mand to search for a pattern, jump to a line number, jump  to
 a
               file percentage or jump to a tag.  The  screen  line  may  be
 speci
               fied  by  a number: the top line on the screen is 1, the next
 is
               2, and so on.  The number may be negative to specify  a  line
 rel
               ative to the bottom of the screen: the  bottom  line  on  the
 screen
               is  -1,  the  second  to  the  bottom  is  -2,  and  so   on.
 Alternately,
               the  screen line may be specified as a fraction of the height
 of
               the screen, starting with a decimal  point:  .5  is  in   the
 middle
               of  the screen, .3 is three tenths down from the first  line,
 and
               so on.  If the line is specified as a  fraction,  the  actual
 line
               number  is  recalculated  if the terminal window is  resized.
 If
               the 1m--header  22moption  is  used  and  the  target  line
 specified by  1m-j0m
               would be obscured by the header, the target line is moved  to
 the
               first line after the header.

               If  any form  of  the  1m-j  22moption  is  used,  repeated
 forward searches
               (invoked with "n" or "N") begin  at  the   line   immediately
 after
               the  target  line,  and  repeated backward searches begin  at
 the
               target line, unless changed by 1m-a 22mor  1m-A22m.   For
 example, if  "1m-j422m"
               is  used,  the  target line is the fourth line on the screen,
 so
               forward searches begin at  the  fifth  line  on  the  screen.
 However
               nonrepeated searches (invoked with "/" or "?")  always  begin
 at
               the first or last line on the screen respectively.

        1m-J 22mor 1m--status-column0m
               Displays  a  status  column at the left edge of  the  screen.
 The
               character displayed in the status column may be one of:

               >      The line is chopped with the 1m-S 22moption, and the
 text that
                      is chopped off beyond the right edge  of  the   screen
 con
                      tains a match for the current search.

               <      The  line  is  horizontally shifted, and the text that
 is
                      shifted beyond the left side of  the  screen  contains
 a
                      match for the current search.

               =      The  line  is  both  chopped  and  shifted, and  there
 are
                      matches beyond both sides of the screen.

               *      There are matches in the visible part  of   the   line
 but
                      none to the right or left of it.

               az, AZ
                      The  line  has  been  marked  with  the  corresponding
 letter
                      via the m or M command.

               #      The line has been marked by  leftclicking  it  with
 the
                      mouse when the 1m--mouse 22moption is in effect.

        1m-k4m22mfilename24m or 1m--lesskey-file=4m22mfilename0m
               Causes 1mless 22mto open and interpret the named file as  a
 1mlesskey22m(1)
               binary   file.    Multiple   1m-k    22moptions    may   be
 specified.  If the
               LESSKEY or LESSKEY_SYSTEM environment variable is set, or  if
 a
               lesskey file is found in a standard place (see KEY BINDINGS),
 it
               is  also  used  as   a   1mlesskey   22mfile.    Note   the
 warning under
               1m--lesskey-content 22mbelow.

        1m--lesskey-src=4m22mfilename0m
               Causes 1mless 22mto open and interpret the named file as  a
 1mlesskey22m(1)
               source  file.   If   the   LESSKEYIN   or    LESSKEYIN_SYSTEM
 environment
               variable is set, or if a lesskey source file is  found  in  a
 stan
               dard  place  (see  KEY  BINDINGS),  it  is  also  used  as  a
 lesskey
               source  file.   Prior  to   version   582,   the   1mlesskey
 22mprogram  needed
               to  be  run to convert a  lesskey  4msource24m  file  to  a
 lesskey 4mbinary0m
               file for 1mless  22mto  use.   Newer  versions  of  1mless
 22mread  the  lesskey
               source  file  directly  and ignore the  binary  file  if  the
 source
               file exists.  Note  the  warning  under  1m--lesskey-content
 22mbelow.

        1m--lesskey-content=4m22mtext0m
               Causes 1mless 22mto interpret the  specified  text  as  the
 contents of a
               1mlesskey22m(1)  source  file.   In  the  text,  1mlesskey
 22mlines may be sepa
               rated by either newlines  as  usual,  or  by  semicolons.   A
 literal
               semicolon  may be represented by a backslash  followed  by  a
 semi
               colon.

               Warning:  certain  environment  variables   such   as   LESS,
 LESSSECURE,
               LESSCHARSET and others, which  are  used  early  in  startup,
 cannot
               be  set in a file specified by a command line  option  (1m--
 lesskey22m,
               1m--lesskey-src  22mor   1m--lesskey-content22m).    When
 using a 1mlesskey  22mfile
               to  set  environment  variables,  it  is  safer  to  use  the
 default
               lesskey file, or to specify the  file  using  the   LESSKEYIN
 or
               LESSKEY_CONTENT  environment  variables rather than  using  a
 com
               mand line option.

        1m-K 22mor 1m--quit-on-intr0m
               Causes 1mless 22mto exit immediately (with status  2)  when
 an  inter
               rupt   character   (usually   ^C)  is  typed.   Normally,  an
 interrupt
               character causes 1mless 22mto stop whatever it is doing and
 return to
               its command prompt.

        1m-L 22mor 1m--no-lessopen0m
               Ignore the LESSOPEN environment variable   (see   the   INPUT
 PRE
               PROCESSOR  section  below).   This option  can  be  set  from
 within
               1mless22m,  but  it  will  apply  only  to   files   opened
 subsequently,  not
               to the file which is currently open.

        1m-m 22mor 1m--long-prompt0m
               Causes 1mless 22mto prompt verbosely (like 1mmore22m(1)),
 with the percent
               into the file.  By default, 1mless 22mprompts with a colon.

        1m-M 22mor 1m--LONG-PROMPT0m
               Causes  1mless  22mto  prompt  even  more  verbosely   than
 1mmore22m(1).

        1m-n 22mor 1m--line-numbers0m
               Suppresses  line numbers.  The default (to use line  numbers)
 may
               cause  1mless  22mto  run  more  slowly  in   some   cases,
 especially  with  a
               very  large input file.  Using line numbers means:  the  line
 num
               ber will be displayed in the verbose prompt and  in   the   =
 com
               mand, and the v command will pass the current line number  to
 the
               editor (see  also  the  discussion  of  LESSEDIT  in  PROMPTS
 below).

        1m-N 22mor 1m--LINE-NUMBERS0m
               Causes  a  line  number to be displayed at the  beginning  of
 each
               line in the display.

        1m-o4m22mfilename24m or 1m--log-file=4m22mfilename0m
               Causes 1mless 22mto copy its input to the named file as  it
 is  being
               viewed.  This applies only when the input file is a pipe, not
 an
               ordinary   file.    If   the  file  already  exists,  1mless
 22mwill ask for
               confirmation before overwriting it.

        1m-O4m22mfilename24m or 1m--LOG-FILE=4m22mfilename0m
               The 1m-O 22moption is like 1m-o, 22mbut it will overwrite
 an existing file
               without asking for confirmation.

               If no log file has been specified, the  1m-o  22mand  1m-O
 22moptions can  be
               used  from  within   1mless   22mto  specify  a  log  file.
 Without a file
               name, they will simply report the name of the log file.   The
 "s"
               command is equivalent to  specifying  1m-o  22mfrom  within
 1mless22m.

        1m-p4m22mpattern24m or 1m--pattern=4m22mpattern0m
               The  -p  option  on  the  command  line  is   equivalent   to
 specifying
               +/4mpattern24m;  that  is, it tells 1mless 22mto start at
 the first occur
               rence of 4mpattern24m in the file.

        1m-P4m22mprompt24m or 1m--prompt=4m22mprompt0m
               Provides a way to tailor the three prompt  styles   to   your
 own
               preference.  This option would normally be put  in  the  LESS
 envi
               ronment variable,  rather  than  being  typed  in  with  each
 1mless 22mcom
               mand.  Such an option must either be the last option  in  the
 LESS
               variable, or be terminated by a dollar sign.

               1m-Ps    22mfollowed  by   a  string  changes  the  default
 (short) prompt
                      to that string.

               1m-Pm    22mchanges the medium (1m-m22m) prompt.

               1m-PM    22mchanges the long (1m-M22m) prompt.

               1m-Ph    22mchanges the prompt for the help screen.

               1m-P=    22mchanges the message printed by the = command.

               1m-Pw    22mchanges the message printed while waiting   for
 data  (in
                      the "F" command).

               All  prompt strings consist of  a  sequence  of  letters  and
 special
               escape sequences.   See  the  section  on  PROMPTS  for  more
 details.

        1m-q 22mor 1m--quiet 22mor 1m--silent0m
               Causes moderately "quiet" operation: the terminal   bell   is
 not
               rung if an attempt is made to scroll past the end of the file
 or
               before the beginning of the file.   If  the  terminal  has  a
 "visual
               bell",  it  is  used  instead.  The  bell  will  be  rung  on
 certain
               other errors, such  as  typing  an  invalid  character.   The
 default
               is to ring the terminal bell in all such cases.

        1m-Q 22mor 1m--QUIET 22mor 1m--SILENT0m
               Causes  totally  "quiet"  operation:  the  terminal  bell  is
 never
               rung.  If the terminal has a "visual bell", it is   used   in
 all
               cases where the terminal bell would have been rung.

        1m-r 22mor 1m--raw-control-chars0m
               Causes "raw" control characters to be displayed.  The default
 is
               to  display control characters using the caret notation;  for
 ex
               ample, a controlA (octal 001) is displayed as "^A"   (with
 some
               exceptions  as  described  under   the   1m-U   22moption).
 Warning: when the
               1m-r  22moption is used, 1mless 22mcannot keep  track  of
 the actual appear
               ance of the screen (since this depends on  how   the   screen
 re
               sponds  to  each type of control character).   Thus,  various
 dis
               play problems may result, such as long lines being  split  in
 the
               wrong place.

               USE  OF  THE  1m-r  22mOPTION  IS  DANGEROUS  AND  IS   NOT
 RECOMMENDED.
               The  1m-r  22moption can be set on the command line or  via
 the - com
               mand, but to avoid unintentional use, it cannot be set  in  a
 LESS
               environment  variable.   If  1m-r  22mappears  in  a   LESS
 environment vari
               able, it is treated as if it were 1m-R22m.

        1m-R 22mor 1m--RAW-CONTROL-CHARS0m
               Like 1m-r22m, but only a limited set  of  escape  sequences
 are  output
               in  "raw"  form.  Unlike 1m-r22m, the screen appearance  is
 maintained
               correctly.  The sequences which are output raw are:

               1. ANSI SGR ("color") sequences

               2. OSC 8 hyperlinks

               3. Other OSC sequences, if the OSC type number is  listed  in
 the
               LESSANSIOSCALLOW environment variable

               4. OSC sequences starting with a nonstandard  introductory
 char
               acter  (that  is, something other than "]"), if the character
 is
               listed in the LESSANSIOSCCHARS environment variable  followed
 by
               an asterisk

               ANSI color escape sequences are sequences of the form:

                    ESC [ ... m

               where   the  "..."  is  zero  or  more  color   specification
 characters.
               Color escape sequences are only  supported  when  the   color
 is
               changed  within one line, not across lines.  In other  words,
 the
               beginning  of  each  line   is   assumed   to    be    normal
 (noncolored),
               regardless of any escape sequences in previous lines.

               You  can  make 1mless 22mthink that characters  other  than
 "m" can end
               ANSI  color  escape  sequences  by  setting  the  environment
 variable
               LESSANSIENDCHARS to the list of characters which  can  end  a
 color
               escape  sequence.   And  you can make 1mless 22mthink  that
 characters
               other than the standard ones may appear between the  ESC  and
 the
               m  by  setting  the environment variable LESSANSIMIDCHARS  to
 the
               list of characters which can appear.

               OSC sequences are of the form:

                    ESC ] N ; ... 7

               where the OSC type  number  N  is  a  decimal  integer.   The
 terminat
               ing sequence may be either a BEL character (7) as  above,  or
 the
               twocharacter sequence "ESC

        1m-s 22mor 1m--squeeze-blank-lines0m
               Causes consecutive blank lines  to   be   squeezed   into   a
 single
               blank line.  This  is  useful  when  viewing  1mnroff22m(1)
 output.

        1m-S 22mor 1m--chop-long-lines0m
               Causes  lines  longer than the screen  width  to  be  chopped
 (trun
               cated) rather than wrapped.  That is, the portion of  a  long
 line
               that does not fit in the screen width is not displayed  until
 you
               press RIGHTARROW.  The default is to wrap long lines; that
 is,
               display the remainder on the next line.  See also  the  1m--
 wordwrap0m
               option.   While  the 1m--header 22moption  is  active,  the
 1m-S 22moption is
               ignored,  and  lines  longer  than  the  screen   width   are
 truncated.

        1m-t4m22mtag24m or 1m--tag=4m22mtag0m
               The 1m-t 22moption, followed immediately  by  a  TAG,  will
 edit the file
               containing that tag.  For this to work, tag information  must
 be
               available;  for  example, there may be a file in the  current
 di
               rectory  called  "tags",  which  was  previously   built   by
 1mctags22m(1) or
               an  equivalent  command.    If   the   environment   variable
 LESSGLOBALT
               AGS is set, it  is  taken  to  be  the  name  of  a   command
 compatible
               with  1mglobal22m(1),  and  that  command  is  executed  to
 find the tag.
               (See  http://www.gnu.org/software/global/global.html).    The
 1m-t0m
               option  may also be specified from within 1mless  22m(using
 the - com
               mand) as a way of examining a new file.   The  command   ":t"
 is
               equivalent to specifying 1m-t 22mfrom within 1mless22m.

        1m-T4m22mtagsfile24m or 1m--tag-file=4m22mtagsfile0m
               Specifies a tags file to be used instead of "tags".

        1m-u 22mor 1m--underline-special0m
               Causes  backspaces  and carriage returns  to  be  treated  as
 print
               able characters; that is, they are sent   to   the   terminal
 when
               they appear in the input.

        1m-U 22mor 1m--UNDERLINE-SPECIAL0m
               Causes  backspaces, tabs, carriage  returns  and  "formatting
 char
               acters" (as defined by Unicode)  to  be  treated  as  control
 charac
               ters; that is, they are handled as  specified  by  the  1m-r
 22moption.

               By default, if neither  1m-u  22mnor  1m-U  22mis  given,
 backspaces which  ap
               pear   adjacent  to  an  underscore  character  are   treated
 specially:
               the underlined text  is  displayed  using  the   terminals
 hardware
               underlining   capability.    Also,  backspaces  which  appear
 between
               two  identical  characters  are   treated   specially:    the
 overstruck
               text is printed  using  the  terminals  hardware  boldface
 capabili
               ty.    Other   backspaces   are   deleted,   along  with  the
 preceding
               character.   Carriage  returns  immediately  followed  by   a
 newline
               are deleted.  Other carriage returns are handled as specified
 by
               the  1m-r 22moption.  Unicode formatting  characters,  such
 as the Byte
               Order  Mark,  are  sent  to  the  terminal.   Text  which  is
 overstruck
               or underlined can be searched for if  neither  1m-u  22mnor
 1m-U 22mis in ef
               fect.

               See  also the 1m--proc-backspace22m,1m--proc-tab22m,  and
 1m--proc-return 22mop
               tions.

        1m-V 22mor 1m--version0m
               Displays the version number of 1mless22m.

        1m-w 22mor 1m--hilite-unread0m
               Temporarily highlights the first "new" line after a  movement
 of
               a  full page.  The first "new" line is the  line  immediately
 fol
               lowing the line previously at the  bottom  of   the   screen.
 Also
               highlights  the  target  line after a g or  p  command.   The
 high
               light is removed at the next command which  causes  movement.
 If
               the  1m--status-line  22moption  is  in  effect, the entire
 line (the
               width of the screen) is highlighted.   Otherwise,  only   the
 text
               in  the  line is highlighted, unless the 1m-J 22moption  is
 in effect,
               in which case only the status column is highlighted.

        1m-W 22mor 1m--HILITE-UNREAD0m
               Like 1m-w22m, but temporarily highlights the first new line
 after any
               movement command larger than one line.

        1m-x4m22mn24m,... or 1m--tabs=4m22mn24m,...
               Sets tab stops.  If only one 4mn24m is specified, tab stops
 are  set
               at  multiples  of 4mn24m.  If multiple values separated  by
 commas are
               specified, tab stops are set at those  positions,  and   then
 con
               tinue  with  the same spacing  as  the  last  two.   Position
 numbers
               are zerobased: the leftmost position is 0, the next is  1,
 etc.
               For  example, "1m-x8,1622m" is the same as "1m-x822m" and
 sets tabs at po
               sition 8, 16, 24, 32, etc.  "1m-x10,14,2022m" will set tabs
 at  posi
               tion 10, 14, 20, 26, 32, etc.  The default for 4mn24m is 8.

        1m-X 22mor 1m--no-init0m
               Disables   sending    the    termcap    initialization    and
 deinitialization
               strings  to  the  terminal.  This is sometimes  desirable  if
 ini
               tialization or deinitialization does  something  unnecessary,
 like
               clearing the screen.  Note that some  terminals  require  the
 ini
               tialization  string for proper operation,  so  they  may  not
 behave
               completely correctly when 1m-X 22mis used.

        1m-y4m22mn24m or 1m--max-forw-scroll=4m22mn0m
               Specifies a maximum number of lines to scroll forward.  If it
 is
               necessary to scroll forward more  than  4mn24m  lines,  the
 screen is re
               painted instead.  The 1m-c 22mor 1m-C 22moption  may   be
 used  to  repaint
               from  the top of the screen  if  desired.   By  default,  any
 forward
               movement causes scrolling.

        1m-z4m22mn24m or 1m--window=4m22mn24m or -4mn0m
               Changes the default scrolling window size to 4mn24m  lines.
 The  de
               fault  is  one screenful.  The z and w commands can  also  be
 used
               to change the window  size.   The  "z"  may  be  omitted  for
 compati
               bility  with some versions of 1mmore22m(1).  If the  number
 4mn24m is nega
               tive, it indicates 4mn24m  lines  less  than  the   current
 screen  size.
               For  example, if the screen is 24 lines, 1m-z-4 22msets the
 scrolling
               window to 20 lines.  If the screen is  later  resized  to  40
 lines,
               the scrolling window automatically changes to 36 lines.

        1m-"4m22mcc24m or 1m--quotes=4m22mcc0m
               Changes  the  filename  quoting  character.   This  may    be
 necessary
               if  you are trying to name a file which contains both  spaces
 and
               quote characters.   Followed  by  a  single  character,  this
 changes
               the   quote   character   to   that   character.    Filenames
 containing a
               space should then be surrounded by that character rather than
 by
               double quotes.  Followed by two   characters,   changes   the
 open
               quote  to the first character, and the  close  quote  to  the
 second
               character.  Filenames  containing  a  space  should  then  be
 preceded
               by the open quote character and   followed   by   the   close
 quote
               character.   Note  that  even  after  the  quote   characters
 are
               changed, this option remains -"  (a  dash   followed   by   a
 double
               quote).

        1m-~ 22mor 1m--tilde0m
               Normally lines after end of file are displayed  as  a  single
 tilde
               (~).  This option causes  lines  after  end  of  file  to  be
 displayed
               as blank lines.

        1m-# 22mor 1m--shift0m
               Specifies  the  default  number  of   positions   to   scroll
 horizontally
               in  the RIGHTARROW and LEFTARROW  commands.   If  the  number
 speci
               fied is zero, it sets the default number  of   positions   to
 one
               half of the screen width.  Alternately,  the  number  may  be
 speci
               fied  as  a fraction of the width  of  the  screen,  starting
 with a
               decimal point: .5 is half of  the   screen   width,   .3   is
 three
               tenths  of the screen width, and so on.   If  the  number  is
 speci
               fied as a fraction, the actual number of scroll positions  is
 re
               calculated if the terminal window is resized.

        1m--autosave=4m22mactions0m
               Normally  the  history  file  is  saved  only  when   1mless
 22mexits.   This
               option specifies other actions which will cause  the  history
 file
               to  be  saved.   Each action is defined by a single character
 in
               the 4mactions24m string:

               m      Setting or clearing  a  mark  while  1m--savemarks
 22mis  in  ef
                      fect.

               /      Searching.

               !      Running a shell command.

               *      Any action; same as "m/!".

               Can be set to "" to specify the default, that only exiting
 1mless0m
               will  cause  the  history  file  to  be  saved.   Note  that,
 depending
               on your shell, if you specify this  option  on  the   command
 line,
               the "!" and "*" characters may need to be escaped or quoted.

        1m--cmd=4m22mcommands0m
               The  specified string is taken to be an  initial  command  to
 1mless22m.
               This is similar to specifying "+4mcommands24m", except that
 commands
               specified  by  1m--cmd   22mare  not  executed  if  1mless
 22mexits immediately
               due to the use of the 1m-E 22mor  1m-F  22moption,  while
 commands  specified
               by the 1m+ 22moption are executed even if 1mless 22mexits
 immediately.

        1m--emouse=4m22mfeatures0m
               4mfeatures24m   is   a  commaseparated  list  of   mouse
 features to be en
               abled, selected from this list:

               vscroll
                      Scrolling the mouse wheel down or  up  moves   forward
 or
                      backward in the file.  The number of lines  to  scroll
 when
                      the  wheel  is  moved can be set  by  the  1m--wheel-
 lines 22mop
                      tion.   The  1m--rmouse   22moption   reverses   the
 direction  of
                      movement.

               vdrag  Holding  down  the  left  button  and dragging  up  or
 down
                      moves forward or backward in the file.

               hscroll
                      Scrolling the side scroll wheel left  or  right  moves
 left
                      or  right  in  the file.  The  number  of  columns  to
 scroll
                      when the wheel is moved can  be  set  by   the   1m--
 wheel-lines0m
                      option.   The  1m--rmouse   22moption  reverses  the
 direction of
                      movement.

               hdrag  Holding down the left button  and  dragging  left   or
 right
                      moves left or right in the file.

               lclick Leftclicking  sets  the   "#"   mark  to  the  line
 where the
                      mouse is clicked.  If a leftclick is performed with
 the
                      mouse  cursor on an OSC 8 hyperlink, the hyperlink  is
 se
                      lected  as  if  by   the   ^O^N   command.     If    a
 leftclick  is
                      performed  with   the   mouse   cursor  on  an  OSC  8
 hyperlink
                      which is already selected, the hyperlink is opened  as
 if
                      by the ^O^O command.

               rclick Rightclicking  (or   clicking   any   button  other
 than the
                      left one) returns to the "#" mark position.

               scroll Same as "vscroll,hscroll".

               drag   Same as "vdrag,hdrag".

               hmove  Same as "hscroll,hdrag".

               vmove  Same as "vscroll,vdrag".

               move   Same as "vmove,hmove".

               click  Same as "lclick,rclick".

               all    Same as "move,click".

               Each  feature  name  may  be  abbreviated  as  long  as   the
 abbreviation
               is unambiguous.  If 4mfeatures24m  is  set  to  "",  all
 mouse  features
               are disabled.  Mouse input  works  only  on  terminals  which
 support
               X11 mouse reporting, and on Windows.

        1m--end-prompt=4m22mstring0m
               Specifies a string which is  printed  immediately  after  the
 prompt
               is  erased.  As with the 1m--prompt  22moption,  the  first
 character of
               the string determines  which  prompt  the  string   will   be
 printed
               after  ("1ms22m"  for the short prompt, "1mm22m" for  the
 medium prompt, or
               "1mM22m" for the long prompt).  Special characters  in  the
 string  are
               processed  as  described in the PROMPTS section, in the  same
 way
               as prompts specified by the 1m--prompt 22moption.   If  set
 to  a  dash
               (1m-22m), nothing is printed after the  prompt  is  erased.
 This option
               can  be useful if the prompt  string  has  been  modified  to
 contain
               an escape sequence that puts the terminal  in  a  mode  which
 should
               be cleared when the prompt is erased.

        1m--exit-follow-on-close0m
               When using the "F" command  on  a  pipe,   1mless   22mwill
 automatically
               stop  waiting  for  more data when the input side of the pipe
 is
               closed.

        1m--file-size0m
               If  1m--file-size   22mis   specified,   1mless   22mwill
 determine the size of the
               file immediately after opening the file.  With  this   option
 en
               abled, the = command and the long  prompt  will  display  the
 number
               of lines in the file.  Normally this is not done, because  it
 can
               be  slow  if the input file  is  nonseekable  (such  as  a
 pipe) and
               is large.

        1m--follow-name0m
               Normally, if the input file is renamed while an F command  is
 ex
               ecuting, 1mless 22mwill continue to display the contents of
 the orig
               inal file  despite  its  name  change.   If  1m--follow-name
 22mis  speci
               fied,  during an  F  command  1mless  22mwill  periodically
 attempt to re
               open the file by name.  If the reopen succeeds and  the  file
 is a
               different file from the original (which means  that   a   new
 file
               has  been  created  with  the same name as the original  (now
 re
               named) file), 1mless 22mwill display the contents  of  that
 new file.

        1m--form-feed0m
               When scrolling forward or backward in the file,  stop  if   a
 line
               beginning  with a form feed character (^L) is reached.   This
 can
               be useful when viewing  a  file   which   uses   form   feeds
 between
               pages.

        1m--header=4m22mL24m,4mC24m,4mN0m
               Sets  the  number  of  header lines and columns displayed  on
 the
               screen.  The number of header lines is set to 4mL24m.    If
 4mL24m  is  0,
               header lines are disabled.  If 4mL24m is empty or  missing,
 the number
               of  header  lines is unchanged.  The number of header columns
 is
               set to 4mC24m.   If  4mC24m  is  0,  header  columns  are
 disabled.  If 4mC24m is emp
               ty or missing, the number of header  columns  is   unchanged.
 The
               first  header line is set to  line  number  4mN24m  in  the
 file.  If 4mN24m is
               empty or missing, it is taken to be the number  of  the  line
 cur
               rently displayed in the first line  of  the  screen  (if  the
 1m--head0m
               1mer   22mcommand   has    been    issued    from    within
 1mless22m), or 1 (if the
               1m--header 22moption has been given on the  command  line).
 The  spe
               cial  form  "1m--header=-22m"  disables  header  lines  and
 header columns,
               and is equivalent to "1m--header=0,022m".

               When  4mL24m  is  nonzero, the first 4mL24m lines at  the
 top of the screen
               are replaced with the 4mL24m lines of the file beginning at
 line  4mN24m,
               regardless of what part of the file is  being  viewed.   When
 head
               er lines are displayed, any file contents before  the  header
 line
               cannot  be  viewed.   When  4mC24m is  nonzero,  the  first
 4mC24m characters
               displayed at the beginning of each line are   replaced   with
 the
               first  4mC24m characters of the line, even if the  rest  of
 the line is
               scrolled horizontally.

               While the 1m--header 22moption  is  active,  lines   longer
 than  the
               screen width are  truncated,  and  the  1m-S  22moption  is
 ignored.

        1m--hilite-target0m
               Highlights the "target" line, as specified by the -j  option.
 If
               the  1m--status-line  22moption  is  in  effect, the entire
 line (the
               width of the screen) is highlighted.   Otherwise,  only   the
 text
               in  the  line is highlighted, unless the 1m-J 22moption  is
 in effect,
               in which case only the status column is highlighted.

        1m--incsearch0m
               Subsequent search commands will be  "incremental";  that  is,
 1mless0m
               will  advance  to the next line containing the search pattern
 as
               each character of the pattern is typed in.

        1m--intr=4m22mc0m
               Use the character 4mc24m instead of ^X to interrupt a  read
 when  the
               "Waiting  for  data"  message  is displayed.   4mc24m  must
 be an ASCII
               character; that is, one with a  value  between  1   and   127
 inclu
               sive.   A  caret  followed  by a single character can be used
 to
               specify a control character.

        1m--line-num-width=4m22mn0m
               Sets the minimum width of the line number field when  the  -N
 op
               tion is in effect to 4mn24m characters.  The default is 7.

        1m--match-shift=4m22mn0m
               When  1m-S  22mis in effect,  if  a  search  match  is  not
 visible because
               it is shifted to the  left  or   right   of   the   currently
 visible
               screen,  the  text  will  horizontally  shift to ensure  that
 the
               search match is visible.  This  option  selects  the   column
 in
               which the first character of the search match will be  placed
 af
               ter the shift.   In  other  words,  there  will  be  4mn24m
 characters visi
               ble to the left of the search match.

               Alternately,  the  number  may be specified as a fraction  of
 the
               width of the screen, starting with a decimal  point:  .5   is
 half
               of the screen width, .3 is three tenths of the screen  width,
 and
               so  on.   If  the  number is specified  as  a  fraction,  the
 actual
               number of scroll positions is recalculated  if  the  terminal
 win
               dow is resized.

        1m--modelines=4m22mn0m
               Before  displaying  a  file, 1mless 22mwill read the  first
 4mn24m lines to
               try to find a vimcompatible 4mmodeline24m.  If  4mn24m
 is zero, 1mless  22mdoes
               not try to find modelines.  By using  a  modeline,  the  file
 itself
               can specify the tab stops that should be  used  when  viewing
 it.

               A modeline contains, anywhere in the  line,  a  program  name
 ("vi",
               "vim",  "ex", or  "less"),  followed  by  a  colon,  possibly
 followed
               by the word "set", and finally  followed  by  zero  or   more
 option
               settings.   If the word "set" is used,  option  settings  are
 sepa
               rated by spaces, and end at the first  colon.   If  the  word
 "set"
               is  not  used, option settings may  be  separated  by  either
 spaces
               or colons.  The word "set" is required if the  program   name
 is
               "less"  but  optional  if any of the other  three  names  are
 used.
               If any option setting is of the  form  "tabstop=4mn24m"  or
 "ts=4mn24m", then
               tab stops are automatically set as if  1m--tabs=4m22mn24m
 had  been  given.
               See the 1m--tabs 22mdescription for  acceptable  values  of
 4mn24m.

        1m--mouse0m
               Enabling   1m--mouse    22mis    the    same    as    1m--
 emouse=vmove,click22m.  Disabling
               1m--mouse 22mis the same as 1m--emouse=22m.

        1m--MOUSE0m
               Like 1m--mouse 22mwith 1m--rmouse22m.

        1m--no-edit-warn0m
               Dont print a warning message when using the v command on a
 file
               which  was  opened  using a LESSOPEN  preprocessor  (see  the
 INPUT
               PREPROCESSOR section below).

        1m--no-keypad0m
               Disables    sending    the    keypad    initialization    and
 deinitialization
               strings to the terminal.  This is  sometimes  useful  if  the
 keypad
               strings make the numeric  keypad  behave  in  an  undesirable
 manner.

        1m--no-histdups0m
               This  option  changes the behavior so that if a search string
 or
               file name is typed in, and the same string  is   already   in
 the
               history list, the existing copy is removed from  the  history
 list
               before  the  new one is added.  Thus,  a  given  string  will
 appear
               only once in the history  list.   Normally,  a   string   may
 appear
               multiple times.

        1m--no-number-headers0m
               Header  lines (defined via the  1m--header  22moption)  are
 not assigned
               line numbers.  Line number 1 is assigned to  the  first  line
 after
               any header lines.

        1m--no-paste0m
               If the terminal supports 1mxterm22mcompatible "bracketed
 paste", any
               text pasted into 1mless 22mis ignored, except that one line
 of  text
               may  be pasted into the command line at  the  bottom  of  the
 screen
               (search strings, file  names,  etc).   That  is,  the   first
 newline
               of  text  pasted into the command  line  and  any  text  that
 follows
               it is ignored.

        1m--no-search-header-lines0m
               Searches do not include  header  lines,  but  still   include
 header
               columns.

        1m--no-search-header-columns0m
               Searches do not include header  columns,  but  still  include
 header
               lines.

        1m--no-search-headers0m
               Searches do not include header lines or header columns.

        1m--no-vbell0m
               Disables the terminals visual bell.

        1m--past-eof0m
               Normally scrolling commands (other than J, K, ESCSPACE and
 ESC
               b) stop scrolling when endoffile is  reached  scrolling
 forward,
               or beginningoffile is reached scrolling backward.  This
 option
               makes all scrolling commands continue past endoffile or
 begin
               ningoffile.

        1m--proc-backspace0m
               If  set,  backspaces are handled  as  if  neither  the  1m-u
 22moption nor
               the 1m-U 22moption were set.  That is, a backspace adjacent
 to an un
               derscore causes text to be displayed in underline  mode,  and
 a
               backspace  between  identical  characters  cause text  to  be
 dis
               played in boldface mode.  This option  overrides  the   1m-u
 22mand  1m-U0m
               options,  so  that display of backspaces  can  be  controlled
 sepa
               rate from tabs and carriage returns.  If not  set,  backspace
 dis
               play is controlled by the 1m-u 22mand 1m-U 22moptions.

        1m--PROC-BACKSPACE0m
               If set, backspaces are handled as if the   1m-U   22moption
 were  set;
               that is backspaces are treated as control characters.

        1m--proc-return0m
               If set, carriage returns are handled as if neither the  1m-u
 22moption
               nor  the 1m-U 22moption were  set.   That  is,  a  carriage
 return immedi
               ately before a newline is deleted.  This option overrides the
 1m-u0m
               and 1m-U 22moptions, so that display  of  carriage  returns
 can be  con
               trolled  separate from that of backspaces and tabs.   If  not
 set,
               carriage return display is controlled by  the  1m-u  22mand
 1m-U 22moptions.

        1m--PROC-RETURN0m
               If set,  carriage  returns  are  handled  as  if  the   1m-U
 22moption  were
               set;  that  is  carriage  returns  are  treated  as   control
 characters.

        1m--proc-tab0m
               If set, tabs are handled as if the 1m-U 22moption were  not
 set.  That
               is,  tabs  are expanded to spaces.  This option overrides the
 1m-U0m
               option, so that display of tabs can  be  controlled  separate
 from
               that  of  backspaces and carriage returns.  If not  set,  tab
 dis
               play is controlled by the 1m-U 22moption.

        1m--PROC-TAB0m
               If set, tabs are handled as if the 1m-U 22moption were set;
 that  is
               tabs are treated as control characters.

        1m--redraw-on-quit0m
               When     quitting,     after     sending     the     terminal
 deinitialization
               string, redraws the entire last screen.  On  terminals  whose
 ter
               minal deinitialization string causes the terminal  to  switch
 from
               an alternate screen, this makes the last  screenful  of   the
 cur
               rent file remain visible after 1mless 22mhas quit.

        1m--rmouse0m
               Reverses   the  normal  direction  of  scrolling  when  mouse
 scrolling
               is   enabled    via    1m--emouse=vscroll    22mor    1m--
 emouse=hscroll22m.

        1m--rscroll=4m22mc0m
               This option changes the  character  used  to  mark  truncated
 lines.
               It may begin with a twocharacter attribute indicator  like
 LESS
               BINFMT  does.   If  there is no attribute indicator, standout
 is
               used.  If set to "-", truncated lines are not marked.

        1m--save-marks0m
               Save marks in the history  file,  so   marks   are   retained
 across
               different invocations of 1mless22m.

        1m--search-options=4m22m...0m
               Sets  default search modifiers.  The value is a string of one
 or
               more of the characters E, F, K, N, R or W.   Setting  any  of
 these
               has the same effect as typing that control character  at  the
 be
               ginning    of    every    search   pattern.    For   example,
 setting
               1m--search-options=4m22mW24m is the same as typing ^W  at
 the beginning  of
               every pattern.  The value may also contain a digit between  1
 and
               5, which has the same effect as typing ^S  followed  by  that
 digit
               at  the  beginning  of every search pattern.  The  value  "-"
 dis
               ables all default search modifiers.

        1m--show-preproc-errors0m
               If a LESSOPEN preprocessor produces data, then exits  with  a
 non
               zero exit code, 1mless 22mwill display a warning.

        1m--status-col-width=4m22mn0m
               Sets the width of the status column when the 1m-J 22moption
 is in ef
               fect.  The default is 2 characters.

        1m--status-line0m
               If a line is marked, the entire line (rather  than  just  the
 sta
               tus  column)  is highlighted.  Also lines highlighted due  to
 the
               1m-w 22mor 1m--hilite-target  22moption  will  have   the
 entire  line  high
               lighted.  If 1m--use-color 22mis set, the line  is  colored
 rather than
               highlighted.

        1m--use-backslash0m
               This  option changes the  interpretations  of  options  which
 follow
               this  one.   After  the  1m--use-backslash  22moption,  any
 backslash in an
               option string is removed and  the  following   character   is
 taken
               literally.   This  allows a dollar sign  to  be  included  in
 option
               strings.

        1m--use-color0m
               Enables  colored  text  in   various   places.    The   1m-D
 22moption  can  be
               used  to change the colors.  Colored text works only  if  the
 ter
               minal supports  ANSI  color  escape  sequences  (as   defined
 in
               https://www.ecma-international.org/publications-and-
 standards/
               standards/ecma-48).

        1m--wheel-lines=4m22mn0m
               Set  the  number  of  lines  or columns to  scroll  when  the
 mouse
               wheel  is  scrolled  and  the  1m--mouse  22mor  1m--MOUSE
 22moption  is  in  ef
               fect.  The default is 1 line or column.

        1m--wordwrap0m
               When  the  1m-S 22moption is not in use, wrap each line  at
 a space or
               tab if possible, so that a word  is  not  split  between  two
 lines.
               The default is to wrap at any character.

        1m--     22mA  command  line  argument of  "1m--22m"  marks  the
 end of option argu
               ments.  Any arguments following  this  are   interpreted   as
 file
               names.  This can be useful when viewing  a  file  whose  name
 begins
               with a "-" or "+".  Otherwise, option arguments and  filename
 ar
               guments can be intermixed; that is, option arguments  do  not
 need
               to   appear   before   filename    arguments,    unless   the
 environment
               variable POSIXLY_CORRECT is set.

        +      If a command line option begins with 1m+22m, the  remainder
 of  that
               option  is taken to be an  initial  command  to  1mless22m.
 For example,
               +G tells 1mless 22mto start at the end of the file   rather
 than  the
               beginning,  and   +/xyz  tells  it  to  start  at  the  first
 occurrence
               of "xyz" in the file.  As a special  case,   +<number>   acts
 like
               +<number>g; that is, it starts the display at  the  specified
 line
               number  (however,  see  the  caveat  under  the  "g"  command
 above).
               If the option starts with ++, the  initial  command   applies
 to
               every  file being viewed, not just  the  first  one.   The  +
 command
               described previously may also be used to set (or  change)  an
 ini
               tial  command  for  every  file.   Also  see   the   1m--cmd
 22moption.

 1mLINE EDITING0m
        When entering a command line  at  the  bottom  of  the  screen  (for
 example,
        a  filename  for  the :e  command,  or  the  pattern  for  a  search
 command),
        certain keys can be used  to  manipulate  the  command  line.   Most
 commands
        have an alternate form in [ brackets ] which can be used  if  a  key
 does
        not  exist  on   a   particular  keyboard.   (Note  that  the  forms
 beginning
        with ESC do not work on some MSDOS and  Windows  systems  because
 ESC  is
        the  line  erase  character.)  Any of  these  special  keys  may  be
 entered
        literally by preceding it with the "literal" character,  either   ^V
 or
        ^A.   A  backslash itself may also be entered literally by  entering
 two
        backslashes.

        LEFTARROW [ ESCh ]
               Move the cursor one space to the left.

        RIGHTARROW [ ESCl ]
               Move the cursor one space to the right.

        ^LEFTARROW [ ESCb or ESCLEFTARROW ]
               (That is, CONTROL and LEFTARROW  simultaneously.)   Move  the
 cur
               sor one word to the left.

        ^RIGHTARROW [ ESCw or ESCRIGHTARROW ]
               (That is, CONTROL and RIGHTARROW simultaneously.)   Move  the
 cur
               sor one word to the right.

        HOME [ ESC0 ]
               Move the cursor to the beginning of the line.

        END [ ESC$ ]
               Move the cursor to the end of the line.

        BACKSPACE
               Delete  the  character  to the left of the cursor, or  cancel
 the
               command if the command line is empty.

        DELETE [ ESCx ]
               Delete the character under the cursor.

        ^BACKSPACE [ ESCBACKSPACE ]
               (That is, CONTROL and  BACKSPACE   simultaneously.)    Delete
 the
               word to the left of the cursor.

        ^DELETE [ ESCX or ESCDELETE ]
               (That  is,  CONTROL and DELETE simultaneously.)   Delete  the
 word
               under the cursor.

        UPARROW [ ESCk ]
               Retrieve the previous command line.  If   you   first   enter
 some
               text  and then press UPARROW, it will retrieve  the  previous
 com
               mand which begins with that text.

        DOWNARROW [ ESCj ]
               Retrieve the next command line.  If you  first   enter   some
 text
               and  then  press  DOWNARROW,   it   will  retrieve  the  next
 command
               which begins with that text.

        TAB    Complete the partial filename to the left of the cursor.   If
 it
               matches  more than one filename, the first match  is  entered
 into
               the command line.  Repeated TABs  will  cycle   through   the
 other
               matching  filenames.   If  the  completed   filename   is   a
 directory, a
               "/"  is  appended  to the filename.  (On MSDOS and Windows
 sys
               tems, a "
               TOR  can be used to specify a different character  to  append
 to a
               directory name.

        BACKTAB (SHIFTTAB) [ ESCTAB ]
               Like TAB, but cycles in the  reverse  direction  through  the
 match
               ing filenames.

        ^L     Complete the partial filename to the left of the cursor.   If
 it
               matches more than one filename, all matches are entered  into
 the
               command line (if they fit).

        ^U (Unix and OS/2) or ESC (MSDOS and Windows)
               Delete  the  entire  command  line, or cancel the command  if
 the
               cursor is at the beginning of the command   line.    If   you
 have
               changed your linekill character in Unix to something other
 than
               ^U, that character is used instead of ^U.

        ^G     Delete the entire command line and return to the main prompt.

 1mKEY BINDINGS0m
        You  may  define  your  own   1mless  22mcommands  by  creating  a
 lesskey source
        file.  This file specifies a set  of  command  keys  and  an  action
 associ
        ated  with  each  key.   You may also change the lineediting keys
 (see
        LINE EDITING), and set environment variables used  by   1mless22m.
 See  the
        1mlesskey22m(1) manual page for details about the file format.

        If  the  environment  variable  LESSKEYIN is set,  1mless  22muses
 that as the
        name of the lesskey source file.  Otherwise, 1mless 22mlooks in  a
 standard
        place  for  the  lesskey  source  file:  On  Unix  systems,  1mless
 22mlooks for a
        lesskey     file      called      "$XDG_CONFIG_HOME/lesskey"      or
 "$HOME/.con
        fig/lesskey"  or "$HOME/.lesskey".  On MSDOS and Windows systems,
 1mless0m
        looks for a lesskey file called "$HOME/_lesskey",  and  if   it   is
 not
        found there, then looks for a lesskey file called "_lesskey" in  any
 di
        rectory  specified  in  the  PATH  environment  variable.   On  OS/2
 systems,
        1mless 22mlooks for a lesskey file called "$HOME/lesskey.ini", and
 if it  is
        not  found,  then  looks for a lesskey file called "lesskey.ini"  in
 any
        directory specified in the INIT environment variable,  and   if   it
 not
        found  there, then looks for a lesskey file called "lesskey.ini"  in
 any
        directory specified in the PATH environment variable.

        A systemwide lesskey source file may also be set  up  to  provide
 key
        bindings.   If a key is defined in both a local lesskey file and  in
 the
        systemwide file, key bindings in the local file take   precedence
 over
        those   in   the    systemwide    file.    If   the   environment
 variable
        LESSKEYIN_SYSTEM is set, 1mless 22muses that as the  name  of  the
 systemwide
        lesskey  file.   Otherwise, 1mless 22mlooks in  a  standard  place
 for the sys
        temwide lesskey file: On Unix systems, the systemwide  lesskey
 file is
        /usr/local/etc/syslesskey.  (However, if 1mless 22mwas built  with
 a  differ
        ent  sysconf directory than /usr/local/etc, that directory is  where
 the
        sysless file is  found.)   On  MSDOS  and  Windows  systems,  the
 systemwide
        lesskey  file  is   c:_syslesskey.     On    OS/2    systems,    the
 systemwide
        lesskey file is c:slesskey.ini.

        Older  versions  of 1mless 22m(before  v582)  used  lesskey  files
 with a binary
        format, produced by the 1mlesskey  22mprogram.  It  is  no  longer
 necessary  to
        use the 1mlesskey 22mprogram.

 1mINPUT PREPROCESSOR0m
        You  may  define an "input preprocessor"  for  1mless22m.   Before
 1mless 22mopens a
        file, it first gives the input preprocessor a chance to  modify  the
 way
        the  contents of the file are displayed.  An input  preprocessor  is
 sim
        ply an executable  program  (or  shell  script),  which  writes  the
 contents
        of the file to a different file, called the replacement  file.   The
 con
        tents  of  the replacement file are then displayed in place  of  the
 con
        tents of the original file.  However, it will appear to the user  as
 if
        the  original  file  is opened; that is,  1mless  22mwill  display
 the original
        filename as the name of the current file.

        An input  preprocessor  receives  one  command  line  argument,  the
 original
        filename,   as   entered   by   the  user.   It  should  create  the
 replacement
        file, and when finished, print the name of the replacement  file  to
 its
        standard  output.  If the  input  preprocessor  does  not  output  a
 replace
        ment filename, 1mless 22muses the original file, as  normal.   The
 input  pre
        processor  is not called when viewing standard input.  To set up  an
 in
        put preprocessor, set  the  LESSOPEN  environment  variable   to   a
 command
        line  which  will  invoke  your  input preprocessor.   This  command
 line
        should include one occurrence of the string "%s",  which   will   be
 re
        placed by the  filename  when  the  input  preprocessor  command  is
 invoked.

        When 1mless 22mcloses a file opened in such a way,  it  will  call
 another pro
        gram,  called  the  input   postprocessor,  which  may  perform  any
 desired
        cleanup  action  (such  as   deleting   the   replacement    file
 created  by
        LESSOPEN).  This program receives two command  line  arguments,  the
 orig
        inal  filename  as  entered  by  the  user,  and  the  name  of  the
 replacement
        file.   To  set  up  an  input  postprocessor,  set  the   LESSCLOSE
 environment
        variable   to  a  command  line  which  will   invoke   your   input
 postprocessor.
        It may include two occurrences of the string "%s";  the   first   is
 re
        placed  with the original name of the file and the second  with  the
 name
        of the replacement file, which was output by LESSOPEN.

        For example, on many Unix systems, these two scripts will allow  you
 to
        keep files in compressed format, but still let 1mless 22mview them
 directly:

        lessopen.sh:
             #! /bin/sh
             case "$1" in
             *.Z) TEMPFILE=$(mktemp)
                  uncompress -c $1  >$TEMPFILE  2>/dev/null
                  if [ -s $TEMPFILE ]; then
                       echo $TEMPFILE
                  else
                       rm -f $TEMPFILE
                  fi
                  ;;
             esac

        lessclose.sh:
             #! /bin/sh
             rm $2

        To  use these scripts, put them both where they can be executed  and
 set
        LESSOPEN="lessopen.sh %s",   and   LESSCLOSE="lessclose.sh  %s  %s".
 More
        complex  LESSOPEN  and LESSCLOSE scripts may be  written  to  accept
 other
        types of compressed files, and so on.

        It is also possible to set up an input preprocessor  to   pipe   the
 file
        data  directly to 1mless22m, rather than putting the data  into  a
 replacement
        file.  This avoids the need to decompress  the  entire  file  before
 start
        ing to view it.  An input preprocessor that works this way is called
 an
        input pipe.  An input pipe,  instead  of  writing  the  name  of   a
 replace
        ment file on its standard output, writes the entire contents of  the
 re
        placement  file  on  its  standard  output.  If the input pipe  does
 not
        write any characters on  its  standard  output,  then  there  is  no
 replace
        ment  file and 1mless 22muses the original file,  as  normal.   To
 use an input
        pipe, make the first character in the LESSOPEN environment  variable
 a
        vertical  bar  (|)  to  signify that the input  preprocessor  is  an
 input
        pipe.  As with nonpipe input preprocessors, the  command   string
 must
        contain  one  occurrence  of %s, which is replaced with the filename
 of
        the input file.

        For example, on many Unix systems, this script will  work  like  the
 pre
        vious example scripts:

        lesspipe.sh:
             #! /bin/sh
             case "$1" in
             *.Z) uncompress -c $1  2>/dev/null
                  ;;
             *)   exit 1
                  ;;
             esac
             exit $?

        To  use  this  script,  put  it  where  it  can  be   executed   and
 set
        LESSOPEN="|lesspipe.sh %s".

        Note that a preprocessor cannot output an empty file, since that  is
 in
        terpreted as meaning there is no replacement, and the original  file
 is
        used.   To  avoid  this, if LESSOPEN starts with two vertical  bars,
 the
        exit status of the script determines the behavior when  the   output
 is
        empty.   If  the output is empty and the exit status  is  zero,  the
 empty
        output is considered to be replacement text.   If  the   output   is
 empty
        and the exit status is nonzero, the  original  file  is  used.   For
 compat
        ibility  with  previous  versions of 1mless22m, if LESSOPEN starts
 with only
        one vertical bar, the exit status of the preprocessor is ignored.

        When an input pipe is used, a LESSCLOSE postprocessor can  be  used,
 but
        it is usually not necessary since there is no  replacement  file  to
 clean
        up.   In  this  case,  the  replacement  file  name  passed  to  the
 LESSCLOSE
        postprocessor is "-".

        For compatibility with previous versions of 1mless22m,  the  input
 preproces
        sor or pipe is not used if 1mless 22mis  viewing  standard  input.
 However, if
        the  first  character of LESSOPEN is a dash  (1m-22m),  the  input
 preprocessor
        is used on standard input as well as other files.  In   this   case,
 the
        dash  is  not  considered  to  be part of the preprocessor  command.
 If
        standard input is being viewed, the input preprocessor is  passed  a
 file
        name consisting of a single  dash.   Similarly,  if  the  first  two
 charac
        ters  of  LESSOPEN  are vertical bar and  dash  (1m|-22m)  or  two
 vertical bars
        and a dash (1m||-22m), the input pipe is used on standard input as
 well  as
        other files.  Again, in this case the dash is not considered  to  be
 part
        of the input pipe command.

 1mNATIONAL CHARACTER SETS0m
        There are five types of characters in the input file:

        normal characters
               can be displayed directly to the screen.

        control characters
               should  not  be displayed directly, but are  expected  to  be
 found
               in ordinary text files (such as backspace and tab).

        binary characters
               should not be displayed directly and  are  not  expected   to
 be
               found in text files.

        composing characters
               are not displayed separately, but modify the display  of  the
 pre
               ceding character. (Only when LESSCHARSET is "utf8".)

        deleted characters
               are simply deleted from the input and not  displayed.   (Only
 when
               LESSCHARSET is "utf8".)

        A  "character  set"  is a description of which of  these  categories
 each
        character belongs to.  The LESSCHARSET environment variable  may  be
 used
        to select a character set.  Possible values for LESSCHARSET are:

        ascii  BS, TAB, NL, CR, and formfeed  are  control  characters,  all
 chars
               with  values  between  32 and 126 are normal, and all  others
 are
               binary.

        iso8859
               Selects an ISO 8859 character set.   This  is  the  same   as
 ASCII,
               except  characters  between  160  and   255  are  treated  as
 normal
               characters.

        latin1 Same as iso8859.

        latin9 Same as iso8859.

        dos    Selects a character set appropriate for MSDOS.

        ebcdic Selects an EBCDIC character set.

        IBM-1047
               Selects  an  EBCDIC  character  set  used  by   OS/390   Unix
 Services.
               This  is the EBCDIC analogue  of  latin1.   You  get  similar
 results
               by setting either LESSCHARSET=IBM-1047 or  LC_CTYPE=en_US  in
 your
               environment.

        koi8-r Selects a Russian character set.

        next   Selects a character set appropriate for NeXT computers.

        utf-8  Selects the UTF8 encoding  of  the  ISO  10646   character
 set.
               UTF8   is   special   in  that  it  supports  multibyte
 characters in
               the input file.  It is the only character set  that  supports
 mul
               tibyte characters.

        windows
               Selects a character set appropriate for   Microsoft   Windows
 (cp
               1252).

        In  rare cases, it may be desired to tailor  1mless  22mto  use  a
 character set
        other than the ones definable by LESSCHARSET.   In  this  case,  the
 envi
        ronment variable LESSCHARDEF can be used to define a character  set.
 It
        should be set to  a  string  where  each  character  in  the  string
 represents
        one  character  in  the character set.  The character  "."  is  used
 for a
        normal character, "c" for control, and "b" for  binary.   A  decimal
 num
        ber  may  be  used  for  repetition.  For example,  "bccc4b."  would
 mean
        character 0 is binary, 1, 2 and 3 are control, 4, 5,  6  and  7  are
 bina
        ry, and 8 is normal.  All characters after the last are taken to  be
 the
        same  as  the last, so characters 9 through  255  would  be  normal.
 (This
        is an  example,  and  does  not  necessarily  represent   any   real
 character
        set.)

        This  table  shows the value of LESSCHARDEF which is  equivalent  to
 each
        of the possible values for LESSCHARSET:
             ascii      8bcccbcc18b95.b
             dos        8bcccbcc12bc5b95.b.
             ebcdic     5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
                        9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
             IBM-1047   4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
                        191.b
             iso8859    8bcccbcc18b95.33b.
             koi8-r     8bcccbcc18b95.b128.
             latin1     8bcccbcc18b95.33b.
             next       8bcccbcc18b95.bb125.bb

        If neither LESSCHARSET nor LESSCHARDEF  is  set,  but  any  of   the
 strings
        "UTF-8",  "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE
 or
        LANG environment variables, then the default character set is utf-8.

        If  that  string  is  not  found,  but  your  system  supports   the
 1msetlocale22m(3)
        interface,  1mless  22mwill   use   setlocale   to  determine  the
 character set.
        setlocale  is  controlled  by  setting  the   LANG    or    LC_CTYPE
 environment
        variables.

        Finally,  if the 1msetlocale 22minterface is also  not  available,
 the default
        character set is utf-8.

        Control  and   binary   characters   are   displayed   in   standout
 (reverse
        video).  Each such character  is  displayed  in  caret  notation  if
 possible
        (e.g.   ^A  for  controlA).   Caret  notation  is  used  only  if
 inverting the
        0100 bit results in a normal printable  character.   Otherwise,  the
 char
        acter is displayed as a hex number in angle brackets.   This  format
 can
        be   changed  by  setting  the  LESSBINFMT   environment   variable.
 LESSBINFMT
        may begin with a  "*"  and  one  character  to  select  the  display
 attribute:
        "*k" is blinking,  "*d"  is  bold,  "*u"  is  underlined,  "*s"   is
 standout,
        and  "*n"  is  normal.  If LESSBINFMT does not  begin  with  a  "*",
 normal
        attribute is assumed.  The remainder of  LESSBINFMT  is   a   string
 which
        may  include one printfstyle escape sequence (a % followed by  x,
 X, o,
        d,  etc.).   For  example,  if  LESSBINFMT  is   "*u[%x]",    binary
 characters
        are  displayed  in  underlined hexadecimal surrounded  by  brackets.
 The
        default if no LESSBINFMT is specified is "*s<%02X>".   Warning:  the
 re
        sult  of  expanding  the  character via LESSBINFMT must be less than
 31
        characters.

        When the character  set  is  utf-8,  the  LESSUTFBINFMT  environment
 variable
        acts similarly to LESSBINFMT but it applies to Unicode  code  points
 that
        were successfully decoded but are  unsuitable  for  display   (e.g.,
 unas
        signed  code  points).   Its  default  value is  "<U+%04lX>".   Note
 that
        LESSUTFBINFMT  and  LESSBINFMT   share   their   display   attribute
 setting
        ("*x")  so specifying one will affect both;  LESSUTFBINFMT  is  read
 after
        LESSBINFMT  so  its  setting,  if  any,    will    have    priority.
 Problematic
        octets  in  a  UTF8  file (octets of a truncated sequence, octets
 of a
        complete but nonshortest form  sequence,  invalid   octets,   and
 stray
        trailing  octets)  are displayed individually using LESSBINFMT so as
 to
        facilitate diagnostic of how the UTF8 file is illformed.

        When the character set is utf-8, in rare cases it may be   desirable
 to
        override the Unicode definition of the type of  certain  characters.
 For
        example, characters in a Private Use Area are  normally  treated  as
 bina
        ry  characters, but if you are using a custom  font  with  printable
 char
        acters in that range, it may be desirable to  tell  1mless   22mto
 treat  such
        characters  as  printable.   This  can  be  done  by   setting   the
 LESSUTFCHARD
        EF   environment   variable   to   a   commaseparated   list   of
 4mcharacter24m 4mtype24m de
        finitions.  Each character type definition consists  of  either  one
 hexa
        decimal codepoint or a pair  of  codepoints  separated  by  a  dash,
 followed
        by  a  colon  and a type character.  Each hexadecimal codepoint  may
 op
        tionally be preceded by a "U" or "U+".  If a pair of  codepoints  is
 giv
        en, the type is set for all characters inclusively between  the  two
 val
        ues.  If there are multiple commaseparated codepoint values, they
 must
        be in ascending numerical order.  The type character may be one of:

               p      A normal printable character.

               w      A wide (2space) printable character.

               b      A binary (nonprintable) character.

               c      A composing (zero width) character.

               d      A deleted character (deleted from the  input  and  not
 dis
                      played).

        For example, setting LESSUTFCHARDEF to

             E000-F8FF:p,F0000-FFFFD:p,100000-10FFFD:p

        would make all Private Use Area characters be treated as printable.

        By  default,  emoji  modifiers,  components and variation  selectors
 are
        deleted because many terminals do not display them  correctly.    If
 you
        use  a  terminal  which does display some or all of them  correctly,
 you
        can cause them to be displayed by setting  LESSUTFCHARDEF  to  treat
 them
        as  composing characters.   For  example,  this  sets  them  all  to
 composing
        characters:

             FE00-FE0F:c,1F3FB-1F3FF:c,1F9B0-1F9B3:c,E0100-E01EF:c

 1mPROMPTS0m
        The 1m-P 22moption  allows  you  to  tailor  the  prompt  to  your
 preference.   The
        string  given  to  the   1m-P  22moption  replaces  the  specified
 prompt string.
        Certain characters in the string  are  interpreted  specially.   The
 prompt
        mechanism is rather complicated to  provide  flexibility,  but   the
 ordi
        nary   user  need  not  understand  the  details   of   constructing
 personalized
        prompt strings.

        A percent sign followed by a single character is expanded  according
 to
        what  the  following  character is.  (References to the  input  file
 size
        below refer to the preprocessed size, if an  input  preprocessor  is
 being
        used.)

        %b4mX24m    Replaced by the byte offset  into  the  current  input
 file.  The  b
               is followed by a single character (shown as  4mX24m  above)
 which spec
               ifies  the line whose byte offset is  to  be  used.   If  the
 charac
               ter is a "t", the byte offset of the top line in the  display
 is
               used, an "m" means use the middle line, a "b" means  use  the
 bot
               tom  line,  a "B" means use the line just  after  the  bottom
 line,
               and a "j" means use the "target" line, as specified  by   the
 1m-j0m
               option.

        %B     Replaced by the size of the current input file.

        %c     Replaced  by  the column number of the text which appears  in
 the
               first column of the screen.

        %C     Replaced by the column number of  the  text   which   appears
 (or
               would appear) in the last column of the screen.

        %d4mX24m    Replaced  by  the  page number of a line in the  input
 file.  The
               line to be used is determined by the 4mX24m, as with the %b
 option.

        %D     Replaced by the number of  pages  in  the  input   file,   or
 equiva
               lently, the page number of the last line in the input file.

        %E     Replaced   by  the  name  of  the  editor  (from  the  VISUAL
 environment
               variable, or the EDITOR environment variable if   VISUAL   is
 not
               defined).  See the discussion of the LESSEDIT feature below.

        %f     Replaced by the name of the current input file.

        %F     Replaced  by the last component of the name  of  the  current
 input
               file.

        %g     Replaced by the shellescaped name of the   current   input
 file.
               This  is useful when the expanded string will be  used  in  a
 shell
               command, such as in LESSEDIT.

        %i     Replaced by the index of the current file  in  the  list   of
 input
               files.

        %l4mX24m    Replaced  by  the  line number of a line in the  input
 file.  The
               line to be used is determined by the 4mX24m, as with the %b
 option.

        %L     Replaced by the line number of the last  line  in  the  input
 file.

        %m     Replaced by the total number of input files.

        %p4mX24m    Replaced by the percent into the current input   file,
 based  on
               byte  offsets.  The line used is determined by  the  4mX24m
 as with the
               %b option.

        %P4mX24m    Replaced by the percent into the current input   file,
 based  on
               line  numbers.  The line used is determined by  the  4mX24m
 as with the
               %b option.

        %Q     Replaced by the percent of the last column of text  displayed
 on
               the  screen compared  to  the  length  of  the  longest  line
 currently
               displayed (that is, %C divided by %W).  Note that using  this
 se
               quence can make displaying the prompt be slower than usual.

        %s     Same as %B.

        %t     Causes any trailing spaces to be removed.  Usually  used   at
 the
               end of the string, but may appear anywhere.

        %T     Normally  expands  to the word "file".   However  if  viewing
 files
               via a tags list using the 1m-t 22moption,  it  expands   to
 the  word
               "tag".

        %W     Replaced by the width of the longest line currently displayed
 on
               the   screen.    Note  that  using  this  sequence  can  make
 displaying
               the prompt be slower than usual.

        %x     Replaced by the name of the next input file in the list.

        If any item is unknown (for example, the file size  if  input  is  a
 pipe),
        a question mark is printed instead.

        The format of the prompt  string  can  be   changed   depending   on
 certain
        conditions.   A  question mark followed by a single  character  acts
 like
        an "IF": depending  on  the  following  character,  a  condition  is
 evaluat
        ed.   If  the  condition  is  true,  any  characters  following  the
 question
        mark and condition character, up to  a  period,  are   included   in
 the
        prompt.   If  the  condition  is  false,  such  characters  are  not
 included.
        A colon appearing between the question mark and the  period  can  be
 used
        to establish an "ELSE": any characters between  the  colon  and  the
 period
        are  included  in  the string if and only if  the  IF  condition  is
 false.
        Condition characters (which follow a question mark) may be:

        ?a     True if any characters have been included in  the  prompt  so
 far.

        ?b4mX24m    True if the byte  offset  of  the  specified  line  is
 known.

        ?B     True if the size of current input file is known.

        ?c     True if the text is horizontally shifted (%c is greater  than
 1).

        ?d4mX24m    True if the page  number  of  the  specified  line  is
 known.

        ?e     True if at endoffile.

        ?f     True if there is an input filename (that is, if input is  not
 a
               pipe).

        ?l4mX24m    True if the line  number  of  the  specified  line  is
 known.

        ?L     True if the line number of the  last  line  in  the  file  is
 known.

        ?m     True if there is more than one input file.

        ?n     True if this is the first prompt in a new input file.

        ?O     True if an OSC 8 hyperlink is selected.

        ?p4mX24m    True  if  the percent into  the  current  input  file,
 based on byte
               offsets, of the specified line is known.

        ?P4mX24m    True if the percent into the current input file, based
 on  line
               numbers, of the specified line is known.

        ?Q     True  if %Q is less than 100.  Note that using this  sequence
 can
               make displaying the prompt be slower than usual.

        ?s     Same as "?B".

        ?x     True if there is a next input file (that is, if  the  current
 in
               put file is not the last one).

        Any characters other than the special ones  (question  mark,  colon,
 peri
        od,  percent,  and backslash) become literally part of  the  prompt.
 Any
        of the special characters may be included in the  prompt   literally
 by
        preceding it with a backslash.

        Some examples:

        ?f%f:Standard input.

        This  prompt prints the filename, if  known;  otherwise  the  string
 "Stan
        dard input".

        ?f%f .?ltLine %lt:?pt%pt:?btByte %bt:-...

        This prompt would print the filename, if known.   The  filename   is
 fol
        lowed  by  the  line  number, if known,  otherwise  the  percent  if
 known,
        otherwise the byte offset if known.  Otherwise, a dash  is  printed.
 No
        tice how each question mark has a matching period,  and  how  the  %
 after
        the %pt is included literally by escaping it with a backslash.
                                                   %x..%t
        ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next
        This  prints  the  filename if this is the first prompt in  a  file,
 fol
        lowed by the "file N of N" message if there   is   more   than   one
 input
        file.   Then,  if  we are at endoffile, the string "(END)"  is
 printed
        followed by the name of the next file, if there is  one.    Finally,
 any
        trailing spaces are truncated.  This is  the  default  prompt.   For
 refer
        ence, here are the defaults for the other two prompts 1m-m  22mand
 1m-M 22mrespec
        tively).  Each is broken into two lines here for readability only.
                                                   %x.:
        ?n?f%?pB%pB:byte %bB?s/%s...%tND) ?x- Next

        ?f%f .?n?m(%T %i of %m) ..?ltlines %lt%x.:?pB%pB..?c (column %c).%t
             byte %bB?s/%s. .?e(END) ?x- Next
        And here is the default message produced by the = command:

        ?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .
             byte %bB?s/%s. ?e(END) :?pB%pB..?c (column %c).%t

        The  prompt expansion features are also used for another purpose: if
 an
        environment variable LESSEDIT is defined, it is used as the  command
 to
        be  executed when the v command is invoked.  The LESSEDIT string  is
 ex
        panded in the same way as the prompt strings.  The   default   value
 for
        LESSEDIT is:

             %E ?lm+%lm. %g

        Note that this expands to the editor name, followed by a +  and  the
 line
        number,  followed  by the shellescaped file name.  If your editor
 does
        not accept the "+linenumber" syntax, or  has  other  differences  in
 invo
        cation  syntax, the LESSEDIT variable can be changed to modify  this
 de
        fault.

 1mSECURITY0m
        When the environment  variable  LESSSECURE  is  set  to  1,  1mless
 22mruns  in  a
        "secure" mode.  In this mode, these features are disabled:

        edit      the edit command (v)

        examine   the examine command (:e)

        glob      metacharacters such as * in filenames,
                  and filename completion (TAB, ^L)

        history   history file

        lesskey   use of lesskey files 1m-k 22mand 1m--lesskey-src22m)

        lessopen  input preprocessor (LESSOPEN environment variable)

        logfile   log files (s and 1m-o22m)

        osc8      opening OSC 8 links (^O^O)

        pipe      the pipe command (|)

        shell     the shell and pshell commands (! and #)

        stop      stopping 1mless 22mvia a SIGTSTP signal

        tags      use of tags files (1m-t22m)

        The   LESSSECURE_ALLOW   environment  variable  can  be  set  to   a
 commasepa
        rated list of names of features  which   are   selectively   enabled
 when
        LESSSECURE is set.  Each feature name is the first word in each line
 in
        the  above  list.  A feature name may be abbreviated as long as  the
 ab
        breviation  is  unambiguous.   For    example,    if    LESSSECURE=1
 and
        LESSSECURE_ALLOW=hist,edit were set, all of the above features would
 be
        disabled except for history files and the edit command.

        Less  can also be compiled to be permanently in "secure"  mode.   In
 that
        case, the LESSSECURE and LESSSECURE_ALLOW variables are ignored.

 1mCOMPATIBILITY WITH MORE0m
        If the environment variable LESS_IS_MORE is set  to  1,  or  if  the
 program
        is invoked via a  file  link  named  "more"  and   the   environment
 variable
        LESS_IS_MORE is not  set  to  0,  1mless  22mbehaves  (mostly)  in
 conformance with
        the  POSIX  1mmore22m(1)  command specification.   In  this  mode,
 1mless 22mbehaves
        differently in these ways:

        The 1m-e 22moption works differently.  If the 1m-e 22moption  is
 not set, 1mless 22mbe
        haves as if the 1m-e 22moption were set.  If the 1m-e  22moption
 is set, 1mless  22mbe
        haves as if the 1m-E 22moption were set.

        The   1m-m   22moption   works   differently.     If   the   1m-m
 22moption is not set, the
        medium prompt is used, and it is  prefixed  with  the   string   "--
 More--".
        If the 1m-m 22moption is set, the short prompt is used.

        The  1m-n  22moption acts like the 1m-z 22moption.   The  normal
 behavior of the 1m-n0m
        option is unavailable in this mode.

        The parameter to the 1m-p 22moption is taken  to  be   a   1mless
 22mcommand  rather
        than a search pattern.

        The   LESS   environment   variable   is   ignored,  and  the   MORE
 environment
        variable is used in its place.

 1mENVIRONMENT VARIABLES0m
        Environment  variables  may  be  specified  either  in  the   system
 environment
        as usual, or in a 1mlesskey22m(1) file.  If environment  variables
 are  de
        fined 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 systemwide  lesskey
 file.

        COLUMNS
               Sets the number of columns on the screen.   Takes  precedence
 over
               the  number  of columns specified by the TERM variable.  (But
 if
               you  have  a  windowing  system  which  supports   TIOCGWINSZ
 or
               WIOCGETD,  the  window  systems  idea  of the screen  size
 takes
               precedence over the LINES and COLUMNS environment variables.)

        EDITOR The name of the editor (used for the v command).

        HOME   Name of the users home directory (used to find a   lesskey
 file
               on Unix and OS/2 systems).

        HOMEDRIVE, HOMEPATH
               Concatenation  of  the  HOMEDRIVE  and  HOMEPATH  environment
 vari
               ables is the name of the users home directory if the  HOME
 vari
               able is not set (only in the Windows version).

        INIT   Name of the users init directory (used to find a   lesskey
 file
               on OS/2 systems).

        LANG   Language for determining the character set.

        LC_CTYPE
               Language for determining the character set.

        LESS   Options which are passed to 1mless 22mautomatically.

        LESSANSIENDCHARS
               Characters  which may  end  an  ANSI  color  escape  sequence
 (default
               "m").

        LESSANSIMIDCHARS
               Characters which may appear between the ESC   character   and
 the
               end    character   in   an   ANSI   color   escape   sequence
 (default
               "0123456789:;[?!"'#%()*+ ").

        LESSANSIOSCALLOW
               A commaseparated  list  of  OSC  types  which  are  output
 directly to
               the terminal when 1m-R 22mis in effect (default "8";   that
 is,  only
               OSC 8 sequences are output directly).

        LESSANSIOSCCHARS
               Characters  which  may follow an ESC character  to  mark  the
 start
               of an "OS Command" sequence.  All  characters   that   follow
 this
               character  up  to a  String  Terminator  (ESCbackslash  or
 BEL) are
               considered to be part of the OSC sequence (default "]").   If
 a
               character  in  LESSANSIOSCCHARS  is followed by an  asterisk,
 se
               quences that begin with that character in the  file  contents
 are
               passed  through  to  the terminal; otherwise  only  sequences
 that
               appear in a prompt string are passed through.

        LESSBINFMT
               Format   for   displaying   nonprintable,    noncontrol
 characters.

        LESSCHARDEF
               Defines a character set.

        LESSCHARSET
               Selects a predefined character set.

        LESSCLOSE
               Command line to invoke the (optional) inputpostprocessor.

        LESSECHO
               Name of  the  lessecho  program  (default  "lessecho").   The
 lessecho
               program is needed to expand metacharacters, such as * and  ?,
 in
               filenames on Unix systems.

        LESSEDIT
               Editor  prototype  string (used  for  the  v  command).   See
 discus
               sion under PROMPTS.

        LESSGLOBALTAGS
               Name of the command used by  the  1m-t  22moption  to  find
 global  tags.
               Normally  should be set to "global" if your  system  has  the
 1mglob0m
               1mal22m(1) command.  If not set, global tags are not used.

        LESSHISTFILE
               Name of the history file used to remember   search   commands
 and
               shell  commands  between  invocations of 1mless22m.  If set
 to "-" or
               "/dev/null", a history file is not used.  The default depends
 on
               the operating system, but is usually:

               Linux and Unix
                      "$XDG_STATE_HOME/lesshst"                           or
 "$HOME/.local/state/lesshst"
                      or "$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst".

               Windows and MSDOS
                      "$HOME/_lesshst".

               OS/2   "$HOME/lesshst.ini" or "$INIT/lesshst.ini".

        LESSHISTSIZE
               The maximum number of commands to save in the  history  file.
 The
               default is 100.

        LESSKEYIN
               Name of the default 4mlesskey24m 4msource24m file.

        LESSKEY
               Name  of  the  default  4mlesskey24m  4mbinary24m   file.
 (Not   used   if
               "$LESSKEYIN" exists.)

        LESSKEY_CONTENT
               The   value  is  parsed  as  if  it  were  the  parameter  of
 a
               1m--lesskey-content 22moption.

        LESSKEYIN_SYSTEM
               Name   of   the    default    systemwide    4mlesskey24m
 4msource24m file.

        LESSKEY_SYSTEM
               Name   of   the    default    systemwide    4mlesskey24m
 4mbinary24m file.  (Not  used
               if "$LESSKEYIN_SYSTEM" exists.)

        LESSMETACHARS
               List  of characters which are considered "metacharacters"  by
 the
               shell.

        LESSMETAESCAPE
               Prefix which less will add before each  metacharacter  in   a
 com
               mand sent to the shell (default "

        LESSNOCONFIG
               If set to "-", all  environment  variables  except  TERM  are
 ignored
               (treated   as  if  they  were  not  set).   If   set   to   a
 commaseparated
               list  of  environment  variable  names,    all    environment
 variables
               except  TERM  and those in the list are ignored.   In  either
 case
               (if set to any nonempty value), all  1mlesskey  22mfiles
 are also  ig
               nored.

        LESSOPEN
               Command line to invoke the (optional) inputpreprocessor.

        LESSSECURE
               Runs less in "secure" mode.  See discussion under SECURITY.

        LESSSECURE_ALLOW
               Enables  individual  features  which  are  normally  disabled
 by
               LESSSECURE.  See discussion under SECURITY.

        LESSSEPARATOR
               String to  be  appended  to  a  directory  name  in  filename
 completion
               (default "

        LESSUTFBINFMT
               Format for displaying nonprintable Unicode code points.

        LESSUTFCHARDEF
               Overrides the type of specified Unicode characters.

        LESS_COLUMNS
               Sets the number of columns on the  screen.   Unlike  COLUMNS,
 takes
               precedence over the systems idea of the screen size, so it
 can
               be  used  to  make 1mless 22muse less than the full  screen
 width.  If
               set to a negative number, sets the number  of  columns   used
 to
               this much less than the actual screen width.

        LESS_LINES
               Sets  the  number  of  lines on the  screen.   Unlike  LINES,
 takes
               precedence over the systems idea of the screen size, so it
 can
               be  used  to make 1mless 22muse less than the  full  screen
 height.  If
               set to a negative number, sets the number of  lines  used  to
 this
               much  less  than   the   actual  screen  height.   When  set,
 1mless 22mre
               paints the  entire  screen  on  every  movement  command,  so
 scrolling
               may be slower.

        LESS_DATA_DELAY
               Duration (in milliseconds) after starting to read  data  from
 the
               input,  after  which the "Waiting for data" message  will  be
 dis
               played.  The default is 4000 (4 seconds).

        LESS_IS_MORE
               Emulate the 1mmore22m(1) command.

        LESS_OSC8_OPEN_xxx
               Where "xxx" is a URI scheme such as "http" or  "file",   sets
 an
               OSC 8 handler for opening OSC 8 links containing a  URI  with
 that
               scheme.

        LESS_OSC8_OPEN_ANY
               Sets an OSC 8 handler for opening OSC 8 links for which there
 is
               no specific LESS_OSC8_OPEN_xxx  handler  set  for  the  "xxx"
 scheme.

        LESS_OSC8_OPEN_NONE
               Sets  an  OSC 8 handler for opening OSC 8 links which contain
 no
               scheme (that is, there is no colon in the URI).

        LESS_SHELL_LINES
               When  the  1m-F  22moption  is   set,   1mless   22mexits
 automatically if the  num
               ber  of  screen  lines  used to display the file is less than
 or
               equal  to  the  screen   height   minus    the    value    of
 the
               LESS_SHELL_LINES  variable.   Thus,  if   you   use  a  shell
 prompt
               which occupies more than one screen line, this variable   can
 be
               set  to  the number of lines used by your prompt,  to  ensure
 that
               the entire file can be seen  when  1m-F  22mis  used.    If
 not  set,
               LESS_SHELL_LINES is assumed to be 1.

        LESS_SIGUSR1
               If set to  a  string  of  one  or  more  1mless  22mcommand
 characters, those
               commands will be executed when 1mless 22mreceives a SIGUSR1
 signal.

        LESS_TERMCAP_xx
               Where  "xx"  is  any two characters, overrides the definition
 of
               the termcap "xx" capability for the  terminal.    No   escape
 se
               quences in the string  are  processed,  so  any  nonprintable
 charac
               ters such as ESC must be in the string literally.

        LESS_TERMINFO_xxxx
               Where  "xxxx" is any  string  of  characters,  overrides  the
 defini
               tion of the terminfo "xxxx" capability  for   the   terminal.
 You
               can  use  either  LESS_TERMCAP_xx  or  LESS_TERMINFO_xxxx  to
 override
               a  terminal capability, regardless of whether 1mless  22mis
 built with
               the 1mtermcap 22mor the 1mterminfo 22mlibrary.

        LESS_TERMCAP_BRACKETED_PASTE_START
               Overrides  the  standard  ANSI  escape  sequence  to   enable
 bracketed
               paste.  This is used when the 1m--no-paste 22moption is  in
 effect.

        LESS_TERMCAP_BRACKETED_PASTE_END
               Overrides  the  standard  ANSI  escape  sequence  to  disable
 bracketed
               paste.

        LESS_TERMCAP_MOUSE_START
               Overrides  the standard ANSI escape sequence to enable  mouse
 re
               porting.  This is used when the 1m--mouse 22moption  is  in
 effect.

        LESS_TERMCAP_MOUSE_END
               Overrides the standard ANSI escape sequence to disable  mouse
 re
               porting.

        LESS_TERMCAP_SUSPEND
               Defines an escape sequence to  temporarily   suspend   screen
 up
               dates.  This is sent to  the  terminal  before  clearing  the
 screen.
               This  can be used to avoid screen tearing when the screen  is
 re
               drawn on certain terminals.

        LESS_TERMCAP_RESUME
               Defines an escape sequence to resume screen  updates.    This
 is
               sent to the terminal after displaying the prompt.

        LESS_UNSUPPORT
               A  spaceseparated  list of command  line  options.   These
 options
               will be ignored (with no error message) if they   appear   on
 the
               command line or in the LESS  environment  variable.   Options
 list
               ed  in  LESS_UNSUPPORT can still be changed by the -  and  --
 com
               mands.  Each option in LESS_UNSUPPORT is a dash  followed  by
 a
               single character option letter, or two dashes followed  by  a
 long
               option name.

        LINES  Sets  the  number of lines on the screen.   Takes  precedence
 over
               the number of lines specified by the TERM variable.  (But  if
 you
               have  a  windowing  system  which  supports  TIOCGWINSZ    or
 WIOCGETD,
               the  window  systems   idea   of  the  screen  size  takes
 precedence
               over the LINES and COLUMNS environment variables.)

        MORE   Options which are passed to  1mless  22mautomatically  when
 running  in
               1mmore22mcompatible mode.

        PATH   Users  search  path  (used  to  find  a  lesskey  file  on
 MSDOS, Win
               dows, and OS/2 systems).

        POSIXLY_CORRECT
               If set to any value, all option arguments  on   the   command
 line
               are expected to appear before any filename  arguments.   This
 must
               be set as an actual environment variable, not in a 1mlesskey
 22mfile.

        SHELL  The  shell  used  to execute the ! command,  as  well  as  to
 expand
               filenames.

        TERM   The type of terminal on which 1mless 22mis being run.

        VISUAL The name of the editor (used for the v command).

        XDG_CONFIG_HOME
               Possible location of the 1mlesskey  22mfile;  see  the  KEY
 BINDINGS sec
               tion.

        XDG_DATA_HOME
               Possible location of the history file; see  the   description
 of
               the LESSHISTFILE environment variable.

        XDG_STATE_HOME
               Possible  location  of  the history file; see the description
 of
               the LESSHISTFILE environment variable.

 1mSEE ALSO0m
        1mlesskey22m(1), 1mlessecho22m(1)

 1mCOPYRIGHT0m
        Copyright (C) 19842026  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  021111307, 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.

 1mAUTHOR0m
        Mark Nudelman
        Report bugs at https://github.com/gwsw/less/issues.
        For more information, see the less homepage at
        https://greenwoodsoftware.com/less.

 less        702                                 22         May         2026
 4mLESS24m(1)