LESS(1)                     General Commands Manual                    LESS(1)

NAME
       less - display the contents of a file in a terminal

SYNOPSIS
       less -?
       less --help
       less -V
       less --version
       less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
            [-b space] [-h lines] [-j line] [-k keyfile]
            [-{oO} logfile] [-p pattern] [-P prompt] [-t tag]
            [-T tagsfile] [-x tab,...] [-y lines] [-[z] lines]
            [-# shift] [+[+]cmd] [--] [filename]...
       (See  the  OPTIONS section for alternate option syntax with long option
       names.)

DESCRIPTION
       Less is a program similar to more(1), but it has  many  more  features.
       Less  does  not  have to read the entire input file before starting, so
       with large input files it starts  up  faster  than  text  editors  like
       vi(1).   Less uses 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.)

       Commands are based on both more and vi.  Commands may be preceded by  a
       decimal number, called N in the descriptions below.  The number is used
       by some commands, as indicated.

COMMANDS
       In  the following descriptions, ^X means control‐X.  ESC stands for the
       ESCAPE key; for example ESC‐v 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  -z  be‐
              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.

       ESC‐SPACE
              Like  SPACE,  but  scrolls  a full screenful, even if it reaches
              end‐of‐file in the process.

       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 ESC‐v
              Scroll backward N lines, default one window (see option  -z  be‐
              low).  If N is more than the screen size, only the final screen‐
              ful is displayed.

       w      Like  ESC‐v,  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.

       ESC‐) or RIGHTARROW
              Scroll horizontally right N characters, default half the  screen
              width  (see  the -# option).  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 -S option
              (chop lines) were in effect.

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

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

       ESC‐{ or ^LEFTARROW
              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 poll(2) you can also use ^X or the character spec‐
              ified by the --intr option.  If the input  is  a  pipe  and  the
              --exit‐follow‐on‐close  option is in effect, less will automati‐
              cally stop waiting for data when the input side of the  pipe  is
              closed.

       ESC‐F  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‐<
              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‐>
              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.)

       ESC‐G  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
              N‐th 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 N‐th 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 the status  column  is  en‐
              abled  via  the  -J  option,  the status column shows the marked
              line.

       M      Acts like m, except the last displayed  line  is  marked  rather
              than the first displayed line.

       '      (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.  Marks are preserved when a new file is  examined,
              so the ' command can be used to switch between input files.

       ^X^X   Same as single quote.

       ESC‐m  Followed  by  any lowercase or uppercase letter, clears the mark
              identified by that letter.

       /pattern
              Search forward in the file for the N‐th 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 case‐sensitive (uppercase and
              lowercase are considered different); the -i option can  be  used
              to  change  this.  The search starts at the first line displayed
              (but see the -a and -j options, 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 -a or -j
                     options.

              ^K     Highlight any text which matches the pattern on the  cur‐
                     rent screen, but don’t move to the first match (KEEP cur‐
                     rent position).

              ^R     Don’t  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 non‐empty match for the N‐th parenthesized SUB‐PAT‐
                     TERN will be considered to match the pattern.  (Supported
                     only  if less is built with one of the regular expression
                     libraries posix, pcre, or pcre2.)  Multiple ^S  modifiers
                     can be specified, to match more than one sub‐pattern.

              ^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.

       ?pattern
              Search  backward  in  the  file for the N‐th line containing the
              pattern.  The search starts at the last line displayed (but  see
              the -a and -j options, 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 -a or -j op‐
                     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.

       ESC‐/pattern
              Same as "/*".

       ESC‐?pattern
              Same as "?*".

       n      Repeat previous search, for N‐th line containing the  last  pat‐
              tern.   If the previous search was modified by ^N, the search is
              made for the N‐th 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.  There is no  effect  if  the
              previous search was modified by ^F or ^K.

       N      Repeat previous search, but in the reverse direction.

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

       ESC‐N  Repeat previous search, but in the reverse direction and  cross‐
              ing file boundaries.

       ESC‐u  Undo  search  highlighting.   Turn  off  highlighting of strings
              matching the current search pattern.  If highlighting is already
              off because of a previous ESC‐u command, turn highlighting  back
              on.   Any  search  command  will also turn highlighting back on.
              (Highlighting can also be disabled by toggling the -G option; in
              that case search commands do not turn highlighting back on.)

       ESC‐U  Like ESC‐u but also clears the saved  search  pattern.   If  the
              status  column  is  enabled  via  the -J option, this clears all
              search matches marked in the status column.

       &pattern
              Display only lines which match the pattern; lines which  do  not
              match  the  pattern  are not displayed.  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 reminder 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     Don’t interpret regular expression  metacharacters;  that
                     is, do a simple textual comparison.

       :e [filename]
              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 re‐examined.  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 -" option).

       ^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 N‐th next  file  is
              examined.

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

       :x     Examine  the first file in the command line list.  If a number N
              is specified, the N‐th 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 -t option 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 N‐th next OSC 8 hyperlink.

       ^O^P or ^Op
              Search backward in the file for the N‐th 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 (CONTROL‐P) 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 -b or -h), or a string value (such as  -P
              or  -t), 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.  You must press ENTER
              or RETURN after typing the option name.  A ^P immediately  after
              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  "-+X" command does the same
              thing as "-+X" on the command line.)  This  does  not  work  for
              string‐valued 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 string‐valued 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.

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

       V      Prints the version number of less being run.

       q or Q or :q or :Q or ZZ
              Exits less.

       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.

       ! shell‐command
              Invokes a shell to run the shell‐command 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  simply  invokes a shell.  If a ^P (CONTROL‐P) 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 MS‐DOS, Windows, and OS/2 systems, the  shell  is  the
              normal command processor.

       # shell‐command
              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".

       | <m> shell‐command
              <m> represents any mark letter.  Pipes a section  of  the  input
              file  to the given shell command.  The section of the file to be
              piped is between the position marked by the letter and the  cur‐
              rent  screen.  The entire current screen is included, regardless
              of whether the marked position is before or  after  the  current
              screen.   <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 (CONTROL‐P) is entered immediately after the
              mark letter, no "done" message is printed after the  shell  com‐
              mand is executed.

       s filename
              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.  To find the
              shell command, the environment variable named "LESS_OSC8_xxx" is
              read, where "xxx" is the scheme from the URI  (the  part  before
              the  first  colon), or is empty if there is no colon in the URI.
              The value of the environment variable is then  expanded  in  the
              same  way as prompt strings (in particular, any instance of "%o"
              is replaced with the URI) to produce an OSC  8  "handler"  shell
              command.   The  standard  output from the handler is an "opener"
              shell command which is then executed to open the URI.

              There are two special cases:

                     1.     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.

                     2.     If the opener begins with the characters ":e" fol‐
                            lowed  by  whitespace and a filename, then instead
                            of running the opener  as  a  shell  command,  the
                            specified  filename  is  opened in the current in‐
                            stance of less.

              In a simple case where the opener accepts the complete URI as  a
              command line parameter, the handler may be as simple as

              echo mybrowser ’%o’

              In  other cases, the URI may need to be modified, so the handler
              may have to do some manipulation of the %o value.

              If  the  LESS_OSC8_xxx  variable  is  not  set,   the   variable
              LESS_OSC8_ANY   is   tried.    If   neither   LESS_OSC8_xxx  nor
              LESS_OSC8_ANY is set, links using the  "xxx"  scheme  cannot  be
              opened.   However,  there  are  default handlers for the schemes
              "man" (used when LESS_OSC8_man is not set) and "file" (used when
              LESS_OSC8_file is not set), which should work on  systems  which
              provide  the  sed(1)  command and a shell with syntax compatible
              with the Bourne shell sh(1).  If you use LESS_OSC8_ANY to  over‐
              ride LESS_OSC8_file, you must set LESS_OSC8_file to "‐" to indi‐
              cate that the default value should not be used, and likewise for
              LESS_OSC8_man.

              The  URI  passed  to an OSC8 handler via %o is guaranteed not to
              contain any single quote or double quote characters, but it  may
              contain  any other shell metacharacters such as semicolons, dol‐
              lar signs, ampersands, etc.  The handler should take care to ap‐
              propriately quote parameters in the opener command,  to  prevent
              execution  of unintended shell commands in the case of opening a
              URI which contains shell metacharacters.  Also, since  the  han‐
              dler  command is expanded like a command prompt, any metacharac‐
              ters interpreted by prompt  expansion  (such  as  percent,  dot,
              colon,  backslash,  etc.)  must be escaped with a backslash (see
              the PROMPTS section for details).

       ^X     When the "Waiting for data" message is displayed, such as  while
              in  the  F  command, pressing ^X will stop less from waiting and
              return to a prompt.  This may cause less to 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 --intr option can be  used
              to  specify  a  different  character to use instead of ^X.  This
              command works only on systems that support the poll(2) function.
              On systems without poll(2), the interrupt character (usually ^C)
              can be used instead.

OPTIONS
       Command line options are described below.  Most options may be  changed
       while less is 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, --quit‐at‐eof may be abbreviated  --quit,  but
       not --qui, since both --quit‐at‐eof and --quiet begin with --qui.  Some
       long  option names are in uppercase, such as --QUIT‐AT‐EOF, as distinct
       from --quit‐at‐eof.  Such option names need only have their first  let‐
       ter  capitalized; the remainder of the name may be in either case.  For
       example, --Quit‐at‐eof is equivalent to --QUIT‐AT‐EOF.

       Options are also taken from the environment variable "LESS".  For exam‐
       ple, to avoid typing "less -options ..." each time less is invoked, you
       might tell csh:

       setenv LESS "-options"

       or if you use sh:

       LESS="-options"; export LESS

       On MS‐DOS and Windows, you don’t 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 "-+".

       Some options like -k or -D require 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 -D options like this:

       LESS="Dnwb$Dsbw"

       If the --use‐backslash option 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 --use‐backslash option is not
       in effect, then backslashes are not treated specially, and there is  no
       way to include a dollar sign in the option string.

       -? or --help
              This  option displays a summary of the commands accepted by less
              (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: "-\?".)

       -a or --search‐skip‐screen
              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 -j option for more about the  target  line).
              The  -a  option  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.

       -A or --SEARCH‐SKIP‐SCREEN
              Causes  all forward searches (not just non‐repeated 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.

       -bn or --buffers=n
              Specifies  the  amount  of  buffer  space less will 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 -B option).  The -b  option  specifies  instead  that  n
              kilobytes of buffer space should be used for each file.  If n is
              -1,  buffer  space is unlimited; that is, the entire file can be
              read into memory.

       -B or --auto‐buffers
              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  -B  option  disables  this automatic allocation of
              buffers for pipes, so that only 64 KB (or the  amount  of  space
              specified  by the -b option) is used for the pipe.  Warning: use
              of -B can 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.

       -c or --clear‐screen
              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.

       -C or --CLEAR‐SCREEN
              Same as -c, for compatibility with older versions of less.

       -d or --dumb
              The -d option 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
              -d  option  does  not otherwise change the behavior of less on a
              dumb terminal.

       -Dxcolor or --color=xcolor
              Changes the color of different parts of the displayed  text.   x
              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 --header option.

              M      Mark letters in the status column.

              N      Line numbers enabled via the -N option.

              P      Prompts.

              R      The rscroll character.

              S      Search results.

              W      The highlight enabled via the -w option.

              1‐5    The  text  in  a  search  result  which matches the first
                     through  fifth  parenthesized  sub‐pattern.   Sub‐pattern
                     coloring works only if less is built with one of the reg‐
                     ular expression libraries posix, pcre, or pcre2.

              d      Bold text.

              k      Blinking text.

              s      Standout text.

              u      Underlined text.

              The  uppercase  letters  and  digits  can  be used only when the
              --use‐color option 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 -U option) and to non‐content text (such  as
              line  numbers and prompts), but not to text formatted using ANSI
              escape sequences with the -R option (but see the note below  for
              different behavior on Windows and MS‐DOS).

              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, -Dug displays underlined text as green with‐
              out  underlining;  the green color has replaced the usual under‐
              line formatting.  But -Du+g displays  underlined  text  as  both
              green and in underlined format.

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

              A  4‐bit  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, -DNGk displays line numbers  as  bright
              green  text on a black background, and -DEbR displays 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 8‐bit 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 corresponding color is set
              to that of normal text.

              A 4‐bit or 8‐bit 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 MS‐DOS and Windows, the --color  option  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 -R, in  addition  to  over‐
                     struck and non‐content text (but see -Da).

              •      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     4‐bit
                     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 MS‐DOS/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.  4‐bit color sequences
                     work, but "CSI 38;5" color sequences do not.

              •      The -Da option makes the behavior of --color more similar
                     to its behavior on non‐MS‐DOS/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 -Da).

       -e or --quit‐at‐eof
              Causes  less  to  automatically  exit the second time it reaches
              end‐of‐file.  By default, the only way to exit less is  via  the
              "q" command.

       -E or --QUIT‐AT‐EOF
              Causes less to automatically exit the first time it reaches end‐
              of‐file.

       -f or --force
              Forces non‐regular files to be opened.  (A non‐regular file is a
              directory  or a device special file.)  Also suppresses the warn‐
              ing message when a binary file is opened.  By default, less will
              refuse to open non‐regular files.  Note that some operating sys‐
              tems will not allow directories to be read, even if -f is set.

       -F or --quit‐if‐one‐screen
              Causes less to automatically exit if the entire file can be dis‐
              played on the first screen.

       -g or --hilite‐search
              Normally, less will highlight ALL strings which match  the  last
              search  command.   The  -g option changes this behavior to high‐
              light only the particular string which was  found  by  the  last
              search command.  This can cause less to run somewhat faster than
              the default.

       -G or --HILITE‐SEARCH
              The  -G  option  suppresses all highlighting of strings found by
              search commands.

       -hn or --max‐back‐scroll=n
              Specifies a maximum number of lines to scroll backward.   If  it
              is necessary to scroll backward more than n lines, the screen is
              repainted in a forward direction instead.  (If the terminal does
              not have the ability to scroll backward, -h0 is implied.)

       -i or --ignore‐case
              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.

       -I or --IGNORE‐CASE
              Like -i, but searches ignore case even if the  pattern  contains
              uppercase letters.

       -jn or --jump‐target=n
              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  --header option is used and the target line specified by -j
              would be obscured by the header, the target line is moved to the
              first line after the header.  While the --header option  is  ac‐
              tive, the -S option is ignored, and lines longer than the screen
              width are truncated.

              If  any form of the -j option 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 -a or -A.  For example, if  "-j4"
              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 start or end of the current screen respectively.

       -J or --status‐column
              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 -S option, 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.

              a‐z, A‐Z
                     The  line  has  been marked with the corresponding letter
                     via the m command.

       -kfilename or --lesskey‐file=filename
              Causes less to open and interpret the named file as a lesskey(1)
              binary file.  Multiple -k options  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  lesskey  file.   Note  the  warning  under
              "--lesskey‐content" below.

       --lesskey‐src=filename
              Causes less to open and interpret the named file as a lesskey(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 lesskey program needed
              to be run to convert a lesskey source file to a  lesskey  binary
              file  for  less to use.  Newer versions of less read the lesskey
              source file directly and ignore the binary file  if  the  source
              file exists.  Note the warning under "--lesskey‐content" below.

       --lesskey‐content=text
              Causes less to interpret the specified text as the contents of a
              lesskey(1) source file.  In the text, lesskey lines 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  (--lesskey,
              --lesskey‐src  or --lesskey‐content).  When using a lesskey file
              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.

       -K or --quit‐on‐intr
              Causes  less  to exit immediately (with status 2) when an inter‐
              rupt character (usually ^C) is typed.   Normally,  an  interrupt
              character causes less to stop whatever it is doing and return to
              its  command  prompt.  Note that use of this option makes it im‐
              possible to return to the command prompt from the "F" command.

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

       -m or --long‐prompt
              Causes less to prompt verbosely (like more(1)), with the percent
              into the file.  By default, less prompts with a colon.

       -M or --LONG‐PROMPT
              Causes less to prompt even more verbosely than more(1).

       -n or --line‐numbers
              Suppresses  line numbers.  The default (to use line numbers) may
              cause less to run more slowly in some cases, especially  with  a
              very large input file.  Suppressing line numbers with the -n op‐
              tion  will  avoid  this  problem.  Using line numbers means: the
              line number will be displayed in the verbose prompt and in the =
              command, and the v command will pass the current line number  to
              the  editor  (see also the discussion of LESSEDIT in PROMPTS be‐
              low).

       -N or --LINE‐NUMBERS
              Causes a line number to be displayed at the  beginning  of  each
              line in the display.

       -ofilename or --log‐file=filename
              Causes  less  to 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, less  will  ask  for
              confirmation before overwriting it.

       -Ofilename or --LOG‐FILE=filename
              The -O option is like -o, but it will overwrite an existing file
              without asking for confirmation.

              If  no log file has been specified, the -o and -O options can be
              used from within less to 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 -o from within less.

       -ppattern or --pattern=pattern
              The  -p  option  on the command line is equivalent to specifying
              +/pattern; that is, it tells less to start at the  first  occur‐
              rence of pattern in the file.

       -Pprompt or --prompt=prompt
              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 less com‐
              mand.  Such an option must either be the last option in the LESS
              variable, or be terminated by a dollar sign.
               -Ps followed by a string changes the default (short) prompt  to
              that string.
               -Pm changes the medium (-m) prompt.
               -PM changes the long (-M) prompt.
               -Ph changes the prompt for the help screen.
               -P= changes the message printed by the = command.
               -Pw  changes 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.

       -q or --quiet or --silent
              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.

       -Q or --QUIET or --SILENT
              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.

       -r or --raw‐control‐chars
              Causes "raw" control characters to be displayed.  The default is
              to display control characters using the caret notation; for  ex‐
              ample,  a  control‐A (octal 001) is displayed as "^A" (with some
              exceptions as described under the -U option).  Warning: when the
              -r option is used, less cannot 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 -r OPTION IS NOT RECOMMENDED.

       -R or --RAW‐CONTROL‐CHARS
              Like -r, but only ANSI "color" escape sequences and OSC 8 hyper‐
              link sequences are output in "raw" form.  Unlike -r, the  screen
              appearance  is  maintained correctly, provided that there are no
              escape sequences in the file other than these  types  of  escape
              sequences.   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 (non‐
              colored), regardless of any escape sequences in previous  lines.
              For the purpose of keeping track of screen appearance, these es‐
              cape sequences are assumed to not move the cursor.

              OSC 8 hyperlinks are sequences of the form:

                   ESC ] 8 ; ... \7

              The  terminating  sequence may be either a BEL character (\7) or
              the two‐character sequence "ESC \".

              ANSI color escape sequences are sequences of the form:

                   ESC [ ... m

              where the "..." is zero or more color specification  characters.
              You  can  make less think 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 less think 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.

       -s or --squeeze‐blank‐lines
              Causes consecutive blank lines to  be  squeezed  into  a  single
              blank line.  This is useful when viewing nroff output.

       -S or --chop‐long‐lines
              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 RIGHT‐ARROW.  The default is to wrap long lines; that  is,
              display the remainder on the next line.  See also the --wordwrap
              option.

       -ttag or --tag=tag
              The -t option, 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 ctags(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 global(1), and that command is executed to  find  the  tag.
              (See  http://www.gnu.org/software/global/global.html).   The  -t
              option may also be specified from within less (using the -  com‐
              mand)  as  a  way  of examining a new file.  The command ":t" is
              equivalent to specifying -t from within less.

       -Ttagsfile or --tag‐file=tagsfile
              Specifies a tags file to be used instead of "tags".

       -u or --underline‐special
              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.

       -U or --UNDERLINE‐SPECIAL
              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 -r option.

              By  default, if neither -u nor -U is given, backspaces which ap‐
              pear adjacent to an underscore character are treated  specially:
              the  underlined  text is displayed using the terminal’s hardware
              underlining capability.  Also, backspaces which  appear  between
              two  identical  characters are treated specially: the overstruck
              text is printed using the terminal’s 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 -r option.  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 -u nor -U is in ef‐
              fect.

              See also the --proc‐backspace, --proc‐tab, and --proc‐return op‐
              tions.

       -V or --version
              Displays the version number of less.

       -w or --hilite‐unread
              Temporarily highlights the first  "new"  line  after  a  forward
              movement of a full page.  The first "new" line is the line imme‐
              diately  following  the  line  previously  at  the bottom of the
              screen.  Also highlights the target line after a g or p command.
              The highlight is removed at the next command which causes  move‐
              ment.  If the --status‐line option is in effect, the entire line
              (the  width  of the screen) is highlighted.  Otherwise, only the
              text in the line is highlighted, unless the -J option is in  ef‐
              fect, in which case only the status column is highlighted.

       -W or --HILITE‐UNREAD
              Like -w, but temporarily highlights the first new line after any
              forward movement command larger than one line.

       -xn,... or --tabs=n,...
              Sets  tab  stops.  If only one n is specified, tab stops are set
              at multiples of n.  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.   For  example,
              "‐x9,17" will set tabs at positions 9, 17, 25, 33, etc.  The de‐
              fault for n is 8.

       -X or --no‐init
              Disables sending the termcap initialization and deinitialization
              strings  to  the  terminal.   This is sometimes desirable if the
              deinitialization string does something unnecessary, like  clear‐
              ing the screen.

       -yn or --max‐forw‐scroll=n
              Specifies a maximum number of lines to scroll forward.  If it is
              necessary to scroll forward more than n lines, the screen is re‐
              painted  instead.   The  -c  or -C option may be used to repaint
              from the top of the screen if desired.  By default, any  forward
              movement causes scrolling.

       -zn or --window=n or -n
              Changes  the  default scrolling window size to n 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 more(1).  If the number n is  nega‐
              tive,  it  indicates  n lines less than the current screen size.
              For example, if the screen is 24 lines, -z-4 sets the  scrolling
              window  to  20 lines.  If the screen is resized to 40 lines, the
              scrolling window automatically changes to 36 lines.

       -"cc or --quotes=cc
              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).

       -~ or --tilde
              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.

       -# or --shift
              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.

       --exit‐follow‐on‐close
              When using the "F" command on a pipe,  less  will  automatically
              stop  waiting  for  more data when the input side of the pipe is
              closed.

       --file‐size
              If --file‐size is specified, less will determine the size of the
              file immediately after opening the file.  Then the  "="  command
              will  display the number of lines in the file.  Normally this is
              not done, because it can be slow if the input file is  non‐seek‐
              able (such as a pipe) and is large.

       --follow‐name
              Normally, if the input file is renamed while an F command is ex‐
              ecuting, less will continue to display the contents of the orig‐
              inal  file  despite its name change.  If --follow‐name is speci‐
              fied, during an F command less will 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), less will display the contents of that new file.

       --header=L,C,N
              Sets  the  number  of  header lines and columns displayed on the
              screen.  The number of header lines is set to L.   If  L  is  0,
              header lines are disabled.  If L is empty or missing, the number
              of  header  lines is unchanged.  The number of header columns is
              set to C.  If C is 0, header columns are disabled.  If C is emp‐
              ty or missing, the number of header columns is  unchanged.   The
              first  header line is set to line number N in the file.  If N 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 --head‐
              er  command  has  been  issued  from  within less), or 1 (if the
              --header option has been given on the command line).   The  spe‐
              cial form "--header=-" disables header lines and header columns,
              and is equivalent to "--header=0,0".

              When  L  is  nonzero, the first L lines at the top of the screen
              are replaced with the L lines of the file beginning at  line  N,
              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  C is nonzero, the first C characters
              displayed at the beginning of each line are  replaced  with  the
              first  C characters of the line, even if the rest of the line is
              scrolled horizontally.

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

       --intr=c
              Use the character c instead of ^X to interrupt a read  when  the
              "Waiting  for  data"  message  is displayed.  c 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.

       --line‐num‐width=n
              Sets the minimum width of the line number field when the -N  op‐
              tion is in effect to n characters.  The default is 7.

       --match‐shift=n
              When  -S  is 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 n 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.

       --modelines=n
              Before  displaying  a  file, less will read the first n lines to
              try to find a vim‐compatible modeline.  If n is zero, less  does
              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=n" or "ts=n", then
              tab stops are automatically set as if --tabs=n had  been  given.
              See the --tabs description for acceptable values of n.

       --mouse
              Enables  mouse  input: scrolling the mouse wheel down moves for‐
              ward in the file, scrolling the mouse wheel up  moves  backwards
              in  the file, left‐click sets the "#" mark to the line where the
              mouse is clicked, and right‐click (or any other) returns to  the
              "#"  mark position.  If a left‐click is performed with the mouse
              cursor on an OSC 8 hyperlink, the hyperlink is selected as if by
              the ^O^N command.  If a left‐click is performed with  the  mouse
              cursor  on an OSC 8 hyperlink which is already selected, the hy‐
              perlink is opened as if by the  ^O^O  command.   The  number  of
              lines  to  scroll  when  the  wheel  is  moved can be set by the
              --wheel‐lines option.  Mouse input works only on terminals which
              support X11 mouse reporting, and on the Windows version of less.

       --MOUSE
              Like --mouse, except the direction scrolled on mouse wheel move‐
              ment is reversed.

       --no‐keypad
              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.

       --no‐histdups
              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.

       --no‐number‐headers
              Header  lines (defined via the --header option) are not assigned
              line numbers.  Line number 1 is assigned to the first line after
              any header lines.

       --no‐search‐header‐lines
              Searches do not include header lines, but still  include  header
              columns.

       --no‐search‐header‐columns
              Searches do not include header columns, but still include header
              lines.

       --no‐search‐headers
              Searches do not include header lines or header columns.

       --no‐vbell
              Disables the terminal’s visual bell.

       --proc‐backspace
              If  set,  backspaces are handled as if neither the -u option nor
              the -U option 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  -u  and  -U
              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 -u and -U options.

       --PROC‐BACKSPACE
              If set, backspaces are handled as if the  -U  option  were  set;
              that is backspaces are treated as control characters.

       --proc‐return
              If set, carriage returns are handled as if neither the -u option
              nor  the -U option were set.  That is, a carriage return immedi‐
              ately before a newline is deleted.  This option overrides the -u
              and -U options, 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 -u and -U options.

       --PROC‐RETURN
              If set, carriage returns are handled as if the  -U  option  were
              set; that is carriage returns are treated as control characters.

       --proc‐tab
              If set, tabs are handled as if the -U option were not set.  That
              is,  tabs  are expanded to spaces.  This option overrides the -U
              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 -U options.

       --PROC‐TAB
              If set, tabs are handled as if the -U option were set;  that  is
              tabs are treated as control characters.

       --redraw‐on‐quit
              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 less has quit.

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

       --save‐marks
              Save  marks  in  the  history file, so marks are retained across
              different invocations of less.

       --search‐options=...
              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 --search‐
              options=W 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  "‐"  disables
              all default search modifiers.

       --show‐preproc‐errors
              If a preprocessor produces data, then exits with a non‐zero exit
              code, less will display a warning.

       --status‐col‐width=n
              Sets the width of the status column when the -J option is in ef‐
              fect.  The default is 2 characters.

       --status‐line
              If  a line is marked, the entire line (rather than just the sta‐
              tus column) is highlighted.  Also lines highlighted due  to  the
              -w option will have the entire line highlighted.  If --use‐color
              is set, the line is colored rather than highlighted.

       --use‐backslash
              This  option changes the interpretations of options which follow
              this one.  After the --use‐backslash option, 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.

       --use‐color
              Enables colored text in various places.  The -D  option  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).

       --wheel‐lines=n
              Set  the  number  of  lines  to  scroll  when the mouse wheel is
              scrolled and the --mouse or --MOUSE option is  in  effect.   The
              default is 1 line.

       --wordwrap
              When  the  -S option 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.

       --     A  command  line  argument of "--" 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 "+".

       +      If  a  command  line option begins with +, the remainder of that
              option is taken to be an initial command to less.  For  example,
              +G  tells  less  to 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.

LINE EDITING
       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 in some MS‐DOS 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 [ ESC‐h ]
              Move the cursor one space to the left.

       RIGHTARROW [ ESC‐l ]
              Move the cursor one space to the right.

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

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

       HOME [ ESC‐0 ]
              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 or [ ESC‐x ]
              Delete the character under the cursor.

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

       ^DELETE [ ESC‐X or ESC‐DELETE ]
              (That is, CONTROL and DELETE simultaneously.)  Delete  the  word
              under the cursor.

       UPARROW [ ESC‐k ]
              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 [ ESC‐j ]
              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 thru the other
              matching filenames.  If the completed filename is a directory, a
              "/" is appended to the filename.  (On MS‐DOS  and  Windows  sys‐
              tems,  a "\" is appended.)  The environment variable LESSSEPARA‐
              TOR can be used to specify a different character to append to  a
              directory name.

       BACKTAB [ ESC‐TAB ]
              Like, TAB, but cycles in the reverse direction thru the matching
              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 (MS‐DOS and Windows)
              Delete the entire command line, or cancel  the  command  if  the
              command line is empty.  If you have changed your line‐kill char‐
              acter 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.

KEY BINDINGS
       You  may  define  your  own  less commands 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 line‐editing keys (see
       LINE EDITING), and set environment variables used  by  less.   See  the
       lesskey(1) manual page for details about the file format.

       If  the  environment  variable  LESSKEYIN is set, less uses that as the
       name of the lesskey source file.  Otherwise, less looks in  a  standard
       place  for  the  lesskey source file: On Unix systems, less looks for a
       lesskey  file   called   "$XDG_CONFIG_HOME/lesskey"   or   "$HOME/.con‐
       fig/lesskey"  or "$HOME/.lesskey".  On MS‐DOS and Windows systems, less
       looks for a lesskey file called "$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,
       less looks 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 system‐wide 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
       system‐wide file, key bindings in the local file take  precedence  over
       those   in   the   system‐wide   file.   If  the  environment  variable
       LESSKEYIN_SYSTEM is set, less uses that as the name of the  system‐wide
       lesskey  file.   Otherwise, less looks in a standard place for the sys‐
       tem‐wide lesskey file: On Unix systems, the system‐wide lesskey file is
       /usr/local/etc/syslesskey.  (However, if less was built with a  differ‐
       ent  sysconf directory than /usr/local/etc, that directory is where the
       sysless file is found.)  On MS‐DOS and Windows systems, the system‐wide
       lesskey file is  c:\_syslesskey.   On  OS/2  systems,  the  system‐wide
       lesskey file is c:\syslesskey.ini.

       Previous versions of less (before v582) used lesskey files with a bina‐
       ry  format,  produced by the lesskey program. It is no longer necessary
       to use the lesskey program.

INPUT PREPROCESSOR
       You may define an "input preprocessor" for less.  Before less  opens  a
       file, it first gives your 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, less will 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, less uses 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 less closes a file opened in such a way, it will call another pro‐
       gram,  called  the  input  postprocessor, which may perform any desired
       clean‐up 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 less view 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 less, 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 less uses 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 non‐pipe 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 less, 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 less, the input  preproces‐
       sor or pipe is not used if less is viewing standard input.  However, if
       the  first  character of LESSOPEN is a dash (-), 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 (|-) or two vertical bars
       and a dash (||-), 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.

NATIONAL CHARACTER SETS
       There are three 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.

       A "character set" is simply a description of which characters are to be
       considered  normal,  control,  and binary.  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 MS‐DOS.

       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  UTF‐8  encoding  of  the  ISO 10646 character set.
              UTF‐8 is special in that it supports  multi‐byte  characters  in
              the input file.  It is the only character set that supports mul‐
              ti‐byte characters.

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

       In rare cases, it may be desired to tailor less to 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 setlocale in‐
       terface,  less will use setlocale to determine the character set.  set‐
       locale is controlled by setting the LANG or LC_CTYPE environment  vari‐
       ables.

       Finally,  if the setlocale interface 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 control‐A).  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 printf‐style 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  UTF‐8  file (octets of a truncated sequence, octets of a
       complete but non‐shortest form  sequence,  invalid  octets,  and  stray
       trailing  octets)  are displayed individually using LESSBINFMT so as to
       facilitate diagnostic of how the UTF‐8 file is ill‐formed.

       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 con‐
       trol characters, but if you are using  a  custom  font  with  printable
       characters  in  that  range,  it may be desirable to tell less to treat
       such characters as printable.  This can be done by setting the  LESSUT‐
       FCHARDEF  environment  variable  to a comma‐separated list of character
       type definitions.  Each character type definition  consists  of  either
       one  hexadecimal codepoint or a pair of codepoints separated by a dash,
       followed by a colon and a type character.  Each  hexadecimal  codepoint
       may  optionally  be preceded by a "U" or "U+".  If a pair of codepoints
       is given, the type is set for all characters  inclusively  between  the
       two  values.   If  there are multiple comma‐separated codepoint values,
       they must be in ascending numerical order.  The type character  may  be
       one of:

              p      A normal printable character.

              w      A wide (2‐space) printable character.

              b      A binary (non‐printable) character.

              c      A composing (zero width) character.

       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.

PROMPTS
       The  -P option allows you to tailor the prompt to your preference.  The
       string given to the -P option 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.)

       %bX    Replaced  by the byte offset into the current input file.  The b
              is followed by a single character (shown as X 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 -j
              option.

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

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

       %dX    Replaced by the page number of a line in the  input  file.   The
              line to be used is determined by the X, 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  shell‐escaped 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.

       %lX    Replaced by the line number of a line in the  input  file.   The
              line to be used is determined by the X, 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.

       %o     Replaced  by  the URI of the currently selected OSC 8 hyperlink,
              or a question mark if no hyperlink is selected.  This is used by
              OSC 8 handlers as explained in the ^O^O command description.

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

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

       %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 -t option,  it  expands  to  the  word
              "tag".

       %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.

       ?bX    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 not zero).

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

       ?e     True if at end‐of‐file.

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

       ?lX    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.

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

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

       ?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.

       ?n?f%f .?m(%T %i of %m) ..?e(END) ?x‐ Next\: %x..%t

       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 end‐of‐file, 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 (-m and -M re‐
       spectively).  Each is broken into two lines here for readability only.

       ?n?f%f .?m(%T %i of %m) ..?e(END) ?x‐ Next\: %x.:
            ?pB%pB\%:byte %bB?s/%s...%t

       ?f%f .?n?m(%T %i of %m) ..?ltlines %lt‐%lb?L/%L. :
            byte %bB?s/%s. .?e(END) ?x‐ Next\: %x.:?pB%pB\%..%t

       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\%..%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 shell‐escaped 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.

SECURITY
       When  the  environment  variable LESSSECURE is set to 1, less runs 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 (‐k and --lesskey‐src)

       lessopen  input preprocessor (LESSOPEN environment variable)

       logfile   log files (s and -o)

       osc8      opening OSC 8 links (^O^O)

       pipe      the pipe command (|)

       shell     the shell and pshell commands (! and #)

       stop      stopping less via a SIGSTOP signal

       tags      use of tags files (‐t)

       The LESSSECURE_ALLOW environment variable can be set to  a  comma‐sepa‐
       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.

COMPATIBILITY WITH MORE
       If the environment variable LESS_IS_MORE is set to 1, or if the program
       is  invoked via a file link named "more", less behaves (mostly) in con‐
       formance with the POSIX more(1) command specification.  In  this  mode,
       less behaves differently in these ways:

       The -e option works differently.  If the -e option is not set, less be‐
       haves  as if the -e option were set.  If the -e option is set, less be‐
       haves as if the -E option were set.

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

       The -n option acts like the -z option.  The normal behavior of  the  -n
       option is unavailable in this mode.

       The  parameter  to  the  -p option is taken to be a less command rather
       than a search pattern.

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

ENVIRONMENT VARIABLES
       Environment variables may be specified either in the system environment
       as  usual,  or  in a lesskey(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 system‐wide 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 system’s 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 user’s 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 user’s home directory if the HOME vari‐
              able is not set (only in the Windows version).

       INIT   Name  of  the user’s 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 less automatically.

       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:;[?!"'#%()*+ ".

       LESSBINFMT
              Format for displaying non‐printable, non‐control characters.

       LESSCHARDEF
              Defines a character set.

       LESSCHARSET
              Selects a predefined character set.

       LESSCLOSE
              Command line to invoke the (optional) input‐postprocessor.

       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 -t option to find global tags.
              Normally should be set to "global" if your system has the  glob‐
              al(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 less.  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 MS‐DOS
                     "$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 lesskey source file.

       LESSKEY
              Name   of   the  default  lesskey  binary  file.  (Not  used  if
              "$LESSKEYIN" exists.)

       LESSKEY_CONTENT
              The value is parsed as if it were the parameter of a  --lesskey‐
              content option.

       LESSKEYIN_SYSTEM
              Name of the default system‐wide lesskey source file.

       LESSKEY_SYSTEM
              Name  of  the default system‐wide lesskey binary 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.  If LESSMETAESCAPE is an  empty  string,
              commands  containing  metacharacters  will  not be passed to the
              shell.

       LESSOPEN
              Command line to invoke the (optional) input‐preprocessor.

       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 comple‐
              tion.

       LESSUTFBINFMT
              Format for displaying non‐printable 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 system’s idea of the screen size, so it  can
              be  used  to  make less use 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 system’s idea of the screen size, so it  can
              be  used  to make less use 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, less re‐
              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 more(1) command.

       LESS_OSC8_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_ANY
              Sets an OSC 8 handler for opening OSC 8 links for which there is
              no specific LESS_OSC8_xxx handler set for the "xxx" scheme.

       LESS_TERMCAP_xx
              Where  "xx"  is  any two characters, overrides the definition of
              the termcap "xx" capability for the terminal.

       LESS_UNSUPPORT
              A space‐separated 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 system’s idea of the  screen  size  takes  precedence
              over the LINES and COLUMNS environment variables.)

       MORE   Options  which  are passed to less automatically when running in
              more‐compatible mode.

       PATH   User’s search path (used to find a lesskey file on MS‐DOS,  Win‐
              dows, and OS/2 systems).

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

       TERM   The type of terminal on which less is being run.

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

       XDG_CONFIG_HOME
              Possible location of the lesskey file; 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.

SEE ALSO
       lesskey(1), lessecho(1)

COPYRIGHT
       Copyright (C) 1984‐2024  Mark Nudelman

       less is part of the GNU project and is free software.  You  can  redis‐
       tribute  it and/or modify it under the terms of either (1) the GNU Gen‐
       eral Public License as published by the Free  Software  Foundation;  or
       (2) the Less License.  See the file README in the less distribution for
       more details regarding redistribution.  You should have received a copy
       of  the  GNU General Public License along with the source for less; see
       the file COPYING.  If not, write to the Free  Software  Foundation,  59
       Temple  Place, Suite 330, Boston, MA  02111‐1307, USA.  You should also
       have received a copy of the Less License; see the file LICENSE.

       less is distributed in the hope that it will be useful, but WITHOUT ANY
       WARRANTY; without even the implied warranty of MERCHANTABILITY or  FIT‐
       NESS  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
       more details.

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

                           Version 668: 06 Oct 2024                    LESS(1)