Provided by: less_590-2ubuntu2.1_amd64 bug

NAME

       less - opposite of more

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 "ESCAPE", 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 below).  If N is more
              than the screen size, only the final screenful 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 displayed, 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 below).  If  N  is  more
              than the screen size, only the final screenful 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 displayed, 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 becomes 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 becomes the default for future  RIGHTARROW
              and LEFTARROW commands.

       ESC-} or ^RIGHTARROW
              Scroll horizontally right to show the end of the longest displayed 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, reload 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 some systems you can also use ^X.

       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).  (Warning: 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.  (Warning: 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 top 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 brackets.

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

       ESC-^F Followed by two characters, acts like {, but uses the two characters  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 characters  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 enabled 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  position  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 pattern.  N defaults to
              1.  The pattern is a regular expression, as recognized by  the  regular  expression
              library  supplied  by  your  system.  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 current screen, but
                     don't move to the first match (KEEP current position).

              ^R     Don't interpret regular expression metacharacters;  that  is,  do  a  simple
                     textual comparison.

              ^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.

       ?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 displayed on the screen or the  settings  of
                     the -a or -j options.

              ^K     As in forward searches.

              ^R     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 pattern.  If the previous
              search was modified by ^N, the search is made for the N-th line NOT containing  the
              pattern.   If  the  previous 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  effect  is  as  if  the
              previous search were modified by *.

       ESC-N  Repeat previous search, but in the reverse direction and crossing 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 replaced 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 literalization 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  command  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.

       = 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  entered  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 setting 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 reset  the  option  to
              its  default  setting  and  print a message describing 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 letters, 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  four  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 neither 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 examined file.  "!!" repeats the last shell command.  "!"
              with no shell command simply invokes a shell.  On Unix systems, the shell is  taken
              from  the  environment  variable  SHELL,  or  defaults to "sh".  On MS-DOS and OS/2
              systems, the shell is the normal command processor.

       | <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 current 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.

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

OPTIONS

       Command line options are described below.  Most options  may  be  changed  while  less  is
       running, via the "-" command.

       Most  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 unambiguous.  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 letter 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 example, 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, you don't need the quotes, but you should replace  any  percent  signs  in  the
       options string by double percent signs.

       The  environment  variable  is  parsed  before  the  command line, so command line options
       override the LESS environment variable.  If an option appears 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 letter.  The  string  for
       that  option  is  considered to end when a dollar sign ($) is found.  For example, you can
       set two -D options on MS-DOS like this:

       LESS="Dn9.1$Ds4.1"

       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 interprets 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 displayed screen (except for repeated  searches
              invoked  by  the  n  or  N  commands, which start after or before the "target" line
              respectively; 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 allocated.  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  recently viewed part of the piped data is kept in
              memory; any earlier data is lost.

       -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.

              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.

              d      Bold text.

              k      Blinking text.

              s      Standout text.

              u      Underlined text.

              The  uppercase  letters  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 normally
              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 "d" and "u" letters refer to bold and underline  text  formed  by  overstriking
              with  backspaces  (see the -u option), not to text using ANSI escape sequences with
              the -R option.

              A lowercase letter may be followed by a + to indicate that both the  normal  format
              change  and  the  specified  color should both be used.  For example, -Dug displays
              underlined text as green without underlining; the  green  color  has  replaced  the
              usual  underline  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 zero, one or two  characters,  where  the  first  character
              specifies  the  foreground  color  and the second specifies the background color as
              follows:

              b      Blue

              c      Cyan

              g      Green

              k      Black

              m      Magenta

              r      Red

              w      White

              y      Yellow

              The corresponding upper-case 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 messages as blue text on  a  bright  red  background.   If
              either  character 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_parameters) If either integer is
              a "-" or is omitted, the corresponding color is set to that of normal text.  On MS-
              DOS  versions  of  less,  8-bit color is not supported; instead, decimal values are
              interpreted as 4-bit CHAR_INFO.Attributes values (see
              https://docs.microsoft.com/en-us/windows/console/char-info-str).

       -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 warning message when a  binary  file  is
              opened.   By  default,  less will refuse to open non-regular files.  Note that some
              operating systems 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 displayed 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 highlight 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 uppercase 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 command 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
              specified  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 relative 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,
              so that the target line remains at the specified fraction of the screen height.  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 status column shows
              the lines that matched the current search, and any lines that are marked (via the m
              or 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.

       --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 standard 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.

       -K or --quit-on-intr
              Causes less to exit  immediately  (with  status  2)  when  an  interrupt  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 impossible to return to the command prompt from the "F" command.

       -L or --no-lessopen
              Ignore  the  LESSOPEN  environment  variable  (see  the  INPUT PREPROCESSOR 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), 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.

       -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 option 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 below).

       -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 occurrence 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 environment variable,  rather  than  being
              typed  in with each less command.  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  example,  a  control-A  (octal  001)  is
              displayed  as "^A".  Warning: when the -r option is used, less cannot keep track of
              the actual appearance of the screen (since this depends on how the screen  responds
              to  each  type  of  control character).  Thus, various display 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 hyperlink  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
              escape 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  (truncated)  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.

       -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 directory called "tags", which was previously built by
              ctags(1) or an equivalent command.  If the environment variable  LESSGLOBALTAGS  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 - command) 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 printable 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 characters"  (as  defined
              by  Unicode)  to  be  treated  as  control characters; that is, they are handled as
              specified by the -r option.

              By default, if neither -u nor -U is given, backspaces which appear 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 capability.   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 effect.

       -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 immediately 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 movement.   The
              entire  line  is highlighted, unless the -J option is in effect, 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 continue with the same spacing as the last two.  For example,
              -x9,17 will set tabs at positions 9, 17, 25, 33, etc.  The default 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 clearing 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 repainted 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  default is one
              screenful.  The z and w commands can also be used to change the window  size.   The
              "z"  may  be omitted for compatibility with some versions of more.  If the number n
              is negative, 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  specified is zero, it sets the default
              number of positions to one half of the screen width.  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 window is resized,  so  that  the  actual
              scroll remains at the specified fraction of the screen width.

       --file-size
              If  --file-size  is specified, less will determine the size of the file immediately
              after opening the file.  Normally this is not done, because it can be slow  if  the
              input file is large.

       --follow-name
              Normally,  if  the input file is renamed while an F command is executing, less will
              continue to display the contents of the original file despite its name change.   If
              --follow-name  is  specified, during an F command less will periodically attempt to
              reopen 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 renamed) file), less will display the  contents  of  that  new
              file.

       --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.

       --line-num-width
              Sets  the  minimum  width of the line number field when the -N option is in effect.
              The default is 7 characters.

       --mouse
              Enables mouse input: scrolling the mouse wheel down  moves  forward  in  the  file,
              scrolling  the  mouse  wheel up moves backwards in the file, and clicking the mouse
              sets the "#" mark to the line where the mouse is clicked.  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 movement 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.

       --rscroll
              This  option changes the character used to mark truncated lines.  It may begin with
              a two-character attribute indicator like LESSBINFMT 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.

       --status-col-width
              Sets the width of the status column when the -J option is in effect.   The  default
              is 2 characters.

       --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 the colored text in various places.  The -D option can be  used  to  change
              the  colors.   Colored  text  works only if the terminal supports ANSI color escape
              sequences (as defined in ECMA-48 SGR; see
              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.

       --     A  command  line argument of "--" marks the end of option arguments.  Any arguments
              following this are interpreted as filenames.  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 initial 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 cursor one word to the
              left.

       ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
              (That is, CONTROL and RIGHTARROW simultaneously.)  Move the cursor 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 command 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 systems, a "\"  is  appended.)   The
              environment  variable LESSSEPARATOR 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)
              Delete the entire command line, or cancel the command if the command line is empty.
              If you have changed your line-kill character in Unix to something  other  than  ^U,
              that character is used instead of ^U.

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

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 associated with  each  key.   You  may  also
       change the line-editing keys (see LINE EDITING), and to set environment variables.  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/.lesskey".   On  MS-DOS  and  Windows systems, less looks for a lesskey file called
       "$HOME/_lesskey", and if it is not found there, then  looks  for  a  lesskey  file  called
       "_lesskey"  in any directory specified in the PATH environment variable.  On OS/2 systems,
       less looks for a lesskey file called "$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.  See the
       lesskey manual page for more details.

       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 system-wide lesskey file: On Unix
       systems, the system-wide lesskey file is /usr/local/etc/syslesskey.  (However, if less was
       built with a different 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 binary 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 simply an executable program (or shell script), which writes the
       contents of the file to a different file, called the replacement file.   The  contents  of
       the  replacement  file  are  then displayed in place of the contents 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 replacement filename,  less  uses  the  original  file,  as  normal.   The  input
       preprocessor  is not called when viewing standard input.  To set up an input 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 replaced by the filename when the input preprocessor command is invoked.

       When less closes a file opened in such a way, it will call  another  program,  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  original  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 replaced 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 starting 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
       replacement file on its standard output, writes the entire  contents  of  the  replacement
       file  on  its  standard  output.   If  the input pipe does not write any characters on its
       standard output, then there is no replacement 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  previous  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 interpreted 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 becomes meaningful.  If the exit
       status is zero, the output is considered to be replacement text, even if it is empty.   If
       the  exit  status  is  nonzero,  any output is ignored and the original file is used.  For
       compatibility 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 preprocessor 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 characters 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 multi-byte characters.

       windows
              Selects a character set appropriate for Microsoft Windows (cp 1251).

       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 environment 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 number 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 binary, 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 interface, less will
       use setlocale to determine the character set.  setlocale is controlled by setting the LANG
       or LC_CTYPE environment variables.

       Finally,  if  the  setlocale interface is also not available, the default character set is
       latin1.

       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 character 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  result 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., unassigned 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.

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 ordinary 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:

       %bX    Replaced  by  the  byte offset into the current input file.  The b is followed by a
              single character (shown as X above) which specifies the line whose byte  offset  is
              to  be  used.   If  the  character 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 bottom 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 equivalently, 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.

       %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 evaluated.  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 input file is not the
              last one).

       Any characters other than the special ones (question mark,  colon,  period,  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 "Standard input".

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

       This prompt would print the filename, if known.  The filename  is  followed  by  the  line
       number,  if  known,  otherwise  the  percent if known, otherwise the byte offset if known.
       Otherwise, a dash is printed.  Notice 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, followed 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  reference,
       here  are the defaults for the other two prompts (-m and -M respectively).  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 expanded 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 invocation syntax, the LESSEDIT variable can be changed to
       modify this default.

SECURITY

       When the environment variable LESSSECURE is set to 1, less runs in a "secure" mode.   This
       means these features are disabled:

              !      the shell command

              |      the pipe command

              :e     the examine command.

              v      the editing command

              s  -o  log files

              -k     use of lesskey files

              -t     use of tags files

                     metacharacters in filenames, such as *

                     filename completion (TAB, ^L)

       Less can also be compiled to be permanently in "secure" mode.

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 conformance with the POSIX "more" command
       specification.  In this mode, less behaves differently in these ways:

       The  -e  option works differently.  If the -e option is not set, less behaves as if the -e
       option were set.  If the -e option is set, less behaves 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 defined 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 variables is the name of
              the user's home directory if the HOME variable 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 discussion 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 global(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 is "$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst" on Unix systems,
              "$HOME/_lesshst"  on  DOS  and   Windows   systems,   or   "$HOME/lesshst.ini"   or
              "$INIT/lesshst.ini" on OS/2 systems.

       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.)

       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  command  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.

       LESSSEPARATOR
              String to be appended to a directory name in filename completion.

       LESSUTFBINFMT
              Format for displaying non-printable Unicode code points.

       LESS_IS_MORE
              Emulate the more(1) command.

       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 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).

SEE ALSO

       lesskey(1)

COPYRIGHT

       Copyright (C) 1984-2021  Mark Nudelman

       less is part of the GNU project and is free software.   You  can  redistribute  it  and/or
       modify it under the terms of either (1) the GNU General Public License as published by the
       Free Software Foundation; or (2) the Less License.   See  the  file  README  in  the  less
       distribution  for  more details regarding redistribution.  You should have received a copy
       of the GNU 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 FITNESS 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 590: 03 Jun 2021                             LESS(1)