less(1)


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.

   r or ^R or ^L
          Repaint the screen.

   R      Repaint the screen, discarding any buffered  input.   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.)

   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 letter,  marks  the  current  position
          with that letter.

   '      (Single  quote.)   Followed  by any lowercase 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.

   /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.

   ?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.

   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.)

   &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.

          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 first line on the current  screen  and  the
          position  marked  by  the  letter.   <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 K  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 K (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
          [MS-DOS  only]  Sets  the  color  of the text displayed.  x is a
          single character which selects the type of text whose  color  is
          being  set: n=normal, s=standout, d=bold, u=underlined, k=blink.
          color is a pair of numbers separated by  a  period.   The  first
          number  selects  the foreground color and the second selects the
          background color of the text.  A single number N is the same  as
          N.M, where M is the normal background color.

   -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.
          The  status  column  is  also  used if the -w or -W option is in
          effect.

   -kfilename or --lesskey-file=filename
          Causes less to open and interpret the named file  as  a  lesskey
          (1) 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.

   -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.

   -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.

   -R or --RAW-CONTROL-CHARS
          Like  -r,  but  only ANSI "color" escape sequences are output in
          "raw" form.  Unlike -r,  the  screen  appearance  is  maintained
          correctly  in  most  cases.   ANSI  "color" escape sequences are
          sequences of the form:

               ESC [ ... m

          where the "..." is zero or more color  specification  characters
          For  the  purpose  of  keeping  track of screen appearance, ANSI
          color escape sequences are assumed to not move the cursor.   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  shown.   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 and carriage returns 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.   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.

   -[z]n or --window=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.

   --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.

   --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.

   --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.

   --     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 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 using the program lesskey (1)
   to create a lesskey file.  This file specifies a set  of  command  keys
   and  an  action  associated with each key.  You may also use lesskey to
   change the line-editing keys (see LINE EDITING), and to set environment
   variables.   If the environment variable LESSKEY is set, less uses that
   as the name of the lesskey file.  Otherwise, less looks in  a  standard
   place  for  the lesskey file: On Unix systems, less looks for a lesskey
   file called "$HOME/.less".  On MS-DOS and Windows systems,  less  looks
   for  a lesskey file called "$HOME/_less", and if it is not found there,
   then looks for a lesskey file called "_less" in any directory specified
   in  the  PATH  environment variable.  On OS/2 systems, less looks for a
   lesskey file called "$HOME/less.ini", and if  it  is  not  found,  then
   looks  for  a lesskey file called "less.ini" in any directory specified
   in the INIT environment variable, and if it not found there, then looks
   for  a lesskey file called "less.ini" in any directory specified in the
   PATH environment variable.   See  the  lesskey  manual  page  for  more
   details.

   A  system-wide lesskey 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 LESSKEY_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/sysless.
   (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:\_sysless.    On  OS/2  systems,  the  system-wide  lesskey  file  is
   c:\sysless.ini.

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) uncompress -c $1  >/tmp/less.$$  2>/dev/null
             if [ -s /tmp/less.$$ ]; then
                  echo /tmp/less.$$
             else
                  rm -f /tmp/less.$$
             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.

   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
   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,  illegal  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.

   %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. %f

   Note that this expands to the editor name, followed by a + and the line
   number, followed by the 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
          "$HOME/.lesshst"  on  Unix  systems, "$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.

   LESSKEY
          Name of the default lesskey(1) file.

   LESSKEY_SYSTEM
          Name of the default system-wide lesskey(1) file.

   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) 1984-2015  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
   Send bug reports or comments to <bug-less@gnu.org>
   See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
   of known bugs in less.
   For more information, see the less homepage at
   http://www.greenwoodsoftware.com/less.

                       Version 481: 31 Aug 2015                    LESS(1)





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