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LESS(1)								       LESS(1)

NAME
       less - opposite of more

SYNOPSIS
       less -?
       less --help
       less -V
       less --version
       less [-[+]aBcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
	    [-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 which allows backward	 move‐
       ment in the file as well as forward movement.  Also, 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  spe‐
	      cial 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.

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

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

       b or ^B or ESC-v
	      Scroll backward N lines,	default	 one  window  (see  option  -z
	      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 dis‐
	      played, even if N is more than the screen size.	Warning:  some
	      systems use ^Y as a special job control character.

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

       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 com‐
	      mands.  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 com‐
	      mands.

       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.)

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

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

       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 brack‐
	      ets.

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

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

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

       m      Followed	by  any	 lowercase  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.  Fol‐
	      lowed 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 ' com‐
	      mand 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 pat‐
	      tern.  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 second line displayed (but see
	      the -a and -j options, which change this).

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

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

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

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

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

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

       ?pattern
	      Search  backward	in  the	 file for the N-th line containing the
	      pattern.	The search starts at the line immediately  before  the
	      top line displayed.

	      Certain characters are special as in the / command:

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

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

	      ^F or @
		     Begin the search at the last line of the last file in the
		     command  line  list, regardless of what is currently dis‐
		     played on the screen or the settings  of  the  -a	or  -j
		     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 pat‐
	      tern.  If the previous search was modified by ^N, the search  is
	      made  for the N-th line NOT containing the pattern.  If the pre‐
	      vious search was modified by ^E, the  search  continues  in  the
	      next  (or	 previous)  file if not satisfied in the current file.
	      If the previous search was modified by ^R, the  search  is  done
	      without  using  regular  expressions.  There is no effect if the
	      previous search was modified by ^F or ^K.

       N      Repeat previous search, but in the reverse direction.

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

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

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

       &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 literal‐
	      ization character.  On such systems, you may not be able to  use
	      ^V.

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

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

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

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

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

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

       = 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  set‐
	      ting is printed and nothing is changed.

       --     Like  the	 -  command, but takes a long option name (see OPTIONS
	      below) rather than a  single  option  letter.   You  must	 press
	      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  let‐
	      ters,  this  will print a message describing the current setting
	      of that option.  The setting of the option is not changed.

       __     (Double underscore.)  Like the _ (underscore) command, but takes
	      a long option name rather than a single option letter.  You must
	      press 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 nei‐
	      ther VISUAL nor EDITOR is defined.  See also the	discussion  of
	      LESSEDIT under the section on PROMPTS below.

       ! shell-command
	      Invokes  a shell to run the shell-command given.	A percent sign
	      (%) in the command is replaced by the name of the current	 file.
	      A pound sign (#) is replaced by the name of the previously exam‐
	      ined file.  "!!" repeats the last shell command.	 "!"  with  no
	      shell  command  simply  invokes  a  shell.  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 indi‐
	      cate beginning or end of file respectively.  If <m> is . or new‐
	      line, 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 let‐
       ter capitalized; the remainder of the name may be in either case.   For
       example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.

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

       setenv LESS "-options"

       or if you use sh:

       LESS="-options"; export LESS

       On  MS-DOS,  you don't need the quotes, but you should replace any per‐
       cent 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 "-+".

       For  options like -P or -D which take a following string, a dollar sign
       ($) must be used to signal the end of the string.  For example, to  set
       two  -D	options	 on  MS-DOS, you must have a dollar sign between them,
       like this:

       LESS="-Dn9.1$-Ds4.1"

       -? 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
	      Causes  searches	to  start after the last line displayed on the
	      screen, thus skipping all lines displayed	 on  the  screen.   By
	      default,	searches  start	 at  the second line on the screen (or
	      after the last found line; see the -j option).

       -bn or --buffers=n
	      Specifies the amount of buffer space  less  will	use  for  each
	      file,  in	 units	of  kilobytes (1024 bytes).  By default 64K of
	      buffer space is used for each file (unless the file is  a	 pipe;
	      see  the	-B  option).   The  -b option specifies instead that n
	      kilobytes of buffer space should be used for each file.  If n is
	      -1,  buffer  space is unlimited; that is, the entire file can be
	      read into memory.

       -B or --auto-buffers
	      By default, when data is read from a pipe, buffers are allocated
	      automatically as needed.	If a large amount of data is read from
	      the pipe, this can cause a large amount of memory	 to  be	 allo‐
	      cated.  The -B option disables this automatic allocation of buf‐
	      fers for pipes, so that only 64K (or the amount of space	speci‐
	      fied 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 sin‐
	      gle  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	 warn‐
	      ing message when a binary file is opened.	 By default, less will
	      refuse to open non-regular files.	 Note that some operating sys‐
	      tems will not allow directories to be read, even if -f is set.

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

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

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

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

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

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

       -jn or --jump-target=n
	      Specifies	 a line on the screen where the "target" line is to be
	      positioned.  The target line is the line specified by  any  com‐
	      mand  to	search for a pattern, jump to a line number, jump to a
	      file percentage or jump to a tag.	 The screen line may be speci‐
	      fied  by	a number: the top line on the screen is 1, the next is
	      2, and so on.  The number may be negative to specify a line rel‐
	      ative to the bottom of the screen: the bottom line on the screen
	      is -1, the second to the bottom is -2, and so on.	  Alternately,
	      the  screen line may be specified as a fraction of the height of
	      the screen, starting with a decimal point: .5 is in  the	middle
	      of  the screen, .3 is three tenths down from the first line, and
	      so on.  If the line is specified as a fraction, the actual  line
	      number  is  recalculated	if  the terminal window is resized, so
	      that the target line remains at the specified  fraction  of  the
	      screen  height.	If  any form of the -j option is used, forward
	      searches begin at the line immediately after  the	 target	 line,
	      and backward searches begin at the target line.  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.

       -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	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  PRE‐
	      PROCESSOR	 section  below).   This option can be set from within
	      less, but it will apply only to files opened  subsequently,  not
	      to the file which is currently open.

       -m or --long-prompt
	      Causes  less  to	prompt verbosely (like more), 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	occur‐
	      rence of pattern in the file.

       -Pprompt or --prompt=prompt
	      Provides	a  way	to  tailor the three prompt styles to your own
	      preference.  This option would normally be put in the LESS envi‐
	      ronment variable, rather than being typed in with each less com‐
	      mand.  Such an option must either be the last option in the LESS
	      variable,	 or be terminated by a dollar sign.  -Ps followed by a
	      string changes the default (short) prompt to that	 string.   -Pm
	      changes  the  medium  (-m)  prompt.   -PM	 changes the long (-M)
	      prompt.  -Ph changes  the	 prompt	 for  the  help	 screen.   -P=
	      changes  the  message printed by the = command.  -Pw changes the
	      message printed while waiting for data (in the F command).   All
	      prompt  strings  consist	of  a  sequence of letters and special
	      escape sequences.	 See the section on PROMPTS for more details.

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

       -Q or --QUIET or --SILENT
	      Causes  totally  "quiet"	operation:  the terminal bell is never
	      rung.

       -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 dis‐
	      play 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 cor‐
	      rectly  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	rather
	      than  folded.  That is, the portion of a long line that does not
	      fit in the screen width is not shown.  The default  is  to  fold
	      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 LESSGLOB‐
	      ALTAGS is set, it is taken to be the name of a command  compati‐
	      ble  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 print‐
	      able 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  spe‐
	      cially:  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	 bold‐
	      face  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	under‐
	      lined 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 imme‐
	      diately  following  the  line  previously	 at  the bottom of the
	      screen.  Also highlights the target line after a g or p command.
	      The  highlight is removed at the next command which causes move‐
	      ment.  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  con‐
	      tinue  with  the	same  spacing  as  the last two.  For example,
	      -x9,17 will set tabs at positions	 9,  17,  25,  33,  etc.   The
	      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 clear‐
	      ing the screen.

       -yn or --max-forw-scroll=n
	      Specifies a maximum number of lines to scroll forward.  If it is
	      necessary	 to  scroll  forward  more than n lines, the screen is
	      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  compati‐
	      bility 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 win‐
	      dow to 20 lines.	If the screen is  resized  to  40  lines,  the
	      scrolling window automatically changes to 36 lines.

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

       -~ or --tilde
	      Normally lines after end of file are displayed as a single tilde
	      (~).  This option causes lines after end of file to be displayed
	      as blank lines.

       -# or --shift
	      Specifies the default number of positions to scroll horizontally
	      in  the RIGHTARROW and LEFTARROW commands.  If the number speci‐
	      fied is zero, it sets the default number	of  positions  to  one
	      half of the screen width.	 Alternately, the number may be speci‐
	      fied as a fraction of the width of the screen, starting  with  a
	      decimal  point:  .5  is  half  of	 the screen width, .3 is three
	      tenths of the screen width, and so on.  If the number is	speci‐
	      fied  as	a  fraction,  the actual number of scroll positions is
	      recalculated if the terminal window  is  resized,	 so  that  the
	      actual  scroll  remains  at the specified fraction of the screen
	      width.

       --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.

       --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.

       --     A	 command  line	argument of "--" marks the end of option argu‐
	      ments.  Any arguments following this are	interpreted  as	 file‐
	      names.  This can be useful when viewing a file whose name begins
	      with a "-" or "+".

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

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

       LEFTARROW [ ESC-h ]
	      Move the cursor one space to the left.

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

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

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

       HOME [ ESC-0 ]
	      Move the cursor to the beginning of the line.

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

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

       DELETE or [ ESC-x ]
	      Delete the character under the cursor.

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

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

       UPARROW [ ESC-k ]
	      Retrieve the previous command line.

       DOWNARROW [ ESC-j ]
	      Retrieve the next command line.

       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 char‐
	      acter in Unix to something other than ^U, that character is used
	      instead of ^U.

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:\_sys‐
       less.  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  sim‐
       ply  an executable program (or shell script), which writes the contents
       of the file to a different file, called the replacement file.  The con‐
       tents  of  the replacement file are then displayed in place of the con‐
       tents of the original file.  However, it will appear to the user as  if
       the  original  file  is opened; that is, less will display the original
       filename as the name of the current file.

       An input preprocessor receives one command line argument, the  original
       filename,  as  entered  by  the user.  It should create the replacement
       file, and when finished, print the name of the replacement file to  its
       standard	 output.  If the input preprocessor does not output a replace‐
       ment filename, less uses the original file, as normal.  The input  pre‐
       processor  is  not  called  when	 viewing standard input.  To set up an
       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 pro‐
       gram,  called  the  input  postprocessor, which may perform any desired
       clean-up action (such as	 deleting  the	replacement  file  created  by
       LESSOPEN).  This program receives two command line arguments, the orig‐
       inal filename as entered by the user, and the name of  the  replacement
       file.   To set up an input postprocessor, set the LESSCLOSE environment
       variable to a command line which will invoke your input	postprocessor.
       It  may	include	 two  occurrences  of  the  string  "%s"; the first is
       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 -
		 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 start‐
       ing to view it.	An input preprocessor that works this way is called an
       input  pipe.   An input pipe, instead of writing the name of a replace‐
       ment file on its standard output, writes the  entire  contents  of  the
       replacement  file  on  its standard output.  If the input pipe does not
       write any characters on its standard output, then there is no  replace‐
       ment  file and less uses the original file, as normal.  To use an input
       pipe, make the first character in the LESSOPEN environment  variable  a
       vertical	 bar  (|)  to  signify that the input preprocessor is an input
       pipe.

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

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

       To  use	this  script,  put  it	where  it  can	be  executed  and  set
       LESSOPEN="|lesspipe.sh %s".  When an input pipe is  used,  a  LESSCLOSE
       postprocessor  can be used, but it is usually not necessary since there
       is no replacement file to clean up.  In this case, the replacement file
       name passed to the LESSCLOSE postprocessor is "-".

       For  compatibility with previous versions of less, the input preproces‐
       sor or pipe is not used if less is viewing standard input.  However, if
       the  first  character of LESSOPEN is a dash (-), the input preprocessor
       is used on standard input as well as other files.  In  this  case,  the
       dash  is	 not  considered  to  be part of the preprocessor command.  If
       standard input is being viewed, the input preprocessor is passed a file
       name  consisting of a single dash.  Similarly, if the first two charac‐
       ters of LESSOPEN are vertical bar and dash (|-), 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 envi‐
       ronment variable LESSCHARDEF can be used to define a character set.  It
       should be set to a string where each character in the string represents
       one character in the character set.  The character "." is  used	for  a
       normal  character, "c" for control, and "b" for binary.	A decimal num‐
       ber may be used for repetition.	 For  example,	"bccc4b."  would  mean
       character  0  is	 binary,  1,  2	 and  3 are control, 4, 5, 6 and 7 are
       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	 char‐
       acter 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_TYPE 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 char‐
       acter is displayed as a hex number in angle brackets.  This format  can
       be  changed by setting the LESSBINFMT environment variable.  LESSBINFMT
       may begin with a "*" and one character to select the display attribute:
       "*k"  is	 blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
       and "*n" is normal.  If LESSBINFMT does not begin with  a  "*",	normal
       attribute  is  assumed.	 The remainder of LESSBINFMT is a string which
       may include one printf-style escape sequence (a % followed by x, X,  o,
       d,  etc.).   For	 example, if LESSBINFMT is "*u[%x]", binary characters
       are displayed in underlined hexadecimal surrounded  by  brackets.   The
       default	if  no LESSBINFMT is specified is "*s<%X>".  The default if no
       LESSBINFMT is specified is "*s<%02X>".  Warning: the result of  expand‐
       ing the character via LESSBINFMT must be less than 31 characters.

       When the character set is utf-8, the LESSUTFBINFMT environment variable
       acts similarly to LESSBINFMT but it applies to Unicode code points that
       were  successfully  decoded but are unsuitable for display (e.g., unas‐
       signed code points).  Its default  value	 is  "<U+%04lX>".   Note  that
       LESSUTFBINFMT  and  LESSBINFMT  share  their  display attribute setting
       ("*x") so specifying one will affect both; LESSUTFBINFMT is read	 after
       LESSBINFMT  so  its  setting,  if any, will have priority.  Problematic
       octets in a UTF-8 file (octets of a truncated  sequence,	 octets	 of  a
       complete	 but  non-shortest  form  sequence,  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	 ordi‐
       nary  user need not understand the details of constructing personalized
       prompt strings.

       A percent sign followed by a single character is expanded according  to
       what the following character is:

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

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

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

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

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

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

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

       %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.

       %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 evalu‐
       ated.  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 "Stan‐
       dard input".

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

       This prompt would print the filename, if known.	The filename  is  fol‐
       lowed  by  the  line  number, if known, otherwise the percent if known,
       otherwise the byte offset if known.   Otherwise,	 a  dash  is  printed.
       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(file %i of %m) ..?e(END) ?x- Next\: %x..%t

       This prints the filename if this is the first prompt in	a  file,  fol‐
       lowed  by  the  "file  N	 of N" message if there is more than one input
       file.  Then, if we are at end-of-file, the string  "(END)"  is  printed
       followed	 by  the name of the next file, if there is one.  Finally, any
       trailing spaces are truncated.  This is the default prompt.  For refer‐
       ence,  here  are	 the  defaults	for  the  other two prompts (-m and -M
       respectively).  Each is broken into  two	 lines	here  for  readability
       only.

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

       ?f%f .?n?m(file %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(file %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  con‐
       formance	 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 and -F options 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 vari‐
	      ables is the name of the user's home directory if the HOME vari‐
	      able is not set (only in the Windows version).

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

       LANG   Language for determining the character set.

       LC_CTYPE
	      Language for determining the character set.

       LESS   Options which are passed to less automatically.

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

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

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

       LESSCHARDEF
	      Defines a character set.

       LESSCHARSET
	      Selects a predefined character set.

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

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

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

       LESSGLOBALTAGS
	      Name of the command used by the -t option to find	 global	 tags.
	      Normally should be set to "global" if your system has the 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 com‐
	      mand sent to the shell.  If LESSMETAESCAPE is an	empty  string,
	      commands	containing  metacharacters  will  not be passed to the
	      shell.

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

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

       LESSSEPARATOR
	      String to be appended to a directory name	 in  filename  comple‐
	      tion.

       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.)

       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) 1984-2009	Mark Nudelman

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

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

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

			   Version 436: 07 Jul 2009		       LESS(1)
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