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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
		     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 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
	      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
	      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
	      buffers  for  pipes,  so	that  only 64K (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 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.

       --old-bot
	      Reverts to the old bottom of screen behavior.  This can be some-
	      times  desirable	if  the	 long lines are not wrapped  correctly
	      when  reaching  the  bottom  of  the  terminal,  while scrolling
	      forward.

       -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  PREPRO-
	      CESSOR 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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