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LESS(1)                              General Commands Manual                              LESS(1)

NAME
       less - opposite of more

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

DESCRIPTION
       Less  is a program similar to more (1), but it has many more features.  Less does not have
       to read the entire input file before starting, so with large  input  files  it  starts  up
       faster than text editors like vi (1).  Less uses termcap (or terminfo on some systems), so
       it can run on a variety of terminals.  There is even limited support for  hardcopy  termi‐
       nals.  (On a hardcopy terminal, lines which should be printed at the top of the screen are
       prefixed with a caret.)

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

COMMANDS
       In  the  following  descriptions,  ^X means control-X.  ESC stands for the ESCAPE key; for
       example ESC-v means the two character sequence "ESCAPE", then "v".

       h or H Help: display a summary of these commands.  If you forget all the  other  commands,
              remember this one.

       SPACE or ^V or f or ^F
              Scroll  forward  N  lines,  default one window (see option -z below).  If N is more
              than the screen size, only the final screenful is displayed.  Warning: some systems
              use ^V as a special literalization character.

       z      Like SPACE, but if N is specified, it becomes the new window size.

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

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

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

       b or ^B or ESC-v
              Scroll backward N lines, default one window (see option -z below).  If  N  is  more
              than the screen size, only the final screenful is displayed.

       w      Like ESC-v, but if N is specified, it becomes the new window size.

       y or ^Y or ^P or k or ^K
              Scroll backward N lines, default 1.  The entire N lines are displayed, even if N is
              more than the screen size.  Warning: some systems use ^Y as a special  job  control
              character.

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

       J      Like j, but continues to scroll beyond the end of the file.

       K or Y Like k, but continues to scroll beyond the beginning of the file.

       ESC-) or RIGHTARROW
              Scroll horizontally right N characters, default half the screen width (see  the  -#
              option).   If a number N is specified, it becomes the default for future RIGHTARROW
              and LEFTARROW commands.  While the text is scrolled,  it  acts  as  though  the  -S
              option (chop lines) were in effect.

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

       r or ^R or ^L
              Repaint the screen.

       R      Repaint  the screen, discarding any buffered input.  Useful if the file is changing
              while it is being viewed.

       F      Scroll forward, and keep trying to read when the end of file is reached.   Normally
              this  command  would  be  used when already at the end of the file.  It is a way to
              monitor the tail of a file which is growing while it is being viewed.  (The  behav‐
              ior is similar to the "tail -f" command.)

       ESC-F  Like  F,  but as soon as a line is found which matches the last search pattern, the
              terminal bell is rung and forward scrolling stops.

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

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

       ESC-G  Same as G, except if no number N is specified and the input is standard input, goes
              to the last line which is currently buffered.

       p or % Go to a position N percent into the file.  N should be between 0 and 100,  and  may
              contain a decimal point.

       P      Go to the line containing byte offset N in the file.

       {      If a left curly bracket appears in the top line displayed on the screen, the { com‐
              mand will go to the matching right curly bracket.  The matching right curly bracket
              is  positioned  on  the  bottom line of the screen.  If there is more than one left
              curly bracket on the top line, a number N may be used to specify the  N-th  bracket
              on the line.

       }      If  a right curly bracket appears in the bottom line displayed on the screen, the }
              command will go to the matching  left  curly  bracket.   The  matching  left  curly
              bracket  is  positioned  on  the top line of the screen.  If there is more than one
              right curly bracket on the top line, a number N may be used  to  specify  the  N-th
              bracket on the line.

       (      Like {, but applies to parentheses rather than curly brackets.

       )      Like }, but applies to parentheses rather than curly brackets.

       [      Like {, but applies to square brackets rather than curly brackets.

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

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

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

       m      Followed by any lowercase letter, marks the current position with that letter.

       '      (Single  quote.)   Followed  by any lowercase letter, returns to the position which
              was previously marked with that letter.  Followed by another single quote,  returns
              to  the position at which the last "large" movement command was executed.  Followed
              by a ^ or $, jumps to the beginning or end of the  file  respectively.   Marks  are
              preserved  when  a  new  file  is  examined, so the ' command can be used to switch
              between input files.

       ^X^X   Same as single quote.

       /pattern
              Search forward in the file for the N-th line containing the pattern.  N defaults to
              1.   The  pattern  is a regular expression, as recognized by the regular expression
              library supplied by your system.  The search starts at  the  first  line  displayed
              (but see the -a and -j options, which change this).

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

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

              ^E or *
                     Search multiple files.  That is, if the search reaches the END of  the  cur‐
                     rent  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 set‐
                     tings of the -a or -j options.

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

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

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

              Certain characters are special as in the / command:

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

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

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

              ^K     As in forward searches.

              ^R     As in forward searches.

       ESC-/pattern
              Same as "/*".

       ESC-?pattern
              Same as "?*".

       n      Repeat previous search, for N-th line containing the last pattern.  If the previous
              search  was modified by ^N, the search is made for the N-th line NOT containing the
              pattern.  If the previous search was modified by ^E, the search  continues  in  the
              next  (or  previous)  file  if  not satisfied in the current file.  If the previous
              search was modified by ^R, the search is done without  using  regular  expressions.
              There is no effect if the previous search was modified by ^F or ^K.

       N      Repeat previous search, but in the reverse direction.

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

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

       ESC-u  Undo search highlighting.  Turn off highlighting of strings  matching  the  current
              search  pattern.   If  highlighting is already off because of a previous ESC-u com‐
              mand, 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 tex‐
                     tual 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.   Simi‐
              larly,  two  consecutive  pound  signs  are replaced with a single pound sign.  The
              filename is inserted into the command line list of files so that it can be seen  by
              subsequent :n and :p commands.  If the filename consists of several files, they are
              all inserted into the list of files and the first one is examined.  If the filename
              contains  one  or  more  spaces,  the  entire filename should be enclosed in double
              quotes (also see the -" option).

       ^X^V or E
              Same as :e.  Warning: some systems use ^V as a  special  literalization  character.
              On such systems, you may not be able to use ^V.

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

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

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

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

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

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

       = or ^G or :f
              Prints  some  information  about  the file being viewed, including its name and the
              line number and byte offset of the bottom line being displayed.   If  possible,  it
              also prints the length of the file, the number of lines in the file and the percent
              of the file above the last displayed line.

       -      Followed by one of the command line option letters (see OPTIONS below),  this  will
              change  the  setting of that option and print a message describing the new setting.
              If a ^P (CONTROL-P) is entered immediately after  the  dash,  the  setting  of  the
              option  is  changed  but no message is printed.  If the option letter has a numeric
              value (such as -b or -h), or a string value (such as -P or -t), a new value may  be
              entered  after the option letter.  If no new value is entered, a message describing
              the current setting is printed and nothing is changed.

       --     Like the - command, but takes a long option name (see OPTIONS below) rather than  a
              single option letter.  You must press ENTER or RETURN after typing the option name.
              A ^P immediately after the second dash suppresses printing of a message  describing
              the new setting, as in the - command.

       -+     Followed  by  one  of the command line option letters this will reset the option to
              its default setting and print a message describing the  new  setting.   (The  "-+X"
              command  does the same thing as "-+X" on the command line.)  This does not work for
              string-valued options.

       --+    Like the -+ command, but takes a long option name rather than a single option  let‐
              ter.

       -!     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  set‐
              ting.  This does not work for numeric or string-valued options.

       --!    Like  the -! command, but takes a long option name rather than a single option let‐
              ter.

       _      (Underscore.)  Followed by one of the command line option letters, this will  print
              a message describing the current setting of that option.  The setting of the option
              is not changed.

       __     (Double underscore.)  Like the _ (underscore) command, but takes a long option name
              rather  than  a  single option letter.  You must press ENTER or RETURN after typing
              the option name.

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

       V      Prints the version number of less being run.

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

       The following four commands may or may not be valid, depending on your particular  instal‐
       lation.

       v      Invokes  an editor to edit the current file being viewed.  The editor is taken from
              the environment variable VISUAL if defined, or EDITOR if VISUAL is not defined,  or
              defaults  to "vi" if neither VISUAL nor EDITOR is defined.  See also the discussion
              of LESSEDIT under the section on PROMPTS below.

       ! shell-command
              Invokes a shell to run the shell-command given.  A percent sign (%) in the  command
              is  replaced  by the name of the current file.  A pound sign (#) is replaced by the
              name of the previously examined file.  "!!" repeats the last  shell  command.   "!"
              with  no shell command simply invokes a shell.  On Unix systems, the shell is taken
              from the environment variable SHELL, or defaults to "sh".  On MS-DOS and OS/2  sys‐
              tems, the shell is the normal command processor.

       |  shell-command
                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.   may also be ^ or $
              to indicate beginning or end of file respectively.  If  is  .  or  newline,  the
              current screen is piped.

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

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

       Most  options may be given in one of two forms: either a dash followed by a single letter,
       or two dashes followed by a long option name.  A long option name may  be  abbreviated  as
       long  as  the  abbreviation is unambiguous.  For example, --quit-at-eof may be abbreviated
       --quit, but not --qui, since both --quit-at-eof and --quiet begin with --qui.   Some  long
       option  names  are  in  uppercase,  such as --QUIT-AT-EOF, as distinct from --quit-at-eof.
       Such option names need only have their first letter capitalized; the remainder of the name
       may be in either case.  For example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.

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

       setenv LESS "-options"

       or if you use sh:

       LESS="-options"; export LESS

       On MS-DOS, you don't need the quotes, but you should replace  any  percent  signs  in  the
       options string by double percent signs.

       The  environment variable is parsed before the command line, so command line options over‐
       ride the LESS environment variable.  If an option appears in the LESS variable, it can  be
       reset  to  its default value on the command line by beginning the command line option with
       "-+".

       Some options like -k or -D require a string to follow the option letter.  The  string  for
       that  option  is  considered to end when a dollar sign ($) is found.  For example, you can
       set two -D options on MS-DOS like this:

       LESS="Dn9.1$Ds4.1"

       If the --use-backslash option appears earlier in the options, then a dollar sign or  back‐
       slash  may be included literally in an option string by preceding it with a backslash.  If
       the --use-backslash option is not in effect, then backslashes are not  treated  specially,
       and there is no way to include a dollar sign in the option string.

       -? or --help
              This  option displays a summary of the commands accepted by less (the same as the h
              command).  (Depending on how your shell interprets the question  mark,  it  may  be
              necessary to quote the question mark, thus: "-\?".)

       -a or --search-skip-screen
              By default, forward searches start at the top of the displayed screen and backwards
              searches start at the bottom of the displayed screen (except for repeated  searches
              invoked  by  the  n  or  N  commands, which start after or before the "target" line
              respectively; see the -j option for more about the target  line).   The  -a  option
              causes  forward  searches to instead start at the bottom of the screen and backward
              searches to start at the top of the screen, thus skipping all  lines  displayed  on
              the screen.

       -A or --SEARCH-SKIP-SCREEN
              Causes  all  forward  searches (not just non-repeated searches) to start just after
              the target line, and all backward searches to start just before  the  target  line.
              Thus,  forward searches will skip part of the displayed screen (from the first line
              up to and including the target line).  Similarly backwards searches will  skip  the
              displayed  screen from the last line up to and including the target line.  This was
              the default behavior in less versions prior to 441.

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

       -B or --auto-buffers
              By default, when data is read from a pipe, buffers are allocated  automatically  as
              needed.   If  a  large amount of data is read from the pipe, this can cause a large
              amount of memory to be allocated.  The -B option disables this automatic allocation
              of buffers for pipes, so that only 64 K (or the amount of space specified by the -b
              option) is used for the pipe.  Warning: use of -B can result in erroneous  display,
              since  only  the most recently viewed part of the piped data is kept in memory; any
              earlier data is lost.

       -c or --clear-screen
              Causes full screen repaints to be painted from the top line down.  By default, full
              screen repaints are done by scrolling from the bottom of the screen.

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

       -d or --dumb
              The  -d  option  suppresses the error message normally displayed if the terminal is
              dumb; that is, lacks some important capability, such as the ability  to  clear  the
              screen or scroll backward.  The -d option does not otherwise change the behavior of
              less on a dumb terminal.

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

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

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

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

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

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

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

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

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

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

       -jn or --jump-target=n
              Specifies  a  line  on the screen where the "target" line is to be positioned.  The
              target line is the line specified by any command to search for a pattern, jump to a
              line  number,  jump  to a file percentage or jump to a tag.  The screen line may be
              specified by a number: the top line on the screen is 1, the next is 2, and  so  on.
              The  number may be negative to specify a line relative to the bottom of the screen:
              the bottom line on the screen is -1, the second to the bottom is  -2,  and  so  on.
              Alternately,  the  screen  line may be specified as a fraction of the height of the
              screen, starting with a decimal point: .5 is in the middle of  the  screen,  .3  is
              three  tenths  down  from the first line, and so on.  If the line is specified as a
              fraction, the actual line number is recalculated if the terminal window is resized,
              so that the target line remains at the specified fraction of the screen height.  If
              any form of the -j option is used, repeated forward searches (invoked with  "n"  or
              "N")  begin  at  the  line immediately after the target line, and repeated backward
              searches begin at the target line, unless changed by -a or  -A.   For  example,  if
              "-j4"  is  used,  the  target  line  is  the  fourth line on the screen, so forward
              searches begin at the fifth line  on  the  screen.   However  nonrepeated  searches
              (invoked  with  "/" or "?")  always begin at the start or end of the current screen
              respectively.

       -J or --status-column
              Displays a status column at the left edge of the screen.  The status  column  shows
              the  lines  that matched the current search.  The status column is also used if the
              -w or -W option is in effect.

       -kfilename or --lesskey-file=filename
              Causes less to open and interpret the named file as a lesskey (1)  file.   Multiple
              -k options may be specified.  If the LESSKEY or LESSKEY_SYSTEM environment variable
              is set, or if a lesskey file is found in a standard place (see KEY BINDINGS), it is
              also used as a lesskey file.

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

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

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

       -M or --LONG-PROMPT
              Causes less to prompt even more verbosely than more.

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

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

       -ofilename or --log-file=filename
              Causes less to copy its input to the named  file  as  it  is  being  viewed.   This
              applies  only  when  the  input  file is a pipe, not an ordinary file.  If the file
              already exists, less will ask for confirmation before overwriting it.

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

              If  no  log  file has been specified, the -o and -O options can be used from within
              less to specify a log file.  Without a file name, they will simply report the  name
              of the log file.  The "s" command is equivalent to specifying -o from within less.

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

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

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

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

       -r or --raw-control-chars
              Causes "raw" control characters to be displayed.  The default is to display control
              characters using the caret notation; for example, a control-A (octal 001)  is  dis‐
              played as "^A".  Warning: when the -r option is used, less cannot keep track of the
              actual appearance of the screen (since this depends on how the screen  responds  to
              each  type  of control character).  Thus, various display problems may result, such
              as long lines being split in the wrong place.

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

                   ESC [ ... m

              where the "..." is zero or more color specification characters For the  purpose  of
              keeping  track of screen appearance, ANSI color escape sequences are assumed to not
              move the cursor.  You can make less think that characters other than  "m"  can  end
              ANSI color escape sequences by setting the environment variable LESSANSIENDCHARS to
              the list of characters which can end a color escape sequence.   And  you  can  make
              less  think that characters other than the standard ones may appear between the ESC
              and the m by setting the environment variable LESSANSIMIDCHARS to the list of char‐
              acters which can appear.

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

       -S or --chop-long-lines
              Causes lines longer than the screen width to be  chopped  (truncated)  rather  than
              wrapped.  That is, the portion of a long line that does not fit in the screen width
              is not shown.  The default is to wrap long lines; that is, display the remainder on
              the next line.

       -ttag or --tag=tag
              The  -t  option,  followed immediately by a TAG, will edit the file containing that
              tag.  For this to work, tag information must be available; for example,  there  may
              be  a  file  in  the current directory called "tags", which was previously built by
              ctags (1) or an equivalent command.  If the environment variable LESSGLOBALTAGS  is
              set,  it  is taken to be the name of a command compatible with global (1), and that
              command   is   executed   to   find   the   tag.    (See   http://www.gnu.org/soft‐
              ware/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 equiv‐
              alent to specifying -t from within less.

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

       -u or --underline-special
              Causes  backspaces and carriage returns to be treated as printable characters; that
              is, they are sent to the terminal when they appear in the input.

       -U or --UNDERLINE-SPECIAL
              Causes backspaces, tabs and carriage returns to be treated as  control  characters;
              that is, they are handled as specified by the -r option.

              By  default,  if neither -u nor -U is given, backspaces which appear adjacent to an
              underscore character are treated specially: the underlined text is displayed  using
              the  terminal's  hardware  underlining  capability.   Also, backspaces which appear
              between two identical characters are treated  specially:  the  overstruck  text  is
              printed  using  the  terminal's hardware boldface capability.  Other backspaces are
              deleted, along with the preceding character.  Carriage returns immediately followed
              by  a  newline are deleted.  Other carriage returns are handled as specified by the
              -r option.  Text which is overstruck or underlined can be searched for  if  neither
              -u nor -U is in effect.

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

       -w or --hilite-unread
              Temporarily  highlights  the  first  "new"  line after a forward movement of a full
              page.  The first "new" line is the line immediately following the  line  previously
              at  the  bottom of the screen.  Also highlights the target line after a g or p com‐
              mand.  The highlight is removed at the next command  which  causes  movement.   The
              entire  line  is highlighted, unless the -J option is in effect, in which case only
              the status column is highlighted.

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

       -xn,... or --tabs=n,...
              Sets  tab  stops.  If only one n is specified, tab stops are set at multiples of n.
              If multiple values separated by commas are specified, tab stops are  set  at  those
              positions,  and  then continue with the same spacing as the last two.  For example,
              -x9,17 will set tabs at positions 9, 17, 25, 33, etc.  The default for n is 8.

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

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

       -[z]n or --window=n
              Changes  the  default scrolling window size to n lines.  The default is one screen‐
              ful.  The z and w commands can also be used to change the window size.  The "z" may
              be  omitted for compatibility with some versions of more.  If the number n is nega‐
              tive, it indicates n lines less than the current screen size.  For example, if  the
              screen  is  24 lines, -z-4 sets the scrolling window to 20 lines.  If the screen is
              resized to 40 lines, the scrolling window automatically changes to 36 lines.

       -"cc or --quotes=cc
              Changes the filename quoting character.  This may be necessary if you are trying to
              name  a file which contains both spaces and quote characters.  Followed by a single
              character, this changes the quote character to that character.  Filenames  contain‐
              ing  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  char‐
              acter.   Note that even after the quote characters are changed, this option remains
              -" (a dash followed by a double quote).

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

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

       --follow-name
              Normally, if the input file is renamed while an F command is executing,  less  will
              continue  to display the contents of the original file despite its name change.  If
              --follow-name is specified, during an F command less will periodically  attempt  to
              reopen  the  file by name.  If the reopen succeeds and the file is a different file
              from the original (which means that a new file has been created with the same  name
              as  the  original  (now  renamed) file), less will display the contents of that new
              file.

       --no-keypad
              Disables sending the keypad initialization and deinitialization strings to the ter‐
              minal.   This  is  sometimes  useful  if the keypad strings make the numeric keypad
              behave in an undesirable manner.

       --use-backslash
              This option changes the interpretations of options which follow  this  one.   After
              the  --use-backslash  option,  any backslash in an option string is removed and the
              following character is taken literally.  This allows a dollar sign to  be  included
              in option strings.

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

       +      If a command line option begins with +, the remainder of that option is taken to be
              an initial command to less.  For example, +G tells less to start at the end of  the
              file rather than the beginning, and +/xyz tells it to start at the first occurrence
              of "xyz" in the file.  As a special case, + acts like +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 previ‐
              ously may also be used to set (or change) an initial command for every file.

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

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

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

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

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

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

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

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

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

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

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

       UPARROW [ ESC-k ]
              Retrieve  the  previous  command line.  If you first enter some text and then press
              UPARROW, it will retrieve the previous command which begins with that text.

       DOWNARROW [ ESC-j ]
              Retrieve the next command line.  If you first enter some text and then  press  DOW‐
              NARROW, it will retrieve the next command which begins with that text.

       TAB    Complete  the  partial filename to the left of the cursor.  If it matches more than
              one filename, the first match is entered into the command line.  Repeated TABs will
              cycle thru the other matching filenames.  If the completed filename is a directory,
              a "/" is appended to the filename.  (On MS-DOS systems, a "\"  is  appended.)   The
              environment  variable LESSSEPARATOR can be used to specify a different character to
              append to a directory name.

       BACKTAB [ ESC-TAB ]
              Like, TAB, but cycles in the reverse direction thru the matching filenames.

       ^L     Complete the partial filename to the left of the cursor.  If it matches  more  than
              one filename, all matches are entered into the command line (if they fit).

       ^U (Unix and OS/2) or ESC (MS-DOS)
              Delete the entire command line, or cancel the command if the command line is empty.
              If you have changed your line-kill character in Unix to something  other  than  ^U,
              that character is used instead of ^U.

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

KEY BINDINGS
       You may define your own less commands by using the program lesskey (1) to create a lesskey
       file.  This file specifies a set of command keys and an action associated with  each  key.
       You  may  also  use lesskey to change the line-editing keys (see LINE EDITING), and to set
       environment variables.  If the environment variable LESSKEY is set, less uses that as  the
       name of the lesskey file.  Otherwise, less looks in a standard place for the lesskey file:
       On Unix systems, less looks for a lesskey file called "$HOME/.less".  On MS-DOS  and  Win‐
       dows  systems,  less looks for a lesskey file called "$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 vari‐
       able 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 sys‐
       tems, 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 sys‐
       less file is found.)  On MS-DOS and Windows  systems,  the  system-wide  lesskey  file  is
       c:\_sysless.  On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.

INPUT PREPROCESSOR
       You may define an "input preprocessor" for less.  Before less opens a file, it first gives
       your input preprocessor a chance to modify the way the contents of the file are displayed.
       An  input preprocessor is simply an executable program (or shell script), which writes the
       contents of the file to a different file, called the replacement file.   The  contents  of
       the  replacement  file  are  then displayed in place of the contents of the original file.
       However, it will appear to the user as if the original file is opened; that is, less  will
       display the original filename as the name of the current file.

       An  input  preprocessor  receives  one  command  line  argument, the original filename, as
       entered by the user.  It should create the replacement file, and when finished, print  the
       name  of  the replacement file to its standard output.  If the input preprocessor does not
       output a replacement filename, less uses the original file, as  normal.   The  input  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  pre‐
       processor.  This command line should include one occurrence of the string "%s", which will
       be replaced by the filename when the input preprocessor command is invoked.

       When less closes a file opened in such a way, it will call  another  program,  called  the
       input  postprocessor,  which may perform any desired clean-up action (such as deleting the
       replacement file created by LESSOPEN).  This program receives two command line  arguments,
       the  original  filename  as entered by the user, and the name of the replacement file.  To
       set up an input postprocessor, set the LESSCLOSE environment variable to  a  command  line
       which  will invoke your input postprocessor.  It may include two occurrences of the string
       "%s"; the first is replaced with the original name of the file and  the  second  with  the
       name of the replacement file, which was output by LESSOPEN.

       For  example, on many Unix systems, these two scripts will allow you to keep files in com‐
       pressed format, but still let less view them directly:

       lessopen.sh:
            #! /bin/sh
            case "$1" in
            *.Z) uncompress -c $1  >/tmp/less.$$  2>/dev/null
                 if [ -s /tmp/less.$$ ]; then
                      echo /tmp/less.$$
                 else
                      rm -f /tmp/less.$$
                 fi
                 ;;
            esac

       lessclose.sh:
            #! /bin/sh
            rm $2

       To  use  these  scripts,  put  them  both   where   they   can   be   executed   and   set
       LESSOPEN="lessopen.sh %s",  and LESSCLOSE="lessclose.sh %s %s".  More complex LESSOPEN and
       LESSCLOSE scripts may be written to accept other types of compressed files, and so on.

       It is also possible to set up an input preprocessor to pipe  the  file  data  directly  to
       less,  rather  than  putting  the  data  into a replacement file.  This avoids the need to
       decompress the entire file before starting to view it.  An input preprocessor  that  works
       this  way  is  called  an  input  pipe.   An  input pipe, instead of writing the name of a
       replacement file on its standard output, writes the entire  contents  of  the  replacement
       file on its standard output.  If the input pipe does not write any characters on its stan‐
       dard output, then there is no replacement file and less uses the original file, as normal.
       To use an input pipe, make the first character in the LESSOPEN environment variable a ver‐
       tical bar (|) to signify that the input preprocessor is an input pipe.

       For example, on many Unix systems,  this  script  will  work  like  the  previous  example
       scripts:

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

       To use this script, put it where it can be executed and set LESSOPEN="|lesspipe.sh %s".

       Note that a preprocessor cannot output an empty file, since that is interpreted as meaning
       there is no replacement, and the original file is used.  To avoid this, if LESSOPEN starts
       with  two  vertical  bars,  the exit status of the script becomes meaningful.  If the exit
       status is zero, the output is considered to be replacement text, even if it empty.  If the
       exit status is nonzero, any output is ignored and the original file is used.  For compati‐
       bility with previous versions of less, if LESSOPEN starts with only one vertical bar,  the
       exit status of the preprocessor is ignored.

       When  an  input pipe is used, a LESSCLOSE postprocessor can be used, but it is usually not
       necessary since there is no replacement file to clean up.  In this case,  the  replacement
       file name passed to the LESSCLOSE postprocessor is "-".

       For  compatibility  with  previous versions of less, the input preprocessor or pipe is not
       used if less is viewing standard input.  However, if the first character of LESSOPEN is  a
       dash  (-),  the  input  preprocessor is used on standard input as well as other files.  In
       this case, the dash is not considered to be part of the preprocessor command.  If standard
       input is being viewed, the input preprocessor is passed a file name consisting of a single
       dash.  Similarly, if the first two characters of LESSOPEN are vertical bar and  dash  (|-)
       or two vertical bars and a dash (||-), the input pipe is used on standard input as well as
       other files.  Again, in this case the dash is not considered to be part of the input  pipe
       command.

NATIONAL CHARACTER SETS
       There are three types of characters in the input file:

       normal characters
              can be displayed directly to the screen.

       control characters
              should  not  be  displayed  directly, but are expected to be found in ordinary text
              files (such as backspace and tab).

       binary characters
              should not be displayed directly and are not expected to be found in text files.

       A "character set" is simply a description of which characters are to be considered normal,
       control, and binary.  The LESSCHARSET environment variable may be used to select a charac‐
       ter set.  Possible values for LESSCHARSET are:

       ascii  BS, TAB, NL, CR, and formfeed are control characters, all chars with values between
              32 and 126 are normal, and all others are binary.

       iso8859
              Selects  an  ISO  8859 character set.  This is the same as ASCII, except characters
              between 160 and 255 are treated as normal characters.

       latin1 Same as iso8859.

       latin9 Same as iso8859.

       dos    Selects a character set appropriate for MS-DOS.

       ebcdic Selects an EBCDIC character set.

       IBM-1047
              Selects an EBCDIC character set used by OS/390 Unix Services.  This is  the  EBCDIC
              analogue of latin1.  You get similar results by setting either LESSCHARSET=IBM-1047
              or LC_CTYPE=en_US in your environment.

       koi8-r Selects a Russian character set.

       next   Selects a character set appropriate for NeXT computers.

       utf-8  Selects the UTF-8 encoding of the ISO 10646 character set.   UTF-8  is  special  in
              that it supports multi-byte characters in the input file.  It is the only character
              set that supports multi-byte characters.

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

       In rare cases, it may be desired to tailor less to use a character set other than the ones
       definable  by LESSCHARSET.  In this case, the environment variable LESSCHARDEF can be used
       to define a character set.  It should be set to a  string  where  each  character  in  the
       string  represents  one  character  in the character set.  The character "." is used for a
       normal character, "c" for control, and "b" for binary.  A decimal number may be  used  for
       repetition.   For example, "bccc4b." would mean character 0 is binary, 1, 2 and 3 are con‐
       trol, 4, 5, 6 and 7 are binary, and 8 is normal.  All characters after the last are  taken
       to  be  the  same  as  the last, so characters 9 through 255 would be normal.  (This is an
       example, and does not necessarily represent any real character set.)

       This table shows the value of LESSCHARDEF which is equivalent to each of the possible val‐
       ues for LESSCHARSET:

            ascii     8bcccbcc18b95.b
            dos       8bcccbcc12bc5b95.b.
            ebcdic    5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
                      9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
            IBM-1047  4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
                      191.b
            iso8859   8bcccbcc18b95.33b.
            koi8-r    8bcccbcc18b95.b128.
            latin1    8bcccbcc18b95.33b.
            next      8bcccbcc18b95.bb125.bb

       If  neither  LESSCHARSET  nor  LESSCHARDEF is set, but any of the strings "UTF-8", "UTF8",
       "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or LANG environment variables, then the
       default character set is utf-8.

       If  that  string is not found, but your system supports the setlocale interface, less will
       use setlocale to determine the character set.  setlocale is controlled by setting the LANG
       or LC_CTYPE environment variables.

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

       Control and binary characters are displayed in standout (reverse video).  Each such  char‐
       acter  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.   Other‐
       wise,  the  character  is displayed as a hex number in angle brackets.  This format can be
       changed by setting the LESSBINFMT environment variable.  LESSBINFMT may begin with  a  "*"
       and one character to select the display attribute: "*k" is blinking, "*d" is bold, "*u" is
       underlined, "*s" is standout, and "*n" is normal.  If LESSBINFMT does  not  begin  with  a
       "*",  normal  attribute  is  assumed.   The  remainder of LESSBINFMT is a string which may
       include one printf-style escape sequence (a % followed by x, X, o, d, etc.).  For example,
       if  LESSBINFMT is "*u[%x]", binary characters are displayed in underlined hexadecimal sur‐
       rounded by brackets.  The default if no LESSBINFMT is specified is  "*s<%02X>".   Warning:
       the result of expanding the character via LESSBINFMT must be less than 31 characters.

       When  the character set is utf-8, the LESSUTFBINFMT environment variable acts similarly to
       LESSBINFMT but it applies to Unicode code points that were successfully  decoded  but  are
       unsuitable  for display (e.g., unassigned code points).  Its default value is "".
       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  diagnos‐
       tic of how the UTF-8 file is ill-formed.

PROMPTS
       The -P option allows you to tailor the prompt to your preference.  The string given to the
       -P option replaces the specified prompt string.  Certain  characters  in  the  string  are
       interpreted specially.  The prompt mechanism is rather complicated to provide flexibility,
       but the ordinary user need not understand the details of constructing personalized  prompt
       strings.

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

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

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

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

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

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

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

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

       %F     Replaced by the last component of the name of the current input file.

       %i     Replaced by the index of the current file in the list of input files.

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

       %L     Replaced by the line number of the last line in the input file.

       %m     Replaced by the total number of input files.

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

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

       %s     Same as %B.

       %t     Causes  any  trailing spaces to be removed.  Usually used at the end of the string,
              but may appear anywhere.

       %T     Normally expands to the word "file".  However if viewing  files  via  a  tags  list
              using the -t option, it expands to the word "tag".

       %x     Replaced by the name of the next input file in the list.

       If any item is unknown (for example, the file size if input is a pipe), a question mark is
       printed instead.

       The format of the prompt string can be changed depending on certain conditions.   A  ques‐
       tion  mark  followed  by  a single character acts like an "IF": depending on the following
       character, a condition is evaluated.  If the condition is true, any  characters  following
       the question mark and condition character, up to a period, are included in the prompt.  If
       the condition is false, such characters are not included.  A colon appearing  between  the
       question  mark  and  the period can be used to establish an "ELSE": any characters between
       the colon and the period are included in the string if and only if  the  IF  condition  is
       false.  Condition characters (which follow a question mark) may be:

       ?a     True if any characters have been included in the prompt so far.

       ?bX    True if the byte offset of the specified line is known.

       ?B     True if the size of current input file is known.

       ?c     True if the text is horizontally shifted (%c is not zero).

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

       ?e     True if at end-of-file.

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

       ?lX    True if the line number of the specified line is known.

       ?L     True if the line number of the last line in the file is known.

       ?m     True if there is more than one input file.

       ?n     True if this is the first prompt in a new input file.

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

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

       ?s     Same as "?B".

       ?x     True  if  there is a next input file (that is, if the current input file is not the
              last one).

       Any characters other than the special ones (question mark,  colon,  period,  percent,  and
       backslash)  become  literally  part  of  the prompt.  Any of the special characters may be
       included in the prompt literally by preceding it with a backslash.

       Some examples:

       ?f%f:Standard input.

       This prompt prints the filename, if known; otherwise the string "Standard input".

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

       This prompt would print the filename, if known.  The filename is followed by the line num‐
       ber, if known, otherwise the percent if known, otherwise the byte offset if known.  Other‐
       wise, a dash is printed.  Notice how each question mark has a matching period, and how the
       % after the %pt is included literally by escaping it with a backslash.

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

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

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

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

       And here is the default message produced by the = command:

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

       The prompt expansion features are also used for another purpose: if an  environment  vari‐
       able  LESSEDIT  is defined, it is used as the command to be executed when the v command is
       invoked.  The LESSEDIT string is expanded in the same way  as  the  prompt  strings.   The
       default value for LESSEDIT is:

            %E ?lm+%lm. %f

       Note  that  this expands to the editor name, followed by a + and the line number, followed
       by the file name.  If your editor does not accept the "+linenumber" syntax, or  has  other
       differences  in  invocation  syntax,  the  LESSEDIT variable can be changed to modify this
       default.

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

              !      the shell command

              |      the pipe command

              :e     the examine command.

              v      the editing command

              s  -o  log files

              -k     use of lesskey files

              -t     use of tags files

                     metacharacters in filenames, such as *

                     filename completion (TAB, ^L)

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

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

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

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

       The -n option acts like the -z option.  The normal behavior of the -n option  is  unavail‐
       able 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 envi‐
       ronment, 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 col‐
              umns specified by the TERM variable.  (But if you have  a  windowing  system  which
              supports  TIOCGWINSZ or WIOCGETD, the window system's idea of the screen size takes
              precedence over the LINES and COLUMNS environment variables.)

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

       HOME   Name of the user's home directory (used to find a lesskey file  on  Unix  and  OS/2
              systems).

       HOMEDRIVE, HOMEPATH
              Concatenation  of  the  HOMEDRIVE and HOMEPATH environment variables is the name of
              the user's home directory if the HOME variable is not set (only in the Windows ver‐
              sion).

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

       LANG   Language for determining the character set.

       LC_CTYPE
              Language for determining the character set.

       LESS   Options which are passed to less automatically.

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

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

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

       LESSCHARDEF
              Defines a character set.

       LESSCHARSET
              Selects a predefined character set.

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

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

       LESSEDIT
              Editor prototype string (used for the v command).  See discussion under PROMPTS.

       LESSGLOBALTAGS
              Name  of the command used by the -t option to find global tags.  Normally should be
              set to "global" if your system has the global (1) command.  If not set, global tags
              are not used.

       LESSHISTFILE
              Name  of  the  history  file  used  to  remember search commands and shell commands
              between invocations of less.  If set to "-" or "/dev/null", a history file  is  not
              used.  The default is "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
              Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini" on OS/2 systems.

       LESSHISTSIZE
              The maximum number of commands to save in the history file.  The default is 100.

       LESSKEY
              Name of the default lesskey(1) file.

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

       LESSMETACHARS
              List of characters which are considered "metacharacters" by the shell.

       LESSMETAESCAPE
              Prefix which less will add before each metacharacter  in  a  command  sent  to  the
              shell.   If  LESSMETAESCAPE  is an empty string, commands containing metacharacters
              will not be passed to the shell.

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

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

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

       LESSUTFBINFMT
              Format for displaying non-printable Unicode code points.

       LESS_IS_MORE
              Emulate the more (1) command.

       LINES  Sets the number of lines on the screen.  Takes precedence over the number of  lines
              specified by the TERM variable.  (But if you have a windowing system which supports
              TIOCGWINSZ or WIOCGETD, the window system's idea of the screen  size  takes  prece‐
              dence over the LINES and COLUMNS environment variables.)

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

       PATH   User's search path (used to find a lesskey file on MS-DOS and OS/2 systems).

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

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

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

SEE ALSO
       lesskey(1)

COPYRIGHT
       Copyright (C) 1984-2015  Mark Nudelman

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

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

AUTHOR
       Mark Nudelman
       Send bug reports or comments to 
       See  http://www.greenwoodsoftware.com/less/bugs.html  for the latest list of known bugs in
       less.
       For more information, see the less homepage at
       http://www.greenwoodsoftware.com/less.

                                     Version 481: 31 Aug 2015                             LESS(1)

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