path: root/contrib/less/less.man

LESS(1)                                                   LESS(1)


NNAAMMEE
       less - opposite of more

SSYYNNOOPPSSIISS
       lleessss --??
       lleessss ----hheellpp
       lleessss --VV
       lleessss ----vveerrssiioonn
       lleessss [[--[[++]]aaBBccCCddeeEEffggGGiiIImmMMnnNNqqQQrrssSSuuUUVVwwXX]]
            [[--bb _b_u_f_s]] [[--hh _l_i_n_e_s]] [[--jj _l_i_n_e]] [[--kk _k_e_y_f_i_l_e]]
            [[--{{ooOO}} _l_o_g_f_i_l_e]] [[--pp _p_a_t_t_e_r_n]] [[--PP _p_r_o_m_p_t]] [[--tt _t_a_g]]
            [[--TT _t_a_g_s_f_i_l_e]] [[--xx _t_a_b]] [[--yy _l_i_n_e_s]] [[--[[zz]] _l_i_n_e_s]]
            [[++[[++]]_c_m_d]] [[----]] [[_f_i_l_e_n_a_m_e]]......
       (See  the OPTIONS section for alternate option syntax with
       long option names.)


DDEESSCCRRIIPPTTIIOONN
       _L_e_s_s is a program similar to _m_o_r_e (1),  but  which  allows
       backward movement in the file as well as forward movement.
       Also, _l_e_s_s does not have to read  the  entire  input  file
       before  starting,  so  with large input files it starts up
       faster than text editors like _v_i (1).  _L_e_s_s  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 _m_o_r_e and _v_i_.  Commands may be
       preceded by a decimal number, called N in the descriptions
       below.  The number is used by some commands, as indicated.


CCOOMMMMAANNDDSS
       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.  Warn-
              ing: some systems use ^V as a  special  literaliza-
              tion 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



                     Version 354: 23 Mar 2000                   1





LESS(1)                                                   LESS(1)


              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 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.

       ESC-) or RIGHTARROW
              Scroll  horizontally right N characters, default 8.
              This behaves best if you also  set  the  -S  option
              (chop  lines).   Note  that  if you wish to enter a
              number N,  you  must  use  ESC-),  not  RIGHTARROW,
              because  the  arrow  is  taken to be a line editing
              command (see the LINE EDITING section).

       ESC-( or LEFTARROW
              Scroll horizontally left N characters, default 8.

       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



                     Version 354: 23 Mar 2000                   2





LESS(1)                                                   LESS(1)


              similar to the "tail -f" command.)

       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.)

       p or % Go to a position N percent into the file.  N should
              be between 0 and 100.

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

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

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

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

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

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

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

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



                     Version 354: 23 Mar 2000                   3





LESS(1)                                                   LESS(1)


       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  con-
              taining the pattern.  N defaults to 1.  The pattern
              is a regular expression, as recognized by _e_d_.   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 pat-
                     tern.

              ^E or *
                     Search  multiple  files.   That  is,  if the
                     search reaches the END of the  current  file
                     without  finding a match, the search contin-
                     ues 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, regard-
                     less  of  what is currently displayed on the
                     screen or the  settings  of  the  -a  or  -j
                     options.

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

              ^R     Don't interpret regular expression metachar-
                     acters; that is, do a simple textual compar-
                     ison.

       ?pattern
              Search  backward  in  the  file  for  the N-th line



                     Version 354: 23 Mar 2000                   4





LESS(1)                                                   LESS(1)


              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 pat-
                     tern.

              ^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  com-
                     mand line list.

              ^F or @
                     Begin  the  search  at  the last line of the
                     last file in the command line list,  regard-
                     less  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 modi-
              fied  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  direc-
              tion.

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

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




                     Version 354: 23 Mar 2000                   5





LESS(1)                                                   LESS(1)


       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.)

       :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  pre-
              viously  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 spe-
              cial 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.

       = 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,



                     Version 354: 23 Mar 2000                   6





LESS(1)                                                   LESS(1)


              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 imme-
              diately 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 letters, this will print a message  describ-
              ing  the  current setting of that option.  The set-
              ting of the option is not changed.

       __     (Double underscore.)  Like the _ (underscore)  com-
              mand,  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  _l_e_s_s
              to  initially display each file starting at the end



                     Version 354: 23 Mar 2000                   7





LESS(1)                                                   LESS(1)


              rather than the beginning.

       V      Prints the version number of _l_e_s_s being run.

       q or Q or :q or :Q or ZZ
              Exits _l_e_s_s_.

       The following four commands  may  or  may  not  be  valid,
       depending on your particular installation.


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

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

       | <m> shell-command
              <m> represents any mark letter.  Pipes a section of
              the input file to the  given  shell  command.   The
              section  of  the  file  to  be piped is between the
              first line on the current screen and  the  position
              marked  by  the  letter.  <m> may also be ^ or $ to
              indicate beginning or end of file respectively.  If
              <m> is . or newline, the current screen is piped.

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


OOPPTTIIOONNSS
       Command line options are described  below.   Most  options
       may be changed while _l_e_s_s 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 abbrevi-
       ated  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



                     Version 354: 23 Mar 2000                   8





LESS(1)                                                   LESS(1)


       --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  capital-
       ized;  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 _l_e_s_s is invoked, you might tell _c_s_h_:

       setenv LESS "-options"

       or if you use _s_h_:

       LESS="-options"; export LESS

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

       The  environment  variable  is  parsed  before the command
       line, so command line options override the  LESS  environ-
       ment 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  _l_e_s_s  (the  same  as  the h command).
              (Depending on how your shell interprets  the  ques-
              tion  mark,  it may be necessary to quote the ques-
              tion mark, thus: "-\?".)

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

       -b_n or --buffers=_n
              Specifies the number of buffers _l_e_s_s will  use  for
              each  file.   Buffers  are  1K,  and  by default 10
              buffers are used for each file (except if the  file
              is a pipe; see the -B option).  The number _n speci-
              fies a different number of buffers to use.



                     Version 354: 23 Mar 2000                   9





LESS(1)                                                   LESS(1)


       -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  the number of
              buffers specified by the -b option are used.  Warn-
              ing:  use  of  -B  can result in erroneous display,
              since only the most recently  viewed  part  of  the
              file 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
              The -C option is like -c, but the screen is cleared
              before it is repainted.

       -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 _l_e_s_s on a
              dumb terminal).

       -Dxx_c_o_l_o_r or --color=xx_c_o_l_o_r
              [MS-DOS only] Sets the color of the text displayed.
              xx  is  a single character which selects the type of
              text whose color is being set:  n=normal,  s=stand-
              out,  d=bold,  u=underlined,  k=blink.   _c_o_l_o_r 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_._0.

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

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

       -f or --force
              Forces non-regular files to be opened.  (A non-reg-
              ular file is a directory or a device special file.)
              Also suppresses the warning message when  a  binary
              file  is  opened.   By default, _l_e_s_s will refuse to



                     Version 354: 23 Mar 2000                  10





LESS(1)                                                   LESS(1)


              open non-regular files.

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

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

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

       -h_n or ---max-back-scroll=_n
              Specifies a maximum number of lines to scroll back-
              ward.  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  pat-
              tern contains uppercase letters.

       -j_n or --jump-target=_n
              Specifies  a  line on the screen where the "target"
              line is to be positioned.  A  target  line  is  the
              object of a text search, tag search, jump to a line
              number, jump to a file percentage,  or  jump  to  a
              marked position.  The screen line is 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.  If  the  -j
              option  is used, searches begin at the line immedi-
              ately after the target line.  For example, if "-j4"
              is  used, the target line is the fourth line on the
              screen, so searches begin at the fifth line on  the
              screen.




                     Version 354: 23 Mar 2000                  11





LESS(1)                                                   LESS(1)


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

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

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

       -n or --line-numbers
              Suppresses  line numbers.  The default (to use line
              numbers) may cause _l_e_s_s 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 begin-
              ning of each line in the display.

       -o_f_i_l_e_n_a_m_e or --log-file=_f_i_l_e_n_a_m_e
              Causes _l_e_s_s 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, _l_e_s_s will ask for confirmation
              before overwriting it.

       -O_f_i_l_e_n_a_m_e or --LOG-FILE=_f_i_l_e_n_a_m_e
              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 _l_e_s_s 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 _l_e_s_s_.

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



                     Version 354: 23 Mar 2000                  12





LESS(1)                                                   LESS(1)


       -P_p_r_o_m_p_t or --prompt=_p_r_o_m_p_t
              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 _l_e_s_s 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.   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,  _l_e_s_s  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 tries to  keep  track  of  the  screen
              appearance  where possible.  This works only if the
              input consists of normal  text  and  possibly  some
              ANSI  "color" escape sequences, which are sequences
              of the form:

                   ESC [ ... m

              where the "..." is zero or  more  characters  other
              than  "m".   For  the  purpose  of keeping track of
              screen appearance, all control characters  and  all



                     Version 354: 23 Mar 2000                  13





LESS(1)                                                   LESS(1)


              ANSI color escape sequences are assumed to not move
              the cursor.  You can make _l_e_s_s think  that  charac-
              ters  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.

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

       -S or --chop-long-lines
              Causes lines longer than the  screen  width  to  be
              chopped rather than folded.  That is, the remainder
              of a long line is simply discarded.  The default is
              to  fold long lines; that is, display the remainder
              on the next line.

       -t_t_a_g or --tag=_t_a_g
              The -t option, followed immediately by a TAG,  will
              edit  the  file  containing  that tag.  For this to
              work, there must be a file  called  "tags"  in  the
              current  directory,  which  was previously built by
              the _c_t_a_g_s (1) command.  This  option  may  also  be
              specified from within _l_e_s_s (using the - command) as
              a way of examining a new file.  The command ":t" is
              equivalent to specifying -t from within _l_e_s_s_.

       -T_t_a_g_s_f_i_l_e or --tag-file=_t_a_g_s_f_i_l_e
              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



                     Version 354: 23 Mar 2000                  14





LESS(1)                                                   LESS(1)


              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 _l_e_s_s_.

       -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 high-
              lights the target line after a g or p command.  The
              highlight  is  removed  at  the  next command which
              causes movement.

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

       -x_n or --tabs=_n
              Sets tab stops every _n positions.  The default  for
              _n is 8.

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

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

       -[z]_n or --window=_n
              Changes the default  scrolling  window  size  to  _n
              lines.   The default is one screenful.  The z and w
              commands can also be  used  to  change  the  window
              size.   The  "z"  may  be omitted for compatibility
              with _m_o_r_e_.  If the number _n is negative,  it  indi-
              cates  _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 automati-
              cally changes to 36 lines.

       -"_c_c or --quotes=_c_c
              Changes  the  filename quoting character.  This may
              be necessary if you are trying to name a file which



                     Version 354: 23 Mar 2000                  15





LESS(1)                                                   LESS(1)


              contains  both  spaces  and quote characters.  Fol-
              lowed 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 char-
              acter.  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.

       --     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 remain-
              der  of  that option is taken to be an initial com-
              mand to _l_e_s_s_.  For example, +G tells _l_e_s_s 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  dis-
              play at the specified line number (however, see the
              caveat under the "g" command above).  If the option
              starts  with  ++,  the  initial  command applies to
              every file being viewed, not just  the  first  one.
              The + command described previously may also be used
              to set (or change) an  initial  command  for  every
              file.


LLIINNEE EEDDIITTIINNGG
       When  entering  command  line  at the bottom of the screen
       (for example, a filename for the :e command, or  the  pat-
       tern  for  a  search command), certain keys can be used to
       manipulate the command line.  Most commands have an alter-
       nate  form in [ brackets ] which can be used if a key does
       not exist on a particular keyboard.  (The bracketed  forms
       do  not work in the MS-DOS version.)  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.




                     Version 354: 23 Mar 2000                  16





LESS(1)                                                   LESS(1)


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

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

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

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

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

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

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

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

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

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

       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  direc-
              tory,  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



                     Version 354: 23 Mar 2000                  17





LESS(1)                                                   LESS(1)


              matches are entered into the command line (if  they
              fit).

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


KKEEYY BBIINNDDIINNGGSS
       You may define your own _l_e_s_s commands by using the program
       _l_e_s_s_k_e_y (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 _l_e_s_s_k_e_y to change the  line-editing
       keys (see LINE EDITING), and to set environment variables.
       If the environment variable LESSKEY is set, _l_e_s_s uses that
       as the name of the lesskey file.  Otherwise, _l_e_s_s looks in
       a standard place for the lesskey file:  On  Unix  systems,
       _l_e_s_s  looks  for  a lesskey file called "$HOME/.less".  On
       MS-DOS and Windows systems, _l_e_s_s looks for a lesskey  file
       called  "$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 sys-
       tems,   _l_e_s_s   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 _l_e_s_s_k_e_y 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,
       _l_e_s_s  uses  that  as  the  name of the system-wide lesskey
       file.  Otherwise, _l_e_s_s looks in a standard place  for  the
       system-wide lesskey file: On Unix systems, the system-wide
       lesskey file  is  /usr/local/bin/.sysless.   (However,  if
       _l_e_s_s  was  built  with  a  different binary directory than
       /usr/local/bin, that directory is where the .sysless  file
       is found.)  On MS-DOS and Windows systems, the system-wide
       lesskey file is c:\_sysless.  On OS/2 systems, the system-
       wide lesskey file is c:\sysless.ini.


IINNPPUUTT PPRREEPPRROOCCEESSSSOORR
       You  may  define an "input preprocessor" for _l_e_s_s_.  Before
       _l_e_s_s 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



                     Version 354: 23 Mar 2000                  18





LESS(1)                                                   LESS(1)


       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, _l_e_s_s 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 file-
       name, _l_e_s_s uses the original file, as normal.   The  input
       preprocessor  is  not  called when viewing standard input.
       To set up an input preprocessor, set the LESSOPEN environ-
       ment  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 _l_e_s_s 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  origi-
       nal  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 _l_e_s_s 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



                     Version 354: 23 Mar 2000                  19





LESS(1)                                                   LESS(1)


       To use these scripts, put them both where they can be exe-
       cuted     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 _l_e_s_s_, rather than putting
       the data into a replacement file.  This avoids the need to
       decompress the entire file before starting to view it.  An
       input preprocessor that works this way is called an  input
       pipe.   An  input  pipe,  instead of writing the name of a
       replacement file on its standard output, writes the entire
       contents  of  the replacement file on its standard output.
       If the input pipe does not write  any  characters  on  its
       standard  output,  then  there  is no replacement file and
       _l_e_s_s 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 pre-
       processor 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
                 ;;
            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 "-".


NNAATTIIOONNAALL CCHHAARRAACCTTEERR SSEETTSS
       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.




                     Version 354: 23 Mar 2000                  20





LESS(1)                                                   LESS(1)


       A "character set" is simply a description of which charac-
       ters  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 charac-
              ters, 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.

       dos    Selects a character set appropriate for MS-DOS.

       ebcdic Selects an EBCDIC character set.

       koi8-r Selects a Russian character set.

       next   Selects  a  character set appropriate for NeXT com-
              puters.

       utf-8  Selects the UTF-8 encoding of the ISO 10646 charac-
              ter set.

       If  the  LESSCHARSET  environment variable is not set, the
       default character set is latin1.  However, if  the  string
       "UTF-8"  is found in the LC_ALL, LC_CTYPE or LANG environ-
       ment variables, then the default character  set  is  utf-8
       instead.

       In  special cases, it may be desired to tailor _l_e_s_s to use
       a character set other than the  ones  definable  by  LESS-
       CHARSET.   In  this  case,  the environment variable LESS-
       CHARDEF can be used to define a character set.  It  should
       be set to a string where each character in the string rep-
       resents 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  repeti-
       tion.   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 neces-
       sarily represent any real character set.)

       This table shows the value of LESSCHARDEF which is equiva-
       lent to each of the possible values for LESSCHARSET:

            ascii     8bcccbcc18b95.b
            dos       8bcccbcc12bc5b95.b.



                     Version 354: 23 Mar 2000                  21





LESS(1)                                                   LESS(1)


            ebcdic    5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
                      9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
            iso8859   8bcccbcc18b95.33b.
            koi8-r    8bcccbcc18b95.b128.
            latin1    8bcccbcc18b95.33b.
            next      8bcccbcc18b95.bb125.bb

       If  neither  LESSCHARSET  nor LESSCHARDEF is set, but your
       system supports the _s_e_t_l_o_c_a_l_e  interface,  _l_e_s_s  will  use
       setlocale  to  determine  the character set.  setlocale is
       controlled by setting the  LANG  or  LC_CTYPE  environment
       variables.

       Control  and  binary  characters are displayed in standout
       (reverse video).  Each  such  character  is  displayed  in
       caret notation if possible (e.g. ^A for control-A).  Caret
       notation is used only if inverting the 0100 bit results in
       a normal printable character.  Otherwise, the character is
       displayed as a hex number in angle brackets.  This  format
       can be changed by setting the LESSBINFMT environment vari-
       able.  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 LESS-
       BINFMT  is  "*u[%x]",  binary  characters are displayed in
       underlined  hexadecimal  surrounded  by   brackets.    The
       default if no LESSBINFMT is specified is "*s<%X>".


PPRROOMMPPTTSS
       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:

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




                     Version 354: 23 Mar 2000                  22





LESS(1)                                                   LESS(1)


       %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.

       %d_X    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 dis-
              cussion 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.

       %l_X    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.

       %p_X    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.

       %P_X    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 any-
              where.

       %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



                     Version 354: 23 Mar 2000                  23





LESS(1)                                                   LESS(1)


       single character acts like an "IF": depending on the  fol-
       lowing character, a condition is evaluated.  If the condi-
       tion 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.

       ?b_X    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).

       ?d_X    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).

       ?l_X    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.

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

       ?P_X    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).



                     Version 354: 23 Mar 2000                  24





LESS(1)                                                   LESS(1)


       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 file-
       name  is  followed by the line number, if known, otherwise
       the percent if known, otherwise the byte offset if  known.
       Otherwise,  a  dash  is printed.  Notice how each question
       mark has a matching period, and how the % after the %pt is
       included literally by escaping it with a backslash.

       ?n?f%f .?m(file %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  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  com-
       mand  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




                     Version 354: 23 Mar 2000                  25





LESS(1)                                                   LESS(1)


       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 vari-
       able can be changed to modify this default.


SSEECCUURRIITTYY
       When the environment variable LESSSECURE is set to 1, _l_e_s_s
       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.


EENNVVIIRROONNMMEENNTT VVAARRIIAABBLLEESS
       Environment variables may be specified either in the  sys-
       tem  environment  as  usual, or in a _l_e_s_s_k_e_y (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).




                     Version 354: 23 Mar 2000                  26





LESS(1)                                                   LESS(1)


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

       HOMEDRIVE, HOMEPATH
              Concatenation  of  the HOMEDRIVE and HOMEPATH envi-
              ronment variables is the name of  the  user's  home
              directory  if the HOME variable is not set (only in
              the Windows version).

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

       LANG   Language for determining the character set.

       LC_CTYPE
              Language for determining the character set.

       LESS   Options which are passed to _l_e_s_s automatically.

       LESSANSIENDCHARS
              Characters  which  are assumed to end an ANSI color
              escape sequence (default "m").

       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-post-
              processor.

       LESSECHO
              Name of the lessecho program (default  "lessecho").
              The  lessecho program is needed to expand metachar-
              acters, such as * and ?, in filenames on Unix  sys-
              tems.

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

       LESSKEY
              Name of the default lesskey(1) file.

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





                     Version 354: 23 Mar 2000                  27





LESS(1)                                                   LESS(1)


       LESSMETACHARS
              List of characters which are considered  "metachar-
              acters" by the shell.

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

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

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

       LESSSEPARATOR
              String to be appended to a directory name in  file-
              name completion.

       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 _l_e_s_s is being run.

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


SSEEEE AALLSSOO
       lesskey(1)


WWAARRNNIINNGGSS
       The  =  command  and prompts (unless changed by -P) report
       the line numbers of the lines at the top and bottom of the
       screen, but the byte and percent of the line after the one
       at the bottom of the screen.

       If the :e command is used to name more than one file,  and
       one of the named files has been viewed previously, the new
       files may be entered into the list in an unexpected order.



                     Version 354: 23 Mar 2000                  28





LESS(1)                                                   LESS(1)


       On  certain  older terminals (the so-called "magic cookie"
       terminals), search highlighting will  cause  an  erroneous
       display.   On  such terminals, search highlighting is dis-
       abled by default to avoid possible problems.

       In certain cases, when search highlighting is enabled  and
       a  search  pattern  begins  with  a  ^, more text than the
       matching string may be highlighted.   (This  problem  does
       not  occur  when less is compiled to use the POSIX regular
       expression package.)

       On some systems, _s_e_t_l_o_c_a_l_e claims that ASCII characters  0
       thru  31 are control characters rather than binary charac-
       ters.  This causes _l_e_s_s to  treat  some  binary  files  as
       ordinary,  non-binary  files.  To workaround this problem,
       set the environment variable LESSCHARSET  to  "ascii"  (or
       whatever character set is appropriate).

       See  http://www.flash.net/~marknu/less for the latest list
       of known bugs in this version of less.


CCOOPPYYRRIIGGHHTT
       Copyright (C) 2000  Mark Nudelman

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

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


AAUUTTHHOORR
       Mark Nudelman <marknu@flash.net>
       Send  bug  reports  or comments to the above address or to
       bug-less@gnu.org.








                     Version 354: 23 Mar 2000                  29