LESS linux command manual

LESS(1)                                                                LESS(1)



NAME
       less - opposite of more

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


DESCRIPTION
       Less is a program similar to more (1), but which allows backward move-
       ment  in  the  file  as well as forward movement.  Also, less does not
       have to read the entire input file  before  starting,  so  with  large
       input  files  it starts up faster than text editors like vi (1).  Less
       uses termcap (or terminfo on some systems), so it can run on a variety
       of  terminals.   There is even limited support for hardcopy terminals.
       (On a hardcopy terminal, lines which should be printed at the  top  of
       the screen are prefixed with a caret.)

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


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

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

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

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

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

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

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

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

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

       y or ^Y or ^P or k or ^K
              Scroll  backward  N  lines,  default 1.  The entire N lines are
              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 half the screen
              width (see the -# option).  If a  number  N  is  specified,  it
              becomes  the  default  for future RIGHTARROW and LEFTARROW com-
              mands.  While the text is scrolled, it acts as  though  the  -S
              option (chop lines) were in effect.

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

       r or ^R or ^L
              Repaint the screen.

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

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

       g or < or ESC-<
              Go  to  line  N  in  the  file,  default 1 (beginning of file).
              (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.   (Warn-
              ing:  this  may be slow if N is large, or if N is not specified
              and standard input, rather than a file, is being read.)

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

       {      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 spec-
              ify the N-th bracket on the line.

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

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

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

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

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

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

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

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

       '      (Single quote.)  Followed by any lowercase letter,  returns  to
              the  position  which  was  previously  marked with that letter.
              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  respec-
              tively.   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 expres-
              sion, as recognized by ed.  The search  starts  at  the  second
              line  displayed  (but  see  the -a and -j options, which change
              this).

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

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

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

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

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

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

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

              Certain characters are special as in the / command:

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

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

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

       N      Repeat previous search, but in the reverse direction.

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

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

       ESC-u  Undo search highlighting.  Turn  off  highlighting  of  strings
              matching  the  current  search  pattern.   If  highlighting  is
              already off because of a previous  ESC-u  command,  turn  high-
              lighting back on.  Any search command will also turn highlight-
              ing back on.  (Highlighting can also be  disabled  by  toggling
              the  -G  option; in that case search commands do not turn high-
              lighting 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  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  exam-
              ined.   If the filename contains one or more spaces, the entire
              filename should be enclosed in double quotes (also see  the  -"
              option).

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

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

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

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

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

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

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

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

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

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

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

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

       -!     Followed by one of the command line option letters,  this  will
              reset  the  option to the "opposite" of its default setting and
              print a message describing the new setting.  This does not work
              for numeric or string-valued options.

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

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

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

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

       V      Prints the version number of less being run.

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

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


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

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

       |  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 indi-
              cate 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 running, via the "-" command.

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

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

       setenv LESS "-options"

       or if you use sh:

       LESS="-options"; export LESS

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

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

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

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


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

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

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

       -B or --auto-buffers
              By default, when data is read from a pipe,  buffers  are  allo-
              cated  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 64K (or the amount of  space
              specified by the -b option) is used for the pipe.  Warning: use
              of -B can result in erroneous  display,  since  only  the  most
              recently viewed part of the 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 capabil-
              ity,  such  as  the ability to clear the screen or scroll back-
              ward.  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.0.

       -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.

       -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 high-
              light only the particular string which was found  by  the  last
              search  command.   This  can  cause less to run somewhat faster
              than the default.

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

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

       -i or --ignore-case
              Causes  searches  to ignore case; that is, uppercase and lower-
              case 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.   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 immediately 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.

       -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.

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

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

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

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

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

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

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

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

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

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

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

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

       -r or --raw-control-chars
              Causes  "raw"  control characters to be displayed.  The default
              is to display control characters using the caret notation;  for
              example,  a  control-A (octal 001) is displayed as "^A".  Warn-
              ing: 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, var-
              ious  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 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  char-
              acters 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 nroff output.

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

       -ttag or --tag=tag
              The  -t  option,  followed  immediately by a TAG, will edit the
              file containing that tag.  For this to  work,  tag  information
              must be available; for example, there may be a file in the cur-
              rent directory called "tags", which  was  previously  built  by
              ctags  (1)  or an equivalent command.  If the environment vari-
              able LESSGLOBALTAGS is set, it is taken to be  the  name  of  a
              command  compatible  with  global (1), and that command is exe-
              cuted  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 equivalent to specifying -t from
              within less.

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

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

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

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

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

       -w or --hilite-unread
              Temporarily highlights the first "new"  line  after  a  forward
              movement  of  a  full  page.   The first "new" line is the line
              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  con-
              tinue  with  the  same  spacing  as the last two.  For example,
              -x9,17 will set tabs at positions 9,  17,  25,  33,  etc.   The
              default for n is 8.

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

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

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

       -[z]n or --window=n
              Changes  the  default  scrolling  window  size to n lines.  The
              default is one screenful.  The z and w  commands  can  also  be
              used  to  change  the  window size.  The "z" may be omitted for
              compatibility with more.  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 automatically changes to 36 lines.

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

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

       -# or --shift
              Specifies  the  default  number of positions to scroll horizon-
              tally in the RIGHTARROW and LEFTARROW commands.  If the  number
              specified  is  zero, it sets the default number of positions to
              one half of the screen width.

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

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


LINE EDITING
       When entering command line at the bottom of the screen (for example, a
       filename for the :e command, or the pattern  for  a  search  command),
       certain  keys  can  be used to manipulate the command line.  Most com-
       mands have an alternate 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  enter-
       ing two backslashes.

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

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

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

       ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
              (That is, CONTROL and  RIGHTARROW  simultaneously.)   Move  the
              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 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 match-
              ing 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.


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  environ-
       ment variables.  If the environment variable LESSKEY is set, less uses
       that as the name of the lesskey file.   Otherwise,  less  looks  in  a
       standard place for the lesskey file: On Unix systems, less looks for a
       lesskey file called "$HOME/.less".  On  MS-DOS  and  Windows  systems,
       less  looks  for a lesskey file called "$HOME/_less", and if it is not
       found there, then looks for a  lesskey  file  called  "_less"  in  any
       directory  specified  in  the PATH environment variable.  On OS/2 sys-
       tems, less looks for a lesskey file called "$HOME/less.ini", and if it
       is  not  found, then looks for a lesskey file called "less.ini" in any
       directory specified in the INIT environment variable, and  if  it  not
       found  there,  then  looks for a lesskey file called "less.ini" in any
       directory specified in the PATH environment variable.  See the lesskey
       manual page for more details.

       A system-wide lesskey file may also be set up to provide key bindings.
       If a key is defined in both a local lesskey file and  in  the  system-
       wide  file,  key bindings in the local file take precedence over those
       in the system-wide file.  If the environment  variable  LESSKEY_SYSTEM
       is  set,  less  uses that as the name of the system-wide lesskey file.
       Otherwise, less looks in a standard place for the system-wide  lesskey
       file:   On   Unix   systems,   the   system-wide   lesskey   file   is
       /usr/local/etc/sysless.  (However, if less was built with a  different
       sysconf  directory  than  /usr/local/etc,  that directory is where the
       sysless file is found.)  On MS-DOS and Windows  systems,  the  system-
       wide  lesskey  file  is c:\_sysless.  On OS/2 systems, the system-wide
       lesskey file is c:\sysless.ini.


INPUT PREPROCESSOR
       You may define an "input preprocessor" for less.  Before less opens  a
       file,  it  first  gives your input preprocessor a chance to modify the
       way the contents of the file are displayed.  An input preprocessor  is
       simply  an executable program (or shell script), which writes the con-
       tents 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 replace-
       ment filename, less uses the original file, as normal.  The input pre-
       processor  is  not  called  when viewing standard input.  To set up an
       input preprocessor, set the LESSOPEN environment variable to a command
       line  which  will  invoke  your input preprocessor.  This command line
       should include one occurrence  of  the  string  "%s",  which  will  be
       replaced  by  the  filename  when  the  input  preprocessor command is
       invoked.

       When less closes a file opened in such a way,  it  will  call  another
       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 replace-
       ment  file.  To set up an input postprocessor, set the LESSCLOSE envi-
       ronment variable to a command line which will invoke your input  post-
       processor.   It  may  include  two occurrences of the string "%s"; the
       first is replaced with the original name of the file  and  the  second
       with the name of the replacement file, which was output by LESSOPEN.

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

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

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

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

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

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

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

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


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 environ-
       ment variable may be used to select a character set.  Possible  values
       for LESSCHARSET are:

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

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

       latin1 Same as iso8859.

       latin9 Same as iso8859.

       dos    Selects a character set appropriate for MS-DOS.

       ebcdic Selects an EBCDIC character set.

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

       koi8-r Selects a Russian character set.

       next   Selects a character set appropriate for NeXT computers.

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

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

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

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

       If neither LESSCHARSET nor LESSCHARDEF is set, but the string  "UTF-8"
       is  found  in  the LC_ALL, LC_TYPE or LANG environment variables, then
       the default character set is utf-8.

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

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

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