less - phpMan

Command: man perldoc info search(apropos)  


LESS(1)                                                                LESS(1)



NAME
       less - opposite of more

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


DESCRIPTION
       Less  is  a  program similar to more (1), but which allows backward movement 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 termi-
       nals.  (On a hardcopy terminal, lines which should be printed at  the  top  of  the
       screen are prefixed with a caret.)

       Commands are based on both more and vi.  Commands may be preceded by a decimal num-
       ber, 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 com-
              mands, remember this one.

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

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

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

       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 speci-
              fied, 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  spe-
              cial job control character.

       u or ^U
              Scroll backward N lines, default one half of the screen size.  If N is spec-
              ified, 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 commands.  While the text  is  scrolled,  it
              acts as though the -S option (chop lines) were in effect.

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

       r or ^R or ^L
              Repaint the screen.

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

       F      Scroll forward, and keep trying to read when the end  of  file  is  reached.
              Normally this command would be used when already at the end of the file.  It
              is a way to monitor the tail of a file which is growing while  it  is  being
              viewed.  (The 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.  (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,
              and may contain a decimal point.

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

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

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

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

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

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

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

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

       ^X^X   Same as single quote.

       /pattern
              Search  forward  in  the  file  for the N-th line containing the pattern.  N
              defaults to 1.  The pattern is a regular expression, as  recognized  by  the
              regular  expression  library  supplied by your system.  The search starts at
              the 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  current  screen,
                     but don't move to the first match (KEEP current position).

              ^R     Don't interpret regular expression metacharacters; that is, do a sim-
                     ple 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 pattern.  If the
              previous search was modified by ^N, the search is made for the N-th line NOT
              containing  the  pattern.   If  the  previous search was modified by ^E, the
              search continues in the next (or previous) file if not satisfied in the cur-
              rent  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  crossing  file
              boundaries.

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

       &pattern
              Display only lines which match the pattern; lines which  do  not  match  the
              pattern  are  not displayed.  If pattern is empty (if you type & immediately
              followed by ENTER), any filtering is turned off,  and  all  lines  are  dis-
              played.   While  filtering  is  in  effect, an ampersand is displayed at the
              beginning of the prompt, as a reminder that some lines in the  file  may  be
              hidden.

              Certain characters are special as in the / command:

              ^N or !
                     Display only lines which do NOT match the pattern.

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

       :e [filename]
              Examine a new file.  If the filename is missing, the "current" file (see the
              :n  and :p commands below) from the list of files in the command line is re-
              examined.  A percent sign (%) in the filename is replaced by the name of the
              current  file.   A  pound sign (#) is replaced by the name of the previously
              examined file.  However, two consecutive percent signs are  simply  replaced
              with  a  single percent sign.  This allows you to enter a filename that con-
              tains a percent sign in the name.  Similarly, two  consecutive  pound  signs
              are  replaced  with  a single pound sign.  The filename is inserted into the
              command line list of files so that it can be seen by subsequent  :n  and  :p
              commands.   If the filename consists of several files, they are all inserted
              into the list of files and the first one is examined.  If the filename  con-
              tains  one  or more spaces, the entire filename should be enclosed in double
              quotes (also see the -" option).

       ^X^V or E
              Same as :e.  Warning: some systems use ^V as a special literalization  char-
              acter.  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 speci-
              fied, the N-th previous file is examined.

       :x     Examine  the  first  file in the command line list.  If a number N is speci-
              fied, 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 pos-
              sible, 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  mes-
              sage 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  set-
              ting.  (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 describ-
              ing  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 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  pro-
              cessor.

       | <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.


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

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

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

       setenv LESS "-options"

       or if you use sh:

       LESS="-options"; export LESS

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

       The environment variable is parsed before the command line, so command line options
       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  speci-
              fies  instead that n kilobytes of buffer space should be used for each file.
              If n is -1, buffer space is unlimited; that is, the entire file can be  read
              into memory.

       -B or --auto-buffers
              By  default,  when data is read from a pipe, buffers are allocated automati-
              cally 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 piped data is kept in memory; any earlier data is lost.

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

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

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

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


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

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

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

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

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

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

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

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

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

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

       -jn or --jump-target=n
              Specifies a line on the screen where the "target" line is to be  positioned.
              The  target  line  is the line specified by any command to search for a pat-
              tern, jump to a line number, jump to a file percentage or  jump  to  a  tag.
              The  screen line may be specified by a number: the top line on the screen is
              1, the next is 2, and so on.  The number may be negative to specify  a  line
              relative  to  the bottom of the screen: the bottom line on the screen is -1,
              the second to the bottom is -2, and so on.  Alternately, the screen line may
              be specified as a fraction of the height of the screen, starting with a dec-
              imal point: .5 is in the middle of the screen, .3 is three tenths down  from
              the  first  line,  and  so  on.  If the line is specified as a fraction, the
              actual line number is recalculated if the terminal  window  is  resized,  so
              that the target line remains at the specified fraction of the screen height.
              If any form of the -j option is used, forward searches  begin  at  the  line
              immediately after the target line, and backward searches begin at the target
              line.  For example, if "-j4" is used, the target line is the fourth line  on
              the screen, so forward searches begin at the fifth line on the screen.

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

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

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

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

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

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

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

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

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

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

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

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

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

                   ESC [ ... m

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

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

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

       -ttag or --tag=tag
              The  -t option, followed immediately by a TAG, will edit the file containing
              that tag.  For this to work, tag information must be available; for example,
              there may be a file in the current directory called "tags", which was previ-
              ously 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 compati-
              ble with global (1), and that command is executed to  find  the  tag.   (See
              http://www.gnu.org/software/global/global.html).   The -t option may also be
              specified from within less (using the - command) as a way of examining a new
              file.  The command ":t" is equivalent to specifying -t from within less.

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

       -u or --underline-special
              Causes  backspaces  and  carriage returns to be treated as printable charac-
              ters; 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 char-
              acters; 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 spe-
              cially: 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 underlined can be searched for if neither -u  nor  -U
              is in effect.

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

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

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

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

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

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

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

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

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

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

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

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

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

       +      If a command line option begins with +, the  remainder  of  that  option  is
              taken to be an initial command to less.  For example, +G tells less to start
              at the end of the file rather than the beginning,  and  +/xyz  tells  it  to
              start  at  the  first  occurrence  of "xyz" in the file.  As a special case,
              +<number> acts like +<number>g; that is, it starts the display at the speci-
              fied  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 commands have an alternate form in [ brackets  ]
       which can be used if a key does not exist on a particular keyboard.  (Note that the
       forms beginning with ESC do not work in some MS-DOS and Windows systems because ESC
       is  the  line erase character.)  Any of these special keys may be entered literally
       by preceding it with the "literal" character, either ^V or ^A.  A backslash  itself
       may also be entered literally by entering two backslashes.

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

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

       ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
              (That  is,  CONTROL and LEFTARROW simultaneously.)  Move the 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  com-
              pleted  filename is a directory, a "/" is appended to the filename.  (On MS-
              DOS systems, a "\" is appended.)  The environment variable LESSSEPARATOR can
              be used to specify a different character to append to a directory name.

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

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

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


KEY BINDINGS
       You may define your own less commands by using the program lesskey (1) to create  a
       lesskey  file.   This file specifies a set of command keys and an action associated
       with each key.  You may also use lesskey to change the line-editing keys (see  LINE
       EDITING), and to set environment variables.  If the environment variable LESSKEY is
       set, less uses that as the name of the lesskey file.  Otherwise, less  looks  in  a
       standard place for the lesskey file: On Unix systems, less looks for a lesskey file
       called "$HOME/.less".  On MS-DOS and Windows systems, less looks for a lesskey file
       called  "$HOME/_less",  and if it is not found there, then looks for a lesskey file
       called "_less" in any directory specified in the  PATH  environment  variable.   On
       OS/2  systems,  less looks for a lesskey file called "$HOME/less.ini", and if it is
       not found, then looks for a lesskey file called "less.ini" in any directory  speci-
       fied  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 environ-
       ment 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/sys-
       less.   (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 contents of the file to a different file, called
       the replacement file.  The contents of the replacement file are then  displayed  in
       place of the contents of the original file.  However, it will appear to the user as
       if the original file is opened; that is, less will display the original filename as
       the name of the current file.

       An input preprocessor receives one command line argument, the original filename, as
       entered by the user.  It should create the replacement  file,  and  when  finished,
       print  the  name of the replacement file to its standard output.  If the input pre-
       processor does not output a replacement filename, less 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 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 com-
       mand 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 environ-
       ment variable to a command line which will invoke your input postprocessor.  It may
       include two occurrences of the string "%s"; the first is replaced with the original
       name of the file and the second with the name of the replacement  file,  which  was
       output by LESSOPEN.

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

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

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

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

       It  is also possible to set up an input preprocessor to pipe the file data directly
       to less, rather than putting the data into a replacement  file.   This  avoids  the
       need to decompress the entire file before starting to view it.  An input preproces-
       sor 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 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 "-".

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


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

       normal characters
              can be displayed directly to the screen.

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

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

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

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

       iso8859
              Selects  an ISO 8859 character set.  This is the same as ASCII, except char-
              acters 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 LESS-
              CHARSET=IBM-1047 or LC_CTYPE=en_US in your environment.

       koi8-r Selects a Russian character set.

       next   Selects a character set appropriate for NeXT computers.

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

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

       In rare cases, it may be desired to tailor less to use a character set  other  than
       the  ones  definable  by LESSCHARSET.  In this case, the environment variable LESS-
       CHARDEF 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 neces-
       sarily represent any real character set.)

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

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

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

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

       Control and binary characters are displayed in standout (reverse video).  Each such
       character is displayed in caret notation  if  possible  (e.g.  ^A  for  control-A).
       Caret notation is used only if inverting the 0100 bit results in a normal printable
       character.  Otherwise, the character is displayed as a hex number in  angle  brack-
       ets.   This  format  can be changed by setting the LESSBINFMT environment variable.
       LESSBINFMT may begin with a "*" and one character to select the display  attribute:
       "*k"  is  blinking, "*d" is bold, "*u" is underlined, "*s" is standout, and "*n" is
       normal.  If LESSBINFMT does not begin with a "*", normal attribute is assumed.  The
       remainder  of  LESSBINFMT  is  a  string  which may include one printf-style escape
       sequence (a % followed by x, X,  o,  d,  etc.).   For  example,  if  LESSBINFMT  is
       "*u[%x]",  binary  characters are displayed in underlined hexadecimal surrounded by
       brackets.  The default if no LESSBINFMT is specified is "*s<%02X>".   Warning:  the
       result of expanding the character via LESSBINFMT must be less than 31 characters.

       When  the character set is utf-8, the LESSUTFBINFMT environment variable acts simi-
       larly to LESSBINFMT but it applies to Unicode code points  that  were  successfully
       decoded but are unsuitable for display (e.g., unassigned code points).  Its default
       value is "<U+%04lX>".  Note that LESSUTFBINFMT and LESSBINFMT share  their  display
       attribute  setting ("*x") so specifying one will affect both; LESSUTFBINFMT is read
       after LESSBINFMT so its setting, if any, will have priority.  Problematic octets in
       a UTF-8 file (octets of a truncated sequence, octets of a complete but non-shortest
       form sequence, illegal octets, and stray trailing octets) are  displayed  individu-
       ally  using LESSBINFMT so as to facilitate diagnostic of how the UTF-8 file is ill-
       formed.


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

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

       %bX    Replaced  by the byte offset into the current input file.  The b is followed
              by a single character (shown as X above) which specifies the line whose byte
              offset is to be used.  If the character is a "t", the byte offset of the top
              line in the 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.

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

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

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

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

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

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

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

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

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

       %m     Replaced by the total number of input files.

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

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

       %s     Same as %B.

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

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

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

       The format of the prompt string can be changed depending on certain conditions.   A
       question  mark  followed  by a single character acts like an "IF": depending on the
       following character, a condition is evaluated.  If the condition is true, any char-
       acters  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 charac-
       ters (which follow a question mark) may be:

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

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

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

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

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

       ?e     True if at end-of-file.

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

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

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

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

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

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

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

       ?s     Same as "?B".

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

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

       Some examples:

       ?f%f:Standard input.

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

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

       This  prompt  would  print the filename, if known.  The filename is followed by the
       line 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 reference, here are the defaults for the other two prompts (-m and -M
       respectively).  Each is broken into two lines here for readability only.

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

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

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

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

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

            %E ?lm+%lm. %f

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


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

              !      the shell command

              |      the pipe command

              :e     the examine command.

              v      the editing command

              s  -o  log files

              -k     use of lesskey files

              -t     use of tags files

                     metacharacters in filenames, such as *

                     filename completion (TAB, ^L)

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


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

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

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

       The -n option acts like the -z option.  The normal behavior of  the  -n  option  is
       unavailable in this mode.

       The  parameter  to the -p option is taken to be a less command rather than a search
       pattern.

       The LESS environment variable is ignored, and the MORE environment variable is used
       in its place.


ENVIRONMENT VARIABLES
       Environment  variables  may be specified either in the system environment as usual,
       or in a lesskey (1) file.  If environment variables are defined in  more  than  one
       place,  variables  defined  in  a local lesskey file take precedence over variables
       defined in the system environment, which take precedence over variables defined  in
       the system-wide lesskey file.

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

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

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

       HOMEDRIVE, HOMEPATH
              Concatenation of the HOMEDRIVE and HOMEPATH  environment  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  sys-
              tems).

       LANG   Language for determining the character set.

       LC_CTYPE
              Language for determining the character set.

       LESS   Options which are passed to less automatically.

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

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

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

       LESSCHARDEF
              Defines a character set.

       LESSCHARSET
              Selects a predefined character set.

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

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

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

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

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

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

       LESSKEY
              Name of the default lesskey(1) file.

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

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

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

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

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

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

       LESSUTFBINFMT
              Format for displaying non-printable Unicode code points.

       LESS_IS_MORE
              Emulate the more (1) command.

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

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

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

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

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


SEE ALSO
       lesskey(1)


COPYRIGHT
       Copyright (C) 1984-2009  Mark Nudelman

       less  is  part  of  the  GNU project and is free software.  You can 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 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.  See the GNU General Public License for more details.


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



                           Version 436: 07 Jul 2009                    LESS(1)

Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2017-08-21 23:28 @127.0.0.1 CrawledBy CCBot/2.0 (http://commoncrawl.org/faq/)
Valid XHTML 1.0!Valid CSS!