1161475SdelphijLESS(1)                                                                LESS(1)
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5170256Sdelphij[1mNAME[0m
660786Sps       less - opposite of more
760786Sps
8170256Sdelphij[1mSYNOPSIS[0m
9170256Sdelphij       [1mless -?[0m
10170256Sdelphij       [1mless --help[0m
11170256Sdelphij       [1mless -V[0m
12170256Sdelphij       [1mless --version[0m
13221715Sdelphij       [1mless [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~][0m
14170256Sdelphij            [1m[-b [4m[22mspace[24m[1m] [-h [4m[22mlines[24m[1m] [-j [4m[22mline[24m[1m] [-k [4m[22mkeyfile[24m[1m][0m
15170256Sdelphij            [1m[-{oO} [4m[22mlogfile[24m[1m] [-p [4m[22mpattern[24m[1m] [-P [4m[22mprompt[24m[1m] [-t [4m[22mtag[24m[1m][0m
16170256Sdelphij            [1m[-T [4m[22mtagsfile[24m[1m] [-x [4m[22mtab[24m[1m,...] [-y [4m[22mlines[24m[1m] [-[z] [4m[22mlines[24m[1m][0m
17170256Sdelphij            [1m[-# [4m[22mshift[24m[1m] [+[+][4m[22mcmd[24m[1m] [--] [[4m[22mfilename[24m[1m]...[0m
18161475Sdelphij       (See  the  OPTIONS section for alternate option syntax with long option
19161475Sdelphij       names.)
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22170256Sdelphij[1mDESCRIPTION[0m
23170256Sdelphij       [4mLess[24m is a program similar to [4mmore[24m (1), but which allows backward  move-
24170256Sdelphij       ment in the file as well as forward movement.  Also, [4mless[24m does not have
25161475Sdelphij       to read the entire input file before  starting,  so  with  large  input
26170256Sdelphij       files  it  starts  up  faster than text editors like [4mvi[24m (1).  [4mLess[24m uses
27161475Sdelphij       termcap (or terminfo on some systems), so it can run on  a  variety  of
28161475Sdelphij       terminals.   There is even limited support for hardcopy terminals.  (On
29161475Sdelphij       a hardcopy terminal, lines which should be printed at the  top  of  the
30161475Sdelphij       screen are prefixed with a caret.)
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32170256Sdelphij       Commands  are based on both [4mmore[24m and [4mvi.[24m  Commands may be preceded by a
33161475Sdelphij       decimal number, called N in the descriptions below.  The number is used
34161475Sdelphij       by some commands, as indicated.
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37170256Sdelphij[1mCOMMANDS[0m
38161475Sdelphij       In  the following descriptions, ^X means control-X.  ESC stands for the
39161475Sdelphij       ESCAPE  key;  for  example  ESC-v  means  the  two  character  sequence
40161475Sdelphij       "ESCAPE", then "v".
4160786Sps
42161475Sdelphij       h or H Help:  display  a  summary of these commands.  If you forget all
43161475Sdelphij              the other commands, remember this one.
4460786Sps
4560786Sps       SPACE or ^V or f or ^F
46161475Sdelphij              Scroll forward N  lines,  default  one  window  (see  option  -z
47161475Sdelphij              below).   If  N  is  more  than  the screen size, only the final
48161475Sdelphij              screenful is displayed.  Warning: some systems use ^V as a  spe-
49161475Sdelphij              cial literalization character.
5060786Sps
51161475Sdelphij       z      Like  SPACE,  but  if  N is specified, it becomes the new window
52161475Sdelphij              size.
5360786Sps
5460786Sps       ESC-SPACE
55161475Sdelphij              Like SPACE, but scrolls a full screenful,  even  if  it  reaches
56161475Sdelphij              end-of-file in the process.
5760786Sps
58221715Sdelphij       ENTER or RETURN or ^N or e or ^E or j or ^J
59161475Sdelphij              Scroll  forward N lines, default 1.  The entire N lines are dis-
60161475Sdelphij              played, even if N is more than the screen size.
6160786Sps
6260786Sps       d or ^D
63161475Sdelphij              Scroll forward N lines, default one half of the screen size.  If
64161475Sdelphij              N  is specified, it becomes the new default for subsequent d and
65161475Sdelphij              u commands.
6660786Sps
6760786Sps       b or ^B or ESC-v
68161475Sdelphij              Scroll backward N lines,  default  one  window  (see  option  -z
69161475Sdelphij              below).   If  N  is  more  than  the screen size, only the final
70161475Sdelphij              screenful is displayed.
7160786Sps
72161475Sdelphij       w      Like ESC-v, but if N is specified, it  becomes  the  new  window
73161475Sdelphij              size.
7460786Sps
7560786Sps       y or ^Y or ^P or k or ^K
76161475Sdelphij              Scroll backward N lines, default 1.  The entire N lines are dis-
77161475Sdelphij              played, even if N is more than the screen size.   Warning:  some
78161475Sdelphij              systems use ^Y as a special job control character.
7960786Sps
8060786Sps       u or ^U
81161475Sdelphij              Scroll  backward  N  lines, default one half of the screen size.
82161475Sdelphij              If N is specified, it becomes the new default for  subsequent  d
83161475Sdelphij              and u commands.
8460786Sps
8560786Sps       ESC-) or RIGHTARROW
86161475Sdelphij              Scroll  horizontally right N characters, default half the screen
87161475Sdelphij              width (see the -# option).  If  a  number  N  is  specified,  it
88161475Sdelphij              becomes  the  default  for  future RIGHTARROW and LEFTARROW com-
89161475Sdelphij              mands.  While the text is scrolled, it acts  as  though  the  -S
9089019Sps              option (chop lines) were in effect.
9160786Sps
9260786Sps       ESC-( or LEFTARROW
93161475Sdelphij              Scroll  horizontally  left N characters, default half the screen
94161475Sdelphij              width (see the -# option).  If  a  number  N  is  specified,  it
95161475Sdelphij              becomes  the  default  for  future RIGHTARROW and LEFTARROW com-
96161475Sdelphij              mands.
9760786Sps
9860786Sps       r or ^R or ^L
9960786Sps              Repaint the screen.
10060786Sps
101161475Sdelphij       R      Repaint the screen, discarding any buffered  input.   Useful  if
102161475Sdelphij              the file is changing while it is being viewed.
10360786Sps
104161475Sdelphij       F      Scroll  forward, and keep trying to read when the end of file is
105161475Sdelphij              reached.  Normally this command would be used  when  already  at
106161475Sdelphij              the  end of the file.  It is a way to monitor the tail of a file
107161475Sdelphij              which is growing while it is being  viewed.   (The  behavior  is
10860786Sps              similar to the "tail -f" command.)
10960786Sps
110240121Sdelphij       ESC-F  Like  F,  but  as soon as a line is found which matches the last
111240121Sdelphij              search pattern, the terminal bell is rung and forward  scrolling
112240121Sdelphij              stops.
113240121Sdelphij
11460786Sps       g or < or ESC-<
115161475Sdelphij              Go to line N in the file, default 1 (beginning of file).  (Warn-
116161475Sdelphij              ing: this may be slow if N is large.)
11760786Sps
11860786Sps       G or > or ESC->
119161475Sdelphij              Go to line N in the file, default the end of the  file.   (Warn-
120161475Sdelphij              ing:  this  may  be slow if N is large, or if N is not specified
121161475Sdelphij              and standard input, rather than a file, is being read.)
12260786Sps
123161475Sdelphij       p or % Go to a position N percent into the file.  N should be between 0
124170256Sdelphij              and 100, and may contain a decimal point.
12560786Sps
126170256Sdelphij       P      Go to the line containing byte offset N in the file.
127170256Sdelphij
128161475Sdelphij       {      If a left curly bracket appears in the top line displayed on the
129161475Sdelphij              screen, the { command  will  go  to  the  matching  right  curly
130161475Sdelphij              bracket.   The matching right curly bracket is positioned on the
131161475Sdelphij              bottom line of the screen.  If there is more than one left curly
132161475Sdelphij              bracket  on  the top line, a number N may be used to specify the
133161475Sdelphij              N-th bracket on the line.
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135161475Sdelphij       }      If a right curly bracket appears in the bottom line displayed on
136161475Sdelphij              the  screen,  the  }  command will go to the matching left curly
137161475Sdelphij              bracket.  The matching left curly bracket is positioned  on  the
138161475Sdelphij              top  line  of the screen.  If there is more than one right curly
139161475Sdelphij              bracket on the top line, a number N may be used to  specify  the
140161475Sdelphij              N-th bracket on the line.
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142161475Sdelphij       (      Like {, but applies to parentheses rather than curly brackets.
14360786Sps
144161475Sdelphij       )      Like }, but applies to parentheses rather than curly brackets.
14560786Sps
146161475Sdelphij       [      Like  {, but applies to square brackets rather than curly brack-
147161475Sdelphij              ets.
14860786Sps
149161475Sdelphij       ]      Like }, but applies to square brackets rather than curly  brack-
150161475Sdelphij              ets.
15160786Sps
152161475Sdelphij       ESC-^F Followed  by two characters, acts like {, but uses the two char-
153161475Sdelphij              acters as open and close brackets, respectively.   For  example,
154161475Sdelphij              "ESC  ^F < >" could be used to go forward to the > which matches
155161475Sdelphij              the < in the top displayed line.
15660786Sps
157161475Sdelphij       ESC-^B Followed by two characters, acts like }, but uses the two  char-
158161475Sdelphij              acters  as  open and close brackets, respectively.  For example,
159161475Sdelphij              "ESC ^B < >" could be used to go backward to the < which matches
160161475Sdelphij              the > in the bottom displayed line.
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162161475Sdelphij       m      Followed  by  any  lowercase  letter, marks the current position
163161475Sdelphij              with that letter.
16460786Sps
165161475Sdelphij       '      (Single quote.)  Followed by any lowercase  letter,  returns  to
166161475Sdelphij              the position which was previously marked with that letter.  Fol-
167161475Sdelphij              lowed by another single quote, returns to the position at  which
168161475Sdelphij              the last "large" movement command was executed.  Followed by a ^
169161475Sdelphij              or $, jumps to the beginning or end of  the  file  respectively.
170161475Sdelphij              Marks  are  preserved when a new file is examined, so the ' com-
171161475Sdelphij              mand can be used to switch between input files.
17260786Sps
17360786Sps       ^X^X   Same as single quote.
17460786Sps
17560786Sps       /pattern
176161475Sdelphij              Search forward in the file for the N-th line containing the pat-
177161475Sdelphij              tern.  N defaults to 1.  The pattern is a regular expression, as
178161475Sdelphij              recognized by the regular expression library  supplied  by  your
179221715Sdelphij              system.   The search starts at the first line displayed (but see
18060786Sps              the -a and -j options, which change this).
18160786Sps
182161475Sdelphij              Certain characters are special if entered at  the  beginning  of
183161475Sdelphij              the  pattern;  they modify the type of search rather than become
184161475Sdelphij              part of the pattern:
18560786Sps
18660786Sps              ^N or !
187161475Sdelphij                     Search for lines which do NOT match the pattern.
18860786Sps
18960786Sps              ^E or *
190161475Sdelphij                     Search multiple files.  That is, if  the  search  reaches
191161475Sdelphij                     the  END of the current file without finding a match, the
192161475Sdelphij                     search continues in the next file  in  the  command  line
19360786Sps                     list.
19460786Sps
19560786Sps              ^F or @
196161475Sdelphij                     Begin  the  search at the first line of the FIRST file in
197161475Sdelphij                     the command line list, regardless of  what  is  currently
198161475Sdelphij                     displayed  on  the screen or the settings of the -a or -j
19960786Sps                     options.
20060786Sps
201161475Sdelphij              ^K     Highlight any text which matches the pattern on the  cur-
202191930Sdelphij                     rent screen, but don't move to the first match (KEEP cur-
203191930Sdelphij                     rent position).
20460786Sps
205161475Sdelphij              ^R     Don't interpret regular expression  metacharacters;  that
206161475Sdelphij                     is, do a simple textual comparison.
20760786Sps
20863128Sps       ?pattern
209161475Sdelphij              Search  backward  in  the  file for the N-th line containing the
210161475Sdelphij              pattern.  The search starts at the line immediately  before  the
211161475Sdelphij              top line displayed.
21263128Sps
21360786Sps              Certain characters are special as in the / command:
21460786Sps
21560786Sps              ^N or !
216161475Sdelphij                     Search for lines which do NOT match the pattern.
21760786Sps
21860786Sps              ^E or *
219161475Sdelphij                     Search  multiple  files.   That is, if the search reaches
220161475Sdelphij                     the beginning of  the  current  file  without  finding  a
221161475Sdelphij                     match,  the  search continues in the previous file in the
222161475Sdelphij                     command line list.
22360786Sps
22460786Sps              ^F or @
225161475Sdelphij                     Begin the search at the last line of the last file in the
226161475Sdelphij                     command  line  list, regardless of what is currently dis-
227161475Sdelphij                     played on the screen or the settings  of  the  -a  or  -j
22860786Sps                     options.
22960786Sps
23060786Sps              ^K     As in forward searches.
23160786Sps
23260786Sps              ^R     As in forward searches.
23360786Sps
23460786Sps       ESC-/pattern
23560786Sps              Same as "/*".
23660786Sps
23760786Sps       ESC-?pattern
23860786Sps              Same as "?*".
23960786Sps
240161475Sdelphij       n      Repeat  previous  search, for N-th line containing the last pat-
241161475Sdelphij              tern.  If the previous search was modified by ^N, the search  is
242161475Sdelphij              made  for the N-th line NOT containing the pattern.  If the pre-
243161475Sdelphij              vious search was modified by ^E, the  search  continues  in  the
244161475Sdelphij              next  (or  previous)  file if not satisfied in the current file.
245161475Sdelphij              If the previous search was modified by ^R, the  search  is  done
246161475Sdelphij              without  using  regular  expressions.  There is no effect if the
247161475Sdelphij              previous search was modified by ^F or ^K.
24860786Sps
249161475Sdelphij       N      Repeat previous search, but in the reverse direction.
25060786Sps
251161475Sdelphij       ESC-n  Repeat previous  search,  but  crossing  file  boundaries.   The
252161475Sdelphij              effect is as if the previous search were modified by *.
25360786Sps
254161475Sdelphij       ESC-N  Repeat  previous search, but in the reverse direction and cross-
255161475Sdelphij              ing file boundaries.
25660786Sps
257161475Sdelphij       ESC-u  Undo search highlighting.   Turn  off  highlighting  of  strings
258161475Sdelphij              matching the current search pattern.  If highlighting is already
259161475Sdelphij              off because of a previous ESC-u command, turn highlighting  back
260161475Sdelphij              on.   Any  search  command  will also turn highlighting back on.
261161475Sdelphij              (Highlighting can also be disabled by toggling the -G option; in
262161475Sdelphij              that case search commands do not turn highlighting back on.)
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264191930Sdelphij       &pattern
265191930Sdelphij              Display  only  lines which match the pattern; lines which do not
266191930Sdelphij              match the pattern are not displayed.  If pattern  is  empty  (if
267191930Sdelphij              you  type  &  immediately  followed  by ENTER), any filtering is
268191930Sdelphij              turned off, and all lines are displayed.  While filtering is  in
269191930Sdelphij              effect,  an  ampersand  is  displayed  at  the  beginning of the
270191930Sdelphij              prompt, as a reminder that some lines in the file may be hidden.
271191930Sdelphij
272191930Sdelphij              Certain characters are special as in the / command:
273191930Sdelphij
274191930Sdelphij              ^N or !
275191930Sdelphij                     Display only lines which do NOT match the pattern.
276191930Sdelphij
277221715Sdelphij              ^R     Don't interpret regular expression  metacharacters;  that
278191930Sdelphij                     is, do a simple textual comparison.
279191930Sdelphij
28060786Sps       :e [filename]
281221715Sdelphij              Examine  a  new file.  If the filename is missing, the "current"
282221715Sdelphij              file (see the :n and :p commands below) from the list  of  files
283221715Sdelphij              in  the  command line is re-examined.  A percent sign (%) in the
284221715Sdelphij              filename is replaced by the name of the current file.   A  pound
285221715Sdelphij              sign  (#)  is  replaced  by  the name of the previously examined
286221715Sdelphij              file.   However,  two  consecutive  percent  signs  are   simply
287161475Sdelphij              replaced with a single percent sign.  This allows you to enter a
288221715Sdelphij              filename that contains a percent sign in the  name.   Similarly,
289221715Sdelphij              two  consecutive  pound  signs  are replaced with a single pound
290221715Sdelphij              sign.  The filename is inserted into the command  line  list  of
291221715Sdelphij              files  so  that it can be seen by subsequent :n and :p commands.
292161475Sdelphij              If the filename consists of several files, they are all inserted
293221715Sdelphij              into  the  list  of files and the first one is examined.  If the
294161475Sdelphij              filename contains one or more spaces, the entire filename should
295161475Sdelphij              be enclosed in double quotes (also see the -" option).
29660786Sps
29760786Sps       ^X^V or E
298221715Sdelphij              Same  as :e.  Warning: some systems use ^V as a special literal-
299221715Sdelphij              ization character.  On such systems, you may not be able to  use
300161475Sdelphij              ^V.
30160786Sps
302221715Sdelphij       :n     Examine  the next file (from the list of files given in the com-
303221715Sdelphij              mand line).  If a number N is specified, the N-th next  file  is
304161475Sdelphij              examined.
30560786Sps
306161475Sdelphij       :p     Examine the previous file in the command line list.  If a number
307161475Sdelphij              N is specified, the N-th previous file is examined.
30860786Sps
309221715Sdelphij       :x     Examine the first file in the command line list.  If a number  N
310161475Sdelphij              is specified, the N-th file in the list is examined.
31160786Sps
31260786Sps       :d     Remove the current file from the list of files.
31360786Sps
314221715Sdelphij       t      Go  to the next tag, if there were more than one matches for the
315161475Sdelphij              current tag.  See the -t option for more details about tags.
31660786Sps
317221715Sdelphij       T      Go to the previous tag, if there were more than one matches  for
318161475Sdelphij              the current tag.
31960786Sps
32089019Sps       = or ^G or :f
321221715Sdelphij              Prints  some  information about the file being viewed, including
322221715Sdelphij              its name and the line number and byte offset of the bottom  line
323221715Sdelphij              being  displayed.  If possible, it also prints the length of the
324221715Sdelphij              file, the number of lines in the file and  the  percent  of  the
325161475Sdelphij              file above the last displayed line.
32660786Sps
327221715Sdelphij       -      Followed  by one of the command line option letters (see OPTIONS
328221715Sdelphij              below), this will change the setting of that option and print  a
329221715Sdelphij              message  describing  the  new  setting.   If a ^P (CONTROL-P) is
330161475Sdelphij              entered immediately after the dash, the setting of the option is
331221715Sdelphij              changed  but  no message is printed.  If the option letter has a
332221715Sdelphij              numeric value (such as -b or -h), or a string value (such as  -P
333221715Sdelphij              or  -t), a new value may be entered after the option letter.  If
334221715Sdelphij              no new value is entered, a message describing the  current  set-
335161475Sdelphij              ting is printed and nothing is changed.
33660786Sps
337221715Sdelphij       --     Like  the  -  command, but takes a long option name (see OPTIONS
338221715Sdelphij              below) rather than a single option letter.  You must press ENTER
339221715Sdelphij              or  RETURN after typing the option name.  A ^P immediately after
340221715Sdelphij              the second dash suppresses printing of a message describing  the
341221715Sdelphij              new setting, as in the - command.
34260786Sps
343221715Sdelphij       -+     Followed  by  one  of  the command line option letters this will
344221715Sdelphij              reset the option to its default  setting  and  print  a  message
345221715Sdelphij              describing  the  new  setting.  (The "-+[4mX[24m" command does the same
346221715Sdelphij              thing as "-+[4mX[24m" on the command line.)  This  does  not  work  for
34760786Sps              string-valued options.
34860786Sps
349221715Sdelphij       --+    Like  the -+ command, but takes a long option name rather than a
350161475Sdelphij              single option letter.
35160786Sps
352221715Sdelphij       -!     Followed by one of the command line option  letters,  this  will
353221715Sdelphij              reset  the  option  to the "opposite" of its default setting and
354221715Sdelphij              print a message describing the new setting.  This does not  work
355161475Sdelphij              for numeric or string-valued options.
35660786Sps
357221715Sdelphij       --!    Like  the -! command, but takes a long option name rather than a
358161475Sdelphij              single option letter.
35960786Sps
360221715Sdelphij       _      (Underscore.)  Followed by one of the command line  option  let-
361221715Sdelphij              ters,  this  will print a message describing the current setting
362161475Sdelphij              of that option.  The setting of the option is not changed.
36360786Sps
364161475Sdelphij       __     (Double underscore.)  Like the _ (underscore) command, but takes
365161475Sdelphij              a long option name rather than a single option letter.  You must
366221715Sdelphij              press ENTER or RETURN after typing the option name.
36760786Sps
368221715Sdelphij       +cmd   Causes the specified cmd to be executed each time a new file  is
369170256Sdelphij              examined.  For example, +G causes [4mless[24m to initially display each
370161475Sdelphij              file starting at the end rather than the beginning.
37160786Sps
372170256Sdelphij       V      Prints the version number of [4mless[24m being run.
37360786Sps
37460786Sps       q or Q or :q or :Q or ZZ
375170256Sdelphij              Exits [4mless.[0m
37660786Sps
377221715Sdelphij       The following four commands may or may not be valid, depending on  your
378161475Sdelphij       particular installation.
37960786Sps
380221715Sdelphij       v      Invokes  an  editor  to edit the current file being viewed.  The
381161475Sdelphij              editor is taken from the environment variable VISUAL if defined,
382221715Sdelphij              or  EDITOR if VISUAL is not defined, or defaults to "vi" if nei-
383221715Sdelphij              ther VISUAL nor EDITOR is defined.  See also the  discussion  of
38460786Sps              LESSEDIT under the section on PROMPTS below.
38560786Sps
38660786Sps       ! shell-command
387221715Sdelphij              Invokes  a shell to run the shell-command given.  A percent sign
388221715Sdelphij              (%) in the command is replaced by the name of the current  file.
389161475Sdelphij              A pound sign (#) is replaced by the name of the previously exam-
390221715Sdelphij              ined file.  "!!" repeats the last shell command.   "!"  with  no
391221715Sdelphij              shell  command  simply  invokes  a  shell.  On Unix systems, the
392221715Sdelphij              shell is taken from the environment variable SHELL, or  defaults
393221715Sdelphij              to  "sh".   On  MS-DOS and OS/2 systems, the shell is the normal
394161475Sdelphij              command processor.
39560786Sps
39660786Sps       | <m> shell-command
397221715Sdelphij              <m> represents any mark letter.  Pipes a section  of  the  input
398221715Sdelphij              file  to the given shell command.  The section of the file to be
399221715Sdelphij              piped is between the first line on the current  screen  and  the
400221715Sdelphij              position  marked by the letter.  <m> may also be ^ or $ to indi-
401161475Sdelphij              cate beginning or end of file respectively.  If <m> is . or new-
402161475Sdelphij              line, the current screen is piped.
40360786Sps
40460786Sps       s filename
405221715Sdelphij              Save  the  input  to  a file.  This only works if the input is a
406161475Sdelphij              pipe, not an ordinary file.
40760786Sps
408170256Sdelphij[1mOPTIONS[0m
409221715Sdelphij       Command line options are described below.  Most options may be  changed
410170256Sdelphij       while [4mless[24m is running, via the "-" command.
41189019Sps
412221715Sdelphij       Most  options  may be given in one of two forms: either a dash followed
413221715Sdelphij       by a single letter, or two dashes followed by a long  option  name.   A
414221715Sdelphij       long  option  name  may  be  abbreviated as long as the abbreviation is
415161475Sdelphij       unambiguous.  For example, --quit-at-eof may be abbreviated --quit, but
416161475Sdelphij       not --qui, since both --quit-at-eof and --quiet begin with --qui.  Some
417221715Sdelphij       long option names are in uppercase, such as --QUIT-AT-EOF, as  distinct
418221715Sdelphij       from  --quit-at-eof.  Such option names need only have their first let-
419221715Sdelphij       ter capitalized; the remainder of the name may be in either case.   For
420170256Sdelphij       example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
42160786Sps
422161475Sdelphij       Options are also taken from the environment variable "LESS".  For exam-
423170256Sdelphij       ple, to avoid typing "less -options ..." each time [4mless[24m is invoked, you
424170256Sdelphij       might tell [4mcsh:[0m
42560786Sps
42660786Sps       setenv LESS "-options"
42760786Sps
428170256Sdelphij       or if you use [4msh:[0m
42960786Sps
43060786Sps       LESS="-options"; export LESS
43160786Sps
432221715Sdelphij       On  MS-DOS,  you don't need the quotes, but you should replace any per-
433161475Sdelphij       cent signs in the options string by double percent signs.
43460786Sps
435221715Sdelphij       The environment variable is parsed before the command line, so  command
436221715Sdelphij       line  options  override  the  LESS  environment variable.  If an option
437221715Sdelphij       appears in the LESS variable, it can be reset to its default  value  on
438161475Sdelphij       the command line by beginning the command line option with "-+".
43960786Sps
440251154Sdelphij       Some  options  like -k or -D require a string to follow the option let-
441251154Sdelphij       ter.  The string for that option is considered to  end  when  a  dollar
442251154Sdelphij       sign  ($)  is found.  For example, you can set two -D options on MS-DOS
443161475Sdelphij       like this:
44460786Sps
445251154Sdelphij       LESS="Dn9.1$Ds4.1"
44660786Sps
447251154Sdelphij       If the --use-backslash option appears earlier in the  options,  then  a
448251154Sdelphij       dollar  sign or backslash may be included literally in an option string
449251154Sdelphij       by preceding it with a backslash.  If the --use-backslash option is not
450251154Sdelphij       in  effect, then backslashes are not treated specially, and there is no
451251154Sdelphij       way to include a dollar sign in the option string.
45260786Sps
45360786Sps       -? or --help
454221715Sdelphij              This option displays a summary of the commands accepted by  [4mless[0m
455221715Sdelphij              (the  same  as  the  h  command).   (Depending on how your shell
456221715Sdelphij              interprets the question mark, it may be necessary to  quote  the
457161475Sdelphij              question mark, thus: "-\?".)
45860786Sps
45960786Sps       -a or --search-skip-screen
460221715Sdelphij              By  default,  forward searches start at the top of the displayed
461221715Sdelphij              screen and backwards searches start at the bottom  of  the  dis-
462221715Sdelphij              played  screen (except for repeated searches invoked by the n or
463221715Sdelphij              N commands, which  start  after  or  before  the  "target"  line
464221715Sdelphij              respectively; see the -j option for more about the target line).
465221715Sdelphij              The -a option causes forward searches to instead  start  at  the
466221715Sdelphij              bottom  of  the screen and backward searches to start at the top
467221715Sdelphij              of the screen, thus skipping all lines displayed on the screen.
46860786Sps
469221715Sdelphij       -A or --SEARCH-SKIP-SCREEN
470221715Sdelphij              Causes all forward searches (not just non-repeated searches)  to
471221715Sdelphij              start  just  after the target line, and all backward searches to
472221715Sdelphij              start just before the target line.  Thus, forward searches  will
473221715Sdelphij              skip part of the displayed screen (from the first line up to and
474221715Sdelphij              including the target line).  Similarly backwards  searches  will
475221715Sdelphij              skip the displayed screen from the last line up to and including
476221715Sdelphij              the target line.  This was the default behavior in less versions
477221715Sdelphij              prior to 441.
478221715Sdelphij
479170256Sdelphij       -b[4mn[24m or --buffers=[4mn[0m
480191930Sdelphij              Specifies  the  amount  of  buffer  space [4mless[24m will use for each
481191930Sdelphij              file, in units of kilobytes (1024 bytes).   By  default  64K  of
482191930Sdelphij              buffer  space  is used for each file (unless the file is a pipe;
483191930Sdelphij              see the -B option).  The -b  option  specifies  instead  that  [4mn[0m
484170256Sdelphij              kilobytes of buffer space should be used for each file.  If [4mn[24m is
485191930Sdelphij              -1, buffer space is unlimited; that is, the entire file  can  be
486173932Sdelphij              read into memory.
48763128Sps
48860786Sps       -B or --auto-buffers
489161475Sdelphij              By default, when data is read from a pipe, buffers are allocated
490161475Sdelphij              automatically as needed.  If a large amount of data is read from
491191930Sdelphij              the  pipe,  this  can cause a large amount of memory to be allo-
492221715Sdelphij              cated.  The -B option disables this automatic allocation of buf-
493221715Sdelphij              fers  for pipes, so that only 64K (or the amount of space speci-
494221715Sdelphij              fied by the -b option) is used for the pipe.  Warning: use of -B
495221715Sdelphij              can  result  in  erroneous display, since only the most recently
496221715Sdelphij              viewed part of the piped data is kept  in  memory;  any  earlier
497221715Sdelphij              data is lost.
49860786Sps
49960786Sps       -c or --clear-screen
500191930Sdelphij              Causes  full  screen  repaints  to  be painted from the top line
501191930Sdelphij              down.  By default, full screen repaints are  done  by  scrolling
502161475Sdelphij              from the bottom of the screen.
50360786Sps
50460786Sps       -C or --CLEAR-SCREEN
505170256Sdelphij              Same as -c, for compatibility with older versions of [4mless.[0m
50660786Sps
50760786Sps       -d or --dumb
508161475Sdelphij              The -d option suppresses the error message normally displayed if
509191930Sdelphij              the terminal is dumb; that is, lacks some important  capability,
510161475Sdelphij              such as the ability to clear the screen or scroll backward.  The
511191930Sdelphij              -d option does not otherwise change the behavior of  [4mless[24m  on  a
512128345Stjr              dumb terminal.
51360786Sps
514170256Sdelphij       -D[1mx[4m[22mcolor[24m or --color=[1mx[4m[22mcolor[0m
515170256Sdelphij              [MS-DOS only] Sets the color of the text displayed.  [1mx [22mis a sin-
516191930Sdelphij              gle character which selects the type  of  text  whose  color  is
517191930Sdelphij              being  set: n=normal, s=standout, d=bold, u=underlined, k=blink.
518191930Sdelphij              [4mcolor[24m is a pair of numbers separated by  a  period.   The  first
519191930Sdelphij              number  selects  the foreground color and the second selects the
520191930Sdelphij              background color of the text.  A single number [4mN[24m is the same  as
521191930Sdelphij              [4mN.M[24m, where [4mM[24m is the normal background color.
52260786Sps
523191930Sdelphij
524128345Stjr       -e or --quit-at-eof
525191930Sdelphij              Causes  [4mless[24m  to  automatically  exit the second time it reaches
526191930Sdelphij              end-of-file.  By default, the only way to exit [4mless[24m is  via  the
527161475Sdelphij              "q" command.
52863128Sps
52989019Sps       -E or --QUIT-AT-EOF
530170256Sdelphij              Causes [4mless[24m to automatically exit the first time it reaches end-
531161475Sdelphij              of-file.
53260786Sps
53363128Sps       -f or --force
534161475Sdelphij              Forces non-regular files to be opened.  (A non-regular file is a
535191930Sdelphij              directory  or a device special file.)  Also suppresses the warn-
536170256Sdelphij              ing message when a binary file is opened.  By default, [4mless[24m will
537170256Sdelphij              refuse to open non-regular files.  Note that some operating sys-
538170256Sdelphij              tems will not allow directories to be read, even if -f is set.
53960786Sps
54060786Sps       -F or --quit-if-one-screen
541170256Sdelphij              Causes [4mless[24m to automatically exit if the entire file can be dis-
542161475Sdelphij              played on the first screen.
54360786Sps
54460786Sps       -g or --hilite-search
545191930Sdelphij              Normally,  [4mless[24m  will highlight ALL strings which match the last
546191930Sdelphij              search command.  The -g option changes this  behavior  to  high-
547191930Sdelphij              light  only  the  particular  string which was found by the last
548170256Sdelphij              search command.  This can cause [4mless[24m to run somewhat faster than
549161475Sdelphij              the default.
55060786Sps
55160786Sps       -G or --HILITE-SEARCH
552191930Sdelphij              The  -G  option  suppresses all highlighting of strings found by
553161475Sdelphij              search commands.
55460786Sps
555170256Sdelphij       -h[4mn[24m or --max-back-scroll=[4mn[0m
556191930Sdelphij              Specifies a maximum number of lines to scroll backward.   If  it
557170256Sdelphij              is necessary to scroll backward more than [4mn[24m lines, the screen is
558161475Sdelphij              repainted in a forward direction instead.  (If the terminal does
559161475Sdelphij              not have the ability to scroll backward, -h0 is implied.)
56060786Sps
56160786Sps       -i or --ignore-case
562161475Sdelphij              Causes searches to ignore case; that is, uppercase and lowercase
563191930Sdelphij              are considered identical.  This option is ignored if any  upper-
564191930Sdelphij              case  letters appear in the search pattern; in other words, if a
565191930Sdelphij              pattern contains uppercase letters, then that  search  does  not
566161475Sdelphij              ignore case.
56760786Sps
56860786Sps       -I or --IGNORE-CASE
569191930Sdelphij              Like  -i,  but searches ignore case even if the pattern contains
570161475Sdelphij              uppercase letters.
57160786Sps
572170256Sdelphij       -j[4mn[24m or --jump-target=[4mn[0m
573191930Sdelphij              Specifies a line on the screen where the "target" line is to  be
574191930Sdelphij              positioned.   The  target line is the line specified by any com-
575191930Sdelphij              mand to search for a pattern, jump to a line number, jump  to  a
576173932Sdelphij              file percentage or jump to a tag.  The screen line may be speci-
577191930Sdelphij              fied by a number: the top line on the screen is 1, the  next  is
578173932Sdelphij              2, and so on.  The number may be negative to specify a line rel-
579173932Sdelphij              ative to the bottom of the screen: the bottom line on the screen
580191930Sdelphij              is  -1, the second to the bottom is -2, and so on.  Alternately,
581191930Sdelphij              the screen line may be specified as a fraction of the height  of
582191930Sdelphij              the  screen,  starting with a decimal point: .5 is in the middle
583191930Sdelphij              of the screen, .3 is three tenths down from the first line,  and
584191930Sdelphij              so  on.  If the line is specified as a fraction, the actual line
585191930Sdelphij              number is recalculated if the terminal  window  is  resized,  so
586191930Sdelphij              that  the  target  line remains at the specified fraction of the
587191930Sdelphij              screen height.  If any form of the -j option  is  used,  forward
588191930Sdelphij              searches  begin  at  the line immediately after the target line,
589221715Sdelphij              and backward searches begin at the target line,  unless  changed
590221715Sdelphij              by  -a or -A.  For example, if "-j4" is used, the target line is
591221715Sdelphij              the fourth line on the screen, so forward searches begin at  the
592221715Sdelphij              fifth line on the screen.
59360786Sps
59463128Sps       -J or --status-column
595221715Sdelphij              Displays  a  status  column at the left edge of the screen.  The
596221715Sdelphij              status column shows the lines that matched the  current  search.
597221715Sdelphij              The  status  column  is  also  used if the -w or -W option is in
598161475Sdelphij              effect.
59963128Sps
600170256Sdelphij       -k[4mfilename[24m or --lesskey-file=[4mfilename[0m
601221715Sdelphij              Causes [4mless[24m to open and interpret the named file  as  a  [4mlesskey[0m
602161475Sdelphij              (1) file.  Multiple -k options may be specified.  If the LESSKEY
603221715Sdelphij              or LESSKEY_SYSTEM environment variable is set, or if  a  lesskey
604161475Sdelphij              file is found in a standard place (see KEY BINDINGS), it is also
605170256Sdelphij              used as a [4mlesskey[24m file.
60660786Sps
607161475Sdelphij       -K or --quit-on-intr
608221715Sdelphij              Causes [4mless[24m to exit immediately (with status 2) when  an  inter-
609221715Sdelphij              rupt  character  (usually  ^C) is typed.  Normally, an interrupt
610221715Sdelphij              character causes [4mless[24m to stop whatever it is doing and return to
611221715Sdelphij              its  command  prompt.   Note  that  use  of this option makes it
612221715Sdelphij              impossible to return to the command prompt from the "F" command.
613161475Sdelphij
614128345Stjr       -L or --no-lessopen
615221715Sdelphij              Ignore the LESSOPEN environment variable  (see  the  INPUT  PRE-
616221715Sdelphij              PROCESSOR  section  below).   This option can be set from within
617221715Sdelphij              [4mless[24m, but it will apply only to files opened  subsequently,  not
618191930Sdelphij              to the file which is currently open.
619128345Stjr
62060786Sps       -m or --long-prompt
621221715Sdelphij              Causes  [4mless[24m  to  prompt verbosely (like [4mmore[24m), with the percent
622170256Sdelphij              into the file.  By default, [4mless[24m prompts with a colon.
62360786Sps
62460786Sps       -M or --LONG-PROMPT
625170256Sdelphij              Causes [4mless[24m to prompt even more verbosely than [4mmore.[0m
62660786Sps
62760786Sps       -n or --line-numbers
628221715Sdelphij              Suppresses line numbers.  The default (to use line numbers)  may
629221715Sdelphij              cause  [4mless[24m  to run more slowly in some cases, especially with a
630221715Sdelphij              very large input file.  Suppressing line  numbers  with  the  -n
631221715Sdelphij              option  will  avoid this problem.  Using line numbers means: the
632161475Sdelphij              line number will be displayed in the verbose prompt and in the =
633221715Sdelphij              command,  and the v command will pass the current line number to
634221715Sdelphij              the editor (see also  the  discussion  of  LESSEDIT  in  PROMPTS
635161475Sdelphij              below).
63660786Sps
637128345Stjr       -N or --LINE-NUMBERS
638221715Sdelphij              Causes  a  line  number to be displayed at the beginning of each
639161475Sdelphij              line in the display.
64060786Sps
641170256Sdelphij       -o[4mfilename[24m or --log-file=[4mfilename[0m
642221715Sdelphij              Causes [4mless[24m to copy its input to the named file as it  is  being
643161475Sdelphij              viewed.  This applies only when the input file is a pipe, not an
644221715Sdelphij              ordinary file.  If the file already exists, [4mless[24m  will  ask  for
645161475Sdelphij              confirmation before overwriting it.
64660786Sps
647170256Sdelphij       -O[4mfilename[24m or --LOG-FILE=[4mfilename[0m
648161475Sdelphij              The -O option is like -o, but it will overwrite an existing file
649161475Sdelphij              without asking for confirmation.
65060786Sps
651221715Sdelphij              If no log file has been specified, the -o and -O options can  be
652221715Sdelphij              used  from  within  [4mless[24m  to specify a log file.  Without a file
653161475Sdelphij              name, they will simply report the name of the log file.  The "s"
654170256Sdelphij              command is equivalent to specifying -o from within [4mless.[0m
65563128Sps
656170256Sdelphij       -p[4mpattern[24m or --pattern=[4mpattern[0m
657221715Sdelphij              The  -p  option  on the command line is equivalent to specifying
658221715Sdelphij              +/[4mpattern[24m; that is, it tells [4mless[24m to start at the  first  occur-
659170256Sdelphij              rence of [4mpattern[24m in the file.
66063128Sps
661170256Sdelphij       -P[4mprompt[24m or --prompt=[4mprompt[0m
662221715Sdelphij              Provides  a  way  to  tailor the three prompt styles to your own
663161475Sdelphij              preference.  This option would normally be put in the LESS envi-
664170256Sdelphij              ronment variable, rather than being typed in with each [4mless[24m com-
665161475Sdelphij              mand.  Such an option must either be the last option in the LESS
666221715Sdelphij              variable,  or be terminated by a dollar sign.  -Ps followed by a
667221715Sdelphij              string changes the default (short) prompt to that  string.   -Pm
668221715Sdelphij              changes  the  medium  (-m)  prompt.   -PM  changes the long (-M)
669221715Sdelphij              prompt.  -Ph changes  the  prompt  for  the  help  screen.   -P=
670221715Sdelphij              changes  the  message printed by the = command.  -Pw changes the
671221715Sdelphij              message printed while waiting for data (in the F command).   All
672221715Sdelphij              prompt  strings  consist  of  a  sequence of letters and special
673221715Sdelphij              escape sequences.  See the section on PROMPTS for more details.
67460786Sps
67560786Sps       -q or --quiet or --silent
676191930Sdelphij              Causes moderately "quiet" operation: the terminal  bell  is  not
677161475Sdelphij              rung if an attempt is made to scroll past the end of the file or
678161475Sdelphij              before the beginning of the file.  If the terminal has a "visual
679191930Sdelphij              bell",  it  is  used  instead.  The bell will be rung on certain
680191930Sdelphij              other errors, such as typing an invalid character.  The  default
681161475Sdelphij              is to ring the terminal bell in all such cases.
68260786Sps
683128345Stjr       -Q or --QUIET or --SILENT
684191930Sdelphij              Causes  totally  "quiet"  operation:  the terminal bell is never
685161475Sdelphij              rung.
686128345Stjr
687128345Stjr       -r or --raw-control-chars
688161475Sdelphij              Causes "raw" control characters to be displayed.  The default is
689191930Sdelphij              to  display  control  characters  using  the caret notation; for
690161475Sdelphij              example, a control-A (octal 001) is displayed as "^A".  Warning:
691170256Sdelphij              when the -r option is used, [4mless[24m cannot keep track of the actual
692191930Sdelphij              appearance of the screen (since this depends on how  the  screen
693161475Sdelphij              responds to each type of control character).  Thus, various dis-
694191930Sdelphij              play problems may result, such as long lines being split in  the
695161475Sdelphij              wrong place.
69660786Sps
69763128Sps       -R or --RAW-CONTROL-CHARS
698191930Sdelphij              Like  -r,  but  only ANSI "color" escape sequences are output in
699161475Sdelphij              "raw" form.  Unlike -r, the screen appearance is maintained cor-
700161475Sdelphij              rectly  in  most  cases.   ANSI  "color"  escape  sequences  are
701161475Sdelphij              sequences of the form:
70263128Sps
70363128Sps                   ESC [ ... m
70463128Sps
705191930Sdelphij              where the "..." is zero or more color  specification  characters
706191930Sdelphij              For  the  purpose  of  keeping  track of screen appearance, ANSI
707191930Sdelphij              color escape sequences are assumed to not move the cursor.   You
708191930Sdelphij              can  make [4mless[24m think that characters other than "m" can end ANSI
709191930Sdelphij              color escape  sequences  by  setting  the  environment  variable
710161475Sdelphij              LESSANSIENDCHARS to the list of characters which can end a color
711191930Sdelphij              escape sequence.  And you can make [4mless[24m  think  that  characters
712191930Sdelphij              other  than the standard ones may appear between the ESC and the
713191930Sdelphij              m by setting the environment variable  LESSANSIMIDCHARS  to  the
714161475Sdelphij              list of characters which can appear.
71560786Sps
71660786Sps       -s or --squeeze-blank-lines
717191930Sdelphij              Causes  consecutive  blank  lines  to  be squeezed into a single
718170256Sdelphij              blank line.  This is useful when viewing [4mnroff[24m output.
71960786Sps
72060786Sps       -S or --chop-long-lines
721240121Sdelphij              Causes lines longer than the screen width to be  chopped  (trun-
722240121Sdelphij              cated) rather than wrapped.  That is, the portion of a long line
723240121Sdelphij              that does not fit in the screen width is not shown.  The default
724240121Sdelphij              is  to  wrap  long  lines; that is, display the remainder on the
725240121Sdelphij              next line.
72660786Sps
727170256Sdelphij       -t[4mtag[24m or --tag=[4mtag[0m
728161475Sdelphij              The -t option, followed immediately by a TAG, will edit the file
729240121Sdelphij              containing  that tag.  For this to work, tag information must be
730240121Sdelphij              available; for example, there may  be  a  file  in  the  current
731170256Sdelphij              directory called "tags", which was previously built by [4mctags[24m (1)
732161475Sdelphij              or an equivalent command.  If the environment variable LESSGLOB-
733240121Sdelphij              ALTAGS  is set, it is taken to be the name of a command compati-
734240121Sdelphij              ble with [4mglobal[24m (1), and that command is executed  to  find  the
735161475Sdelphij              tag.  (See http://www.gnu.org/software/global/global.html).  The
736240121Sdelphij              -t option may also be specified from within [4mless[24m  (using  the  -
737240121Sdelphij              command)  as a way of examining a new file.  The command ":t" is
738170256Sdelphij              equivalent to specifying -t from within [4mless.[0m
73960786Sps
740170256Sdelphij       -T[4mtagsfile[24m or --tag-file=[4mtagsfile[0m
74189019Sps              Specifies a tags file to be used instead of "tags".
74260786Sps
74389019Sps       -u or --underline-special
744240121Sdelphij              Causes backspaces and carriage returns to be treated  as  print-
745240121Sdelphij              able  characters;  that  is,  they are sent to the terminal when
746161475Sdelphij              they appear in the input.
74760786Sps
74889019Sps       -U or --UNDERLINE-SPECIAL
749240121Sdelphij              Causes backspaces, tabs and carriage returns to  be  treated  as
750240121Sdelphij              control  characters;  that  is, they are handled as specified by
751161475Sdelphij              the -r option.
75260786Sps
753240121Sdelphij              By default, if neither -u nor  -U  is  given,  backspaces  which
754240121Sdelphij              appear  adjacent  to  an  underscore  character are treated spe-
755240121Sdelphij              cially: the underlined text is displayed  using  the  terminal's
756240121Sdelphij              hardware  underlining capability.  Also, backspaces which appear
757240121Sdelphij              between two identical  characters  are  treated  specially:  the
758240121Sdelphij              overstruck  text  is printed using the terminal's hardware bold-
759240121Sdelphij              face capability.  Other backspaces are deleted, along  with  the
760161475Sdelphij              preceding character.  Carriage returns immediately followed by a
761240121Sdelphij              newline are deleted.  Other  carriage  returns  are  handled  as
762240121Sdelphij              specified  by the -r option.  Text which is overstruck or under-
763161475Sdelphij              lined can be searched for if neither -u nor -U is in effect.
76460786Sps
76560786Sps       -V or --version
766170256Sdelphij              Displays the version number of [4mless.[0m
76760786Sps
76860786Sps       -w or --hilite-unread
769240121Sdelphij              Temporarily highlights the first  "new"  line  after  a  forward
770161475Sdelphij              movement of a full page.  The first "new" line is the line imme-
771240121Sdelphij              diately following the line  previously  at  the  bottom  of  the
772161475Sdelphij              screen.  Also highlights the target line after a g or p command.
773240121Sdelphij              The highlight is removed at the next command which causes  move-
774240121Sdelphij              ment.   The  entire line is highlighted, unless the -J option is
775221715Sdelphij              in effect, in which case only the status column is highlighted.
77660786Sps
77760786Sps       -W or --HILITE-UNREAD
778161475Sdelphij              Like -w, but temporarily highlights the first new line after any
779161475Sdelphij              forward movement command larger than one line.
78060786Sps
781170256Sdelphij       -x[4mn[24m,... or --tabs=[4mn[24m,...
782240121Sdelphij              Sets  tab  stops.  If only one [4mn[24m is specified, tab stops are set
783240121Sdelphij              at multiples of [4mn[24m.  If multiple values separated by  commas  are
784240121Sdelphij              specified,  tab  stops are set at those positions, and then con-
785240121Sdelphij              tinue with the same spacing  as  the  last  two.   For  example,
786240121Sdelphij              [4m-x9,17[24m  will  set  tabs  at  positions  9, 17, 25, 33, etc.  The
787170256Sdelphij              default for [4mn[24m is 8.
78860786Sps
78989019Sps       -X or --no-init
790161475Sdelphij              Disables sending the termcap initialization and deinitialization
791240121Sdelphij              strings  to  the  terminal.   This is sometimes desirable if the
792240121Sdelphij              deinitialization string does something unnecessary, like  clear-
793161475Sdelphij              ing the screen.
79460786Sps
795170256Sdelphij       -y[4mn[24m or --max-forw-scroll=[4mn[0m
796161475Sdelphij              Specifies a maximum number of lines to scroll forward.  If it is
797240121Sdelphij              necessary to scroll forward more than [4mn[24m  lines,  the  screen  is
798240121Sdelphij              repainted  instead.   The -c or -C option may be used to repaint
799240121Sdelphij              from the top of the screen if desired.  By default, any  forward
80089019Sps              movement causes scrolling.
80160786Sps
802170256Sdelphij       -[z][4mn[24m or --window=[4mn[0m
803240121Sdelphij              Changes  the  default  scrolling  window  size  to [4mn[24m lines.  The
804161475Sdelphij              default is one screenful.  The z and w commands can also be used
805240121Sdelphij              to  change the window size.  The "z" may be omitted for compati-
806170256Sdelphij              bility with some versions of [4mmore.[24m  If the number [4mn[24m is negative,
807240121Sdelphij              it  indicates  [4mn[24m  lines  less than the current screen size.  For
808170256Sdelphij              example, if the screen is 24 lines, [4m-z-4[24m sets the scrolling win-
809240121Sdelphij              dow  to  20  lines.   If  the screen is resized to 40 lines, the
810170256Sdelphij              scrolling window automatically changes to 36 lines.
81163128Sps
812170256Sdelphij       -[4m"cc[24m or --quotes=[4mcc[0m
813240121Sdelphij              Changes the filename quoting character.  This may  be  necessary
814240121Sdelphij              if  you are trying to name a file which contains both spaces and
815240121Sdelphij              quote characters.  Followed by a single character, this  changes
816240121Sdelphij              the  quote  character to that character.  Filenames containing a
817161475Sdelphij              space should then be surrounded by that character rather than by
818240121Sdelphij              double  quotes.   Followed  by  two characters, changes the open
819240121Sdelphij              quote to the first character, and the close quote to the  second
820161475Sdelphij              character.  Filenames containing a space should then be preceded
821240121Sdelphij              by the open quote character and  followed  by  the  close  quote
822240121Sdelphij              character.   Note  that  even  after  the  quote  characters are
823240121Sdelphij              changed, this option remains -" (a dash  followed  by  a  double
824161475Sdelphij              quote).
82560786Sps
826128345Stjr       -~ or --tilde
827161475Sdelphij              Normally lines after end of file are displayed as a single tilde
828161475Sdelphij              (~).  This option causes lines after end of file to be displayed
829161475Sdelphij              as blank lines.
83060786Sps
83163128Sps       -# or --shift
832161475Sdelphij              Specifies the default number of positions to scroll horizontally
833240121Sdelphij              in the RIGHTARROW and LEFTARROW commands.  If the number  speci-
834240121Sdelphij              fied  is  zero,  it  sets the default number of positions to one
835195941Sdelphij              half of the screen width.  Alternately, the number may be speci-
836240121Sdelphij              fied  as  a fraction of the width of the screen, starting with a
837240121Sdelphij              decimal point: .5 is half of  the  screen  width,  .3  is  three
838240121Sdelphij              tenths  of the screen width, and so on.  If the number is speci-
839240121Sdelphij              fied as a fraction, the actual number  of  scroll  positions  is
840240121Sdelphij              recalculated  if  the  terminal  window  is resized, so that the
841240121Sdelphij              actual scroll remains at the specified fraction  of  the  screen
842195941Sdelphij              width.
84363128Sps
844173682Sdelphij       --follow-name
845240121Sdelphij              Normally,  if  the  input  file is renamed while an F command is
846240121Sdelphij              executing, [4mless[24m will continue to display  the  contents  of  the
847240121Sdelphij              original  file  despite  its  name  change.  If --follow-name is
848173682Sdelphij              specified, during an F command [4mless[24m will periodically attempt to
849173682Sdelphij              reopen the file by name.  If the reopen succeeds and the file is
850240121Sdelphij              a different file from the original (which means that a new  file
851240121Sdelphij              has  been  created  with  the  same  name  as  the original (now
852173682Sdelphij              renamed) file), [4mless[24m will display the contents of that new file.
853173682Sdelphij
854251154Sdelphij       --no-keypad
855251154Sdelphij              Disables sending the keypad initialization and  deinitialization
856251154Sdelphij              strings to the terminal.  This is sometimes useful if the keypad
857251154Sdelphij              strings make the numeric keypad behave in an undesirable manner.
858251154Sdelphij
859251154Sdelphij       --use-backslash
860251154Sdelphij              This option changes the interpretations of options which  follow
861251154Sdelphij              this one.  After the --use-backslash option, any backslash in an
862251154Sdelphij              option string is removed and the following  character  is  taken
863251154Sdelphij              literally.   This  allows a dollar sign to be included in option
864251154Sdelphij              strings.
865251154Sdelphij
866240121Sdelphij       --     A command line argument of "--" marks the end  of  option  argu-
867240121Sdelphij              ments.   Any  arguments  following this are interpreted as file-
868161475Sdelphij              names.  This can be useful when viewing a file whose name begins
869161475Sdelphij              with a "-" or "+".
87060786Sps
871240121Sdelphij       +      If  a  command  line option begins with [1m+[22m, the remainder of that
872240121Sdelphij              option is taken to be an initial command to [4mless.[24m  For  example,
873240121Sdelphij              +G  tells  [4mless[24m  to start at the end of the file rather than the
874240121Sdelphij              beginning, and +/xyz tells it to start at the  first  occurrence
875240121Sdelphij              of  "xyz"  in  the file.  As a special case, +<number> acts like
876161475Sdelphij              +<number>g; that is, it starts the display at the specified line
877240121Sdelphij              number  (however,  see  the caveat under the "g" command above).
878240121Sdelphij              If the option starts with ++, the  initial  command  applies  to
879240121Sdelphij              every  file being viewed, not just the first one.  The + command
880161475Sdelphij              described previously may also be used to set (or change) an ini-
881161475Sdelphij              tial command for every file.
88260786Sps
88360786Sps
884170256Sdelphij[1mLINE EDITING[0m
885240121Sdelphij       When  entering command line at the bottom of the screen (for example, a
886170256Sdelphij       filename for the :e command, or the pattern for a search command), cer-
887240121Sdelphij       tain  keys  can  be used to manipulate the command line.  Most commands
888240121Sdelphij       have an alternate form in [ brackets ] which can be used if a key  does
889240121Sdelphij       not  exist  on  a  particular keyboard.  (Note that the forms beginning
890240121Sdelphij       with ESC do not work in some MS-DOS and Windows systems because ESC  is
891240121Sdelphij       the  line  erase  character.)  Any of these special keys may be entered
892240121Sdelphij       literally by preceding it with the "literal" character,  either  ^V  or
893240121Sdelphij       ^A.   A  backslash itself may also be entered literally by entering two
894191930Sdelphij       backslashes.
89560786Sps
89663128Sps       LEFTARROW [ ESC-h ]
89763128Sps              Move the cursor one space to the left.
89860786Sps
899128345Stjr       RIGHTARROW [ ESC-l ]
900128345Stjr              Move the cursor one space to the right.
90189019Sps
902128345Stjr       ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
903240121Sdelphij              (That is, CONTROL and LEFTARROW simultaneously.)  Move the  cur-
904161475Sdelphij              sor one word to the left.
90589019Sps
906128345Stjr       ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
907161475Sdelphij              (That is, CONTROL and RIGHTARROW simultaneously.)  Move the cur-
908161475Sdelphij              sor one word to the right.
90960786Sps
91060786Sps       HOME [ ESC-0 ]
91160786Sps              Move the cursor to the beginning of the line.
91260786Sps
91360786Sps       END [ ESC-$ ]
91460786Sps              Move the cursor to the end of the line.
91560786Sps
91660786Sps       BACKSPACE
917240121Sdelphij              Delete the character to the left of the cursor,  or  cancel  the
918161475Sdelphij              command if the command line is empty.
91960786Sps
92060786Sps       DELETE or [ ESC-x ]
92160786Sps              Delete the character under the cursor.
92260786Sps
92360786Sps       ^BACKSPACE [ ESC-BACKSPACE ]
924240121Sdelphij              (That  is,  CONTROL  and  BACKSPACE simultaneously.)  Delete the
925161475Sdelphij              word to the left of the cursor.
92660786Sps
92760786Sps       ^DELETE [ ESC-X or ESC-DELETE ]
928240121Sdelphij              (That is, CONTROL and DELETE simultaneously.)  Delete  the  word
929161475Sdelphij              under the cursor.
93060786Sps
93163128Sps       UPARROW [ ESC-k ]
932240121Sdelphij              Retrieve  the  previous  command  line.  If you first enter some
933240121Sdelphij              text and then press UPARROW, it will retrieve the previous  com-
934240121Sdelphij              mand which begins with that text.
93560786Sps
93663128Sps       DOWNARROW [ ESC-j ]
937240121Sdelphij              Retrieve  the  next  command line.  If you first enter some text
938240121Sdelphij              and then press DOWNARROW, it  will  retrieve  the  next  command
939240121Sdelphij              which begins with that text.
94060786Sps
941240121Sdelphij       TAB    Complete  the partial filename to the left of the cursor.  If it
942240121Sdelphij              matches more than one filename, the first match is entered  into
943240121Sdelphij              the  command  line.   Repeated  TABs  will  cycle thru the other
944161475Sdelphij              matching filenames.  If the completed filename is a directory, a
945240121Sdelphij              "/"  is  appended to the filename.  (On MS-DOS systems, a "\" is
946240121Sdelphij              appended.)  The environment variable LESSSEPARATOR can  be  used
947221715Sdelphij              to specify a different character to append to a directory name.
94860786Sps
94963128Sps       BACKTAB [ ESC-TAB ]
950161475Sdelphij              Like, TAB, but cycles in the reverse direction thru the matching
951161475Sdelphij              filenames.
95260786Sps
953240121Sdelphij       ^L     Complete the partial filename to the left of the cursor.  If  it
954161475Sdelphij              matches more than one filename, all matches are entered into the
955161475Sdelphij              command line (if they fit).
95660786Sps
957128345Stjr       ^U (Unix and OS/2) or ESC (MS-DOS)
958240121Sdelphij              Delete the entire command line, or cancel  the  command  if  the
959161475Sdelphij              command line is empty.  If you have changed your line-kill char-
960161475Sdelphij              acter in Unix to something other than ^U, that character is used
961161475Sdelphij              instead of ^U.
962128345Stjr
963221715Sdelphij       ^G     Delete the entire command line and return to the main prompt.
964128345Stjr
965221715Sdelphij
966170256Sdelphij[1mKEY BINDINGS[0m
967240121Sdelphij       You  may define your own [4mless[24m commands by using the program [4mlesskey[24m (1)
968240121Sdelphij       to create a lesskey file.  This file specifies a set  of  command  keys
969240121Sdelphij       and  an  action  associated with each key.  You may also use [4mlesskey[24m to
970161475Sdelphij       change the line-editing keys (see LINE EDITING), and to set environment
971240121Sdelphij       variables.   If the environment variable LESSKEY is set, [4mless[24m uses that
972240121Sdelphij       as the name of the lesskey file.  Otherwise, [4mless[24m looks in  a  standard
973240121Sdelphij       place  for  the lesskey file: On Unix systems, [4mless[24m looks for a lesskey
974240121Sdelphij       file called "$HOME/.less".  On MS-DOS and Windows systems,  [4mless[24m  looks
975240121Sdelphij       for  a lesskey file called "$HOME/_less", and if it is not found there,
976161475Sdelphij       then looks for a lesskey file called "_less" in any directory specified
977240121Sdelphij       in  the  PATH  environment variable.  On OS/2 systems, [4mless[24m looks for a
978240121Sdelphij       lesskey file called "$HOME/less.ini", and if  it  is  not  found,  then
979240121Sdelphij       looks  for  a lesskey file called "less.ini" in any directory specified
980161475Sdelphij       in the INIT environment variable, and if it not found there, then looks
981240121Sdelphij       for  a lesskey file called "less.ini" in any directory specified in the
982240121Sdelphij       PATH environment variable.   See  the  [4mlesskey[24m  manual  page  for  more
983161475Sdelphij       details.
98460786Sps
985240121Sdelphij       A  system-wide lesskey file may also be set up to provide key bindings.
986161475Sdelphij       If a key is defined in both a local lesskey file and in the system-wide
987240121Sdelphij       file,  key bindings in the local file take precedence over those in the
988240121Sdelphij       system-wide file.  If the environment variable LESSKEY_SYSTEM  is  set,
989170256Sdelphij       [4mless[24m uses that as the name of the system-wide lesskey file.  Otherwise,
990240121Sdelphij       [4mless[24m looks in a standard place for the  system-wide  lesskey  file:  On
991240121Sdelphij       Unix  systems,  the system-wide lesskey file is /usr/local/etc/sysless.
992240121Sdelphij       (However, if [4mless[24m was built with a  different  sysconf  directory  than
993161475Sdelphij       /usr/local/etc, that directory is where the sysless file is found.)  On
994240121Sdelphij       MS-DOS and Windows systems, the system-wide lesskey  file  is  c:\_sys-
995161475Sdelphij       less.  On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
99660786Sps
99760786Sps
998170256Sdelphij[1mINPUT PREPROCESSOR[0m
999240121Sdelphij       You  may  define an "input preprocessor" for [4mless.[24m  Before [4mless[24m opens a
1000161475Sdelphij       file, it first gives your input preprocessor a chance to modify the way
1001240121Sdelphij       the  contents of the file are displayed.  An input preprocessor is sim-
1002240121Sdelphij       ply an executable program (or shell script), which writes the  contents
1003161475Sdelphij       of the file to a different file, called the replacement file.  The con-
1004240121Sdelphij       tents of the replacement file are then displayed in place of  the  con-
1005240121Sdelphij       tents  of the original file.  However, it will appear to the user as if
1006240121Sdelphij       the original file is opened; that is, [4mless[24m will  display  the  original
1007161475Sdelphij       filename as the name of the current file.
100860786Sps
1009240121Sdelphij       An  input preprocessor receives one command line argument, the original
1010240121Sdelphij       filename, as entered by the user.  It  should  create  the  replacement
1011240121Sdelphij       file,  and when finished, print the name of the replacement file to its
1012240121Sdelphij       standard output.  If the input preprocessor does not output a  replace-
1013240121Sdelphij       ment  filename, [4mless[24m uses the original file, as normal.  The input pre-
1014240121Sdelphij       processor is not called when viewing standard  input.   To  set  up  an
1015240121Sdelphij       input  preprocessor, set the LESSOPEN environment variable to a command
1016240121Sdelphij       line which will invoke your  input  preprocessor.   This  command  line
1017240121Sdelphij       should  include  one  occurrence  of  the  string  "%s",  which will be
1018240121Sdelphij       replaced by  the  filename  when  the  input  preprocessor  command  is
101989019Sps       invoked.
102089019Sps
1021170256Sdelphij       When [4mless[24m closes a file opened in such a way, it will call another pro-
1022240121Sdelphij       gram, called the input postprocessor, which  may  perform  any  desired
1023240121Sdelphij       clean-up  action  (such  as  deleting  the  replacement file created by
1024161475Sdelphij       LESSOPEN).  This program receives two command line arguments, the orig-
1025240121Sdelphij       inal  filename  as entered by the user, and the name of the replacement
1026240121Sdelphij       file.  To set up an input postprocessor, set the LESSCLOSE  environment
1027240121Sdelphij       variable  to a command line which will invoke your input postprocessor.
1028240121Sdelphij       It may include two  occurrences  of  the  string  "%s";  the  first  is
1029240121Sdelphij       replaced  with  the  original  name of the file and the second with the
1030161475Sdelphij       name of the replacement file, which was output by LESSOPEN.
103160786Sps
1032240121Sdelphij       For example, on many Unix systems, these two scripts will allow you  to
1033170256Sdelphij       keep files in compressed format, but still let [4mless[24m view them directly:
103460786Sps
103560786Sps       lessopen.sh:
103660786Sps            #! /bin/sh
103760786Sps            case "$1" in
1038161475Sdelphij            *.Z) uncompress -
103960786Sps                 if [ -s /tmp/less.$$ ]; then
104060786Sps                      echo /tmp/less.$$
104160786Sps                 else
104260786Sps                      rm -f /tmp/less.$$
104360786Sps                 fi
104460786Sps                 ;;
104560786Sps            esac
104660786Sps
104760786Sps       lessclose.sh:
104860786Sps            #! /bin/sh
104960786Sps            rm $2
105060786Sps
1051240121Sdelphij       To  use these scripts, put them both where they can be executed and set
1052161475Sdelphij       LESSOPEN="lessopen.sh %s",  and  LESSCLOSE="lessclose.sh %s %s".   More
1053240121Sdelphij       complex  LESSOPEN  and LESSCLOSE scripts may be written to accept other
1054161475Sdelphij       types of compressed files, and so on.
105560786Sps
1056240121Sdelphij       It is also possible to set up an input preprocessor to  pipe  the  file
1057240121Sdelphij       data  directly to [4mless,[24m rather than putting the data into a replacement
1058161475Sdelphij       file.  This avoids the need to decompress the entire file before start-
1059161475Sdelphij       ing to view it.  An input preprocessor that works this way is called an
1060240121Sdelphij       input pipe.  An input pipe, instead of writing the name of  a  replace-
1061240121Sdelphij       ment  file  on  its  standard output, writes the entire contents of the
1062240121Sdelphij       replacement file on its standard output.  If the input  pipe  does  not
1063240121Sdelphij       write  any characters on its standard output, then there is no replace-
1064240121Sdelphij       ment file and [4mless[24m uses the original file, as normal.  To use an  input
1065240121Sdelphij       pipe,  make  the first character in the LESSOPEN environment variable a
1066240121Sdelphij       vertical bar (|) to signify that the input  preprocessor  is  an  input
1067161475Sdelphij       pipe.
106889019Sps
1069240121Sdelphij       For  example, on many Unix systems, this script will work like the pre-
1070161475Sdelphij       vious example scripts:
107189019Sps
107260786Sps       lesspipe.sh:
107360786Sps            #! /bin/sh
107460786Sps            case "$1" in
107560786Sps            *.Z) uncompress -c $1  2>/dev/null
1076240121Sdelphij            *)   exit 1
107760786Sps                 ;;
107860786Sps            esac
1079240121Sdelphij            exit $?
108060786Sps
1081161475Sdelphij       To  use  this  script,  put  it  where  it  can  be  executed  and  set
1082240121Sdelphij       LESSOPEN="|lesspipe.sh %s".
108360786Sps
1084240121Sdelphij       Note  that  a  preprocessor  cannot output an empty file, since that is
1085240121Sdelphij       interpreted as meaning there is no replacement, and the  original  file
1086240121Sdelphij       is used.  To avoid this, if LESSOPEN starts with two vertical bars, the
1087240121Sdelphij       exit status of the script becomes meaningful.  If the  exit  status  is
1088240121Sdelphij       zero,  the  output  is  considered  to  be replacement text, even if it
1089240121Sdelphij       empty.  If the exit status is nonzero, any output is  ignored  and  the
1090240121Sdelphij       original  file  is  used.   For compatibility with previous versions of
1091240121Sdelphij       [4mless,[24m if LESSOPEN starts with only one vertical bar, the exit status of
1092240121Sdelphij       the preprocessor is ignored.
1093240121Sdelphij
1094240121Sdelphij       When  an input pipe is used, a LESSCLOSE postprocessor can be used, but
1095240121Sdelphij       it is usually not necessary since there is no replacement file to clean
1096240121Sdelphij       up.   In  this  case, the replacement file name passed to the LESSCLOSE
1097240121Sdelphij       postprocessor is "-".
1098240121Sdelphij
1099240121Sdelphij       For compatibility with previous versions of [4mless,[24m the input  preproces-
1100195941Sdelphij       sor or pipe is not used if [4mless[24m is viewing standard input.  However, if
1101240121Sdelphij       the first character of LESSOPEN is a dash (-), the  input  preprocessor
1102240121Sdelphij       is  used  on  standard input as well as other files.  In this case, the
1103240121Sdelphij       dash is not considered to be part  of  the  preprocessor  command.   If
1104195941Sdelphij       standard input is being viewed, the input preprocessor is passed a file
1105240121Sdelphij       name consisting of a single dash.  Similarly, if the first two  charac-
1106240121Sdelphij       ters  of  LESSOPEN  are vertical bar and dash (|-) or two vertical bars
1107240121Sdelphij       and a dash (||-), the input pipe is used on standard input as  well  as
1108240121Sdelphij       other files.  Again, in this case the dash is not considered to be part
1109240121Sdelphij       of the input pipe command.
111060786Sps
1111191930Sdelphij
1112170256Sdelphij[1mNATIONAL CHARACTER SETS[0m
111360786Sps       There are three types of characters in the input file:
111460786Sps
111560786Sps       normal characters
111660786Sps              can be displayed directly to the screen.
111760786Sps
111860786Sps       control characters
1119195941Sdelphij              should not be displayed directly, but are expected to  be  found
1120161475Sdelphij              in ordinary text files (such as backspace and tab).
112160786Sps
112260786Sps       binary characters
1123195941Sdelphij              should  not  be  displayed  directly  and are not expected to be
1124161475Sdelphij              found in text files.
112560786Sps
1126161475Sdelphij       A "character set" is simply a description of which characters are to be
1127195941Sdelphij       considered  normal,  control,  and binary.  The LESSCHARSET environment
1128195941Sdelphij       variable may be used to select a character set.   Possible  values  for
1129161475Sdelphij       LESSCHARSET are:
113060786Sps
1131195941Sdelphij       ascii  BS,  TAB, NL, CR, and formfeed are control characters, all chars
1132195941Sdelphij              with values between 32 and 126 are normal, and  all  others  are
1133161475Sdelphij              binary.
113460786Sps
113589019Sps       iso8859
1136195941Sdelphij              Selects  an  ISO 8859 character set.  This is the same as ASCII,
1137195941Sdelphij              except characters between 160 and  255  are  treated  as  normal
1138161475Sdelphij              characters.
113960786Sps
114089019Sps       latin1 Same as iso8859.
114160786Sps
114289019Sps       latin9 Same as iso8859.
114360786Sps
114489019Sps       dos    Selects a character set appropriate for MS-DOS.
114560786Sps
114689019Sps       ebcdic Selects an EBCDIC character set.
114760786Sps
114889019Sps       IBM-1047
1149195941Sdelphij              Selects  an  EBCDIC  character set used by OS/390 Unix Services.
1150195941Sdelphij              This is the EBCDIC analogue of latin1.  You get similar  results
1151161475Sdelphij              by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1152161475Sdelphij              environment.
115360786Sps
115489019Sps       koi8-r Selects a Russian character set.
115560786Sps
1156161475Sdelphij       next   Selects a character set appropriate for NeXT computers.
115789019Sps
1158195941Sdelphij       utf-8  Selects the UTF-8 encoding  of  the  ISO  10646  character  set.
1159195941Sdelphij              UTF-8  is  special  in that it supports multi-byte characters in
1160195941Sdelphij              the input file.  It is the  only  character  set  that  supports
1161170256Sdelphij              multi-byte characters.
116289019Sps
1163161475Sdelphij       windows
1164195941Sdelphij              Selects  a  character  set appropriate for Microsoft Windows (cp
1165161475Sdelphij              1251).
116660786Sps
1167195941Sdelphij       In rare cases, it may be desired to tailor [4mless[24m to use a character  set
1168195941Sdelphij       other  than the ones definable by LESSCHARSET.  In this case, the envi-
1169191930Sdelphij       ronment variable LESSCHARDEF can be used to define a character set.  It
1170191930Sdelphij       should be set to a string where each character in the string represents
1171195941Sdelphij       one character in the character set.  The character "." is  used  for  a
1172195941Sdelphij       normal  character, "c" for control, and "b" for binary.  A decimal num-
1173195941Sdelphij       ber may be used for repetition.   For  example,  "bccc4b."  would  mean
1174195941Sdelphij       character  0  is  binary,  1,  2  and  3 are control, 4, 5, 6 and 7 are
1175161475Sdelphij       binary, and 8 is normal.  All characters after the last are taken to be
1176195941Sdelphij       the  same  as  the  last,  so characters 9 through 255 would be normal.
1177195941Sdelphij       (This is an example, and does not necessarily represent any real  char-
1178161475Sdelphij       acter set.)
117960786Sps
1180195941Sdelphij       This  table  shows the value of LESSCHARDEF which is equivalent to each
1181161475Sdelphij       of the possible values for LESSCHARSET:
118289019Sps
1183128345Stjr            ascii     8bcccbcc18b95.b
1184128345Stjr            dos       8bcccbcc12bc5b95.b.
1185128345Stjr            ebcdic    5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1186128345Stjr                      9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1187128345Stjr            IBM-1047  4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1188128345Stjr                      191.b
1189128345Stjr            iso8859   8bcccbcc18b95.33b.
1190128345Stjr            koi8-r    8bcccbcc18b95.b128.
119160786Sps            latin1    8bcccbcc18b95.33b.
119260786Sps            next      8bcccbcc18b95.bb125.bb
119360786Sps
1194195941Sdelphij       If neither LESSCHARSET nor LESSCHARDEF is set, but any of  the  strings
1195222906Sdelphij       "UTF-8",  "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
1196161475Sdelphij       LANG environment variables, then the default character set is utf-8.
119760786Sps
1198195941Sdelphij       If that string is not found, but your  system  supports  the  [4msetlocale[0m
1199195941Sdelphij       interface,  [4mless[24m  will  use  setlocale  to determine the character set.
1200195941Sdelphij       setlocale is controlled by setting the  LANG  or  LC_CTYPE  environment
1201161475Sdelphij       variables.
120289019Sps
1203195941Sdelphij       Finally,  if the [4msetlocale[24m interface is also not available, the default
1204161475Sdelphij       character set is latin1.
120589019Sps
1206195941Sdelphij       Control and  binary  characters  are  displayed  in  standout  (reverse
1207161475Sdelphij       video).  Each such character is displayed in caret notation if possible
1208195941Sdelphij       (e.g. ^A for control-A).  Caret notation is used only if inverting  the
1209161475Sdelphij       0100 bit results in a normal printable character.  Otherwise, the char-
1210195941Sdelphij       acter is displayed as a hex number in angle brackets.  This format  can
1211195941Sdelphij       be  changed by setting the LESSBINFMT environment variable.  LESSBINFMT
1212161475Sdelphij       may begin with a "*" and one character to select the display attribute:
1213195941Sdelphij       "*k"  is  blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1214195941Sdelphij       and "*n" is normal.  If LESSBINFMT does not begin with  a  "*",  normal
1215195941Sdelphij       attribute  is  assumed.   The remainder of LESSBINFMT is a string which
1216195941Sdelphij       may include one printf-style escape sequence (a % followed by x, X,  o,
1217195941Sdelphij       d,  etc.).   For  example, if LESSBINFMT is "*u[%x]", binary characters
1218195941Sdelphij       are displayed in underlined hexadecimal surrounded  by  brackets.   The
1219221715Sdelphij       default  if  no  LESSBINFMT  is  specified is "*s<%02X>".  Warning: the
1220221715Sdelphij       result of expanding the character via LESSBINFMT must be less  than  31
1221221715Sdelphij       characters.
122260786Sps
1223161475Sdelphij       When the character set is utf-8, the LESSUTFBINFMT environment variable
1224161475Sdelphij       acts similarly to LESSBINFMT but it applies to Unicode code points that
1225195941Sdelphij       were  successfully  decoded but are unsuitable for display (e.g., unas-
1226195941Sdelphij       signed code points).  Its default  value  is  "<U+%04lX>".   Note  that
1227195941Sdelphij       LESSUTFBINFMT  and  LESSBINFMT  share  their  display attribute setting
1228195941Sdelphij       ("*x") so specifying one will affect both; LESSUTFBINFMT is read  after
1229195941Sdelphij       LESSBINFMT  so  its  setting,  if any, will have priority.  Problematic
1230195941Sdelphij       octets in a UTF-8 file (octets of a truncated  sequence,  octets  of  a
1231195941Sdelphij       complete  but  non-shortest  form  sequence,  illegal octets, and stray
1232195941Sdelphij       trailing octets) are displayed individually using LESSBINFMT so  as  to
1233161475Sdelphij       facilitate diagnostic of how the UTF-8 file is ill-formed.
123460786Sps
1235161475Sdelphij
1236170256Sdelphij[1mPROMPTS[0m
1237195941Sdelphij       The  -P option allows you to tailor the prompt to your preference.  The
1238195941Sdelphij       string given to the -P option replaces  the  specified  prompt  string.
1239161475Sdelphij       Certain characters in the string are interpreted specially.  The prompt
1240195941Sdelphij       mechanism is rather complicated to provide flexibility, but  the  ordi-
1241195941Sdelphij       nary  user need not understand the details of constructing personalized
1242161475Sdelphij       prompt strings.
124360786Sps
1244195941Sdelphij       A percent sign followed by a single character is expanded according  to
1245161475Sdelphij       what the following character is:
124660786Sps
1247195941Sdelphij       %b[4mX[24m    Replaced  by the byte offset into the current input file.  The b
1248170256Sdelphij              is followed by a single character (shown as [4mX[24m above) which spec-
1249195941Sdelphij              ifies  the line whose byte offset is to be used.  If the charac-
1250195941Sdelphij              ter is a "t", the byte offset of the top line in the display  is
1251173932Sdelphij              used, an "m" means use the middle line, a "b" means use the bot-
1252195941Sdelphij              tom line, a "B" means use the line just after the  bottom  line,
1253195941Sdelphij              and  a  "j"  means use the "target" line, as specified by the -j
1254173932Sdelphij              option.
125560786Sps
125660786Sps       %B     Replaced by the size of the current input file.
125760786Sps
1258161475Sdelphij       %c     Replaced by the column number of the text appearing in the first
1259161475Sdelphij              column of the screen.
126060786Sps
1261195941Sdelphij       %d[4mX[24m    Replaced  by  the  page number of a line in the input file.  The
1262170256Sdelphij              line to be used is determined by the [4mX[24m, as with the %b option.
126360786Sps
1264195941Sdelphij       %D     Replaced by the number of pages in the input  file,  or  equiva-
1265161475Sdelphij              lently, the page number of the last line in the input file.
126660786Sps
1267195941Sdelphij       %E     Replaced  by the name of the editor (from the VISUAL environment
1268195941Sdelphij              variable, or the EDITOR environment variable if  VISUAL  is  not
1269161475Sdelphij              defined).  See the discussion of the LESSEDIT feature below.
127060786Sps
127160786Sps       %f     Replaced by the name of the current input file.
127260786Sps
1273221715Sdelphij       %F     Replaced  by the last component of the name of the current input
1274221715Sdelphij              file.
1275221715Sdelphij
1276221715Sdelphij       %i     Replaced by the index of the current file in the list  of  input
1277161475Sdelphij              files.
127860786Sps
1279221715Sdelphij       %l[4mX[24m    Replaced  by  the  line number of a line in the input file.  The
1280170256Sdelphij              line to be used is determined by the [4mX[24m, as with the %b option.
128160786Sps
1282221715Sdelphij       %L     Replaced by the line number of the last line in the input file.
128360786Sps
128460786Sps       %m     Replaced by the total number of input files.
128560786Sps
1286195941Sdelphij       %p[4mX[24m    Replaced by the percent into the current input  file,  based  on
1287195941Sdelphij              byte  offsets.  The line used is determined by the [4mX[24m as with the
1288161475Sdelphij              %b option.
128960786Sps
1290195941Sdelphij       %P[4mX[24m    Replaced by the percent into the current input  file,  based  on
1291195941Sdelphij              line  numbers.  The line used is determined by the [4mX[24m as with the
1292161475Sdelphij              %b option.
129360786Sps
129489019Sps       %s     Same as %B.
129560786Sps
1296195941Sdelphij       %t     Causes any trailing spaces to be removed.  Usually used  at  the
1297161475Sdelphij              end of the string, but may appear anywhere.
129860786Sps
1299161475Sdelphij       %x     Replaced by the name of the next input file in the list.
130060786Sps
1301161475Sdelphij       If any item is unknown (for example, the file size if input is a pipe),
1302161475Sdelphij       a question mark is printed instead.
130360786Sps
1304195941Sdelphij       The format of the prompt string can be  changed  depending  on  certain
1305195941Sdelphij       conditions.   A  question mark followed by a single character acts like
1306195941Sdelphij       an "IF": depending on the following character, a  condition  is  evalu-
1307195941Sdelphij       ated.   If the condition is true, any characters following the question
1308195941Sdelphij       mark and condition character, up to  a  period,  are  included  in  the
1309195941Sdelphij       prompt.   If  the condition is false, such characters are not included.
1310195941Sdelphij       A colon appearing between the question mark and the period can be  used
1311161475Sdelphij       to establish an "ELSE": any characters between the colon and the period
1312195941Sdelphij       are included in the string if and only if the IF  condition  is  false.
1313161475Sdelphij       Condition characters (which follow a question mark) may be:
131460786Sps
1315221715Sdelphij       ?a     True if any characters have been included in the prompt so far.
131660786Sps
1317170256Sdelphij       ?b[4mX[24m    True if the byte offset of the specified line is known.
131860786Sps
131960786Sps       ?B     True if the size of current input file is known.
132060786Sps
1321161475Sdelphij       ?c     True if the text is horizontally shifted (%c is not zero).
132260786Sps
1323170256Sdelphij       ?d[4mX[24m    True if the page number of the specified line is known.
132460786Sps
132560786Sps       ?e     True if at end-of-file.
132660786Sps
1327221715Sdelphij       ?f     True  if  there is an input filename (that is, if input is not a
1328161475Sdelphij              pipe).
132960786Sps
1330170256Sdelphij       ?l[4mX[24m    True if the line number of the specified line is known.
133163128Sps
1332161475Sdelphij       ?L     True if the line number of the last line in the file is known.
133363128Sps
133489019Sps       ?m     True if there is more than one input file.
133563128Sps
1336161475Sdelphij       ?n     True if this is the first prompt in a new input file.
133763128Sps
1338221715Sdelphij       ?p[4mX[24m    True if the percent into the current input file, based  on  byte
1339161475Sdelphij              offsets, of the specified line is known.
134063128Sps
1341221715Sdelphij       ?P[4mX[24m    True  if  the percent into the current input file, based on line
1342161475Sdelphij              numbers, of the specified line is known.
134363128Sps
1344128345Stjr       ?s     Same as "?B".
134560786Sps
1346221715Sdelphij       ?x     True if there is a next input file  (that  is,  if  the  current
1347161475Sdelphij              input file is not the last one).
134860786Sps
1349221715Sdelphij       Any  characters  other  than  the  special  ones (question mark, colon,
1350221715Sdelphij       period, percent, and backslash) become literally part  of  the  prompt.
1351221715Sdelphij       Any  of  the special characters may be included in the prompt literally
1352161475Sdelphij       by preceding it with a backslash.
135360786Sps
135460786Sps       Some examples:
135560786Sps
135660786Sps       ?f%f:Standard input.
135760786Sps
1358221715Sdelphij       This prompt prints the filename, if known; otherwise the string  "Stan-
1359161475Sdelphij       dard input".
136060786Sps
136160786Sps       ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
136260786Sps
1363221715Sdelphij       This  prompt  would print the filename, if known.  The filename is fol-
1364221715Sdelphij       lowed by the line number, if known, otherwise  the  percent  if  known,
1365221715Sdelphij       otherwise  the  byte  offset  if  known.  Otherwise, a dash is printed.
1366221715Sdelphij       Notice how each question mark has a matching  period,  and  how  the  %
1367161475Sdelphij       after the %pt is included literally by escaping it with a backslash.
136860786Sps
136960786Sps       ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
137060786Sps
1371221715Sdelphij       This  prints  the  filename if this is the first prompt in a file, fol-
1372221715Sdelphij       lowed by the "file N of N" message if there  is  more  than  one  input
1373221715Sdelphij       file.   Then,  if  we are at end-of-file, the string "(END)" is printed
1374221715Sdelphij       followed by the name of the next file, if there is one.   Finally,  any
1375161475Sdelphij       trailing spaces are truncated.  This is the default prompt.  For refer-
1376221715Sdelphij       ence, here are the defaults for  the  other  two  prompts  (-m  and  -M
1377221715Sdelphij       respectively).   Each  is  broken  into  two lines here for readability
1378161475Sdelphij       only.
137963128Sps
138089019Sps       ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
138189019Sps            ?pB%pB\%:byte %bB?s/%s...%t
138263128Sps
138389019Sps       ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
138489019Sps            byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
138563128Sps
138689019Sps       And here is the default message produced by the = command:
138763128Sps
138889019Sps       ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1389128345Stjr            byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1390128345Stjr
1391221715Sdelphij       The prompt expansion features are also used for another purpose: if  an
1392221715Sdelphij       environment  variable LESSEDIT is defined, it is used as the command to
1393221715Sdelphij       be executed when the v command is  invoked.   The  LESSEDIT  string  is
1394221715Sdelphij       expanded  in the same way as the prompt strings.  The default value for
1395128345Stjr       LESSEDIT is:
1396128345Stjr
139760786Sps            %E ?lm+%lm. %f
139860786Sps
1399161475Sdelphij       Note that this expands to the editor name, followed by a + and the line
1400221715Sdelphij       number,  followed by the file name.  If your editor does not accept the
1401221715Sdelphij       "+linenumber" syntax, or has other differences  in  invocation  syntax,
1402161475Sdelphij       the LESSEDIT variable can be changed to modify this default.
140360786Sps
140460786Sps
1405170256Sdelphij[1mSECURITY[0m
1406221715Sdelphij       When  the  environment  variable LESSSECURE is set to 1, [4mless[24m runs in a
1407161475Sdelphij       "secure" mode.  This means these features are disabled:
140860786Sps
140960786Sps              !      the shell command
141060786Sps
141160786Sps              |      the pipe command
141260786Sps
141360786Sps              :e     the examine command.
141460786Sps
141560786Sps              v      the editing command
141660786Sps
141760786Sps              s  -o  log files
141860786Sps
141960786Sps              -k     use of lesskey files
142060786Sps
142160786Sps              -t     use of tags files
142260786Sps
142360786Sps                     metacharacters in filenames, such as *
142460786Sps
142560786Sps                     filename completion (TAB, ^L)
142660786Sps
1427161475Sdelphij       Less can also be compiled to be permanently in "secure" mode.
142860786Sps
142960786Sps
1430170256Sdelphij[1mCOMPATIBILITY WITH MORE[0m
1431170256Sdelphij       If the environment variable LESS_IS_MORE is set to 1, or if the program
1432221715Sdelphij       is  invoked via a file link named "more", [4mless[24m behaves (mostly) in con-
1433221715Sdelphij       formance with the POSIX "more" command specification.   In  this  mode,
1434170256Sdelphij       less behaves differently in these ways:
1435170256Sdelphij
1436221715Sdelphij       The  -e  option  works  differently.  If the -e option is not set, [4mless[0m
1437221715Sdelphij       behaves as if the -E option were set.  If the -e option  is  set,  [4mless[0m
1438170256Sdelphij       behaves as if the -e and -F options were set.
1439170256Sdelphij
1440221715Sdelphij       The  -m  option  works  differently.   If the -m option is not set, the
1441221715Sdelphij       medium prompt is used, and it is prefixed with the  string  "--More--".
1442170256Sdelphij       If the -m option is set, the short prompt is used.
1443170256Sdelphij
1444221715Sdelphij       The  -n  option acts like the -z option.  The normal behavior of the -n
1445170256Sdelphij       option is unavailable in this mode.
1446170256Sdelphij
1447221715Sdelphij       The parameter to the -p option is taken to be  a  [4mless[24m  command  rather
1448170256Sdelphij       than a search pattern.
1449170256Sdelphij
1450221715Sdelphij       The  LESS  environment  variable  is  ignored, and the MORE environment
1451170256Sdelphij       variable is used in its place.
1452170256Sdelphij
1453170256Sdelphij
1454170256Sdelphij[1mENVIRONMENT VARIABLES[0m
1455161475Sdelphij       Environment variables may be specified either in the system environment
1456221715Sdelphij       as  usual,  or  in  a  [4mlesskey[24m  (1) file.  If environment variables are
1457221715Sdelphij       defined in more than one place, variables defined in  a  local  lesskey
1458221715Sdelphij       file  take precedence over variables defined in the system environment,
1459161475Sdelphij       which take precedence over variables defined in the system-wide lesskey
1460161475Sdelphij       file.
146160786Sps
1462128345Stjr       COLUMNS
1463161475Sdelphij              Sets the number of columns on the screen.  Takes precedence over
1464221715Sdelphij              the number of columns specified by the TERM variable.   (But  if
1465161475Sdelphij              you  have  a  windowing  system  which  supports  TIOCGWINSZ  or
1466221715Sdelphij              WIOCGETD, the window system's idea  of  the  screen  size  takes
1467161475Sdelphij              precedence over the LINES and COLUMNS environment variables.)
1468128345Stjr
146963128Sps       EDITOR The name of the editor (used for the v command).
147060786Sps
1471221715Sdelphij       HOME   Name  of  the user's home directory (used to find a lesskey file
1472161475Sdelphij              on Unix and OS/2 systems).
147360786Sps
147460786Sps       HOMEDRIVE, HOMEPATH
1475221715Sdelphij              Concatenation of the HOMEDRIVE and  HOMEPATH  environment  vari-
1476161475Sdelphij              ables is the name of the user's home directory if the HOME vari-
1477161475Sdelphij              able is not set (only in the Windows version).
147860786Sps
1479221715Sdelphij       INIT   Name of the user's init directory (used to find a  lesskey  file
1480161475Sdelphij              on OS/2 systems).
148160786Sps
148260786Sps       LANG   Language for determining the character set.
148360786Sps
148460786Sps       LC_CTYPE
148560786Sps              Language for determining the character set.
148660786Sps
1487170256Sdelphij       LESS   Options which are passed to [4mless[24m automatically.
148860786Sps
148960786Sps       LESSANSIENDCHARS
1490221715Sdelphij              Characters  which may end an ANSI color escape sequence (default
1491161475Sdelphij              "m").
149260786Sps
1493161475Sdelphij       LESSANSIMIDCHARS
1494221715Sdelphij              Characters which may appear between the ESC  character  and  the
1495221715Sdelphij              end   character  in  an  ANSI  color  escape  sequence  (default
1496161475Sdelphij              "0123456789;[?!"'#%()*+ ".
1497161475Sdelphij
149860786Sps       LESSBINFMT
1499161475Sdelphij              Format for displaying non-printable, non-control characters.
150060786Sps
150160786Sps       LESSCHARDEF
150260786Sps              Defines a character set.
150360786Sps
150489019Sps       LESSCHARSET
150589019Sps              Selects a predefined character set.
150663128Sps
150789019Sps       LESSCLOSE
1508161475Sdelphij              Command line to invoke the (optional) input-postprocessor.
150963128Sps
151089019Sps       LESSECHO
1511161475Sdelphij              Name of the lessecho program (default "lessecho").  The lessecho
1512221715Sdelphij              program  is needed to expand metacharacters, such as * and ?, in
1513161475Sdelphij              filenames on Unix systems.
151463128Sps
1515161475Sdelphij       LESSEDIT
1516221715Sdelphij              Editor prototype string (used for the v command).   See  discus-
1517161475Sdelphij              sion under PROMPTS.
151863128Sps
1519161475Sdelphij       LESSGLOBALTAGS
1520221715Sdelphij              Name  of  the command used by the -t option to find global tags.
1521170256Sdelphij              Normally should be set to "global" if your system has the [4mglobal[0m
1522161475Sdelphij              (1) command.  If not set, global tags are not used.
152363128Sps
1524161475Sdelphij       LESSHISTFILE
1525221715Sdelphij              Name  of  the  history file used to remember search commands and
1526221715Sdelphij              shell commands between invocations of [4mless.[24m  If set  to  "-"  or
1527221715Sdelphij              "/dev/null",  a  history  file  is  not  used.   The  default is
1528221715Sdelphij              "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst"  on  DOS  and
1529221715Sdelphij              Windows  systems,  or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1530170256Sdelphij              on OS/2 systems.
153163128Sps
1532161475Sdelphij       LESSHISTSIZE
1533161475Sdelphij              The maximum number of commands to save in the history file.  The
1534161475Sdelphij              default is 100.
153563128Sps
153660786Sps       LESSKEY
153760786Sps              Name of the default lesskey(1) file.
153860786Sps
153960786Sps       LESSKEY_SYSTEM
154060786Sps              Name of the default system-wide lesskey(1) file.
154160786Sps
154260786Sps       LESSMETACHARS
1543221715Sdelphij              List  of characters which are considered "metacharacters" by the
1544161475Sdelphij              shell.
154560786Sps
154660786Sps       LESSMETAESCAPE
1547221715Sdelphij              Prefix which less will add before each metacharacter in  a  com-
1548221715Sdelphij              mand  sent  to the shell.  If LESSMETAESCAPE is an empty string,
1549221715Sdelphij              commands containing metacharacters will not  be  passed  to  the
1550161475Sdelphij              shell.
155160786Sps
155260786Sps       LESSOPEN
1553161475Sdelphij              Command line to invoke the (optional) input-preprocessor.
155460786Sps
155560786Sps       LESSSECURE
1556161475Sdelphij              Runs less in "secure" mode.  See discussion under SECURITY.
155760786Sps
155860786Sps       LESSSEPARATOR
1559221715Sdelphij              String  to  be  appended to a directory name in filename comple-
1560161475Sdelphij              tion.
156160786Sps
1562161475Sdelphij       LESSUTFBINFMT
1563161475Sdelphij              Format for displaying non-printable Unicode code points.
156460786Sps
1565170256Sdelphij       LESS_IS_MORE
1566170256Sdelphij              Emulate the [4mmore[24m (1) command.
1567170256Sdelphij
1568221715Sdelphij       LINES  Sets the number of lines on the screen.  Takes  precedence  over
1569161475Sdelphij              the number of lines specified by the TERM variable.  (But if you
1570221715Sdelphij              have a windowing system which supports TIOCGWINSZ  or  WIOCGETD,
1571221715Sdelphij              the  window  system's  idea  of the screen size takes precedence
1572161475Sdelphij              over the LINES and COLUMNS environment variables.)
157363128Sps
1574240121Sdelphij       MORE   Options which are passed to [4mless[24m automatically when  running  in
1575240121Sdelphij              [4mmore[24m compatible mode.
1576240121Sdelphij
1577240121Sdelphij       PATH   User's  search  path  (used to find a lesskey file on MS-DOS and
1578161475Sdelphij              OS/2 systems).
157963128Sps
1580240121Sdelphij       SHELL  The shell used to execute the ! command, as well  as  to  expand
1581161475Sdelphij              filenames.
1582161475Sdelphij
1583170256Sdelphij       TERM   The type of terminal on which [4mless[24m is being run.
158463128Sps
1585128345Stjr       VISUAL The name of the editor (used for the v command).
158660786Sps
158760786Sps
1588170256Sdelphij[1mSEE ALSO[0m
1589128345Stjr       lesskey(1)
159060786Sps
159160786Sps
1592170256Sdelphij[1mCOPYRIGHT[0m
1593240121Sdelphij       Copyright (C) 1984-2012  Mark Nudelman
159460786Sps
1595240121Sdelphij       less  is  part of the GNU project and is free software.  You can redis-
1596240121Sdelphij       tribute it and/or modify it under the terms of either (1) the GNU  Gen-
1597240121Sdelphij       eral  Public  License  as published by the Free Software Foundation; or
1598161475Sdelphij       (2) the Less License.  See the file README in the less distribution for
1599161475Sdelphij       more details regarding redistribution.  You should have received a copy
1600240121Sdelphij       of the GNU General Public License along with the source for  less;  see
1601240121Sdelphij       the  file  COPYING.   If not, write to the Free Software Foundation, 59
1602240121Sdelphij       Temple Place, Suite 330, Boston, MA  02111-1307, USA.  You should  also
1603161475Sdelphij       have received a copy of the Less License; see the file LICENSE.
160460786Sps
1605161475Sdelphij       less is distributed in the hope that it will be useful, but WITHOUT ANY
1606240121Sdelphij       WARRANTY; without even the implied warranty of MERCHANTABILITY or  FIT-
1607240121Sdelphij       NESS  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
1608161475Sdelphij       more details.
160960786Sps
161060786Sps
1611170256Sdelphij[1mAUTHOR[0m
1612251154Sdelphij       Mark Nudelman
1613251154Sdelphij       Send bug reports or comments to <bug-less@gnu.org>
1614191930Sdelphij       See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
1615191930Sdelphij       of known bugs in less.
1616170256Sdelphij       For more information, see the less homepage at
1617170256Sdelphij       http://www.greenwoodsoftware.com/less.
161860786Sps
161960786Sps
162060786Sps
1621251154Sdelphij                           Version 458: 04 Apr 2013                    LESS(1)
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