6 less - opposite of more
12 \e[1mless --version
\e[0m
13 \e[1mless [-[+]aBcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
\e[0m
14 \e[1m[-b
\e[4m
\e[22mspace
\e[24m
\e[1m] [-h
\e[4m
\e[22mlines
\e[24m
\e[1m] [-j
\e[4m
\e[22mline
\e[24m
\e[1m] [-k
\e[4m
\e[22mkeyfile
\e[24m
\e[1m]
\e[0m
15 \e[1m[-{oO}
\e[4m
\e[22mlogfile
\e[24m
\e[1m] [-p
\e[4m
\e[22mpattern
\e[24m
\e[1m] [-P
\e[4m
\e[22mprompt
\e[24m
\e[1m] [-t
\e[4m
\e[22mtag
\e[24m
\e[1m]
\e[0m
16 \e[1m[-T
\e[4m
\e[22mtagsfile
\e[24m
\e[1m] [-x
\e[4m
\e[22mtab
\e[24m
\e[1m,...] [-y
\e[4m
\e[22mlines
\e[24m
\e[1m] [-[z]
\e[4m
\e[22mlines
\e[24m
\e[1m]
\e[0m
17 \e[1m[-#
\e[4m
\e[22mshift
\e[24m
\e[1m] [+[+]
\e[4m
\e[22mcmd
\e[24m
\e[1m] [--] [
\e[4m
\e[22mfilename
\e[24m
\e[1m]...
\e[0m
18 (See the OPTIONS section for alternate option syntax with long option
23 \e[4mLess
\e[24m is a program similar to
\e[4mmore
\e[24m (1), but which allows backward move-
24 ment in the file as well as forward movement. Also,
\e[4mless
\e[24m does not have
25 to read the entire input file before starting, so with large input
26 files it starts up faster than text editors like
\e[4mvi
\e[24m (1).
\e[4mLess
\e[24m uses
27 termcap (or terminfo on some systems), so it can run on a variety of
28 terminals. There is even limited support for hardcopy terminals. (On
29 a hardcopy terminal, lines which should be printed at the top of the
30 screen are prefixed with a caret.)
32 Commands are based on both
\e[4mmore
\e[24m and
\e[4mvi.
\e[24m Commands may be preceded by a
33 decimal number, called N in the descriptions below. The number is used
34 by some commands, as indicated.
38 In the following descriptions, ^X means control-X. ESC stands for the
39 ESCAPE key; for example ESC-v means the two character sequence
42 h or H Help: display a summary of these commands. If you forget all
43 the other commands, remember this one.
45 SPACE or ^V or f or ^F
46 Scroll forward N lines, default one window (see option -z
47 below). If N is more than the screen size, only the final
48 screenful is displayed. Warning: some systems use ^V as a spe-
49 cial literalization character.
51 z Like SPACE, but if N is specified, it becomes the new window
55 Like SPACE, but scrolls a full screenful, even if it reaches
56 end-of-file in the process.
58 RETURN or ^N or e or ^E or j or ^J
59 Scroll forward N lines, default 1. The entire N lines are dis-
60 played, even if N is more than the screen size.
63 Scroll forward N lines, default one half of the screen size. If
64 N is specified, it becomes the new default for subsequent d and
68 Scroll backward N lines, default one window (see option -z
69 below). If N is more than the screen size, only the final
70 screenful is displayed.
72 w Like ESC-v, but if N is specified, it becomes the new window
75 y or ^Y or ^P or k or ^K
76 Scroll backward N lines, default 1. The entire N lines are dis-
77 played, even if N is more than the screen size. Warning: some
78 systems use ^Y as a special job control character.
81 Scroll backward N lines, default one half of the screen size.
82 If N is specified, it becomes the new default for subsequent d
86 Scroll horizontally right N characters, default half the screen
87 width (see the -# option). If a number N is specified, it
88 becomes the default for future RIGHTARROW and LEFTARROW com-
89 mands. While the text is scrolled, it acts as though the -S
90 option (chop lines) were in effect.
93 Scroll horizontally left N characters, default half the screen
94 width (see the -# option). If a number N is specified, it
95 becomes the default for future RIGHTARROW and LEFTARROW com-
101 R Repaint the screen, discarding any buffered input. Useful if
102 the file is changing while it is being viewed.
104 F Scroll forward, and keep trying to read when the end of file is
105 reached. Normally this command would be used when already at
106 the end of the file. It is a way to monitor the tail of a file
107 which is growing while it is being viewed. (The behavior is
108 similar to the "tail -f" command.)
111 Go to line N in the file, default 1 (beginning of file). (Warn-
112 ing: this may be slow if N is large.)
115 Go to line N in the file, default the end of the file. (Warn-
116 ing: this may be slow if N is large, or if N is not specified
117 and standard input, rather than a file, is being read.)
119 p or % Go to a position N percent into the file. N should be between 0
120 and 100, and may contain a decimal point.
122 P Go to the line containing byte offset N in the file.
124 { If a left curly bracket appears in the top line displayed on the
125 screen, the { command will go to the matching right curly
126 bracket. The matching right curly bracket is positioned on the
127 bottom line of the screen. If there is more than one left curly
128 bracket on the top line, a number N may be used to specify the
129 N-th bracket on the line.
131 } If a right curly bracket appears in the bottom line displayed on
132 the screen, the } command will go to the matching left curly
133 bracket. The matching left curly bracket is positioned on the
134 top line of the screen. If there is more than one right curly
135 bracket on the top line, a number N may be used to specify the
136 N-th bracket on the line.
138 ( Like {, but applies to parentheses rather than curly brackets.
140 ) Like }, but applies to parentheses rather than curly brackets.
142 [ Like {, but applies to square brackets rather than curly brack-
145 ] Like }, but applies to square brackets rather than curly brack-
148 ESC-^F Followed by two characters, acts like {, but uses the two char-
149 acters as open and close brackets, respectively. For example,
150 "ESC ^F < >" could be used to go forward to the > which matches
151 the < in the top displayed line.
153 ESC-^B Followed by two characters, acts like }, but uses the two char-
154 acters as open and close brackets, respectively. For example,
155 "ESC ^B < >" could be used to go backward to the < which matches
156 the > in the bottom displayed line.
158 m Followed by any lowercase letter, marks the current position
161 ' (Single quote.) Followed by any lowercase letter, returns to
162 the position which was previously marked with that letter. Fol-
163 lowed by another single quote, returns to the position at which
164 the last "large" movement command was executed. Followed by a ^
165 or $, jumps to the beginning or end of the file respectively.
166 Marks are preserved when a new file is examined, so the ' com-
167 mand can be used to switch between input files.
169 ^X^X Same as single quote.
172 Search forward in the file for the N-th line containing the pat-
173 tern. N defaults to 1. The pattern is a regular expression, as
174 recognized by the regular expression library supplied by your
175 system. The search starts at the second line displayed (but see
176 the -a and -j options, which change this).
178 Certain characters are special if entered at the beginning of
179 the pattern; they modify the type of search rather than become
183 Search for lines which do NOT match the pattern.
186 Search multiple files. That is, if the search reaches
187 the END of the current file without finding a match, the
188 search continues in the next file in the command line
192 Begin the search at the first line of the FIRST file in
193 the command line list, regardless of what is currently
194 displayed on the screen or the settings of the -a or -j
197 ^K Highlight any text which matches the pattern on the cur-
198 rent screen, but don't move to the first match (KEEP
201 ^R Don't interpret regular expression metacharacters; that
202 is, do a simple textual comparison.
205 Search backward in the file for the N-th line containing the
206 pattern. The search starts at the line immediately before the
209 Certain characters are special as in the / command:
212 Search for lines which do NOT match the pattern.
215 Search multiple files. That is, if the search reaches
216 the beginning of the current file without finding a
217 match, the search continues in the previous file in the
221 Begin the search at the last line of the last file in the
222 command line list, regardless of what is currently dis-
223 played on the screen or the settings of the -a or -j
226 ^K As in forward searches.
228 ^R As in forward searches.
236 n Repeat previous search, for N-th line containing the last pat-
237 tern. If the previous search was modified by ^N, the search is
238 made for the N-th line NOT containing the pattern. If the pre-
239 vious search was modified by ^E, the search continues in the
240 next (or previous) file if not satisfied in the current file.
241 If the previous search was modified by ^R, the search is done
242 without using regular expressions. There is no effect if the
243 previous search was modified by ^F or ^K.
245 N Repeat previous search, but in the reverse direction.
247 ESC-n Repeat previous search, but crossing file boundaries. The
248 effect is as if the previous search were modified by *.
250 ESC-N Repeat previous search, but in the reverse direction and cross-
253 ESC-u Undo search highlighting. Turn off highlighting of strings
254 matching the current search pattern. If highlighting is already
255 off because of a previous ESC-u command, turn highlighting back
256 on. Any search command will also turn highlighting back on.
257 (Highlighting can also be disabled by toggling the -G option; in
258 that case search commands do not turn highlighting back on.)
261 Examine a new file. If the filename is missing, the "current"
262 file (see the :n and :p commands below) from the list of files
263 in the command line is re-examined. A percent sign (%) in the
264 filename is replaced by the name of the current file. A pound
265 sign (#) is replaced by the name of the previously examined
266 file. However, two consecutive percent signs are simply
267 replaced with a single percent sign. This allows you to enter a
268 filename that contains a percent sign in the name. Similarly,
269 two consecutive pound signs are replaced with a single pound
270 sign. The filename is inserted into the command line list of
271 files so that it can be seen by subsequent :n and :p commands.
272 If the filename consists of several files, they are all inserted
273 into the list of files and the first one is examined. If the
274 filename contains one or more spaces, the entire filename should
275 be enclosed in double quotes (also see the -" option).
278 Same as :e. Warning: some systems use ^V as a special literal-
279 ization character. On such systems, you may not be able to use
282 :n Examine the next file (from the list of files given in the com-
283 mand line). If a number N is specified, the N-th next file is
286 :p Examine the previous file in the command line list. If a number
287 N is specified, the N-th previous file is examined.
289 :x Examine the first file in the command line list. If a number N
290 is specified, the N-th file in the list is examined.
292 :d Remove the current file from the list of files.
294 t Go to the next tag, if there were more than one matches for the
295 current tag. See the -t option for more details about tags.
297 T Go to the previous tag, if there were more than one matches for
301 Prints some information about the file being viewed, including
302 its name and the line number and byte offset of the bottom line
303 being displayed. If possible, it also prints the length of the
304 file, the number of lines in the file and the percent of the
305 file above the last displayed line.
307 - Followed by one of the command line option letters (see OPTIONS
308 below), this will change the setting of that option and print a
309 message describing the new setting. If a ^P (CONTROL-P) is
310 entered immediately after the dash, the setting of the option is
311 changed but no message is printed. If the option letter has a
312 numeric value (such as -b or -h), or a string value (such as -P
313 or -t), a new value may be entered after the option letter. If
314 no new value is entered, a message describing the current set-
315 ting is printed and nothing is changed.
317 -- Like the - command, but takes a long option name (see OPTIONS
318 below) rather than a single option letter. You must press
319 RETURN after typing the option name. A ^P immediately after the
320 second dash suppresses printing of a message describing the new
321 setting, as in the - command.
323 -+ Followed by one of the command line option letters this will
324 reset the option to its default setting and print a message
325 describing the new setting. (The "-+
\e[4mX
\e[24m" command does the same
326 thing as "-+
\e[4mX
\e[24m" on the command line.) This does not work for
327 string-valued options.
329 --+ Like the -+ command, but takes a long option name rather than a
330 single option letter.
332 -! Followed by one of the command line option letters, this will
333 reset the option to the "opposite" of its default setting and
334 print a message describing the new setting. This does not work
335 for numeric or string-valued options.
337 --! Like the -! command, but takes a long option name rather than a
338 single option letter.
340 _ (Underscore.) Followed by one of the command line option let-
341 ters, this will print a message describing the current setting
342 of that option. The setting of the option is not changed.
344 __ (Double underscore.) Like the _ (underscore) command, but takes
345 a long option name rather than a single option letter. You must
346 press RETURN after typing the option name.
348 +cmd Causes the specified cmd to be executed each time a new file is
349 examined. For example, +G causes
\e[4mless
\e[24m to initially display each
350 file starting at the end rather than the beginning.
352 V Prints the version number of
\e[4mless
\e[24m being run.
354 q or Q or :q or :Q or ZZ
355 Exits
\e[4mless.
\e[0m
357 The following four commands may or may not be valid, depending on your
358 particular installation.
361 v Invokes an editor to edit the current file being viewed. The
362 editor is taken from the environment variable VISUAL if defined,
363 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei-
364 ther VISUAL nor EDITOR is defined. See also the discussion of
365 LESSEDIT under the section on PROMPTS below.
368 Invokes a shell to run the shell-command given. A percent sign
369 (%) in the command is replaced by the name of the current file.
370 A pound sign (#) is replaced by the name of the previously exam-
371 ined file. "!!" repeats the last shell command. "!" with no
372 shell command simply invokes a shell. On Unix systems, the
373 shell is taken from the environment variable SHELL, or defaults
374 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
378 <m> represents any mark letter. Pipes a section of the input
379 file to the given shell command. The section of the file to be
380 piped is between the first line on the current screen and the
381 position marked by the letter. <m> may also be ^ or $ to indi-
382 cate beginning or end of file respectively. If <m> is . or new-
383 line, the current screen is piped.
386 Save the input to a file. This only works if the input is a
387 pipe, not an ordinary file.
391 Command line options are described below. Most options may be changed
392 while
\e[4mless
\e[24m is running, via the "-" command.
394 Most options may be given in one of two forms: either a dash followed
395 by a single letter, or two dashes followed by a long option name. A
396 long option name may be abbreviated as long as the abbreviation is
397 unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
398 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
399 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
400 from --quit-at-eof. Such option names need only have their first let-
401 ter capitalized; the remainder of the name may be in either case. For
402 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
404 Options are also taken from the environment variable "LESS". For exam-
405 ple, to avoid typing "less -options ..." each time
\e[4mless
\e[24m is invoked, you
406 might tell
\e[4mcsh:
\e[0m
408 setenv LESS "-options"
410 or if you use
\e[4msh:
\e[0m
412 LESS="-options"; export LESS
414 On MS-DOS, you don't need the quotes, but you should replace any per-
415 cent signs in the options string by double percent signs.
417 The environment variable is parsed before the command line, so command
418 line options override the LESS environment variable. If an option
419 appears in the LESS variable, it can be reset to its default value on
420 the command line by beginning the command line option with "-+".
422 For options like -P or -D which take a following string, a dollar sign
423 ($) must be used to signal the end of the string. For example, to set
424 two -D options on MS-DOS, you must have a dollar sign between them,
431 This option displays a summary of the commands accepted by
\e[4mless
\e[0m
432 (the same as the h command). (Depending on how your shell
433 interprets the question mark, it may be necessary to quote the
434 question mark, thus: "-\?".)
436 -a or --search-skip-screen
437 Causes searches to start after the last line displayed on the
438 screen, thus skipping all lines displayed on the screen. By
439 default, searches start at the second line on the screen (or
440 after the last found line; see the -j option).
442 -b
\e[4mn
\e[24m or --buffers=
\e[4mn
\e[0m
443 Specifies the amount of buffer space
\e[4mless
\e[24m will use for each
444 file, in units of kilobytes (1024 bytes). By default 64K of
445 buffer space is used for each file (unless the file is a pipe;
446 see the -B option). The -b option specifies instead that
\e[4mn
\e[0m
447 kilobytes of buffer space should be used for each file. If
\e[4mn
\e[24m is
448 -1, buffer space is unlimited; that is, the entire file can be
452 By default, when data is read from a pipe, buffers are allocated
453 automatically as needed. If a large amount of data is read from
454 the pipe, this can cause a large amount of memory to be allo-
455 cated. The -B option disables this automatic allocation of
456 buffers for pipes, so that only 64K (or the amount of space
457 specified by the -b option) is used for the pipe. Warning: use
458 of -B can result in erroneous display, since only the most
459 recently viewed part of the piped data is kept in memory; any
460 earlier data is lost.
463 Causes full screen repaints to be painted from the top line
464 down. By default, full screen repaints are done by scrolling
465 from the bottom of the screen.
468 Same as -c, for compatibility with older versions of
\e[4mless.
\e[0m
471 The -d option suppresses the error message normally displayed if
472 the terminal is dumb; that is, lacks some important capability,
473 such as the ability to clear the screen or scroll backward. The
474 -d option does not otherwise change the behavior of
\e[4mless
\e[24m on a
477 -D
\e[1mx
\e[4m
\e[22mcolor
\e[24m or --color=
\e[1mx
\e[4m
\e[22mcolor
\e[0m
478 [MS-DOS only] Sets the color of the text displayed.
\e[1mx
\e[22mis a sin-
479 gle character which selects the type of text whose color is
480 being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
481 \e[4mcolor
\e[24m is a pair of numbers separated by a period. The first
482 number selects the foreground color and the second selects the
483 background color of the text. A single number
\e[4mN
\e[24m is the same as
487 Causes
\e[4mless
\e[24m to automatically exit the second time it reaches
488 end-of-file. By default, the only way to exit
\e[4mless
\e[24m is via the
492 Causes
\e[4mless
\e[24m to automatically exit the first time it reaches end-
496 Forces non-regular files to be opened. (A non-regular file is a
497 directory or a device special file.) Also suppresses the warn-
498 ing message when a binary file is opened. By default,
\e[4mless
\e[24m will
499 refuse to open non-regular files. Note that some operating sys-
500 tems will not allow directories to be read, even if -f is set.
502 -F or --quit-if-one-screen
503 Causes
\e[4mless
\e[24m to automatically exit if the entire file can be dis-
504 played on the first screen.
506 -g or --hilite-search
507 Normally,
\e[4mless
\e[24m will highlight ALL strings which match the last
508 search command. The -g option changes this behavior to high-
509 light only the particular string which was found by the last
510 search command. This can cause
\e[4mless
\e[24m to run somewhat faster than
513 -G or --HILITE-SEARCH
514 The -G option suppresses all highlighting of strings found by
517 -h
\e[4mn
\e[24m or --max-back-scroll=
\e[4mn
\e[0m
518 Specifies a maximum number of lines to scroll backward. If it
519 is necessary to scroll backward more than
\e[4mn
\e[24m lines, the screen is
520 repainted in a forward direction instead. (If the terminal does
521 not have the ability to scroll backward, -h0 is implied.)
524 Causes searches to ignore case; that is, uppercase and lowercase
525 are considered identical. This option is ignored if any upper-
526 case letters appear in the search pattern; in other words, if a
527 pattern contains uppercase letters, then that search does not
531 Like -i, but searches ignore case even if the pattern contains
534 -j
\e[4mn
\e[24m or --jump-target=
\e[4mn
\e[0m
535 Specifies a line on the screen where the "target" line is to be
536 positioned. The target line is the line specified by any com-
537 mand to search for a pattern, jump to a line number, jump to a
538 file percentage or jump to a tag. The screen line may be speci-
539 fied by a number: the top line on the screen is 1, the next is
540 2, and so on. The number may be negative to specify a line rel-
541 ative to the bottom of the screen: the bottom line on the screen
542 is -1, the second to the bottom is -2, and so on. Alternately,
543 the screen line may be specified as a fraction of the height of
544 the screen, starting with a decimal point: .5 is in the middle
545 of the screen, .3 is three tenths down from the first line, and
546 so on. If the line is specified as a fraction, the actual line
547 number is recalculated if the terminal window is resized, so
548 that the target line remains at the specified fraction of the
549 screen height. If any form of the -j option is used, forward
550 searches begin at the line immediately after the target line,
551 and backward searches begin at the target line. For example, if
552 "-j4" is used, the target line is the fourth line on the screen,
553 so forward searches begin at the fifth line on the screen.
555 -J or --status-column
556 Displays a status column at the left edge of the screen. The
557 status column shows the lines that matched the current search.
558 The status column is also used if the -w or -W option is in
561 -k
\e[4mfilename
\e[24m or --lesskey-file=
\e[4mfilename
\e[0m
562 Causes
\e[4mless
\e[24m to open and interpret the named file as a
\e[4mlesskey
\e[0m
563 (1) file. Multiple -k options may be specified. If the LESSKEY
564 or LESSKEY_SYSTEM environment variable is set, or if a lesskey
565 file is found in a standard place (see KEY BINDINGS), it is also
566 used as a
\e[4mlesskey
\e[24m file.
569 Causes
\e[4mless
\e[24m to exit immediately when an interrupt character
570 (usually ^C) is typed. Normally, an interrupt character causes
571 \e[4mless
\e[24m to stop whatever it is doing and return to its command
572 prompt. Note that use of this option makes it impossible to
573 return to the command prompt from the "F" command.
576 Ignore the LESSOPEN environment variable (see the INPUT PREPRO-
577 CESSOR section below). This option can be set from within
\e[4mless
\e[24m,
578 but it will apply only to files opened subsequently, not to the
579 file which is currently open.
582 Causes
\e[4mless
\e[24m to prompt verbosely (like
\e[4mmore
\e[24m), with the percent
583 into the file. By default,
\e[4mless
\e[24m prompts with a colon.
586 Causes
\e[4mless
\e[24m to prompt even more verbosely than
\e[4mmore.
\e[0m
589 Suppresses line numbers. The default (to use line numbers) may
590 cause
\e[4mless
\e[24m to run more slowly in some cases, especially with a
591 very large input file. Suppressing line numbers with the -n
592 option will avoid this problem. Using line numbers means: the
593 line number will be displayed in the verbose prompt and in the =
594 command, and the v command will pass the current line number to
595 the editor (see also the discussion of LESSEDIT in PROMPTS
599 Causes a line number to be displayed at the beginning of each
602 -o
\e[4mfilename
\e[24m or --log-file=
\e[4mfilename
\e[0m
603 Causes
\e[4mless
\e[24m to copy its input to the named file as it is being
604 viewed. This applies only when the input file is a pipe, not an
605 ordinary file. If the file already exists,
\e[4mless
\e[24m will ask for
606 confirmation before overwriting it.
608 -O
\e[4mfilename
\e[24m or --LOG-FILE=
\e[4mfilename
\e[0m
609 The -O option is like -o, but it will overwrite an existing file
610 without asking for confirmation.
612 If no log file has been specified, the -o and -O options can be
613 used from within
\e[4mless
\e[24m to specify a log file. Without a file
614 name, they will simply report the name of the log file. The "s"
615 command is equivalent to specifying -o from within
\e[4mless.
\e[0m
617 -p
\e[4mpattern
\e[24m or --pattern=
\e[4mpattern
\e[0m
618 The -p option on the command line is equivalent to specifying
619 +/
\e[4mpattern
\e[24m; that is, it tells
\e[4mless
\e[24m to start at the first occur-
620 rence of
\e[4mpattern
\e[24m in the file.
622 -P
\e[4mprompt
\e[24m or --prompt=
\e[4mprompt
\e[0m
623 Provides a way to tailor the three prompt styles to your own
624 preference. This option would normally be put in the LESS envi-
625 ronment variable, rather than being typed in with each
\e[4mless
\e[24m com-
626 mand. Such an option must either be the last option in the LESS
627 variable, or be terminated by a dollar sign. -Ps followed by a
628 string changes the default (short) prompt to that string. -Pm
629 changes the medium (-m) prompt. -PM changes the long (-M)
630 prompt. -Ph changes the prompt for the help screen. -P=
631 changes the message printed by the = command. -Pw changes the
632 message printed while waiting for data (in the F command). All
633 prompt strings consist of a sequence of letters and special
634 escape sequences. See the section on PROMPTS for more details.
636 -q or --quiet or --silent
637 Causes moderately "quiet" operation: the terminal bell is not
638 rung if an attempt is made to scroll past the end of the file or
639 before the beginning of the file. If the terminal has a "visual
640 bell", it is used instead. The bell will be rung on certain
641 other errors, such as typing an invalid character. The default
642 is to ring the terminal bell in all such cases.
644 -Q or --QUIET or --SILENT
645 Causes totally "quiet" operation: the terminal bell is never
648 -r or --raw-control-chars
649 Causes "raw" control characters to be displayed. The default is
650 to display control characters using the caret notation; for
651 example, a control-A (octal 001) is displayed as "^A". Warning:
652 when the -r option is used,
\e[4mless
\e[24m cannot keep track of the actual
653 appearance of the screen (since this depends on how the screen
654 responds to each type of control character). Thus, various dis-
655 play problems may result, such as long lines being split in the
658 -R or --RAW-CONTROL-CHARS
659 Like -r, but only ANSI "color" escape sequences are output in
660 "raw" form. Unlike -r, the screen appearance is maintained cor-
661 rectly in most cases. ANSI "color" escape sequences are
662 sequences of the form:
666 where the "..." is zero or more color specification characters
667 For the purpose of keeping track of screen appearance, ANSI
668 color escape sequences are assumed to not move the cursor. You
669 can make
\e[4mless
\e[24m think that characters other than "m" can end ANSI
670 color escape sequences by setting the environment variable
671 LESSANSIENDCHARS to the list of characters which can end a color
672 escape sequence. And you can make
\e[4mless
\e[24m think that characters
673 other than the standard ones may appear between the ESC and the
674 m by setting the environment variable LESSANSIMIDCHARS to the
675 list of characters which can appear.
677 -s or --squeeze-blank-lines
678 Causes consecutive blank lines to be squeezed into a single
679 blank line. This is useful when viewing
\e[4mnroff
\e[24m output.
681 -S or --chop-long-lines
682 Causes lines longer than the screen width to be chopped rather
683 than folded. That is, the portion of a long line that does not
684 fit in the screen width is not shown. The default is to fold
685 long lines; that is, display the remainder on the next line.
687 -t
\e[4mtag
\e[24m or --tag=
\e[4mtag
\e[0m
688 The -t option, followed immediately by a TAG, will edit the file
689 containing that tag. For this to work, tag information must be
690 available; for example, there may be a file in the current
691 directory called "tags", which was previously built by
\e[4mctags
\e[24m (1)
692 or an equivalent command. If the environment variable LESSGLOB-
693 ALTAGS is set, it is taken to be the name of a command compati-
694 ble with
\e[4mglobal
\e[24m (1), and that command is executed to find the
695 tag. (See http://www.gnu.org/software/global/global.html). The
696 -t option may also be specified from within
\e[4mless
\e[24m (using the -
697 command) as a way of examining a new file. The command ":t" is
698 equivalent to specifying -t from within
\e[4mless.
\e[0m
700 -T
\e[4mtagsfile
\e[24m or --tag-file=
\e[4mtagsfile
\e[0m
701 Specifies a tags file to be used instead of "tags".
703 -u or --underline-special
704 Causes backspaces and carriage returns to be treated as print-
705 able characters; that is, they are sent to the terminal when
706 they appear in the input.
708 -U or --UNDERLINE-SPECIAL
709 Causes backspaces, tabs and carriage returns to be treated as
710 control characters; that is, they are handled as specified by
713 By default, if neither -u nor -U is given, backspaces which
714 appear adjacent to an underscore character are treated spe-
715 cially: the underlined text is displayed using the terminal's
716 hardware underlining capability. Also, backspaces which appear
717 between two identical characters are treated specially: the
718 overstruck text is printed using the terminal's hardware bold-
719 face capability. Other backspaces are deleted, along with the
720 preceding character. Carriage returns immediately followed by a
721 newline are deleted. other carriage returns are handled as
722 specified by the -r option. Text which is overstruck or under-
723 lined can be searched for if neither -u nor -U is in effect.
726 Displays the version number of
\e[4mless.
\e[0m
728 -w or --hilite-unread
729 Temporarily highlights the first "new" line after a forward
730 movement of a full page. The first "new" line is the line imme-
731 diately following the line previously at the bottom of the
732 screen. Also highlights the target line after a g or p command.
733 The highlight is removed at the next command which causes move-
734 ment. The entire line is highlighted, unless the -J option is
735 in effect, in which case only the status column is highlighted.
737 -W or --HILITE-UNREAD
738 Like -w, but temporarily highlights the first new line after any
739 forward movement command larger than one line.
741 -x
\e[4mn
\e[24m,... or --tabs=
\e[4mn
\e[24m,...
742 Sets tab stops. If only one
\e[4mn
\e[24m is specified, tab stops are set
743 at multiples of
\e[4mn
\e[24m. If multiple values separated by commas are
744 specified, tab stops are set at those positions, and then con-
745 tinue with the same spacing as the last two. For example,
746 \e[4m-x9,17
\e[24m will set tabs at positions 9, 17, 25, 33, etc. The
747 default for
\e[4mn
\e[24m is 8.
750 Disables sending the termcap initialization and deinitialization
751 strings to the terminal. This is sometimes desirable if the
752 deinitialization string does something unnecessary, like clear-
755 -y
\e[4mn
\e[24m or --max-forw-scroll=
\e[4mn
\e[0m
756 Specifies a maximum number of lines to scroll forward. If it is
757 necessary to scroll forward more than
\e[4mn
\e[24m lines, the screen is
758 repainted instead. The -c or -C option may be used to repaint
759 from the top of the screen if desired. By default, any forward
760 movement causes scrolling.
762 -[z]
\e[4mn
\e[24m or --window=
\e[4mn
\e[0m
763 Changes the default scrolling window size to
\e[4mn
\e[24m lines. The
764 default is one screenful. The z and w commands can also be used
765 to change the window size. The "z" may be omitted for compati-
766 bility with some versions of
\e[4mmore.
\e[24m If the number
\e[4mn
\e[24m is negative,
767 it indicates
\e[4mn
\e[24m lines less than the current screen size. For
768 example, if the screen is 24 lines,
\e[4m-z-4
\e[24m sets the scrolling win-
769 dow to 20 lines. If the screen is resized to 40 lines, the
770 scrolling window automatically changes to 36 lines.
772 -
\e[4m"cc
\e[24m or --quotes=
\e[4mcc
\e[0m
773 Changes the filename quoting character. This may be necessary
774 if you are trying to name a file which contains both spaces and
775 quote characters. Followed by a single character, this changes
776 the quote character to that character. Filenames containing a
777 space should then be surrounded by that character rather than by
778 double quotes. Followed by two characters, changes the open
779 quote to the first character, and the close quote to the second
780 character. Filenames containing a space should then be preceded
781 by the open quote character and followed by the close quote
782 character. Note that even after the quote characters are
783 changed, this option remains -" (a dash followed by a double
787 Normally lines after end of file are displayed as a single tilde
788 (~). This option causes lines after end of file to be displayed
792 Specifies the default number of positions to scroll horizontally
793 in the RIGHTARROW and LEFTARROW commands. If the number speci-
794 fied is zero, it sets the default number of positions to one
795 half of the screen width.
798 Disables sending the keypad initialization and deinitialization
799 strings to the terminal. This is sometimes useful if the keypad
800 strings make the numeric keypad behave in an undesirable manner.
803 Normally, if the input file is renamed while an F command is
804 executing,
\e[4mless
\e[24m will continue to display the contents of the
805 original file despite its name change. If --follow-name is
806 specified, during an F command
\e[4mless
\e[24m will periodically attempt to
807 reopen the file by name. If the reopen succeeds and the file is
808 a different file from the original (which means that a new file
809 has been created with the same name as the original (now
810 renamed) file),
\e[4mless
\e[24m will display the contents of that new file.
812 -- A command line argument of "--" marks the end of option argu-
813 ments. Any arguments following this are interpreted as file-
814 names. This can be useful when viewing a file whose name begins
817 + If a command line option begins with
\e[1m+
\e[22m, the remainder of that
818 option is taken to be an initial command to
\e[4mless.
\e[24m For example,
819 +G tells
\e[4mless
\e[24m to start at the end of the file rather than the
820 beginning, and +/xyz tells it to start at the first occurrence
821 of "xyz" in the file. As a special case, +<number> acts like
822 +<number>g; that is, it starts the display at the specified line
823 number (however, see the caveat under the "g" command above).
824 If the option starts with ++, the initial command applies to
825 every file being viewed, not just the first one. The + command
826 described previously may also be used to set (or change) an ini-
827 tial command for every file.
830 \e[1mLINE EDITING
\e[0m
831 When entering command line at the bottom of the screen (for example, a
832 filename for the :e command, or the pattern for a search command), cer-
833 tain keys can be used to manipulate the command line. Most commands
834 have an alternate form in [ brackets ] which can be used if a key does
835 not exist on a particular keyboard. (The bracketed forms do not work
836 in the MS-DOS version.) Any of these special keys may be entered lit-
837 erally by preceding it with the "literal" character, either ^V or ^A.
838 A backslash itself may also be entered literally by entering two back-
842 Move the cursor one space to the left.
845 Move the cursor one space to the right.
847 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
848 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur-
849 sor one word to the left.
851 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
852 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur-
853 sor one word to the right.
856 Move the cursor to the beginning of the line.
859 Move the cursor to the end of the line.
862 Delete the character to the left of the cursor, or cancel the
863 command if the command line is empty.
866 Delete the character under the cursor.
868 ^BACKSPACE [ ESC-BACKSPACE ]
869 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
870 word to the left of the cursor.
872 ^DELETE [ ESC-X or ESC-DELETE ]
873 (That is, CONTROL and DELETE simultaneously.) Delete the word
877 Retrieve the previous command line.
880 Retrieve the next command line.
882 TAB Complete the partial filename to the left of the cursor. If it
883 matches more than one filename, the first match is entered into
884 the command line. Repeated TABs will cycle thru the other
885 matching filenames. If the completed filename is a directory, a
886 "/" is appended to the filename. (On MS-DOS systems, a "\" is
887 appended.) The environment variable LESSSEPARATOR can be used
888 to specify a different character to append to a directory name.
891 Like, TAB, but cycles in the reverse direction thru the matching
894 ^L Complete the partial filename to the left of the cursor. If it
895 matches more than one filename, all matches are entered into the
896 command line (if they fit).
898 ^U (Unix and OS/2) or ESC (MS-DOS)
899 Delete the entire command line, or cancel the command if the
900 command line is empty. If you have changed your line-kill char-
901 acter in Unix to something other than ^U, that character is used
905 \e[1mKEY BINDINGS
\e[0m
906 You may define your own
\e[4mless
\e[24m commands by using the program
\e[4mlesskey
\e[24m (1)
907 to create a lesskey file. This file specifies a set of command keys
908 and an action associated with each key. You may also use
\e[4mlesskey
\e[24m to
909 change the line-editing keys (see LINE EDITING), and to set environment
910 variables. If the environment variable LESSKEY is set,
\e[4mless
\e[24m uses that
911 as the name of the lesskey file. Otherwise,
\e[4mless
\e[24m looks in a standard
912 place for the lesskey file: On Unix systems,
\e[4mless
\e[24m looks for a lesskey
913 file called "$HOME/.less". On MS-DOS and Windows systems,
\e[4mless
\e[24m looks
914 for a lesskey file called "$HOME/_less", and if it is not found there,
915 then looks for a lesskey file called "_less" in any directory specified
916 in the PATH environment variable. On OS/2 systems,
\e[4mless
\e[24m looks for a
917 lesskey file called "$HOME/less.ini", and if it is not found, then
918 looks for a lesskey file called "less.ini" in any directory specified
919 in the INIT environment variable, and if it not found there, then looks
920 for a lesskey file called "less.ini" in any directory specified in the
921 PATH environment variable. See the
\e[4mlesskey
\e[24m manual page for more
924 A system-wide lesskey file may also be set up to provide key bindings.
925 If a key is defined in both a local lesskey file and in the system-wide
926 file, key bindings in the local file take precedence over those in the
927 system-wide file. If the environment variable LESSKEY_SYSTEM is set,
928 \e[4mless
\e[24m uses that as the name of the system-wide lesskey file. Otherwise,
929 \e[4mless
\e[24m looks in a standard place for the system-wide lesskey file: On
930 Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
931 (However, if
\e[4mless
\e[24m was built with a different sysconf directory than
932 /usr/local/etc, that directory is where the sysless file is found.) On
933 MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys-
934 less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
937 \e[1mINPUT PREPROCESSOR
\e[0m
938 You may define an "input preprocessor" for
\e[4mless.
\e[24m Before
\e[4mless
\e[24m opens a
939 file, it first gives your input preprocessor a chance to modify the way
940 the contents of the file are displayed. An input preprocessor is sim-
941 ply an executable program (or shell script), which writes the contents
942 of the file to a different file, called the replacement file. The con-
943 tents of the replacement file are then displayed in place of the con-
944 tents of the original file. However, it will appear to the user as if
945 the original file is opened; that is,
\e[4mless
\e[24m will display the original
946 filename as the name of the current file.
948 An input preprocessor receives one command line argument, the original
949 filename, as entered by the user. It should create the replacement
950 file, and when finished, print the name of the replacement file to its
951 standard output. If the input preprocessor does not output a replace-
952 ment filename,
\e[4mless
\e[24m uses the original file, as normal. The input pre-
953 processor is not called when viewing standard input. To set up an
954 input preprocessor, set the LESSOPEN environment variable to a command
955 line which will invoke your input preprocessor. This command line
956 should include one occurrence of the string "%s", which will be
957 replaced by the filename when the input preprocessor command is
960 When
\e[4mless
\e[24m closes a file opened in such a way, it will call another pro-
961 gram, called the input postprocessor, which may perform any desired
962 clean-up action (such as deleting the replacement file created by
963 LESSOPEN). This program receives two command line arguments, the orig-
964 inal filename as entered by the user, and the name of the replacement
965 file. To set up an input postprocessor, set the LESSCLOSE environment
966 variable to a command line which will invoke your input postprocessor.
967 It may include two occurrences of the string "%s"; the first is
968 replaced with the original name of the file and the second with the
969 name of the replacement file, which was output by LESSOPEN.
971 For example, on many Unix systems, these two scripts will allow you to
972 keep files in compressed format, but still let
\e[4mless
\e[24m view them directly:
978 if [ -s /tmp/less.$$ ]; then
990 To use these scripts, put them both where they can be executed and set
991 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
992 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
993 types of compressed files, and so on.
995 It is also possible to set up an input preprocessor to pipe the file
996 data directly to
\e[4mless,
\e[24m rather than putting the data into a replacement
997 file. This avoids the need to decompress the entire file before start-
998 ing to view it. An input preprocessor that works this way is called an
999 input pipe. An input pipe, instead of writing the name of a replace-
1000 ment file on its standard output, writes the entire contents of the
1001 replacement file on its standard output. If the input pipe does not
1002 write any characters on its standard output, then there is no replace-
1003 ment file and
\e[4mless
\e[24m uses the original file, as normal. To use an input
1004 pipe, make the first character in the LESSOPEN environment variable a
1005 vertical bar (|) to signify that the input preprocessor is an input
1008 For example, on many Unix systems, this script will work like the pre-
1009 vious example scripts:
1014 *.Z) uncompress -c $1 2>/dev/null
1018 To use this script, put it where it can be executed and set
1019 LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE
1020 postprocessor can be used, but it is usually not necessary since there
1021 is no replacement file to clean up. In this case, the replacement file
1022 name passed to the LESSCLOSE postprocessor is "-".
1025 \e[1mNATIONAL CHARACTER SETS
\e[0m
1026 There are three types of characters in the input file:
1029 can be displayed directly to the screen.
1032 should not be displayed directly, but are expected to be found
1033 in ordinary text files (such as backspace and tab).
1036 should not be displayed directly and are not expected to be
1037 found in text files.
1039 A "character set" is simply a description of which characters are to be
1040 considered normal, control, and binary. The LESSCHARSET environment
1041 variable may be used to select a character set. Possible values for
1044 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1045 with values between 32 and 126 are normal, and all others are
1049 Selects an ISO 8859 character set. This is the same as ASCII,
1050 except characters between 160 and 255 are treated as normal
1053 latin1 Same as iso8859.
1055 latin9 Same as iso8859.
1057 dos Selects a character set appropriate for MS-DOS.
1059 ebcdic Selects an EBCDIC character set.
1062 Selects an EBCDIC character set used by OS/390 Unix Services.
1063 This is the EBCDIC analogue of latin1. You get similar results
1064 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1067 koi8-r Selects a Russian character set.
1069 next Selects a character set appropriate for NeXT computers.
1071 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1072 UTF-8 is special in that it supports multi-byte characters in
1073 the input file. It is the only character set that supports
1074 multi-byte characters.
1077 Selects a character set appropriate for Microsoft Windows (cp
1080 In special cases, it may be desired to tailor
\e[4mless
\e[24m to use a character
1081 set other than the ones definable by LESSCHARSET. In this case, the
1082 environment variable LESSCHARDEF can be used to define a character set.
1083 It should be set to a string where each character in the string repre-
1084 sents one character in the character set. The character "." is used
1085 for a normal character, "c" for control, and "b" for binary. A decimal
1086 number may be used for repetition. For example, "bccc4b." would mean
1087 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
1088 binary, and 8 is normal. All characters after the last are taken to be
1089 the same as the last, so characters 9 through 255 would be normal.
1090 (This is an example, and does not necessarily represent any real char-
1093 This table shows the value of LESSCHARDEF which is equivalent to each
1094 of the possible values for LESSCHARSET:
1096 ascii 8bcccbcc18b95.b
1097 dos 8bcccbcc12bc5b95.b.
1098 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1099 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1100 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1102 iso8859 8bcccbcc18b95.33b.
1103 koi8-r 8bcccbcc18b95.b128.
1104 latin1 8bcccbcc18b95.33b.
1105 next 8bcccbcc18b95.bb125.bb
1107 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1108 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_TYPE or
1109 LANG environment variables, then the default character set is utf-8.
1111 If that string is not found, but your system supports the
\e[4msetlocale
\e[0m
1112 interface,
\e[4mless
\e[24m will use setlocale to determine the character set.
1113 setlocale is controlled by setting the LANG or LC_CTYPE environment
1116 Finally, if the
\e[4msetlocale
\e[24m interface is also not available, the default
1117 character set is latin1.
1119 Control and binary characters are displayed in standout (reverse
1120 video). Each such character is displayed in caret notation if possible
1121 (e.g. ^A for control-A). Caret notation is used only if inverting the
1122 0100 bit results in a normal printable character. Otherwise, the char-
1123 acter is displayed as a hex number in angle brackets. This format can
1124 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1125 may begin with a "*" and one character to select the display attribute:
1126 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1127 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1128 attribute is assumed. The remainder of LESSBINFMT is a string which
1129 may include one printf-style escape sequence (a % followed by x, X, o,
1130 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1131 are displayed in underlined hexadecimal surrounded by brackets. The
1132 default if no LESSBINFMT is specified is "*s<%X>". The default if no
1133 LESSBINFMT is specified is "*s<%02X>". Warning: the result of expand-
1134 ing the character via LESSBINFMT must be less than 31 characters.
1136 When the character set is utf-8, the LESSUTFBINFMT environment variable
1137 acts similarly to LESSBINFMT but it applies to Unicode code points that
1138 were successfully decoded but are unsuitable for display (e.g., unas-
1139 signed code points). Its default value is "<U+%04lX>". Note that
1140 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1141 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1142 LESSBINFMT so its setting, if any, will have priority. Problematic
1143 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1144 complete but non-shortest form sequence, illegal octets, and stray
1145 trailing octets) are displayed individually using LESSBINFMT so as to
1146 facilitate diagnostic of how the UTF-8 file is ill-formed.
1150 The -P option allows you to tailor the prompt to your preference. The
1151 string given to the -P option replaces the specified prompt string.
1152 Certain characters in the string are interpreted specially. The prompt
1153 mechanism is rather complicated to provide flexibility, but the ordi-
1154 nary user need not understand the details of constructing personalized
1157 A percent sign followed by a single character is expanded according to
1158 what the following character is:
1160 %b
\e[4mX
\e[24m Replaced by the byte offset into the current input file. The b
1161 is followed by a single character (shown as
\e[4mX
\e[24m above) which spec-
1162 ifies the line whose byte offset is to be used. If the charac-
1163 ter is a "t", the byte offset of the top line in the display is
1164 used, an "m" means use the middle line, a "b" means use the bot-
1165 tom line, a "B" means use the line just after the bottom line,
1166 and a "j" means use the "target" line, as specified by the -j
1169 %B Replaced by the size of the current input file.
1171 %c Replaced by the column number of the text appearing in the first
1172 column of the screen.
1174 %d
\e[4mX
\e[24m Replaced by the page number of a line in the input file. The
1175 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1177 %D Replaced by the number of pages in the input file, or equiva-
1178 lently, the page number of the last line in the input file.
1180 %E Replaced by the name of the editor (from the VISUAL environment
1181 variable, or the EDITOR environment variable if VISUAL is not
1182 defined). See the discussion of the LESSEDIT feature below.
1184 %f Replaced by the name of the current input file.
1186 %i Replaced by the index of the current file in the list of input
1189 %l
\e[4mX
\e[24m Replaced by the line number of a line in the input file. The
1190 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1192 %L Replaced by the line number of the last line in the input file.
1194 %m Replaced by the total number of input files.
1196 %p
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1197 byte offsets. The line used is determined by the
\e[4mX
\e[24m as with the
1200 %P
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1201 line numbers. The line used is determined by the
\e[4mX
\e[24m as with the
1206 %t Causes any trailing spaces to be removed. Usually used at the
1207 end of the string, but may appear anywhere.
1209 %x Replaced by the name of the next input file in the list.
1211 If any item is unknown (for example, the file size if input is a pipe),
1212 a question mark is printed instead.
1214 The format of the prompt string can be changed depending on certain
1215 conditions. A question mark followed by a single character acts like
1216 an "IF": depending on the following character, a condition is evalu-
1217 ated. If the condition is true, any characters following the question
1218 mark and condition character, up to a period, are included in the
1219 prompt. If the condition is false, such characters are not included.
1220 A colon appearing between the question mark and the period can be used
1221 to establish an "ELSE": any characters between the colon and the period
1222 are included in the string if and only if the IF condition is false.
1223 Condition characters (which follow a question mark) may be:
1225 ?a True if any characters have been included in the prompt so far.
1227 ?b
\e[4mX
\e[24m True if the byte offset of the specified line is known.
1229 ?B True if the size of current input file is known.
1231 ?c True if the text is horizontally shifted (%c is not zero).
1233 ?d
\e[4mX
\e[24m True if the page number of the specified line is known.
1235 ?e True if at end-of-file.
1237 ?f True if there is an input filename (that is, if input is not a
1240 ?l
\e[4mX
\e[24m True if the line number of the specified line is known.
1242 ?L True if the line number of the last line in the file is known.
1244 ?m True if there is more than one input file.
1246 ?n True if this is the first prompt in a new input file.
1248 ?p
\e[4mX
\e[24m True if the percent into the current input file, based on byte
1249 offsets, of the specified line is known.
1251 ?P
\e[4mX
\e[24m True if the percent into the current input file, based on line
1252 numbers, of the specified line is known.
1256 ?x True if there is a next input file (that is, if the current
1257 input file is not the last one).
1259 Any characters other than the special ones (question mark, colon,
1260 period, percent, and backslash) become literally part of the prompt.
1261 Any of the special characters may be included in the prompt literally
1262 by preceding it with a backslash.
1266 ?f%f:Standard input.
1268 This prompt prints the filename, if known; otherwise the string "Stan-
1271 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1273 This prompt would print the filename, if known. The filename is fol-
1274 lowed by the line number, if known, otherwise the percent if known,
1275 otherwise the byte offset if known. Otherwise, a dash is printed.
1276 Notice how each question mark has a matching period, and how the %
1277 after the %pt is included literally by escaping it with a backslash.
1279 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
1281 This prints the filename if this is the first prompt in a file, fol-
1282 lowed by the "file N of N" message if there is more than one input
1283 file. Then, if we are at end-of-file, the string "(END)" is printed
1284 followed by the name of the next file, if there is one. Finally, any
1285 trailing spaces are truncated. This is the default prompt. For refer-
1286 ence, here are the defaults for the other two prompts (-m and -M
1287 respectively). Each is broken into two lines here for readability
1290 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
1291 ?pB%pB\%:byte %bB?s/%s...%t
1293 ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
1294 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1296 And here is the default message produced by the = command:
1298 ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1299 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1301 The prompt expansion features are also used for another purpose: if an
1302 environment variable LESSEDIT is defined, it is used as the command to
1303 be executed when the v command is invoked. The LESSEDIT string is
1304 expanded in the same way as the prompt strings. The default value for
1309 Note that this expands to the editor name, followed by a + and the line
1310 number, followed by the file name. If your editor does not accept the
1311 "+linenumber" syntax, or has other differences in invocation syntax,
1312 the LESSEDIT variable can be changed to modify this default.
1316 When the environment variable LESSSECURE is set to 1,
\e[4mless
\e[24m runs in a
1317 "secure" mode. This means these features are disabled:
1323 :e the examine command.
1325 v the editing command
1329 -k use of lesskey files
1331 -t use of tags files
1333 metacharacters in filenames, such as *
1335 filename completion (TAB, ^L)
1337 Less can also be compiled to be permanently in "secure" mode.
1340 \e[1mCOMPATIBILITY WITH MORE
\e[0m
1341 If the environment variable LESS_IS_MORE is set to 1, or if the program
1342 is invoked via a file link named "more",
\e[4mless
\e[24m behaves (mostly) in con-
1343 formance with the POSIX "more" command specification. In this mode,
1344 less behaves differently in these ways:
1346 The -e option works differently. If the -e option is not set,
\e[4mless
\e[0m
1347 behaves as if the -E option were set. If the -e option is set,
\e[4mless
\e[0m
1348 behaves as if the -e and -F options were set.
1350 The -m option works differently. If the -m option is not set, the
1351 medium prompt is used, and it is prefixed with the string "--More--".
1352 If the -m option is set, the short prompt is used.
1354 The -n option acts like the -z option. The normal behavior of the -n
1355 option is unavailable in this mode.
1357 The parameter to the -p option is taken to be a
\e[4mless
\e[24m command rather
1358 than a search pattern.
1360 The LESS environment variable is ignored, and the MORE environment
1361 variable is used in its place.
1364 \e[1mENVIRONMENT VARIABLES
\e[0m
1365 Environment variables may be specified either in the system environment
1366 as usual, or in a
\e[4mlesskey
\e[24m (1) file. If environment variables are
1367 defined in more than one place, variables defined in a local lesskey
1368 file take precedence over variables defined in the system environment,
1369 which take precedence over variables defined in the system-wide lesskey
1373 Sets the number of columns on the screen. Takes precedence over
1374 the number of columns specified by the TERM variable. (But if
1375 you have a windowing system which supports TIOCGWINSZ or
1376 WIOCGETD, the window system's idea of the screen size takes
1377 precedence over the LINES and COLUMNS environment variables.)
1379 EDITOR The name of the editor (used for the v command).
1381 HOME Name of the user's home directory (used to find a lesskey file
1382 on Unix and OS/2 systems).
1385 Concatenation of the HOMEDRIVE and HOMEPATH environment vari-
1386 ables is the name of the user's home directory if the HOME vari-
1387 able is not set (only in the Windows version).
1389 INIT Name of the user's init directory (used to find a lesskey file
1392 LANG Language for determining the character set.
1395 Language for determining the character set.
1397 LESS Options which are passed to
\e[4mless
\e[24m automatically.
1400 Characters which may end an ANSI color escape sequence (default
1404 Characters which may appear between the ESC character and the
1405 end character in an ANSI color escape sequence (default
1406 "0123456789;[?!"'#%()*+ ".
1409 Format for displaying non-printable, non-control characters.
1412 Defines a character set.
1415 Selects a predefined character set.
1418 Command line to invoke the (optional) input-postprocessor.
1421 Name of the lessecho program (default "lessecho"). The lessecho
1422 program is needed to expand metacharacters, such as * and ?, in
1423 filenames on Unix systems.
1426 Editor prototype string (used for the v command). See discus-
1430 Name of the command used by the -t option to find global tags.
1431 Normally should be set to "global" if your system has the
\e[4mglobal
\e[0m
1432 (1) command. If not set, global tags are not used.
1435 Name of the history file used to remember search commands and
1436 shell commands between invocations of
\e[4mless.
\e[24m If set to "-" or
1437 "/dev/null", a history file is not used. The default is
1438 "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
1439 Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1443 The maximum number of commands to save in the history file. The
1447 Name of the default lesskey(1) file.
1450 Name of the default system-wide lesskey(1) file.
1453 List of characters which are considered "metacharacters" by the
1457 Prefix which less will add before each metacharacter in a com-
1458 mand sent to the shell. If LESSMETAESCAPE is an empty string,
1459 commands containing metacharacters will not be passed to the
1463 Command line to invoke the (optional) input-preprocessor.
1466 Runs less in "secure" mode. See discussion under SECURITY.
1469 String to be appended to a directory name in filename comple-
1473 Format for displaying non-printable Unicode code points.
1476 Emulate the
\e[4mmore
\e[24m (1) command.
1478 LINES Sets the number of lines on the screen. Takes precedence over
1479 the number of lines specified by the TERM variable. (But if you
1480 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1481 the window system's idea of the screen size takes precedence
1482 over the LINES and COLUMNS environment variables.)
1484 PATH User's search path (used to find a lesskey file on MS-DOS and
1487 SHELL The shell used to execute the ! command, as well as to expand
1490 TERM The type of terminal on which
\e[4mless
\e[24m is being run.
1492 VISUAL The name of the editor (used for the v command).
1500 The = command and prompts (unless changed by -P) report the line num-
1501 bers of the lines at the top and bottom of the screen, but the byte and
1502 percent of the line after the one at the bottom of the screen.
1504 On certain older terminals (the so-called "magic cookie" terminals),
1505 search highlighting will cause an erroneous display. On such termi-
1506 nals, search highlighting is disabled by default to avoid possible
1509 When searching in a binary file, text which follows a null byte may not
1510 be found. This problem does not occur when searching with regular
1511 expressions turned off via ^R, and also does not occur when
\e[4mless
\e[24m is
1512 compiled to use the PCRE regular expression library.
1514 In certain cases, when search highlighting is enabled and a search pat-
1515 tern begins with a ^, more text than the matching string may be high-
1516 lighted. (This problem does not occur when less is compiled to use the
1517 POSIX regular expression package.)
1519 On some systems,
\e[4msetlocale
\e[24m claims that ASCII characters 0 thru 31 are
1520 control characters rather than binary characters. This causes
\e[4mless
\e[24m to
1521 treat some binary files as ordinary, non-binary files. To workaround
1522 this problem, set the environment variable LESSCHARSET to "ascii" (or
1523 whatever character set is appropriate).
1525 This manual is too long.
1527 See http://www.greenwoodsoftware.com/less for the latest list of known
1532 Copyright (C) 1984-2007 Mark Nudelman
1534 less is part of the GNU project and is free software. You can redis-
1535 tribute it and/or modify it under the terms of either (1) the GNU Gen-
1536 eral Public License as published by the Free Software Foundation; or
1537 (2) the Less License. See the file README in the less distribution for
1538 more details regarding redistribution. You should have received a copy
1539 of the GNU General Public License along with the source for less; see
1540 the file COPYING. If not, write to the Free Software Foundation, 59
1541 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
1542 have received a copy of the Less License; see the file LICENSE.
1544 less is distributed in the hope that it will be useful, but WITHOUT ANY
1545 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT-
1546 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
1551 Mark Nudelman <markn@greenwoodsoftware.com>
1552 Send bug reports or comments to the above address or to
1554 For more information, see the less homepage at
1555 http://www.greenwoodsoftware.com/less.
1559 Version 416: 22 Nov 2007 LESS(1)