1LESS(1) General Commands Manual LESS(1)
2
6 less - opposite of more
7
9 less -?
10 less --help
11 less -V
12 less --version
13 less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
14 [-b space] [-h lines] [-j line] [-k keyfile]
15 [-{oO} logfile] [-p pattern] [-P prompt] [-t tag]
16 [-T tagsfile] [-x tab,...] [-y lines] [-[z] lines]
17 [-# shift] [+[+]cmd] [--] [filename]...
18 (See the OPTIONS section for alternate option syntax with long option
19 names.)
20
22 Less is a program similar to more(1), but which allows backward move‐
23 ment in the file as well as forward movement. Also, less does not have
24 to read the entire input file before starting, so with large input
25 files it starts up faster than text editors like vi(1). Less uses
26 termcap (or terminfo on some systems), so it can run on a variety of
27 terminals. There is even limited support for hardcopy terminals. (On
28 a hardcopy terminal, lines which should be printed at the top of the
29 screen are prefixed with a caret.)
30 Commands are based on both more and vi. Commands may be preceded by a
32 decimal number, called N in the descriptions below. The number is used
33 by some commands, as indicated.
34
36 In the following descriptions, ^X means control-X. ESC stands for the
37 ESCAPE key; for example ESC-v means the two character sequence "ES‐
38 CAPE", then "v".
39 h or H Help: display a summary of these commands. If you forget all
41 the other commands, remember this one.
42 SPACE or ^V or f or ^F
44 Scroll forward N lines, default one window (see option -z be‐
45 low). If N is more than the screen size, only the final screen‐
46 ful is displayed. Warning: some systems use ^V as a special
47 literalization character.
48 z Like SPACE, but if N is specified, it becomes the new window
50 size.
51 ESC-SPACE
53 Like SPACE, but scrolls a full screenful, even if it reaches
54 end-of-file in the process.
55 ENTER or RETURN or ^N or e or ^E or j or ^J
57 Scroll forward N lines, default 1. The entire N lines are dis‐
58 played, even if N is more than the screen size.
59 d or ^D
61 Scroll forward N lines, default one half of the screen size. If
62 N is specified, it becomes the new default for subsequent d and
63 u commands.
64 b or ^B or ESC-v
66 Scroll backward N lines, default one window (see option -z be‐
67 low). If N is more than the screen size, only the final screen‐
68 ful is displayed.
69 w Like ESC-v, but if N is specified, it becomes the new window
71 size.
72 y or ^Y or ^P or k or ^K
74 Scroll backward N lines, default 1. The entire N lines are dis‐
75 played, even if N is more than the screen size. Warning: some
76 systems use ^Y as a special job control character.
77 u or ^U
79 Scroll backward N lines, default one half of the screen size.
80 If N is specified, it becomes the new default for subsequent d
81 and u commands.
82 J Like j, but continues to scroll beyond the end of the file.
84 K or Y Like k, but continues to scroll beyond the beginning of the
86 file.
87 ESC-) or RIGHTARROW
89 Scroll horizontally right N characters, default half the screen
90 width (see the -# option). If a number N is specified, it be‐
91 comes the default for future RIGHTARROW and LEFTARROW commands.
92 While the text is scrolled, it acts as though the -S option
93 (chop lines) were in effect.
94 ESC-( or LEFTARROW
96 Scroll horizontally left N characters, default half the screen
97 width (see the -# option). If a number N is specified, it be‐
98 comes the default for future RIGHTARROW and LEFTARROW commands.
99 ESC-} or ^RIGHTARROW
101 Scroll horizontally right to show the end of the longest dis‐
102 played line.
103 ESC-{ or ^LEFTARROW
105 Scroll horizontally left back to the first column.
106 r or ^R or ^L
108 Repaint the screen.
109 R Repaint the screen, discarding any buffered input. That is,
111 reload the current file. Useful if the file is changing while
112 it is being viewed.
113 F Scroll forward, and keep trying to read when the end of file is
115 reached. Normally this command would be used when already at
116 the end of the file. It is a way to monitor the tail of a file
117 which is growing while it is being viewed. (The behavior is
118 similar to the "tail -f" command.) To stop waiting for more
119 data, enter the interrupt character (usually ^C). On systems
120 which support poll(1) you can also use ^X or the character spec‐
121 ified by the --intr option. If the input is a pipe and the
122 --exit-follow-on-close option is in effect, less will automati‐
123 cally stop waiting for data when the input side of the pipe is
124 closed.
125 ESC-F Like F, but as soon as a line is found which matches the last
127 search pattern, the terminal bell is rung and forward scrolling
128 stops.
129 g or < or ESC-<
131 Go to line N in the file, default 1 (beginning of file). (Warn‐
132 ing: this may be slow if N is large.)
133 G or > or ESC->
135 Go to line N in the file, default the end of the file. (Warn‐
136 ing: this may be slow if N is large, or if N is not specified
137 and standard input, rather than a file, is being read.)
138 ESC-G Same as G, except if no number N is specified and the input is
140 standard input, goes to the last line which is currently
141 buffered.
142 p or % Go to a position N percent into the file. N should be between 0
144 and 100, and may contain a decimal point.
145 P Go to the line containing byte offset N in the file.
147 { If a left curly bracket appears in the top line displayed on the
149 screen, the { command will go to the matching right curly
150 bracket. The matching right curly bracket is positioned on the
151 bottom line of the screen. If there is more than one left curly
152 bracket on the top line, a number N may be used to specify the
153 N-th bracket on the line.
154 } If a right curly bracket appears in the bottom line displayed on
156 the screen, the } command will go to the matching left curly
157 bracket. The matching left curly bracket is positioned on the
158 top line of the screen. If there is more than one right curly
159 bracket on the bottom line, a number N may be used to specify
160 the N-th bracket on the line.
161 ( Like {, but applies to parentheses rather than curly brackets.
163 ) Like }, but applies to parentheses rather than curly brackets.
165 [ Like {, but applies to square brackets rather than curly brack‐
167 ets.
168 ] Like }, but applies to square brackets rather than curly brack‐
170 ets.
171 ESC-^F Followed by two characters, acts like {, but uses the two char‐
173 acters as open and close brackets, respectively. For example,
174 "ESC ^F < >" could be used to go forward to the > which matches
175 the < in the top displayed line.
176 ESC-^B Followed by two characters, acts like }, but uses the two char‐
178 acters as open and close brackets, respectively. For example,
179 "ESC ^B < >" could be used to go backward to the < which matches
180 the > in the bottom displayed line.
181 m Followed by any lowercase or uppercase letter, marks the first
183 displayed line with that letter. If the status column is en‐
184 abled via the -J option, the status column shows the marked
185 line.
186 M Acts like m, except the last displayed line is marked rather
188 than the first displayed line.
189 ' (Single quote.) Followed by any lowercase or uppercase letter,
191 returns to the position which was previously marked with that
192 letter. Followed by another single quote, returns to the posi‐
193 tion at which the last "large" movement command was executed.
194 Followed by a ^ or $, jumps to the beginning or end of the file
195 respectively. Marks are preserved when a new file is examined,
196 so the ' command can be used to switch between input files.
197 ^X^X Same as single quote.
199 ESC-m Followed by any lowercase or uppercase letter, clears the mark
201 identified by that letter.
202 /pattern
204 Search forward in the file for the N-th line containing the pat‐
205 tern. N defaults to 1. The pattern is a regular expression, as
206 recognized by the regular expression library supplied by your
207 system. The search starts at the first line displayed (but see
208 the -a and -j options, which change this).
209 Certain characters are special if entered at the beginning of
211 the pattern; they modify the type of search rather than become
212 part of the pattern:
213 ^N or !
215 Search for lines which do NOT match the pattern.
216 ^E or *
218 Search multiple files. That is, if the search reaches
219 the END of the current file without finding a match, the
220 search continues in the next file in the command line
221 list.
222 ^F or @
224 Begin the search at the first line of the FIRST file in
225 the command line list, regardless of what is currently
226 displayed on the screen or the settings of the -a or -j
227 options.
228 ^K Highlight any text which matches the pattern on the cur‐
230 rent screen, but don't move to the first match (KEEP cur‐
231 rent position).
232 ^R Don't interpret regular expression metacharacters; that
234 is, do a simple textual comparison.
235 ^S Followed by a digit N between 1 and 5. Only text which
237 has a non-empty match for the N-th parenthesized SUB-PAT‐
238 TERN will be considered to match the pattern. (Supported
239 only if less is built with one of the regular expression
240 libraries posix, pcre, or pcre2.) Multiple ^S modifiers
241 can be specified, to match more than one sub-pattern.
242 ^W WRAP around the current file. That is, if the search
244 reaches the end of the current file without finding a
245 match, the search continues from the first line of the
246 current file up to the line where it started. If the ^W
247 modifier is set, the ^E modifier is ignored.
248 ?pattern
250 Search backward in the file for the N-th line containing the
251 pattern. The search starts at the last line displayed (but see
252 the -a and -j options, which change this).
253 Certain characters are special as in the / command:
255 ^N or !
257 Search for lines which do NOT match the pattern.
258 ^E or *
260 Search multiple files. That is, if the search reaches
261 the beginning of the current file without finding a
262 match, the search continues in the previous file in the
263 command line list.
264 ^F or @
266 Begin the search at the last line of the last file in the
267 command line list, regardless of what is currently dis‐
268 played on the screen or the settings of the -a or -j op‐
269 tions.
270 ^K As in forward searches.
272 ^R As in forward searches.
274 ^S As in forward searches.
276 ^W WRAP around the current file. That is, if the search
278 reaches the beginning of the current file without finding
279 a match, the search continues from the last line of the
280 current file up to the line where it started.
281 ESC-/pattern
283 Same as "/*".
284 ESC-?pattern
286 Same as "?*".
287 n Repeat previous search, for N-th line containing the last pat‐
289 tern. If the previous search was modified by ^N, the search is
290 made for the N-th line NOT containing the pattern. If the pre‐
291 vious search was modified by ^E, the search continues in the
292 next (or previous) file if not satisfied in the current file.
293 If the previous search was modified by ^R, the search is done
294 without using regular expressions. There is no effect if the
295 previous search was modified by ^F or ^K.
296 N Repeat previous search, but in the reverse direction.
298 ESC-n Repeat previous search, but crossing file boundaries. The ef‐
300 fect is as if the previous search were modified by *.
301 ESC-N Repeat previous search, but in the reverse direction and cross‐
303 ing file boundaries.
304 ESC-u Undo search highlighting. Turn off highlighting of strings
306 matching the current search pattern. If highlighting is already
307 off because of a previous ESC-u command, turn highlighting back
308 on. Any search command will also turn highlighting back on.
309 (Highlighting can also be disabled by toggling the -G option; in
310 that case search commands do not turn highlighting back on.)
311 ESC-U Like ESC-u but also clears the saved search pattern. If the
313 status column is enabled via the -J option, this clears all
314 search matches marked in the status column.
315 &pattern
317 Display only lines which match the pattern; lines which do not
318 match the pattern are not displayed. If pattern is empty (if
319 you type & immediately followed by ENTER), any filtering is
320 turned off, and all lines are displayed. While filtering is in
321 effect, an ampersand is displayed at the beginning of the
322 prompt, as a reminder that some lines in the file may be hidden.
323 Multiple & commands may be entered, in which case only lines
324 which match all of the patterns will be displayed.
325 Certain characters are special as in the / command:
327 ^N or !
329 Display only lines which do NOT match the pattern.
330 ^R Don't interpret regular expression metacharacters; that
332 is, do a simple textual comparison.
333 :e [filename]
335 Examine a new file. If the filename is missing, the "current"
336 file (see the :n and :p commands below) from the list of files
337 in the command line is re-examined. A percent sign (%) in the
338 filename is replaced by the name of the current file. A pound
339 sign (#) is replaced by the name of the previously examined
340 file. However, two consecutive percent signs are simply re‐
341 placed with a single percent sign. This allows you to enter a
342 filename that contains a percent sign in the name. Similarly,
343 two consecutive pound signs are replaced with a single pound
344 sign. The filename is inserted into the command line list of
345 files so that it can be seen by subsequent :n and :p commands.
346 If the filename consists of several files, they are all inserted
347 into the list of files and the first one is examined. If the
348 filename contains one or more spaces, the entire filename should
349 be enclosed in double quotes (also see the -" option).
350 ^X^V or E
352 Same as :e. Warning: some systems use ^V as a special literal‐
353 ization character. On such systems, you may not be able to use
354 ^V.
355 :n Examine the next file (from the list of files given in the com‐
357 mand line). If a number N is specified, the N-th next file is
358 examined.
359 :p Examine the previous file in the command line list. If a number
361 N is specified, the N-th previous file is examined.
362 :x Examine the first file in the command line list. If a number N
364 is specified, the N-th file in the list is examined.
365 :d Remove the current file from the list of files.
367 t Go to the next tag, if there were more than one matches for the
369 current tag. See the -t option for more details about tags.
370 T Go to the previous tag, if there were more than one matches for
372 the current tag.
373 = or ^G or :f
375 Prints some information about the file being viewed, including
376 its name and the line number and byte offset of the bottom line
377 being displayed. If possible, it also prints the length of the
378 file, the number of lines in the file and the percent of the
379 file above the last displayed line.
380 - Followed by one of the command line option letters (see OPTIONS
382 below), this will change the setting of that option and print a
383 message describing the new setting. If a ^P (CONTROL-P) is en‐
384 tered immediately after the dash, the setting of the option is
385 changed but no message is printed. If the option letter has a
386 numeric value (such as -b or -h), or a string value (such as -P
387 or -t), a new value may be entered after the option letter. If
388 no new value is entered, a message describing the current set‐
389 ting is printed and nothing is changed.
390 -- Like the - command, but takes a long option name (see OPTIONS
392 below) rather than a single option letter. You must press ENTER
393 or RETURN after typing the option name. A ^P immediately after
394 the second dash suppresses printing of a message describing the
395 new setting, as in the - command.
396 -+ Followed by one of the command line option letters this will re‐
398 set the option to its default setting and print a message de‐
399 scribing the new setting. (The "-+X" command does the same
400 thing as "-+X" on the command line.) This does not work for
401 string-valued options.
402 --+ Like the -+ command, but takes a long option name rather than a
404 single option letter.
405 -! Followed by one of the command line option letters, this will
407 reset the option to the "opposite" of its default setting and
408 print a message describing the new setting. This does not work
409 for numeric or string-valued options.
410 --! Like the -! command, but takes a long option name rather than a
412 single option letter.
413 _ (Underscore.) Followed by one of the command line option let‐
415 ters, this will print a message describing the current setting
416 of that option. The setting of the option is not changed.
417 __ (Double underscore.) Like the _ (underscore) command, but takes
419 a long option name rather than a single option letter. You must
420 press ENTER or RETURN after typing the option name.
421 +cmd Causes the specified cmd to be executed each time a new file is
423 examined. For example, +G causes less to initially display each
424 file starting at the end rather than the beginning.
425 V Prints the version number of less being run.
427 q or Q or :q or :Q or ZZ
429 Exits less.
430 The following six commands may or may not be valid, depending on your
432 particular installation.
433 v Invokes an editor to edit the current file being viewed. The
435 editor is taken from the environment variable VISUAL if defined,
436 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei‐
437 ther VISUAL nor EDITOR is defined. See also the discussion of
438 LESSEDIT under the section on PROMPTS below.
439 ! shell-command
441 Invokes a shell to run the shell-command given. A percent sign
442 (%) in the command is replaced by the name of the current file.
443 A pound sign (#) is replaced by the name of the previously exam‐
444 ined file. "!!" repeats the last shell command. "!" with no
445 shell command simply invokes a shell. On Unix systems, the
446 shell is taken from the environment variable SHELL, or defaults
447 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
448 command processor.
449 # shell-command
451 Similar to the "!" command, except that the command is expanded
452 in the same way as prompt strings. For example, the name of the
453 current file would be given as "%f".
454 | <m> shell-command
456 <m> represents any mark letter. Pipes a section of the input
457 file to the given shell command. The section of the file to be
458 piped is between the position marked by the letter and the cur‐
459 rent screen. The entire current screen is included, regardless
460 of whether the marked position is before or after the current
461 screen. <m> may also be ^ or $ to indicate beginning or end of
462 file respectively. If <m> is . or newline, the current screen
463 is piped.
464 s filename
466 Save the input to a file. This works only if the input is a
467 pipe, not an ordinary file.
468 ^X When the "Waiting for data" message is displayed, such as while
470 in the F command, pressing ^X will stop less from waiting and
471 return to a prompt. This may cause less to think that the file
472 ends at the current position, so it may be necessary to use the
473 R or F command to see more data. The --intr option can be used
474 to specify a different character to use instead of ^X. This
475 command works only on systems that support the poll(1) function.
476 On systems without poll(1), the interrupt character (usually ^C)
477 can be used instead.
478
480 Command line options are described below. Most options may be changed
481 while less is running, via the "-" command.
482 Some options may be given in one of two forms: either a dash followed
484 by a single letter, or two dashes followed by a long option name. A
485 long option name may be abbreviated as long as the abbreviation is un‐
486 ambiguous. For example, --quit-at-eof may be abbreviated --quit, but
487 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
488 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
489 from --quit-at-eof. Such option names need only have their first let‐
490 ter capitalized; the remainder of the name may be in either case. For
491 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
492 Options are also taken from the environment variable "LESS". For exam‐
494 ple, to avoid typing "less -options ..." each time less is invoked, you
495 might tell csh:
496 setenv LESS "-options"
498 or if you use sh:
500 LESS="-options"; export LESS
502 On MS-DOS, you don't need the quotes, but you should replace any per‐
504 cent signs in the options string by double percent signs.
505 The environment variable is parsed before the command line, so command
507 line options override the LESS environment variable. If an option ap‐
508 pears in the LESS variable, it can be reset to its default value on the
509 command line by beginning the command line option with "-+".
510 Some options like -k or -D require a string to follow the option let‐
512 ter. The string for that option is considered to end when a dollar
513 sign ($) is found. For example, you can set two -D options like this:
514 LESS="Dn9.1$Ds4.1"
516 If the --use-backslash option appears earlier in the options, then a
518 dollar sign or backslash may be included literally in an option string
519 by preceding it with a backslash. If the --use-backslash option is not
520 in effect, then backslashes are not treated specially, and there is no
521 way to include a dollar sign in the option string.
522 -? or --help
524 This option displays a summary of the commands accepted by less
525 (the same as the h command). (Depending on how your shell in‐
526 terprets the question mark, it may be necessary to quote the
527 question mark, thus: "-\?".)
528 -a or --search-skip-screen
530 By default, forward searches start at the top of the displayed
531 screen and backwards searches start at the bottom of the dis‐
532 played screen (except for repeated searches invoked by the n or
533 N commands, which start after or before the "target" line re‐
534 spectively; see the -j option for more about the target line).
535 The -a option causes forward searches to instead start at the
536 bottom of the screen and backward searches to start at the top
537 of the screen, thus skipping all lines displayed on the screen.
538 -A or --SEARCH-SKIP-SCREEN
540 Causes all forward searches (not just non-repeated searches) to
541 start just after the target line, and all backward searches to
542 start just before the target line. Thus, forward searches will
543 skip part of the displayed screen (from the first line up to and
544 including the target line). Similarly backwards searches will
545 skip the displayed screen from the last line up to and including
546 the target line. This was the default behavior in less versions
547 prior to 441.
548 -bn or --buffers=n
550 Specifies the amount of buffer space less will use for each
551 file, in units of kilobytes (1024 bytes). By default 64 KB of
552 buffer space is used for each file (unless the file is a pipe;
553 see the -B option). The -b option specifies instead that n
554 kilobytes of buffer space should be used for each file. If n is
555 -1, buffer space is unlimited; that is, the entire file can be
556 read into memory.
557 -B or --auto-buffers
559 By default, when data is read from a pipe, buffers are allocated
560 automatically as needed. If a large amount of data is read from
561 the pipe, this can cause a large amount of memory to be allo‐
562 cated. The -B option disables this automatic allocation of buf‐
563 fers for pipes, so that only 64 KB (or the amount of space spec‐
564 ified by the -b option) is used for the pipe. Warning: use of
565 -B can result in erroneous display, since only the most recently
566 viewed part of the piped data is kept in memory; any earlier
567 data is lost. Lost characters are displayed as question marks.
568 -c or --clear-screen
570 Causes full screen repaints to be painted from the top line
571 down. By default, full screen repaints are done by scrolling
572 from the bottom of the screen.
573 -C or --CLEAR-SCREEN
575 Same as -c, for compatibility with older versions of less.
576 -d or --dumb
578 The -d option suppresses the error message normally displayed if
579 the terminal is dumb; that is, lacks some important capability,
580 such as the ability to clear the screen or scroll backward. The
581 -d option does not otherwise change the behavior of less on a
582 dumb terminal.
583 -Dxcolor or --color=xcolor
585 Changes the color of different parts of the displayed text. x
586 is a single character which selects the type of text whose color
587 is being set:
588 B Binary characters.
590 C Control characters.
592 E Errors and informational messages.
594 H Header lines and columns, set via the --header option.
596 M Mark letters in the status column.
598 N Line numbers enabled via the -N option.
600 P Prompts.
602 R The rscroll character.
604 S Search results.
606 1-5 The text in a search result which matches the first
608 through fifth parenthesized sub-pattern. Sub-pattern
609 coloring works only if less is built with one of the reg‐
610 ular expression libraries posix, pcre, or pcre2.
611 W The highlight enabled via the -w option.
613 d Bold text.
615 k Blinking text.
617 s Standout text.
619 u Underlined text.
621 The uppercase letters and digits can be used only when the
623 --use-color option is enabled. When text color is specified by
624 both an uppercase letter and a lowercase letter, the uppercase
625 letter takes precedence. For example, error messages are nor‐
626 mally displayed as standout text. So if both "s" and "E" are
627 given a color, the "E" color applies to error messages, and the
628 "s" color applies to other standout text. The "d" and "u" let‐
629 ters refer to bold and underline text formed by overstriking
630 with backspaces (see the -U option), not to text using ANSI es‐
631 cape sequences with the -R option.
632 A lowercase letter may be followed by a + to indicate that the
634 normal format change and the specified color should both be
635 used. For example, -Dug displays underlined text as green with‐
636 out underlining; the green color has replaced the usual under‐
637 line formatting. But -Du+g displays underlined text as both
638 green and in underlined format.
639 color is either a 4-bit color string or an 8-bit color string:
641 A 4-bit color string is zero, one or two characters, where the
643 first character specifies the foreground color and the second
644 specifies the background color as follows:
645 b Blue
647 c Cyan
649 g Green
651 k Black
653 m Magenta
655 r Red
657 w White
659 y Yellow
661 The corresponding uppercase letter denotes a brighter shade of
663 the color. For example, -DNGk displays line numbers as bright
664 green text on a black background, and -DEbR displays error mes‐
665 sages as blue text on a bright red background. If either char‐
666 acter is a "-" or is omitted, the corresponding color is set to
667 that of normal text.
668 An 8-bit color string is one or two decimal integers separated
670 by a dot, where the first integer specifies the foreground color
671 and the second specifies the background color. Each integer is
672 a value between 0 and 255 inclusive which selects a "CSI 38;5"
673 color value (see
674 https://en.wikipedia.org/wiki/ANSI_escape_code#SGR) If either
675 integer is a "-" or is omitted, the corresponding color is set
676 to that of normal text. On MS-DOS versions of less, 8-bit color
677 is not supported; instead, decimal values are interpreted as
678 4-bit CHAR_INFO.Attributes values (see
679 https://docs.microsoft.com/en-us/windows/console/char-info-str).
680 -e or --quit-at-eof
682 Causes less to automatically exit the second time it reaches
683 end-of-file. By default, the only way to exit less is via the
684 "q" command.
685 -E or --QUIT-AT-EOF
687 Causes less to automatically exit the first time it reaches end-
688 of-file.
689 -f or --force
691 Forces non-regular files to be opened. (A non-regular file is a
692 directory or a device special file.) Also suppresses the warn‐
693 ing message when a binary file is opened. By default, less will
694 refuse to open non-regular files. Note that some operating sys‐
695 tems will not allow directories to be read, even if -f is set.
696 -F or --quit-if-one-screen
698 Causes less to automatically exit if the entire file can be dis‐
699 played on the first screen.
700 -g or --hilite-search
702 Normally, less will highlight ALL strings which match the last
703 search command. The -g option changes this behavior to high‐
704 light only the particular string which was found by the last
705 search command. This can cause less to run somewhat faster than
706 the default.
707 -G or --HILITE-SEARCH
709 The -G option suppresses all highlighting of strings found by
710 search commands.
711 --old-bot
713 Reverts to the old bottom of screen behavior. This can be some‐
714 times desirable if the long lines are not wrapped correctly
715 when reaching the bottom of the terminal, while scrolling
716 forward.
717 -hn or --max-back-scroll=n
719 Specifies a maximum number of lines to scroll backward. If it
720 is necessary to scroll backward more than n lines, the screen is
721 repainted in a forward direction instead. (If the terminal does
722 not have the ability to scroll backward, -h0 is implied.)
723 -i or --ignore-case
725 Causes searches to ignore case; that is, uppercase and lowercase
726 are considered identical. This option is ignored if any upper‐
727 case letters appear in the search pattern; in other words, if a
728 pattern contains uppercase letters, then that search does not
729 ignore case.
730 -I or --IGNORE-CASE
732 Like -i, but searches ignore case even if the pattern contains
733 uppercase letters.
734 -jn or --jump-target=n
736 Specifies a line on the screen where the "target" line is to be
737 positioned. The target line is the line specified by any com‐
738 mand to search for a pattern, jump to a line number, jump to a
739 file percentage or jump to a tag. The screen line may be speci‐
740 fied by a number: the top line on the screen is 1, the next is
741 2, and so on. The number may be negative to specify a line rel‐
742 ative to the bottom of the screen: the bottom line on the screen
743 is -1, the second to the bottom is -2, and so on. Alternately,
744 the screen line may be specified as a fraction of the height of
745 the screen, starting with a decimal point: .5 is in the middle
746 of the screen, .3 is three tenths down from the first line, and
747 so on. If the line is specified as a fraction, the actual line
748 number is recalculated if the terminal window is resized. If
749 any form of the -j option is used, repeated forward searches
750 (invoked with "n" or "N") begin at the line immediately after
751 the target line, and repeated backward searches begin at the
752 target line, unless changed by -a or -A. For example, if "-j4"
753 is used, the target line is the fourth line on the screen, so
754 forward searches begin at the fifth line on the screen. However
755 nonrepeated searches (invoked with "/" or "?") always begin at
756 the start or end of the current screen respectively.
757 -J or --status-column
759 Displays a status column at the left edge of the screen. The
760 character displayed in the status column may be one of:
761 > The line is chopped with the -S option, and the text that
763 is chopped off beyond the right edge of the screen con‐
764 tains a match for the current search.
765 < The line is horizontally shifted, and the text that is
767 shifted beyond the left side of the screen contains a
768 match for the current search.
769 = The line is both chopped and shifted, and there are
771 matches beyond both sides of the screen.
772 * There are matches in the visible part of the line but
774 none to the right or left of it.
775 a-z, A-Z
777 The line has been marked with the corresponding letter
778 via the m command.
779 -kfilename or --lesskey-file=filename
781 Causes less to open and interpret the named file as a lesskey(1)
782 binary file. Multiple -k options may be specified. If the
783 LESSKEY or LESSKEY_SYSTEM environment variable is set, or if a
784 lesskey file is found in a standard place (see KEY BINDINGS), it
785 is also used as a lesskey file.
786 --lesskey-src=filename
788 Causes less to open and interpret the named file as a lesskey(1)
789 source file. If the LESSKEYIN or LESSKEYIN_SYSTEM environment
790 variable is set, or if a lesskey source file is found in a stan‐
791 dard place (see KEY BINDINGS), it is also used as a lesskey
792 source file. Prior to version 582, the lesskey program needed
793 to be run to convert a lesskey source file to a lesskey binary
794 file for less to use. Newer versions of less read the lesskey
795 source file directly and ignore the binary file if the source
796 file exists.
797 -K or --quit-on-intr
799 Causes less to exit immediately (with status 2) when an inter‐
800 rupt character (usually ^C) is typed. Normally, an interrupt
801 character causes less to stop whatever it is doing and return to
802 its command prompt. Note that use of this option makes it im‐
803 possible to return to the command prompt from the "F" command.
804 -L or --no-lessopen
806 Ignore the LESSOPEN environment variable (see the INPUT PRE‐
807 PROCESSOR section below). This option can be set from within
808 less, but it will apply only to files opened subsequently, not
809 to the file which is currently open.
810 -m or --long-prompt
812 Causes less to prompt verbosely (like more(1)), with the percent
813 into the file. By default, less prompts with a colon.
814 -M or --LONG-PROMPT
816 Causes less to prompt even more verbosely than more(1).
817 -n or --line-numbers
819 Suppresses line numbers. The default (to use line numbers) may
820 cause less to run more slowly in some cases, especially with a
821 very large input file. Suppressing line numbers with the -n op‐
822 tion will avoid this problem. Using line numbers means: the
823 line number will be displayed in the verbose prompt and in the =
824 command, and the v command will pass the current line number to
825 the editor (see also the discussion of LESSEDIT in PROMPTS be‐
826 low).
827 -N or --LINE-NUMBERS
829 Causes a line number to be displayed at the beginning of each
830 line in the display.
831 -ofilename or --log-file=filename
833 Causes less to copy its input to the named file as it is being
834 viewed. This applies only when the input file is a pipe, not an
835 ordinary file. If the file already exists, less will ask for
836 confirmation before overwriting it.
837 -Ofilename or --LOG-FILE=filename
839 The -O option is like -o, but it will overwrite an existing file
840 without asking for confirmation.
841 If no log file has been specified, the -o and -O options can be
843 used from within less to specify a log file. Without a file
844 name, they will simply report the name of the log file. The "s"
845 command is equivalent to specifying -o from within less.
846 -ppattern or --pattern=pattern
848 The -p option on the command line is equivalent to specifying
849 +/pattern; that is, it tells less to start at the first occur‐
850 rence of pattern in the file.
851 -Pprompt or --prompt=prompt
853 Provides a way to tailor the three prompt styles to your own
854 preference. This option would normally be put in the LESS envi‐
855 ronment variable, rather than being typed in with each less com‐
856 mand. Such an option must either be the last option in the LESS
857 variable, or be terminated by a dollar sign.
858 -Ps followed by a string changes the default (short) prompt to
859 that string.
860 -Pm changes the medium (-m) prompt.
861 -PM changes the long (-M) prompt.
862 -Ph changes the prompt for the help screen.
863 -P= changes the message printed by the = command.
864 -Pw changes the message printed while waiting for data (in the
865 "F" command).
866 All prompt strings consist of a sequence of letters and special
868 escape sequences. See the section on PROMPTS for more details.
869 -q or --quiet or --silent
871 Causes moderately "quiet" operation: the terminal bell is not
872 rung if an attempt is made to scroll past the end of the file or
873 before the beginning of the file. If the terminal has a "visual
874 bell", it is used instead. The bell will be rung on certain
875 other errors, such as typing an invalid character. The default
876 is to ring the terminal bell in all such cases.
877 -Q or --QUIET or --SILENT
879 Causes totally "quiet" operation: the terminal bell is never
880 rung. If the terminal has a "visual bell", it is used in all
881 cases where the terminal bell would have been rung.
882 -r or --raw-control-chars
884 Causes "raw" control characters to be displayed. The default is
885 to display control characters using the caret notation; for ex‐
886 ample, a control-A (octal 001) is displayed as "^A" (with some
887 exceptions as described under the -U option). Warning: when the
888 -r option is used, less cannot keep track of the actual appear‐
889 ance of the screen (since this depends on how the screen re‐
890 sponds to each type of control character). Thus, various dis‐
891 play problems may result, such as long lines being split in the
892 wrong place.
893 USE OF THE -r OPTION IS NOT RECOMMENDED.
895 -R or --RAW-CONTROL-CHARS
897 Like -r, but only ANSI "color" escape sequences and OSC 8 hyper‐
898 link sequences are output in "raw" form. Unlike -r, the screen
899 appearance is maintained correctly, provided that there are no
900 escape sequences in the file other than these types of escape
901 sequences. Color escape sequences are only supported when the
902 color is changed within one line, not across lines. In other
903 words, the beginning of each line is assumed to be normal (non-
904 colored), regardless of any escape sequences in previous lines.
905 For the purpose of keeping track of screen appearance, these es‐
906 cape sequences are assumed to not move the cursor.
907 OSC 8 hyperlinks are sequences of the form:
909 ESC ] 8 ; ... \7
911 The terminating sequence may be either a BEL character (\7) or
913 the two-character sequence "ESC \".
914 ANSI color escape sequences are sequences of the form:
916 ESC [ ... m
918 where the "..." is zero or more color specification characters.
920 You can make less think that characters other than "m" can end
921 ANSI color escape sequences by setting the environment variable
922 LESSANSIENDCHARS to the list of characters which can end a color
923 escape sequence. And you can make less think that characters
924 other than the standard ones may appear between the ESC and the
925 m by setting the environment variable LESSANSIMIDCHARS to the
926 list of characters which can appear.
927 -s or --squeeze-blank-lines
929 Causes consecutive blank lines to be squeezed into a single
930 blank line. This is useful when viewing nroff output.
931 -S or --chop-long-lines
933 Causes lines longer than the screen width to be chopped (trun‐
934 cated) rather than wrapped. That is, the portion of a long line
935 that does not fit in the screen width is not displayed until you
936 press RIGHT-ARROW. The default is to wrap long lines; that is,
937 display the remainder on the next line. See also the --wordwrap
938 option.
939 -ttag or --tag=tag
941 The -t option, followed immediately by a TAG, will edit the file
942 containing that tag. For this to work, tag information must be
943 available; for example, there may be a file in the current di‐
944 rectory called "tags", which was previously built by ctags(1) or
945 an equivalent command. If the environment variable LESSGLOBALT‐
946 AGS is set, it is taken to be the name of a command compatible
947 with global(1), and that command is executed to find the tag.
948 (See http://www.gnu.org/software/global/global.html). The -t
949 option may also be specified from within less (using the - com‐
950 mand) as a way of examining a new file. The command ":t" is
951 equivalent to specifying -t from within less.
952 -Ttagsfile or --tag-file=tagsfile
954 Specifies a tags file to be used instead of "tags".
955 -u or --underline-special
957 Causes backspaces and carriage returns to be treated as print‐
958 able characters; that is, they are sent to the terminal when
959 they appear in the input.
960 -U or --UNDERLINE-SPECIAL
962 Causes backspaces, tabs, carriage returns and "formatting char‐
963 acters" (as defined by Unicode) to be treated as control charac‐
964 ters; that is, they are handled as specified by the -r option.
965 By default, if neither -u nor -U is given, backspaces which ap‐
967 pear adjacent to an underscore character are treated specially:
968 the underlined text is displayed using the terminal's hardware
969 underlining capability. Also, backspaces which appear between
970 two identical characters are treated specially: the overstruck
971 text is printed using the terminal's hardware boldface capabili‐
972 ty. Other backspaces are deleted, along with the preceding
973 character. Carriage returns immediately followed by a newline
974 are deleted. Other carriage returns are handled as specified by
975 the -r option. Unicode formatting characters, such as the Byte
976 Order Mark, are sent to the terminal. Text which is overstruck
977 or underlined can be searched for if neither -u nor -U is in ef‐
978 fect.
979 See also the --proc-backspace, --proc-tab, and --proc-return op‐
981 tions.
982 -V or --version
984 Displays the version number of less.
985 -w or --hilite-unread
987 Temporarily highlights the first "new" line after a forward
988 movement of a full page. The first "new" line is the line imme‐
989 diately following the line previously at the bottom of the
990 screen. Also highlights the target line after a g or p command.
991 The highlight is removed at the next command which causes move‐
992 ment. If the --status-line option is in effect, the entire line
993 (the width of the screen) is highlighted. Otherwise, only the
994 text in the line is highlighted, unless the -J option is in ef‐
995 fect, in which case only the status column is highlighted.
996 -W or --HILITE-UNREAD
998 Like -w, but temporarily highlights the first new line after any
999 forward movement command larger than one line.
1000 -xn,... or --tabs=n,...
1002 Sets tab stops. If only one n is specified, tab stops are set
1003 at multiples of n. If multiple values separated by commas are
1004 specified, tab stops are set at those positions, and then con‐
1005 tinue with the same spacing as the last two. For example,
1006 "-x9,17" will set tabs at positions 9, 17, 25, 33, etc. The de‐
1007 fault for n is 8.
1008 -X or --no-init
1010 Disables sending the termcap initialization and deinitialization
1011 strings to the terminal. This is sometimes desirable if the
1012 deinitialization string does something unnecessary, like clear‐
1013 ing the screen.
1014 -yn or --max-forw-scroll=n
1016 Specifies a maximum number of lines to scroll forward. If it is
1017 necessary to scroll forward more than n lines, the screen is re‐
1018 painted instead. The -c or -C option may be used to repaint
1019 from the top of the screen if desired. By default, any forward
1020 movement causes scrolling.
1021 -zn or --window=n or -n
1023 Changes the default scrolling window size to n lines. The de‐
1024 fault is one screenful. The z and w commands can also be used
1025 to change the window size. The "z" may be omitted for compati‐
1026 bility with some versions of more(1). If the number n is nega‐
1027 tive, it indicates n lines less than the current screen size.
1028 For example, if the screen is 24 lines, -z-4 sets the scrolling
1029 window to 20 lines. If the screen is resized to 40 lines, the
1030 scrolling window automatically changes to 36 lines.
1031 -"cc or --quotes=cc
1033 Changes the filename quoting character. This may be necessary
1034 if you are trying to name a file which contains both spaces and
1035 quote characters. Followed by a single character, this changes
1036 the quote character to that character. Filenames containing a
1037 space should then be surrounded by that character rather than by
1038 double quotes. Followed by two characters, changes the open
1039 quote to the first character, and the close quote to the second
1040 character. Filenames containing a space should then be preceded
1041 by the open quote character and followed by the close quote
1042 character. Note that even after the quote characters are
1043 changed, this option remains -" (a dash followed by a double
1044 quote).
1045 -~ or --tilde
1047 Normally lines after end of file are displayed as a single tilde
1048 (~). This option causes lines after end of file to be displayed
1049 as blank lines.
1050 -# or --shift
1052 Specifies the default number of positions to scroll horizontally
1053 in the RIGHTARROW and LEFTARROW commands. If the number speci‐
1054 fied is zero, it sets the default number of positions to one
1055 half of the screen width. Alternately, the number may be speci‐
1056 fied as a fraction of the width of the screen, starting with a
1057 decimal point: .5 is half of the screen width, .3 is three
1058 tenths of the screen width, and so on. If the number is speci‐
1059 fied as a fraction, the actual number of scroll positions is re‐
1060 calculated if the terminal window is resized.
1061 --exit-follow-on-close
1063 When using the "F" command on a pipe, less will automatically
1064 stop waiting for more data when the input side of the pipe is
1065 closed.
1066 --file-size
1068 If --file-size is specified, less will determine the size of the
1069 file immediately after opening the file. Then the "=" command
1070 will display the number of lines in the file. Normally this is
1071 not done, because it can be slow if the input file is non-seek‐
1072 able (such as a pipe) and is large.
1073 --follow-name
1075 Normally, if the input file is renamed while an F command is ex‐
1076 ecuting, less will continue to display the contents of the orig‐
1077 inal file despite its name change. If --follow-name is speci‐
1078 fied, during an F command less will periodically attempt to re‐
1079 open the file by name. If the reopen succeeds and the file is a
1080 different file from the original (which means that a new file
1081 has been created with the same name as the original (now re‐
1082 named) file), less will display the contents of that new file.
1083 --header=N[,M]
1085 Sets the number of header lines and columns displayed on the
1086 screen. The value may be of the form "N,M" where N and M are
1087 integers, to set the header lines to N and the header columns to
1088 M, or it may be a single integer "N" which sets the header lines
1089 to N and the header columns to zero, or it may be ",M" which
1090 sets the header columns to M and the header lines to zero. When
1091 N is nonzero, the first N lines at the top of the screen are re‐
1092 placed with the first N lines of the file, regardless of what
1093 part of the file are being viewed. When M is nonzero, the char‐
1094 acters displayed at the beginning of each line are replaced with
1095 the first M characters of the line, even if the rest of the line
1096 is scrolled horizontally. If either N or M is zero, less stops
1097 displaying header lines or columns, respectively. (Note that it
1098 may be necessary to change the setting of the -j option to en‐
1099 sure that the target line is not obscured by the header
1100 line(s).)
1101 --incsearch
1103 Subsequent search commands will be "incremental"; that is, less
1104 will advance to the next line containing the search pattern as
1105 each character of the pattern is typed in.
1106 --intr=c
1108 Use the character c instead of ^X to interrupt a read when the
1109 "Waiting for data" message is displayed. c must be an ASCII
1110 character; that is, one with a value between 1 and 127 inclu‐
1111 sive. A caret followed by a single character can be used to
1112 specify a control character.
1113 --line-num-width=n
1115 Sets the minimum width of the line number field when the -N op‐
1116 tion is in effect to n characters. The default is 7.
1117 --modelines=n
1119 Before displaying a file, less will read the first n lines to
1120 try to find a vim-compatible modeline. If n is zero, less does
1121 not try to find modelines. By using a modeline, the file itself
1122 can specify the tab stops that should be used when viewing it.
1123 A modeline contains, anywhere in the line, a program name ("vi",
1125 "vim", "ex", or "less"), followed by a colon, possibly followed
1126 by the word "set", and finally followed by zero or more option
1127 settings. If the word "set" is used, option settings are sepa‐
1128 rated by spaces, and end at the first colon. If the word "set"
1129 is not used, option settings may be separated by either spaces
1130 or colons. The word "set" is required if the program name is
1131 "less" but optional if any of the other three names are used.
1132 If any option setting is of the form "tabstop=n" or "ts=n", then
1133 tab stops are automatically set as if --tabs=n had been given.
1134 See the --tabs description for acceptable values of n.
1135 --mouse
1137 Enables mouse input: scrolling the mouse wheel down moves for‐
1138 ward in the file, scrolling the mouse wheel up moves backwards
1139 in the file, and clicking the mouse sets the "#" mark to the
1140 line where the mouse is clicked. The number of lines to scroll
1141 when the wheel is moved can be set by the --wheel-lines option.
1142 Mouse input works only on terminals which support X11 mouse re‐
1143 porting, and on the Windows version of less.
1144 --MOUSE
1146 Like --mouse, except the direction scrolled on mouse wheel move‐
1147 ment is reversed.
1148 --no-keypad
1150 Disables sending the keypad initialization and deinitialization
1151 strings to the terminal. This is sometimes useful if the keypad
1152 strings make the numeric keypad behave in an undesirable manner.
1153 --no-histdups
1155 This option changes the behavior so that if a search string or
1156 file name is typed in, and the same string is already in the
1157 history list, the existing copy is removed from the history list
1158 before the new one is added. Thus, a given string will appear
1159 only once in the history list. Normally, a string may appear
1160 multiple times.
1161 --no-number-headers
1163 Header lines (defined via the --header option) are not assigned
1164 line numbers. Line number 1 is assigned to the first line after
1165 any header lines.
1166 --no-search-headers
1168 Searches do not include header lines or header columns.
1169 --no-vbell
1171 Disables the terminal's visual bell.
1172 --proc-backspace
1174 If set, backspaces are handled as if neither the -u option nor
1175 the -U option were set. That is, a backspace adjacent to an un‐
1176 derscore causes text to be displayed in underline mode, and a
1177 backspace between identical characters cause text to be dis‐
1178 played in boldface mode. This option overrides the -u and -U
1179 options, so that display of backspaces can be controlled sepa‐
1180 rate from tabs and carriage returns. If not set, backspace dis‐
1181 play is controlled by the -u and -U options.
1182 --PROC-BACKSPACE
1184 If set, backspaces are handled as if the -U option were set;
1185 that is backspaces are treated as control characters.
1186 --proc-return
1188 If set, carriage returns are handled as if neither the -u option
1189 nor the -U option were set. That is, a carriage return immedi‐
1190 ately before a newline is deleted. This option overrides the -u
1191 and -U options, so that display of carriage returns can be con‐
1192 trolled separate from that of backspaces and tabs. If not set,
1193 carriage return display is controlled by the -u and -U options.
1194 --PROC-RETURN
1196 If set, carriage returns are handled as if the -U option were
1197 set; that is carriage returns are treated as control characters.
1198 --proc-tab
1200 If set, tabs are handled as if the -U option were not set. That
1201 is, tabs are expanded to spaces. This option overrides the -U
1202 option, so that display of tabs can be controlled separate from
1203 that of backspaces and carriage returns. If not set, tab dis‐
1204 play is controlled by the -U options.
1205 --PROC-TAB
1207 If set, tabs are handled as if the -U option were set; that is
1208 tabs are treated as control characters.
1209 --redraw-on-quit
1211 When quitting, after sending the terminal deinitialization
1212 string, redraws the entire last screen. On terminals whose ter‐
1213 minal deinitialization string causes the terminal to switch from
1214 an alternate screen, this makes the last screenful of the cur‐
1215 rent file remain visible after less has quit.
1216 --rscroll=c
1218 This option changes the character used to mark truncated lines.
1219 It may begin with a two-character attribute indicator like LESS‐
1220 BINFMT does. If there is no attribute indicator, standout is
1221 used. If set to "-", truncated lines are not marked.
1222 --save-marks
1224 Save marks in the history file, so marks are retained across
1225 different invocations of less.
1226 --search-options=...
1228 Sets default search modifiers. The value is a string of one or
1229 more of the characters E, F, K, N, R or W. Setting any of these
1230 has the same effect as typing that control character at the be‐
1231 ginning of every search pattern. For example, setting --search-
1232 options=W is the same as typing ^W at the beginning of every
1233 pattern. The value may also contain a digit between 1 and 5,
1234 which has the same effect as typing ^S followed by that digit at
1235 the beginning of every search pattern. The value "-" disables
1236 all default search modifiers.
1237 --show-preproc-errors
1239 If a preprocessor produces data, then exits with a non-zero exit
1240 code, less will display a warning.
1241 --status-col-width=n
1243 Sets the width of the status column when the -J option is in ef‐
1244 fect. The default is 2 characters.
1245 --status-line
1247 If a line is marked, the entire line (rather than just the sta‐
1248 tus column) is highlighted. Also lines highlighted due to the
1249 -w option will have the entire line highlighted. If --use-color
1250 is set, the line is colored rather than highlighted.
1251 --use-backslash
1253 This option changes the interpretations of options which follow
1254 this one. After the --use-backslash option, any backslash in an
1255 option string is removed and the following character is taken
1256 literally. This allows a dollar sign to be included in option
1257 strings.
1258 --use-color
1260 Enables colored text in various places. The -D option can be
1261 used to change the colors. Colored text works only if the ter‐
1262 minal supports ANSI color escape sequences (as defined in EC‐
1263 MA-48 SGR; see
1264 https://www.ecma-international.org/publications-and-
1265 standards/standards/ecma-48).
1266 --wheel-lines=n
1268 Set the number of lines to scroll when the mouse wheel is
1269 scrolled and the --mouse or --MOUSE option is in effect. The
1270 default is 1 line.
1271 --wordwrap
1273 When the -S option is not in use, wrap each line at a space or
1274 tab if possible, so that a word is not split between two lines.
1275 The default is to wrap at any character.
1276 -- A command line argument of "--" marks the end of option argu‐
1278 ments. Any arguments following this are interpreted as file‐
1279 names. This can be useful when viewing a file whose name begins
1280 with a "-" or "+".
1281 + If a command line option begins with +, the remainder of that
1283 option is taken to be an initial command to less. For example,
1284 +G tells less to start at the end of the file rather than the
1285 beginning, and +/xyz tells it to start at the first occurrence
1286 of "xyz" in the file. As a special case, +<number> acts like
1287 +<number>g; that is, it starts the display at the specified line
1288 number (however, see the caveat under the "g" command above).
1289 If the option starts with ++, the initial command applies to ev‐
1290 ery file being viewed, not just the first one. The + command
1291 described previously may also be used to set (or change) an ini‐
1292 tial command for every file.
1293
1295 When entering a command line at the bottom of the screen (for example,
1296 a filename for the :e command, or the pattern for a search command),
1297 certain keys can be used to manipulate the command line. Most commands
1298 have an alternate form in [ brackets ] which can be used if a key does
1299 not exist on a particular keyboard. (Note that the forms beginning
1300 with ESC do not work in some MS-DOS and Windows systems because ESC is
1301 the line erase character.) Any of these special keys may be entered
1302 literally by preceding it with the "literal" character, either ^V or
1303 ^A. A backslash itself may also be entered literally by entering two
1304 backslashes.
1305 LEFTARROW [ ESC-h ]
1307 Move the cursor one space to the left.
1308 RIGHTARROW [ ESC-l ]
1310 Move the cursor one space to the right.
1311 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
1313 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur‐
1314 sor one word to the left.
1315 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
1317 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur‐
1318 sor one word to the right.
1319 HOME [ ESC-0 ]
1321 Move the cursor to the beginning of the line.
1322 END [ ESC-$ ]
1324 Move the cursor to the end of the line.
1325 BACKSPACE
1327 Delete the character to the left of the cursor, or cancel the
1328 command if the command line is empty.
1329 DELETE or [ ESC-x ]
1331 Delete the character under the cursor.
1332 ^BACKSPACE [ ESC-BACKSPACE ]
1334 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
1335 word to the left of the cursor.
1336 ^DELETE [ ESC-X or ESC-DELETE ]
1338 (That is, CONTROL and DELETE simultaneously.) Delete the word
1339 under the cursor.
1340 UPARROW [ ESC-k ]
1342 Retrieve the previous command line. If you first enter some
1343 text and then press UPARROW, it will retrieve the previous com‐
1344 mand which begins with that text.
1345 DOWNARROW [ ESC-j ]
1347 Retrieve the next command line. If you first enter some text
1348 and then press DOWNARROW, it will retrieve the next command
1349 which begins with that text.
1350 TAB Complete the partial filename to the left of the cursor. If it
1352 matches more than one filename, the first match is entered into
1353 the command line. Repeated TABs will cycle thru the other
1354 matching filenames. If the completed filename is a directory, a
1355 "/" is appended to the filename. (On MS-DOS systems, a "\" is
1356 appended.) The environment variable LESSSEPARATOR can be used
1357 to specify a different character to append to a directory name.
1358 BACKTAB [ ESC-TAB ]
1360 Like, TAB, but cycles in the reverse direction thru the matching
1361 filenames.
1362 ^L Complete the partial filename to the left of the cursor. If it
1364 matches more than one filename, all matches are entered into the
1365 command line (if they fit).
1366 ^U (Unix and OS/2) or ESC (MS-DOS)
1368 Delete the entire command line, or cancel the command if the
1369 command line is empty. If you have changed your line-kill char‐
1370 acter in Unix to something other than ^U, that character is used
1371 instead of ^U.
1372 ^G Delete the entire command line and return to the main prompt.
1374
1376 You may define your own less commands by creating a lesskey source
1377 file. This file specifies a set of command keys and an action associ‐
1378 ated with each key. You may also change the line-editing keys (see
1379 LINE EDITING), and set environment variables used by less. See the
1380 lesskey(1) manual page for details about the file format.
1381 If the environment variable LESSKEYIN is set, less uses that as the
1383 name of the lesskey source file. Otherwise, less looks in a standard
1384 place for the lesskey source file: On Unix systems, less looks for a
1385 lesskey file called "$XDG_CONFIG_HOME/lesskey" or "$HOME/.con‐
1386 fig/lesskey" or "$HOME/.lesskey". On MS-DOS and Windows systems, less
1387 looks for a lesskey file called "$HOME/_lesskey", and if it is not
1388 found there, then looks for a lesskey file called "_lesskey" in any di‐
1389 rectory specified in the PATH environment variable. On OS/2 systems,
1390 less looks for a lesskey file called "$HOME/lesskey.ini", and if it is
1391 not found, then looks for a lesskey file called "lesskey.ini" in any
1392 directory specified in the INIT environment variable, and if it not
1393 found there, then looks for a lesskey file called "lesskey.ini" in any
1394 directory specified in the PATH environment variable.
1395 A system-wide lesskey source file may also be set up to provide key
1397 bindings. If a key is defined in both a local lesskey file and in the
1398 system-wide file, key bindings in the local file take precedence over
1399 those in the system-wide file. If the environment variable
1400 LESSKEYIN_SYSTEM is set, less uses that as the name of the system-wide
1401 lesskey file. Otherwise, less looks in a standard place for the sys‐
1402 tem-wide lesskey file: On Unix systems, the system-wide lesskey file is
1403 /usr/local/etc/syslesskey. (However, if less was built with a differ‐
1404 ent sysconf directory than /usr/local/etc, that directory is where the
1405 sysless file is found.) On MS-DOS and Windows systems, the system-wide
1406 lesskey file is c:\_syslesskey. On OS/2 systems, the system-wide
1407 lesskey file is c:\syslesskey.ini.
1408 Previous versions of less (before v582) used lesskey files with a bina‐
1410 ry format, produced by the lesskey program. It is no longer necessary
1411 to use the lesskey program.
1412
1414 You may define an "input preprocessor" for less. Before less opens a
1415 file, it first gives your input preprocessor a chance to modify the way
1416 the contents of the file are displayed. An input preprocessor is sim‐
1417 ply an executable program (or shell script), which writes the contents
1418 of the file to a different file, called the replacement file. The con‐
1419 tents of the replacement file are then displayed in place of the con‐
1420 tents of the original file. However, it will appear to the user as if
1421 the original file is opened; that is, less will display the original
1422 filename as the name of the current file.
1423 An input preprocessor receives one command line argument, the original
1425 filename, as entered by the user. It should create the replacement
1426 file, and when finished, print the name of the replacement file to its
1427 standard output. If the input preprocessor does not output a replace‐
1428 ment filename, less uses the original file, as normal. The input pre‐
1429 processor is not called when viewing standard input. To set up an in‐
1430 put preprocessor, set the LESSOPEN environment variable to a command
1431 line which will invoke your input preprocessor. This command line
1432 should include one occurrence of the string "%s", which will be re‐
1433 placed by the filename when the input preprocessor command is invoked.
1434 When less closes a file opened in such a way, it will call another pro‐
1436 gram, called the input postprocessor, which may perform any desired
1437 clean-up action (such as deleting the replacement file created by
1438 LESSOPEN). This program receives two command line arguments, the orig‐
1439 inal filename as entered by the user, and the name of the replacement
1440 file. To set up an input postprocessor, set the LESSCLOSE environment
1441 variable to a command line which will invoke your input postprocessor.
1442 It may include two occurrences of the string "%s"; the first is re‐
1443 placed with the original name of the file and the second with the name
1444 of the replacement file, which was output by LESSOPEN.
1445 For example, on many Unix systems, these two scripts will allow you to
1447 keep files in compressed format, but still let less view them directly:
1448 lessopen.sh:
1450 #! /bin/sh
1451 case "$1" in
1452 *.Z) TEMPFILE=$(mktemp)
1453 uncompress -c $1 >$TEMPFILE 2>/dev/null
1454 if [ -s $TEMPFILE ]; then
1455 echo $TEMPFILE
1456 else
1457 rm -f $TEMPFILE
1458 fi
1459 ;;
1460 esac
1461 lessclose.sh:
1463 #! /bin/sh
1464 rm $2
1465 To use these scripts, put them both where they can be executed and set
1467 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
1468 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
1469 types of compressed files, and so on.
1470 It is also possible to set up an input preprocessor to pipe the file
1472 data directly to less, rather than putting the data into a replacement
1473 file. This avoids the need to decompress the entire file before start‐
1474 ing to view it. An input preprocessor that works this way is called an
1475 input pipe. An input pipe, instead of writing the name of a replace‐
1476 ment file on its standard output, writes the entire contents of the re‐
1477 placement file on its standard output. If the input pipe does not
1478 write any characters on its standard output, then there is no replace‐
1479 ment file and less uses the original file, as normal. To use an input
1480 pipe, make the first character in the LESSOPEN environment variable a
1481 vertical bar (|) to signify that the input preprocessor is an input
1482 pipe. As with non-pipe input preprocessors, the command string must
1483 contain one occurrence of %s, which is replaced with the filename of
1484 the input file.
1485 For example, on many Unix systems, this script will work like the pre‐
1487 vious example scripts:
1488 lesspipe.sh:
1490 #! /bin/sh
1491 case "$1" in
1492 *.Z) uncompress -c $1 2>/dev/null
1493 ;;
1494 *) exit 1
1495 ;;
1496 esac
1497 exit $?
1498 To use this script, put it where it can be executed and set
1500 LESSOPEN="|lesspipe.sh %s".
1501 Note that a preprocessor cannot output an empty file, since that is in‐
1503 terpreted as meaning there is no replacement, and the original file is
1504 used. To avoid this, if LESSOPEN starts with two vertical bars, the
1505 exit status of the script determines the behavior when the output is
1506 empty. If the output is empty and the exit status is zero, the empty
1507 output is considered to be replacement text. If the output is empty
1508 and the exit status is nonzero, the original file is used. For compat‐
1509 ibility with previous versions of less, if LESSOPEN starts with only
1510 one vertical bar, the exit status of the preprocessor is ignored.
1511 When an input pipe is used, a LESSCLOSE postprocessor can be used, but
1513 it is usually not necessary since there is no replacement file to clean
1514 up. In this case, the replacement file name passed to the LESSCLOSE
1515 postprocessor is "-".
1516 For compatibility with previous versions of less, the input preproces‐
1518 sor or pipe is not used if less is viewing standard input. However, if
1519 the first character of LESSOPEN is a dash (-), the input preprocessor
1520 is used on standard input as well as other files. In this case, the
1521 dash is not considered to be part of the preprocessor command. If
1522 standard input is being viewed, the input preprocessor is passed a file
1523 name consisting of a single dash. Similarly, if the first two charac‐
1524 ters of LESSOPEN are vertical bar and dash (|-) or two vertical bars
1525 and a dash (||-), the input pipe is used on standard input as well as
1526 other files. Again, in this case the dash is not considered to be part
1527 of the input pipe command.
1528 There are used following files to set up default preprocessor:
1530 /etc/profile.d/less.sh
1531 /etc/profile.d/less.csh
1532 These files set up /usr/bin/lesspipe.sh as a default filter. An user
1533 defined filter can be specified in ~/.lessfilter. This file should have
1534 an execute bit set and accept only one parameter, which represents a
1535 filename. If the user defined filter process the file, zero should be
1536 returned. Otherwise ~/.lessfilter tries to handle the file.
1537
1540 There are three types of characters in the input file:
1541 normal characters
1543 can be displayed directly to the screen.
1544 control characters
1546 should not be displayed directly, but are expected to be found
1547 in ordinary text files (such as backspace and tab).
1548 binary characters
1550 should not be displayed directly and are not expected to be
1551 found in text files.
1552 A "character set" is simply a description of which characters are to be
1554 considered normal, control, and binary. The LESSCHARSET environment
1555 variable may be used to select a character set. Possible values for
1556 LESSCHARSET are:
1557 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1559 with values between 32 and 126 are normal, and all others are
1560 binary.
1561 iso8859
1563 Selects an ISO 8859 character set. This is the same as ASCII,
1564 except characters between 160 and 255 are treated as normal
1565 characters.
1566 latin1 Same as iso8859.
1568 latin9 Same as iso8859.
1570 dos Selects a character set appropriate for MS-DOS.
1572 ebcdic Selects an EBCDIC character set.
1574 IBM-1047
1576 Selects an EBCDIC character set used by OS/390 Unix Services.
1577 This is the EBCDIC analogue of latin1. You get similar results
1578 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1579 environment.
1580 koi8-r Selects a Russian character set.
1582 next Selects a character set appropriate for NeXT computers.
1584 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1586 UTF-8 is special in that it supports multi-byte characters in
1587 the input file. It is the only character set that supports mul‐
1588 ti-byte characters.
1589 windows
1591 Selects a character set appropriate for Microsoft Windows (cp
1592 1251).
1593 In rare cases, it may be desired to tailor less to use a character set
1595 other than the ones definable by LESSCHARSET. In this case, the envi‐
1596 ronment variable LESSCHARDEF can be used to define a character set. It
1597 should be set to a string where each character in the string represents
1598 one character in the character set. The character "." is used for a
1599 normal character, "c" for control, and "b" for binary. A decimal num‐
1600 ber may be used for repetition. For example, "bccc4b." would mean
1601 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are bina‐
1602 ry, and 8 is normal. All characters after the last are taken to be the
1603 same as the last, so characters 9 through 255 would be normal. (This
1604 is an example, and does not necessarily represent any real character
1605 set.)
1606 This table shows the value of LESSCHARDEF which is equivalent to each
1608 of the possible values for LESSCHARSET:
1609 ascii 8bcccbcc18b95.b
1611 dos 8bcccbcc12bc5b95.b.
1612 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1613 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1614 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1615 191.b
1616 iso8859 8bcccbcc18b95.33b.
1617 koi8-r 8bcccbcc18b95.b128.
1618 latin1 8bcccbcc18b95.33b.
1619 next 8bcccbcc18b95.bb125.bb
1620 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1622 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
1623 LANG environment variables, then the default character set is utf-8.
1624 If that string is not found, but your system supports the setlocale in‐
1626 terface, less will use setlocale to determine the character set. set‐
1627 locale is controlled by setting the LANG or LC_CTYPE environment vari‐
1628 ables.
1629 Finally, if the setlocale interface is also not available, the default
1631 character set is latin1.
1632 Control and binary characters are displayed in standout (reverse
1634 video). Each such character is displayed in caret notation if possible
1635 (e.g. ^A for control-A). Caret notation is used only if inverting the
1636 0100 bit results in a normal printable character. Otherwise, the char‐
1637 acter is displayed as a hex number in angle brackets. This format can
1638 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1639 may begin with a "*" and one character to select the display attribute:
1640 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1641 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1642 attribute is assumed. The remainder of LESSBINFMT is a string which
1643 may include one printf-style escape sequence (a % followed by x, X, o,
1644 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1645 are displayed in underlined hexadecimal surrounded by brackets. The
1646 default if no LESSBINFMT is specified is "*s<%02X>". Warning: the re‐
1647 sult of expanding the character via LESSBINFMT must be less than 31
1648 characters.
1649 When the character set is utf-8, the LESSUTFBINFMT environment variable
1651 acts similarly to LESSBINFMT but it applies to Unicode code points that
1652 were successfully decoded but are unsuitable for display (e.g., unas‐
1653 signed code points). Its default value is "<U+%04lX>". Note that
1654 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1655 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1656 LESSBINFMT so its setting, if any, will have priority. Problematic
1657 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1658 complete but non-shortest form sequence, invalid octets, and stray
1659 trailing octets) are displayed individually using LESSBINFMT so as to
1660 facilitate diagnostic of how the UTF-8 file is ill-formed.
1661 When the character set is utf-8, in rare cases it may be desirable to
1663 override the Unicode definition of the type of certain characters. For
1664 example, characters in a Private Use Area are normally treated as con‐
1665 trol characters, but if you are using a custom font with printable
1666 characters in that range, it may be desirable to tell less to treat
1667 such characters as printable. This can be done by setting the LESSUT‐
1668 FCHARDEF environment variable to a comma-separated list of character
1669 type definitions. Each character type definition consists of either
1670 one hexadecimal codepoint or a pair of codepoints separated by a dash,
1671 followed by a colon and a type character. Each hexadecimal codepoint
1672 may optionally be preceded by a "U" or "U+". If a pair of codepoints
1673 is given, the type is set for all characters inclusively between the
1674 two values. If there are multiple comma-separated codepoint values,
1675 they must be in ascending numerical order. The type character may be
1676 one of:
1677 p A normal printable character.
1679 w A wide (2-space) printable character.
1681 b A binary (non-printable) character.
1683 c A composing (zero width) character.
1685 For example, setting LESSUTFCHARDEF to
1687 E000-F8FF:p,F0000-FFFFD:p,100000-10FFFD:p
1689 would make all Private Use Area characters be treated as printable.
1691
1693 The -P option allows you to tailor the prompt to your preference. The
1694 string given to the -P option replaces the specified prompt string.
1695 Certain characters in the string are interpreted specially. The prompt
1696 mechanism is rather complicated to provide flexibility, but the ordi‐
1697 nary user need not understand the details of constructing personalized
1698 prompt strings.
1699 A percent sign followed by a single character is expanded according to
1701 what the following character is. (References to the input file size
1702 below refer to the preprocessed size, if an input preprocessor is being
1703 used.)
1704 %bX Replaced by the byte offset into the current input file. The b
1706 is followed by a single character (shown as X above) which spec‐
1707 ifies the line whose byte offset is to be used. If the charac‐
1708 ter is a "t", the byte offset of the top line in the display is
1709 used, an "m" means use the middle line, a "b" means use the bot‐
1710 tom line, a "B" means use the line just after the bottom line,
1711 and a "j" means use the "target" line, as specified by the -j
1712 option.
1713 %B Replaced by the size of the current input file.
1715 %c Replaced by the column number of the text appearing in the first
1717 column of the screen.
1718 %dX Replaced by the page number of a line in the input file. The
1720 line to be used is determined by the X, as with the %b option.
1721 %D Replaced by the number of pages in the input file, or equiva‐
1723 lently, the page number of the last line in the input file.
1724 %E Replaced by the name of the editor (from the VISUAL environment
1726 variable, or the EDITOR environment variable if VISUAL is not
1727 defined). See the discussion of the LESSEDIT feature below.
1728 %f Replaced by the name of the current input file.
1730 %F Replaced by the last component of the name of the current input
1732 file.
1733 %g Replaced by the shell-escaped name of the current input file.
1735 This is useful when the expanded string will be used in a shell
1736 command, such as in LESSEDIT.
1737 %i Replaced by the index of the current file in the list of input
1739 files.
1740 %lX Replaced by the line number of a line in the input file. The
1742 line to be used is determined by the X, as with the %b option.
1743 %L Replaced by the line number of the last line in the input file.
1745 %m Replaced by the total number of input files.
1747 %pX Replaced by the percent into the current input file, based on
1749 byte offsets. The line used is determined by the X as with the
1750 %b option.
1751 %PX Replaced by the percent into the current input file, based on
1753 line numbers. The line used is determined by the X as with the
1754 %b option.
1755 %s Same as %B.
1757 %t Causes any trailing spaces to be removed. Usually used at the
1759 end of the string, but may appear anywhere.
1760 %T Normally expands to the word "file". However if viewing files
1762 via a tags list using the -t option, it expands to the word
1763 "tag".
1764 %x Replaced by the name of the next input file in the list.
1766 If any item is unknown (for example, the file size if input is a pipe),
1768 a question mark is printed instead.
1769 The format of the prompt string can be changed depending on certain
1771 conditions. A question mark followed by a single character acts like
1772 an "IF": depending on the following character, a condition is evaluat‐
1773 ed. If the condition is true, any characters following the question
1774 mark and condition character, up to a period, are included in the
1775 prompt. If the condition is false, such characters are not included.
1776 A colon appearing between the question mark and the period can be used
1777 to establish an "ELSE": any characters between the colon and the period
1778 are included in the string if and only if the IF condition is false.
1779 Condition characters (which follow a question mark) may be:
1780 ?a True if any characters have been included in the prompt so far.
1782 ?bX True if the byte offset of the specified line is known.
1784 ?B True if the size of current input file is known.
1786 ?c True if the text is horizontally shifted (%c is not zero).
1788 ?dX True if the page number of the specified line is known.
1790 ?e True if at end-of-file.
1792 ?f True if there is an input filename (that is, if input is not a
1794 pipe).
1795 ?lX True if the line number of the specified line is known.
1797 ?L True if the line number of the last line in the file is known.
1799 ?m True if there is more than one input file.
1801 ?n True if this is the first prompt in a new input file.
1803 ?pX True if the percent into the current input file, based on byte
1805 offsets, of the specified line is known.
1806 ?PX True if the percent into the current input file, based on line
1808 numbers, of the specified line is known.
1809 ?s Same as "?B".
1811 ?x True if there is a next input file (that is, if the current in‐
1813 put file is not the last one).
1814 Any characters other than the special ones (question mark, colon, peri‐
1816 od, percent, and backslash) become literally part of the prompt. Any
1817 of the special characters may be included in the prompt literally by
1818 preceding it with a backslash.
1819 Some examples:
1821 ?f%f:Standard input.
1823 This prompt prints the filename, if known; otherwise the string "Stan‐
1825 dard input".
1826 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1828 This prompt would print the filename, if known. The filename is fol‐
1830 lowed by the line number, if known, otherwise the percent if known,
1831 otherwise the byte offset if known. Otherwise, a dash is printed. No‐
1832 tice how each question mark has a matching period, and how the % after
1833 the %pt is included literally by escaping it with a backslash.
1834 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x..%t";
1836 This prints the filename if this is the first prompt in a file, fol‐
1838 lowed by the "file N of N" message if there is more than one input
1839 file. Then, if we are at end-of-file, the string "(END)" is printed
1840 followed by the name of the next file, if there is one. Finally, any
1841 trailing spaces are truncated. This is the default prompt. For refer‐
1842 ence, here are the defaults for the other two prompts (-m and -M re‐
1843 spectively). Each is broken into two lines here for readability only.
1844 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x.:
1846 ?pB%pB\%:byte %bB?s/%s...%t
1847 ?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :
1849 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1850 And here is the default message produced by the = command:
1852 ?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .
1854 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1855 The prompt expansion features are also used for another purpose: if an
1857 environment variable LESSEDIT is defined, it is used as the command to
1858 be executed when the v command is invoked. The LESSEDIT string is ex‐
1859 panded in the same way as the prompt strings. The default value for
1860 LESSEDIT is:
1861 %E ?lm+%lm. %g
1863 Note that this expands to the editor name, followed by a + and the line
1865 number, followed by the shell-escaped file name. If your editor does
1866 not accept the "+linenumber" syntax, or has other differences in invo‐
1867 cation syntax, the LESSEDIT variable can be changed to modify this de‐
1868 fault.
1869
1871 When the environment variable LESSSECURE is set to 1, less runs in a
1872 "secure" mode. This means these features are disabled:
1873 ! the shell command
1875 # the pshell command
1877 | the pipe command
1879 :e the examine command.
1881 v the editing command
1883 s -o log files
1885 -k use of lesskey files
1887 -t use of tags files
1889 metacharacters in filenames, such as *
1891 filename completion (TAB, ^L)
1893 history file
1895 Less can also be compiled to be permanently in "secure" mode.
1897
1899 If the environment variable LESS_IS_MORE is set to 1, or if the program
1900 is invoked via a file link named "more", less behaves (mostly) in con‐
1901 formance with the POSIX more(1) command specification. In this mode,
1902 less behaves differently in these ways:
1903 The -e option works differently. If the -e option is not set, less be‐
1905 haves as if the -e option were set. If the -e option is set, less be‐
1906 haves as if the -E option were set.
1907 The -m option works differently. If the -m option is not set, the
1909 medium prompt is used, and it is prefixed with the string "--More--".
1910 If the -m option is set, the short prompt is used.
1911 The -n option acts like the -z option. The normal behavior of the -n
1913 option is unavailable in this mode.
1914 The parameter to the -p option is taken to be a less command rather
1916 than a search pattern.
1917 The LESS environment variable is ignored, and the MORE environment
1919 variable is used in its place.
1920
1922 Environment variables may be specified either in the system environment
1923 as usual, or in a lesskey(1) file. If environment variables are de‐
1924 fined in more than one place, variables defined in a local lesskey file
1925 take precedence over variables defined in the system environment, which
1926 take precedence over variables defined in the system-wide lesskey file.
1927 COLUMNS
1929 Sets the number of columns on the screen. Takes precedence over
1930 the number of columns specified by the TERM variable. (But if
1931 you have a windowing system which supports TIOCGWINSZ or
1932 WIOCGETD, the window system's idea of the screen size takes
1933 precedence over the LINES and COLUMNS environment variables.)
1934 EDITOR The name of the editor (used for the v command).
1936 HOME Name of the user's home directory (used to find a lesskey file
1938 on Unix and OS/2 systems).
1939 HOMEDRIVE, HOMEPATH
1941 Concatenation of the HOMEDRIVE and HOMEPATH environment vari‐
1942 ables is the name of the user's home directory if the HOME vari‐
1943 able is not set (only in the Windows version).
1944 INIT Name of the user's init directory (used to find a lesskey file
1946 on OS/2 systems).
1947 LANG Language for determining the character set.
1949 LC_CTYPE
1951 Language for determining the character set.
1952 LESS Options which are passed to less automatically.
1954 LESSANSIENDCHARS
1956 Characters which may end an ANSI color escape sequence (default
1957 "m").
1958 LESSANSIMIDCHARS
1960 Characters which may appear between the ESC character and the
1961 end character in an ANSI color escape sequence (default
1962 "0123456789:;[?!"'#%()*+ ".
1963 LESSBINFMT
1965 Format for displaying non-printable, non-control characters.
1966 LESSCHARDEF
1968 Defines a character set.
1969 LESSCHARSET
1971 Selects a predefined character set.
1972 LESSCLOSE
1974 Command line to invoke the (optional) input-postprocessor.
1975 LESSECHO
1977 Name of the lessecho program (default "lessecho"). The lessecho
1978 program is needed to expand metacharacters, such as * and ?, in
1979 filenames on Unix systems.
1980 LESSEDIT
1982 Editor prototype string (used for the v command). See discus‐
1983 sion under PROMPTS.
1984 LESSGLOBALTAGS
1986 Name of the command used by the -t option to find global tags.
1987 Normally should be set to "global" if your system has the glob‐
1988 al(1) command. If not set, global tags are not used.
1989 LESSHISTFILE
1991 Name of the history file used to remember search commands and
1992 shell commands between invocations of less. If set to "-" or
1993 "/dev/null", a history file is not used. The default depends on
1994 the operating system, but is usually:
1995 Linux and Unix
1997 "$XDG_STATE_HOME/lesshst" or "$HOME/.local/state/lesshst"
1998 or "$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst".
1999 Windows and MS-DOS
2001 "$HOME/_lesshst".
2002 OS/2 "$HOME/lesshst.ini" or "$INIT/lesshst.ini".
2004 LESSHISTSIZE
2006 The maximum number of commands to save in the history file. The
2007 default is 100.
2008 LESSKEYIN
2010 Name of the default lesskey source file.
2011 LESSKEY
2013 Name of the default lesskey binary file. (Not used if
2014 "$LESSKEYIN" exists.)
2015 LESSKEYIN_SYSTEM
2017 Name of the default system-wide lesskey source file.
2018 LESSKEY_SYSTEM
2020 Name of the default system-wide lesskey binary file. (Not used
2021 if "$LESSKEYIN_SYSTEM" exists.)
2022 LESSMETACHARS
2024 List of characters which are considered "metacharacters" by the
2025 shell.
2026 LESSMETAESCAPE
2028 Prefix which less will add before each metacharacter in a com‐
2029 mand sent to the shell. If LESSMETAESCAPE is an empty string,
2030 commands containing metacharacters will not be passed to the
2031 shell.
2032 LESSOPEN
2034 Command line to invoke the (optional) input-preprocessor.
2035 LESSSECURE
2037 Runs less in "secure" mode. See discussion under SECURITY.
2038 LESSSEPARATOR
2040 String to be appended to a directory name in filename comple‐
2041 tion.
2042 LESSUTFBINFMT
2044 Format for displaying non-printable Unicode code points.
2045 LESSUTFCHARDEF
2047 Overrides the type of specified Unicode characters.
2048 LESS_COLUMNS
2050 Sets the number of columns on the screen. Unlike COLUMNS, takes
2051 precedence over the system's idea of the screen size, so it can
2052 be used to make less use less than the full screen width. If
2053 set to a negative number, sets the number of columns used to
2054 this much less than the actual screen width.
2055 LESS_LINES
2057 Sets the number of lines on the screen. Unlike LINES, takes
2058 precedence over the system's idea of the screen size, so it can
2059 be used to make less use less than the full screen height. If
2060 set to a negative number, sets the number of lines used to this
2061 much less than the actual screen height. When set, less re‐
2062 paints the entire screen on every movement command, so scrolling
2063 may be slower.
2064 LESS_DATA_DELAY
2066 Duration (in milliseconds) after starting to read data from the
2067 input, after which the "Waiting for data" message will be dis‐
2068 played. The default is 4000 (4 seconds).
2069 LESS_IS_MORE
2071 Emulate the more(1) command.
2072 LESS_TERMCAP_xx
2074 Where "xx" is any two characters, overrides the definition of
2075 the termcap "xx" capability for the terminal.
2076 LINES Sets the number of lines on the screen. Takes precedence over
2078 the number of lines specified by the TERM variable. (But if you
2079 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
2080 the window system's idea of the screen size takes precedence
2081 over the LINES and COLUMNS environment variables.)
2082 MORE Options which are passed to less automatically when running in
2084 more-compatible mode.
2085 PATH User's search path (used to find a lesskey file on MS-DOS and
2087 OS/2 systems).
2088 SHELL The shell used to execute the ! command, as well as to expand
2090 filenames.
2091 TERM The type of terminal on which less is being run.
2093 VISUAL The name of the editor (used for the v command).
2095 XDG_CONFIG_HOME
2097 Possible location of the lesskey file; see the KEY BINDINGS sec‐
2098 tion.
2099 XDG_DATA_HOME
2101 Possible location of the history file; see the description of
2102 the LESSHISTFILE environment variable.
2103 XDG_STATE_HOME
2105 Possible location of the history file; see the description of
2106 the LESSHISTFILE environment variable.
2107
2109 lesskey(1), lessecho(1)
2110
2112 Copyright (C) 1984-2023 Mark Nudelman
2113 less is part of the GNU project and is free software. You can redis‐
2115 tribute it and/or modify it under the terms of either (1) the GNU Gen‐
2116 eral Public License as published by the Free Software Foundation; or
2117 (2) the Less License. See the file README in the less distribution for
2118 more details regarding redistribution. You should have received a copy
2119 of the GNU General Public License along with the source for less; see
2120 the file COPYING. If not, write to the Free Software Foundation, 59
2121 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
2122 have received a copy of the Less License; see the file LICENSE.
2123 less is distributed in the hope that it will be useful, but WITHOUT ANY
2125 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT‐
2126 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
2127 more details.
2128
2130 Mark Nudelman
2131 Report bugs at https://github.com/gwsw/less/issues.
2132 For more information, see the less homepage at
2133 https://greenwoodsoftware.com/less
2134 Version 633: 03 May 2023 LESS(1)