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
23 Less is a program similar to more (1), but which allows backward move‐
24 ment in the file as well as forward movement. Also, less 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 vi (1). Less 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.)
31 Commands are based on both more and vi. 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.
35
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
40 "ESCAPE", then "v".
41 h or H Help: display a summary of these commands. If you forget all
43 the other commands, remember this one.
44 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.
50 z Like SPACE, but if N is specified, it becomes the new window
52 size.
53 ESC-SPACE
55 Like SPACE, but scrolls a full screenful, even if it reaches
56 end-of-file in the process.
57 ENTER or 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.
61 d or ^D
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
65 u commands.
66 b or ^B or ESC-v
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.
71 w Like ESC-v, but if N is specified, it becomes the new window
73 size.
74 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.
79 u or ^U
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
83 and u commands.
84 ESC-) or RIGHTARROW
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.
91 ESC-( or LEFTARROW
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‐
96 mands.
97 r or ^R or ^L
99 Repaint the screen.
100 R Repaint the screen, discarding any buffered input. Useful if
102 the file is changing while it is being viewed.
103 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.)
109 ESC-F Like F, but as soon as a line is found which matches the last
111 search pattern, the terminal bell is rung and forward scrolling
112 stops.
113 g or < or ESC-<
115 Go to line N in the file, default 1 (beginning of file). (Warn‐
116 ing: this may be slow if N is large.)
117 G or > or ESC->
119 Go to line N in the file, default the end of the file. (Warn‐
120 ing: this may be slow if N is large, or if N is not specified
121 and standard input, rather than a file, is being read.)
122 p or % Go to a position N percent into the file. N should be between 0
124 and 100, and may contain a decimal point.
125 P Go to the line containing byte offset N in the file.
127 { If a left curly bracket appears in the top line displayed on the
129 screen, the { command will go to the matching right curly
130 bracket. The matching right curly bracket is positioned on the
131 bottom line of the screen. If there is more than one left curly
132 bracket on the top line, a number N may be used to specify the
133 N-th bracket on the line.
134 } If a right curly bracket appears in the bottom line displayed on
136 the screen, the } command will go to the matching left curly
137 bracket. The matching left curly bracket is positioned on the
138 top line of the screen. If there is more than one right curly
139 bracket on the top line, a number N may be used to specify the
140 N-th bracket on the line.
141 ( Like {, but applies to parentheses rather than curly brackets.
143 ) Like }, but applies to parentheses rather than curly brackets.
145 [ Like {, but applies to square brackets rather than curly brack‐
147 ets.
148 ] Like }, but applies to square brackets rather than curly brack‐
150 ets.
151 ESC-^F Followed by two characters, acts like {, but uses the two char‐
153 acters as open and close brackets, respectively. For example,
154 "ESC ^F < >" could be used to go forward to the > which matches
155 the < in the top displayed line.
156 ESC-^B Followed by two characters, acts like }, but uses the two char‐
158 acters as open and close brackets, respectively. For example,
159 "ESC ^B < >" could be used to go backward to the < which matches
160 the > in the bottom displayed line.
161 m Followed by any lowercase letter, marks the current position
163 with that letter.
164 ' (Single quote.) Followed by any lowercase letter, returns to
166 the position which was previously marked with that letter. Fol‐
167 lowed by another single quote, returns to the position at which
168 the last "large" movement command was executed. Followed by a ^
169 or $, jumps to the beginning or end of the file respectively.
170 Marks are preserved when a new file is examined, so the ' com‐
171 mand can be used to switch between input files.
172 ^X^X Same as single quote.
174 /pattern
176 Search forward in the file for the N-th line containing the pat‐
177 tern. N defaults to 1. The pattern is a regular expression, as
178 recognized by the regular expression library supplied by your
179 system. The search starts at the first line displayed (but see
180 the -a and -j options, which change this).
181 Certain characters are special if entered at the beginning of
183 the pattern; they modify the type of search rather than become
184 part of the pattern:
185 ^N or !
187 Search for lines which do NOT match the pattern.
188 ^E or *
190 Search multiple files. That is, if the search reaches
191 the END of the current file without finding a match, the
192 search continues in the next file in the command line
193 list.
194 ^F or @
196 Begin the search at the first line of the FIRST file in
197 the command line list, regardless of what is currently
198 displayed on the screen or the settings of the -a or -j
199 options.
200 ^K Highlight any text which matches the pattern on the cur‐
202 rent screen, but don't move to the first match (KEEP cur‐
203 rent position).
204 ^R Don't interpret regular expression metacharacters; that
206 is, do a simple textual comparison.
207 ?pattern
209 Search backward in the file for the N-th line containing the
210 pattern. The search starts at the line immediately before the
211 top line displayed.
212 Certain characters are special as in the / command:
214 ^N or !
216 Search for lines which do NOT match the pattern.
217 ^E or *
219 Search multiple files. That is, if the search reaches
220 the beginning of the current file without finding a
221 match, the search continues in the previous file in the
222 command line list.
223 ^F or @
225 Begin the search at the last line of the last file in the
226 command line list, regardless of what is currently dis‐
227 played on the screen or the settings of the -a or -j
228 options.
229 ^K As in forward searches.
231 ^R As in forward searches.
233 ESC-/pattern
235 Same as "/*".
236 ESC-?pattern
238 Same as "?*".
239 n Repeat previous search, for N-th line containing the last pat‐
241 tern. If the previous search was modified by ^N, the search is
242 made for the N-th line NOT containing the pattern. If the pre‐
243 vious search was modified by ^E, the search continues in the
244 next (or previous) file if not satisfied in the current file.
245 If the previous search was modified by ^R, the search is done
246 without using regular expressions. There is no effect if the
247 previous search was modified by ^F or ^K.
248 N Repeat previous search, but in the reverse direction.
250 ESC-n Repeat previous search, but crossing file boundaries. The
252 effect is as if the previous search were modified by *.
253 ESC-N Repeat previous search, but in the reverse direction and cross‐
255 ing file boundaries.
256 ESC-u Undo search highlighting. Turn off highlighting of strings
258 matching the current search pattern. If highlighting is already
259 off because of a previous ESC-u command, turn highlighting back
260 on. Any search command will also turn highlighting back on.
261 (Highlighting can also be disabled by toggling the -G option; in
262 that case search commands do not turn highlighting back on.)
263 &pattern
265 Display only lines which match the pattern; lines which do not
266 match the pattern are not displayed. If pattern is empty (if
267 you type & immediately followed by ENTER), any filtering is
268 turned off, and all lines are displayed. While filtering is in
269 effect, an ampersand is displayed at the beginning of the
270 prompt, as a reminder that some lines in the file may be hidden.
271 Certain characters are special as in the / command:
273 ^N or !
275 Display only lines which do NOT match the pattern.
276 ^R Don't interpret regular expression metacharacters; that
278 is, do a simple textual comparison.
279 :e [filename]
281 Examine a new file. If the filename is missing, the "current"
282 file (see the :n and :p commands below) from the list of files
283 in the command line is re-examined. A percent sign (%) in the
284 filename is replaced by the name of the current file. A pound
285 sign (#) is replaced by the name of the previously examined
286 file. However, two consecutive percent signs are simply
287 replaced with a single percent sign. This allows you to enter a
288 filename that contains a percent sign in the name. Similarly,
289 two consecutive pound signs are replaced with a single pound
290 sign. The filename is inserted into the command line list of
291 files so that it can be seen by subsequent :n and :p commands.
292 If the filename consists of several files, they are all inserted
293 into the list of files and the first one is examined. If the
294 filename contains one or more spaces, the entire filename should
295 be enclosed in double quotes (also see the -" option).
296 ^X^V or E
298 Same as :e. Warning: some systems use ^V as a special literal‐
299 ization character. On such systems, you may not be able to use
300 ^V.
301 :n Examine the next file (from the list of files given in the com‐
303 mand line). If a number N is specified, the N-th next file is
304 examined.
305 :p Examine the previous file in the command line list. If a number
307 N is specified, the N-th previous file is examined.
308 :x Examine the first file in the command line list. If a number N
310 is specified, the N-th file in the list is examined.
311 :d Remove the current file from the list of files.
313 t Go to the next tag, if there were more than one matches for the
315 current tag. See the -t option for more details about tags.
316 T Go to the previous tag, if there were more than one matches for
318 the current tag.
319 = or ^G or :f
321 Prints some information about the file being viewed, including
322 its name and the line number and byte offset of the bottom line
323 being displayed. If possible, it also prints the length of the
324 file, the number of lines in the file and the percent of the
325 file above the last displayed line.
326 - Followed by one of the command line option letters (see OPTIONS
328 below), this will change the setting of that option and print a
329 message describing the new setting. If a ^P (CONTROL-P) is
330 entered immediately after the dash, the setting of the option is
331 changed but no message is printed. If the option letter has a
332 numeric value (such as -b or -h), or a string value (such as -P
333 or -t), a new value may be entered after the option letter. If
334 no new value is entered, a message describing the current set‐
335 ting is printed and nothing is changed.
336 -- Like the - command, but takes a long option name (see OPTIONS
338 below) rather than a single option letter. You must press ENTER
339 or RETURN after typing the option name. A ^P immediately after
340 the second dash suppresses printing of a message describing the
341 new setting, as in the - command.
342 -+ Followed by one of the command line option letters this will
344 reset the option to its default setting and print a message
345 describing the new setting. (The "-+X" command does the same
346 thing as "-+X" on the command line.) This does not work for
347 string-valued options.
348 --+ Like the -+ command, but takes a long option name rather than a
350 single option letter.
351 -! Followed by one of the command line option letters, this will
353 reset the option to the "opposite" of its default setting and
354 print a message describing the new setting. This does not work
355 for numeric or string-valued options.
356 --! Like the -! command, but takes a long option name rather than a
358 single option letter.
359 _ (Underscore.) Followed by one of the command line option let‐
361 ters, this will print a message describing the current setting
362 of that option. The setting of the option is not changed.
363 __ (Double underscore.) Like the _ (underscore) command, but takes
365 a long option name rather than a single option letter. You must
366 press ENTER or RETURN after typing the option name.
367 +cmd Causes the specified cmd to be executed each time a new file is
369 examined. For example, +G causes less to initially display each
370 file starting at the end rather than the beginning.
371 V Prints the version number of less being run.
373 q or Q or :q or :Q or ZZ
375 Exits less.
376 The following four commands may or may not be valid, depending on your
378 particular installation.
379 v Invokes an editor to edit the current file being viewed. The
381 editor is taken from the environment variable VISUAL if defined,
382 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei‐
383 ther VISUAL nor EDITOR is defined. See also the discussion of
384 LESSEDIT under the section on PROMPTS below.
385 ! shell-command
387 Invokes a shell to run the shell-command given. A percent sign
388 (%) in the command is replaced by the name of the current file.
389 A pound sign (#) is replaced by the name of the previously exam‐
390 ined file. "!!" repeats the last shell command. "!" with no
391 shell command simply invokes a shell. On Unix systems, the
392 shell is taken from the environment variable SHELL, or defaults
393 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
394 command processor.
395 | <m> shell-command
397 <m> represents any mark letter. Pipes a section of the input
398 file to the given shell command. The section of the file to be
399 piped is between the first line on the current screen and the
400 position marked by the letter. <m> may also be ^ or $ to indi‐
401 cate beginning or end of file respectively. If <m> is . or new‐
402 line, the current screen is piped.
403 s filename
405 Save the input to a file. This only works if the input is a
406 pipe, not an ordinary file.
407
409 Command line options are described below. Most options may be changed
410 while less is running, via the "-" command.
411 Most options may be given in one of two forms: either a dash followed
413 by a single letter, or two dashes followed by a long option name. A
414 long option name may be abbreviated as long as the abbreviation is
415 unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
416 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
417 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
418 from --quit-at-eof. Such option names need only have their first let‐
419 ter capitalized; the remainder of the name may be in either case. For
420 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
421 Options are also taken from the environment variable "LESS". For exam‐
423 ple, to avoid typing "less -options ..." each time less is invoked, you
424 might tell csh:
425 setenv LESS "-options"
427 or if you use sh:
429 LESS="-options"; export LESS
431 On MS-DOS, you don't need the quotes, but you should replace any per‐
433 cent signs in the options string by double percent signs.
434 The environment variable is parsed before the command line, so command
436 line options override the LESS environment variable. If an option
437 appears in the LESS variable, it can be reset to its default value on
438 the command line by beginning the command line option with "-+".
439 Some options like -k or -D require a string to follow the option let‐
441 ter. The string for that option is considered to end when a dollar
442 sign ($) is found. For example, you can set two -D options on MS-DOS
443 like this:
444 LESS="Dn9.1$Ds4.1"
446 If the --use-backslash option appears earlier in the options, then a
448 dollar sign or backslash may be included literally in an option string
449 by preceding it with a backslash. If the --use-backslash option is not
450 in effect, then backslashes are not treated specially, and there is no
451 way to include a dollar sign in the option string.
452 -? or --help
454 This option displays a summary of the commands accepted by less
455 (the same as the h command). (Depending on how your shell
456 interprets the question mark, it may be necessary to quote the
457 question mark, thus: "-\?".)
458 -a or --search-skip-screen
460 By default, forward searches start at the top of the displayed
461 screen and backwards searches start at the bottom of the dis‐
462 played screen (except for repeated searches invoked by the n or
463 N commands, which start after or before the "target" line
464 respectively; see the -j option for more about the target line).
465 The -a option causes forward searches to instead start at the
466 bottom of the screen and backward searches to start at the top
467 of the screen, thus skipping all lines displayed on the screen.
468 -A or --SEARCH-SKIP-SCREEN
470 Causes all forward searches (not just non-repeated searches) to
471 start just after the target line, and all backward searches to
472 start just before the target line. Thus, forward searches will
473 skip part of the displayed screen (from the first line up to and
474 including the target line). Similarly backwards searches will
475 skip the displayed screen from the last line up to and including
476 the target line. This was the default behavior in less versions
477 prior to 441.
478 -bn or --buffers=n
480 Specifies the amount of buffer space less will use for each
481 file, in units of kilobytes (1024 bytes). By default 64K of
482 buffer space is used for each file (unless the file is a pipe;
483 see the -B option). The -b option specifies instead that n
484 kilobytes of buffer space should be used for each file. If n is
485 -1, buffer space is unlimited; that is, the entire file can be
486 read into memory.
487 -B or --auto-buffers
489 By default, when data is read from a pipe, buffers are allocated
490 automatically as needed. If a large amount of data is read from
491 the pipe, this can cause a large amount of memory to be allo‐
492 cated. The -B option disables this automatic allocation of buf‐
493 fers for pipes, so that only 64K (or the amount of space speci‐
494 fied by the -b option) is used for the pipe. Warning: use of -B
495 can result in erroneous display, since only the most recently
496 viewed part of the piped data is kept in memory; any earlier
497 data is lost.
498 -c or --clear-screen
500 Causes full screen repaints to be painted from the top line
501 down. By default, full screen repaints are done by scrolling
502 from the bottom of the screen.
503 -C or --CLEAR-SCREEN
505 Same as -c, for compatibility with older versions of less.
506 -d or --dumb
508 The -d option suppresses the error message normally displayed if
509 the terminal is dumb; that is, lacks some important capability,
510 such as the ability to clear the screen or scroll backward. The
511 -d option does not otherwise change the behavior of less on a
512 dumb terminal.
513 -Dxcolor or --color=xcolor
515 [MS-DOS only] Sets the color of the text displayed. x is a sin‐
516 gle character which selects the type of text whose color is
517 being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
518 color is a pair of numbers separated by a period. The first
519 number selects the foreground color and the second selects the
520 background color of the text. A single number N is the same as
521 N.M, where M is the normal background color.
522 -e or --quit-at-eof
525 Causes less to automatically exit the second time it reaches
526 end-of-file. By default, the only way to exit less is via the
527 "q" command.
528 -E or --QUIT-AT-EOF
530 Causes less to automatically exit the first time it reaches end-
531 of-file.
532 -f or --force
534 Forces non-regular files to be opened. (A non-regular file is a
535 directory or a device special file.) Also suppresses the warn‐
536 ing message when a binary file is opened. By default, less will
537 refuse to open non-regular files. Note that some operating sys‐
538 tems will not allow directories to be read, even if -f is set.
539 -F or --quit-if-one-screen
541 Causes less to automatically exit if the entire file can be dis‐
542 played on the first screen.
543 -g or --hilite-search
545 Normally, less will highlight ALL strings which match the last
546 search command. The -g option changes this behavior to high‐
547 light only the particular string which was found by the last
548 search command. This can cause less to run somewhat faster than
549 the default.
550 -G or --HILITE-SEARCH
552 The -G option suppresses all highlighting of strings found by
553 search commands.
554 --old-bot
556 Reverts to the old bottom of screen behavior. This can be some‐
557 times desirable if the long lines are not wrapped correctly
558 when reaching the bottom of the terminal, while scrolling
559 forward.
560 -hn or --max-back-scroll=n
562 Specifies a maximum number of lines to scroll backward. If it
563 is necessary to scroll backward more than n lines, the screen is
564 repainted in a forward direction instead. (If the terminal does
565 not have the ability to scroll backward, -h0 is implied.)
566 -i or --ignore-case
568 Causes searches to ignore case; that is, uppercase and lowercase
569 are considered identical. This option is ignored if any upper‐
570 case letters appear in the search pattern; in other words, if a
571 pattern contains uppercase letters, then that search does not
572 ignore case.
573 -I or --IGNORE-CASE
575 Like -i, but searches ignore case even if the pattern contains
576 uppercase letters.
577 -jn or --jump-target=n
579 Specifies a line on the screen where the "target" line is to be
580 positioned. The target line is the line specified by any com‐
581 mand to search for a pattern, jump to a line number, jump to a
582 file percentage or jump to a tag. The screen line may be speci‐
583 fied by a number: the top line on the screen is 1, the next is
584 2, and so on. The number may be negative to specify a line rel‐
585 ative to the bottom of the screen: the bottom line on the screen
586 is -1, the second to the bottom is -2, and so on. Alternately,
587 the screen line may be specified as a fraction of the height of
588 the screen, starting with a decimal point: .5 is in the middle
589 of the screen, .3 is three tenths down from the first line, and
590 so on. If the line is specified as a fraction, the actual line
591 number is recalculated if the terminal window is resized, so
592 that the target line remains at the specified fraction of the
593 screen height. If any form of the -j option is used, forward
594 searches begin at the line immediately after the target line,
595 and backward searches begin at the target line, unless changed
596 by -a or -A. For example, if "-j4" is used, the target line is
597 the fourth line on the screen, so forward searches begin at the
598 fifth line on the screen.
599 -J or --status-column
601 Displays a status column at the left edge of the screen. The
602 status column shows the lines that matched the current search.
603 The status column is also used if the -w or -W option is in
604 effect.
605 -kfilename or --lesskey-file=filename
607 Causes less to open and interpret the named file as a lesskey
608 (1) file. Multiple -k options may be specified. If the LESSKEY
609 or LESSKEY_SYSTEM environment variable is set, or if a lesskey
610 file is found in a standard place (see KEY BINDINGS), it is also
611 used as a lesskey file.
612 -K or --quit-on-intr
614 Causes less to exit immediately (with status 2) when an inter‐
615 rupt character (usually ^C) is typed. Normally, an interrupt
616 character causes less to stop whatever it is doing and return to
617 its command prompt. Note that use of this option makes it
618 impossible to return to the command prompt from the "F" command.
619 -L or --no-lessopen
621 Ignore the LESSOPEN environment variable (see the INPUT PRE‐
622 PROCESSOR section below). This option can be set from within
623 less, but it will apply only to files opened subsequently, not
624 to the file which is currently open.
625 -m or --long-prompt
627 Causes less to prompt verbosely (like more), with the percent
628 into the file. By default, less prompts with a colon.
629 -M or --LONG-PROMPT
631 Causes less to prompt even more verbosely than more.
632 -n or --line-numbers
634 Suppresses line numbers. The default (to use line numbers) may
635 cause less to run more slowly in some cases, especially with a
636 very large input file. Suppressing line numbers with the -n
637 option will avoid this problem. Using line numbers means: the
638 line number will be displayed in the verbose prompt and in the =
639 command, and the v command will pass the current line number to
640 the editor (see also the discussion of LESSEDIT in PROMPTS
641 below).
642 -N or --LINE-NUMBERS
644 Causes a line number to be displayed at the beginning of each
645 line in the display.
646 -ofilename or --log-file=filename
648 Causes less to copy its input to the named file as it is being
649 viewed. This applies only when the input file is a pipe, not an
650 ordinary file. If the file already exists, less will ask for
651 confirmation before overwriting it.
652 -Ofilename or --LOG-FILE=filename
654 The -O option is like -o, but it will overwrite an existing file
655 without asking for confirmation.
656 If no log file has been specified, the -o and -O options can be
658 used from within less to specify a log file. Without a file
659 name, they will simply report the name of the log file. The "s"
660 command is equivalent to specifying -o from within less.
661 -ppattern or --pattern=pattern
663 The -p option on the command line is equivalent to specifying
664 +/pattern; that is, it tells less to start at the first occur‐
665 rence of pattern in the file.
666 -Pprompt or --prompt=prompt
668 Provides a way to tailor the three prompt styles to your own
669 preference. This option would normally be put in the LESS envi‐
670 ronment variable, rather than being typed in with each less com‐
671 mand. Such an option must either be the last option in the LESS
672 variable, or be terminated by a dollar sign. -Ps followed by a
673 string changes the default (short) prompt to that string. -Pm
674 changes the medium (-m) prompt. -PM changes the long (-M)
675 prompt. -Ph changes the prompt for the help screen. -P=
676 changes the message printed by the = command. -Pw changes the
677 message printed while waiting for data (in the F command). All
678 prompt strings consist of a sequence of letters and special
679 escape sequences. See the section on PROMPTS for more details.
680 -q or --quiet or --silent
682 Causes moderately "quiet" operation: the terminal bell is not
683 rung if an attempt is made to scroll past the end of the file or
684 before the beginning of the file. If the terminal has a "visual
685 bell", it is used instead. The bell will be rung on certain
686 other errors, such as typing an invalid character. The default
687 is to ring the terminal bell in all such cases.
688 -Q or --QUIET or --SILENT
690 Causes totally "quiet" operation: the terminal bell is never
691 rung.
692 -r or --raw-control-chars
694 Causes "raw" control characters to be displayed. The default is
695 to display control characters using the caret notation; for
696 example, a control-A (octal 001) is displayed as "^A". Warning:
697 when the -r option is used, less cannot keep track of the actual
698 appearance of the screen (since this depends on how the screen
699 responds to each type of control character). Thus, various dis‐
700 play problems may result, such as long lines being split in the
701 wrong place.
702 -R or --RAW-CONTROL-CHARS
704 Like -r, but only ANSI "color" escape sequences are output in
705 "raw" form. Unlike -r, the screen appearance is maintained cor‐
706 rectly in most cases. ANSI "color" escape sequences are
707 sequences of the form:
708 ESC [ ... m
710 where the "..." is zero or more color specification characters
712 For the purpose of keeping track of screen appearance, ANSI
713 color escape sequences are assumed to not move the cursor. You
714 can make less think that characters other than "m" can end ANSI
715 color escape sequences by setting the environment variable
716 LESSANSIENDCHARS to the list of characters which can end a color
717 escape sequence. And you can make less think that characters
718 other than the standard ones may appear between the ESC and the
719 m by setting the environment variable LESSANSIMIDCHARS to the
720 list of characters which can appear.
721 -s or --squeeze-blank-lines
723 Causes consecutive blank lines to be squeezed into a single
724 blank line. This is useful when viewing nroff output.
725 -S or --chop-long-lines
727 Causes lines longer than the screen width to be chopped (trun‐
728 cated) rather than wrapped. That is, the portion of a long line
729 that does not fit in the screen width is not shown. The default
730 is to wrap long lines; that is, display the remainder on the
731 next line.
732 -ttag or --tag=tag
734 The -t option, followed immediately by a TAG, will edit the file
735 containing that tag. For this to work, tag information must be
736 available; for example, there may be a file in the current
737 directory called "tags", which was previously built by ctags (1)
738 or an equivalent command. If the environment variable LESSGLOB‐
739 ALTAGS is set, it is taken to be the name of a command compati‐
740 ble with global (1), and that command is executed to find the
741 tag. (See http://www.gnu.org/software/global/global.html). The
742 -t option may also be specified from within less (using the -
743 command) as a way of examining a new file. The command ":t" is
744 equivalent to specifying -t from within less.
745 -Ttagsfile or --tag-file=tagsfile
747 Specifies a tags file to be used instead of "tags".
748 -u or --underline-special
750 Causes backspaces and carriage returns to be treated as print‐
751 able characters; that is, they are sent to the terminal when
752 they appear in the input.
753 -U or --UNDERLINE-SPECIAL
755 Causes backspaces, tabs and carriage returns to be treated as
756 control characters; that is, they are handled as specified by
757 the -r option.
758 By default, if neither -u nor -U is given, backspaces which
760 appear adjacent to an underscore character are treated spe‐
761 cially: the underlined text is displayed using the terminal's
762 hardware underlining capability. Also, backspaces which appear
763 between two identical characters are treated specially: the
764 overstruck text is printed using the terminal's hardware bold‐
765 face capability. Other backspaces are deleted, along with the
766 preceding character. Carriage returns immediately followed by a
767 newline are deleted. Other carriage returns are handled as
768 specified by the -r option. Text which is overstruck or under‐
769 lined can be searched for if neither -u nor -U is in effect.
770 -V or --version
772 Displays the version number of less.
773 -w or --hilite-unread
775 Temporarily highlights the first "new" line after a forward
776 movement of a full page. The first "new" line is the line imme‐
777 diately following the line previously at the bottom of the
778 screen. Also highlights the target line after a g or p command.
779 The highlight is removed at the next command which causes move‐
780 ment. The entire line is highlighted, unless the -J option is
781 in effect, in which case only the status column is highlighted.
782 -W or --HILITE-UNREAD
784 Like -w, but temporarily highlights the first new line after any
785 forward movement command larger than one line.
786 -xn,... or --tabs=n,...
788 Sets tab stops. If only one n is specified, tab stops are set
789 at multiples of n. If multiple values separated by commas are
790 specified, tab stops are set at those positions, and then con‐
791 tinue with the same spacing as the last two. For example,
792 -x9,17 will set tabs at positions 9, 17, 25, 33, etc. The
793 default for n is 8.
794 -X or --no-init
796 Disables sending the termcap initialization and deinitialization
797 strings to the terminal. This is sometimes desirable if the
798 deinitialization string does something unnecessary, like clear‐
799 ing the screen.
800 -yn or --max-forw-scroll=n
802 Specifies a maximum number of lines to scroll forward. If it is
803 necessary to scroll forward more than n lines, the screen is
804 repainted instead. The -c or -C option may be used to repaint
805 from the top of the screen if desired. By default, any forward
806 movement causes scrolling.
807 -[z]n or --window=n
809 Changes the default scrolling window size to n lines. The
810 default is one screenful. The z and w commands can also be used
811 to change the window size. The "z" may be omitted for compati‐
812 bility with some versions of more. If the number n is negative,
813 it indicates n lines less than the current screen size. For
814 example, if the screen is 24 lines, -z-4 sets the scrolling win‐
815 dow to 20 lines. If the screen is resized to 40 lines, the
816 scrolling window automatically changes to 36 lines.
817 -"cc or --quotes=cc
819 Changes the filename quoting character. This may be necessary
820 if you are trying to name a file which contains both spaces and
821 quote characters. Followed by a single character, this changes
822 the quote character to that character. Filenames containing a
823 space should then be surrounded by that character rather than by
824 double quotes. Followed by two characters, changes the open
825 quote to the first character, and the close quote to the second
826 character. Filenames containing a space should then be preceded
827 by the open quote character and followed by the close quote
828 character. Note that even after the quote characters are
829 changed, this option remains -" (a dash followed by a double
830 quote).
831 -~ or --tilde
833 Normally lines after end of file are displayed as a single tilde
834 (~). This option causes lines after end of file to be displayed
835 as blank lines.
836 -# or --shift
838 Specifies the default number of positions to scroll horizontally
839 in the RIGHTARROW and LEFTARROW commands. If the number speci‐
840 fied is zero, it sets the default number of positions to one
841 half of the screen width. Alternately, the number may be speci‐
842 fied as a fraction of the width of the screen, starting with a
843 decimal point: .5 is half of the screen width, .3 is three
844 tenths of the screen width, and so on. If the number is speci‐
845 fied as a fraction, the actual number of scroll positions is
846 recalculated if the terminal window is resized, so that the
847 actual scroll remains at the specified fraction of the screen
848 width.
849 --follow-name
851 Normally, if the input file is renamed while an F command is
852 executing, less will continue to display the contents of the
853 original file despite its name change. If --follow-name is
854 specified, during an F command less will periodically attempt to
855 reopen the file by name. If the reopen succeeds and the file is
856 a different file from the original (which means that a new file
857 has been created with the same name as the original (now
858 renamed) file), less will display the contents of that new file.
859 --no-keypad
861 Disables sending the keypad initialization and deinitialization
862 strings to the terminal. This is sometimes useful if the keypad
863 strings make the numeric keypad behave in an undesirable manner.
864 --use-backslash
866 This option changes the interpretations of options which follow
867 this one. After the --use-backslash option, any backslash in an
868 option string is removed and the following character is taken
869 literally. This allows a dollar sign to be included in option
870 strings.
871 -- A command line argument of "--" marks the end of option argu‐
873 ments. Any arguments following this are interpreted as file‐
874 names. This can be useful when viewing a file whose name begins
875 with a "-" or "+".
876 + If a command line option begins with +, the remainder of that
878 option is taken to be an initial command to less. For example,
879 +G tells less to start at the end of the file rather than the
880 beginning, and +/xyz tells it to start at the first occurrence
881 of "xyz" in the file. As a special case, +<number> acts like
882 +<number>g; that is, it starts the display at the specified line
883 number (however, see the caveat under the "g" command above).
884 If the option starts with ++, the initial command applies to
885 every file being viewed, not just the first one. The + command
886 described previously may also be used to set (or change) an ini‐
887 tial command for every file.
888
891 When entering command line at the bottom of the screen (for example, a
892 filename for the :e command, or the pattern for a search command), cer‐
893 tain keys can be used to manipulate the command line. Most commands
894 have an alternate form in [ brackets ] which can be used if a key does
895 not exist on a particular keyboard. (Note that the forms beginning
896 with ESC do not work in some MS-DOS and Windows systems because ESC is
897 the line erase character.) Any of these special keys may be entered
898 literally by preceding it with the "literal" character, either ^V or
899 ^A. A backslash itself may also be entered literally by entering two
900 backslashes.
901 LEFTARROW [ ESC-h ]
903 Move the cursor one space to the left.
904 RIGHTARROW [ ESC-l ]
906 Move the cursor one space to the right.
907 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
909 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur‐
910 sor one word to the left.
911 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
913 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur‐
914 sor one word to the right.
915 HOME [ ESC-0 ]
917 Move the cursor to the beginning of the line.
918 END [ ESC-$ ]
920 Move the cursor to the end of the line.
921 BACKSPACE
923 Delete the character to the left of the cursor, or cancel the
924 command if the command line is empty.
925 DELETE or [ ESC-x ]
927 Delete the character under the cursor.
928 ^BACKSPACE [ ESC-BACKSPACE ]
930 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
931 word to the left of the cursor.
932 ^DELETE [ ESC-X or ESC-DELETE ]
934 (That is, CONTROL and DELETE simultaneously.) Delete the word
935 under the cursor.
936 UPARROW [ ESC-k ]
938 Retrieve the previous command line. If you first enter some
939 text and then press UPARROW, it will retrieve the previous com‐
940 mand which begins with that text.
941 DOWNARROW [ ESC-j ]
943 Retrieve the next command line. If you first enter some text
944 and then press DOWNARROW, it will retrieve the next command
945 which begins with that text.
946 TAB Complete the partial filename to the left of the cursor. If it
948 matches more than one filename, the first match is entered into
949 the command line. Repeated TABs will cycle thru the other
950 matching filenames. If the completed filename is a directory, a
951 "/" is appended to the filename. (On MS-DOS systems, a "\" is
952 appended.) The environment variable LESSSEPARATOR can be used
953 to specify a different character to append to a directory name.
954 BACKTAB [ ESC-TAB ]
956 Like, TAB, but cycles in the reverse direction thru the matching
957 filenames.
958 ^L Complete the partial filename to the left of the cursor. If it
960 matches more than one filename, all matches are entered into the
961 command line (if they fit).
962 ^U (Unix and OS/2) or ESC (MS-DOS)
964 Delete the entire command line, or cancel the command if the
965 command line is empty. If you have changed your line-kill char‐
966 acter in Unix to something other than ^U, that character is used
967 instead of ^U.
968 ^G Delete the entire command line and return to the main prompt.
970
973 You may define your own less commands by using the program lesskey (1)
974 to create a lesskey file. This file specifies a set of command keys
975 and an action associated with each key. You may also use lesskey to
976 change the line-editing keys (see LINE EDITING), and to set environment
977 variables. If the environment variable LESSKEY is set, less uses that
978 as the name of the lesskey file. Otherwise, less looks in a standard
979 place for the lesskey file: On Unix systems, less looks for a lesskey
980 file called "$HOME/.less". On MS-DOS and Windows systems, less looks
981 for a lesskey file called "$HOME/_less", and if it is not found there,
982 then looks for a lesskey file called "_less" in any directory specified
983 in the PATH environment variable. On OS/2 systems, less looks for a
984 lesskey file called "$HOME/less.ini", and if it is not found, then
985 looks for a lesskey file called "less.ini" in any directory specified
986 in the INIT environment variable, and if it not found there, then looks
987 for a lesskey file called "less.ini" in any directory specified in the
988 PATH environment variable. See the lesskey manual page for more
989 details.
990 A system-wide lesskey file may also be set up to provide key bindings.
992 If a key is defined in both a local lesskey file and in the system-wide
993 file, key bindings in the local file take precedence over those in the
994 system-wide file. If the environment variable LESSKEY_SYSTEM is set,
995 less uses that as the name of the system-wide lesskey file. Otherwise,
996 less looks in a standard place for the system-wide lesskey file: On
997 Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
998 (However, if less was built with a different sysconf directory than
999 /usr/local/etc, that directory is where the sysless file is found.) On
1000 MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys‐
1001 less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
1002
1005 You may define an "input preprocessor" for less. Before less opens a
1006 file, it first gives your input preprocessor a chance to modify the way
1007 the contents of the file are displayed. An input preprocessor is sim‐
1008 ply an executable program (or shell script), which writes the contents
1009 of the file to a different file, called the replacement file. The con‐
1010 tents of the replacement file are then displayed in place of the con‐
1011 tents of the original file. However, it will appear to the user as if
1012 the original file is opened; that is, less will display the original
1013 filename as the name of the current file.
1014 An input preprocessor receives one command line argument, the original
1016 filename, as entered by the user. It should create the replacement
1017 file, and when finished, print the name of the replacement file to its
1018 standard output. If the input preprocessor does not output a replace‐
1019 ment filename, less uses the original file, as normal. The input pre‐
1020 processor is not called when viewing standard input. To set up an
1021 input preprocessor, set the LESSOPEN environment variable to a command
1022 line which will invoke your input preprocessor. This command line
1023 should include one occurrence of the string "%s", which will be
1024 replaced by the filename when the input preprocessor command is
1025 invoked.
1026 When less closes a file opened in such a way, it will call another pro‐
1028 gram, called the input postprocessor, which may perform any desired
1029 clean-up action (such as deleting the replacement file created by
1030 LESSOPEN). This program receives two command line arguments, the orig‐
1031 inal filename as entered by the user, and the name of the replacement
1032 file. To set up an input postprocessor, set the LESSCLOSE environment
1033 variable to a command line which will invoke your input postprocessor.
1034 It may include two occurrences of the string "%s"; the first is
1035 replaced with the original name of the file and the second with the
1036 name of the replacement file, which was output by LESSOPEN.
1037 For example, on many Unix systems, these two scripts will allow you to
1039 keep files in compressed format, but still let less view them directly:
1040 lessopen.sh:
1042 #! /bin/sh
1043 case "$1" in
1044 *.Z) uncompress -
1045 if [ -s /tmp/less.$$ ]; then
1046 echo /tmp/less.$$
1047 else
1048 rm -f /tmp/less.$$
1049 fi
1050 ;;
1051 esac
1052 lessclose.sh:
1054 #! /bin/sh
1055 rm $2
1056 To use these scripts, put them both where they can be executed and set
1058 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
1059 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
1060 types of compressed files, and so on.
1061 It is also possible to set up an input preprocessor to pipe the file
1063 data directly to less, rather than putting the data into a replacement
1064 file. This avoids the need to decompress the entire file before start‐
1065 ing to view it. An input preprocessor that works this way is called an
1066 input pipe. An input pipe, instead of writing the name of a replace‐
1067 ment file on its standard output, writes the entire contents of the
1068 replacement file on its standard output. If the input pipe does not
1069 write any characters on its standard output, then there is no replace‐
1070 ment file and less uses the original file, as normal. To use an input
1071 pipe, make the first character in the LESSOPEN environment variable a
1072 vertical bar (|) to signify that the input preprocessor is an input
1073 pipe.
1074 For example, on many Unix systems, this script will work like the pre‐
1076 vious example scripts:
1077 lesspipe.sh:
1079 #! /bin/sh
1080 case "$1" in
1081 *.Z) uncompress -c $1 2>/dev/null
1082 *) exit 1
1083 ;;
1084 esac
1085 exit $?
1086 To use this script, put it where it can be executed and set
1088 LESSOPEN="|lesspipe.sh %s".
1089 Note that a preprocessor cannot output an empty file, since that is
1091 interpreted as meaning there is no replacement, and the original file
1092 is used. To avoid this, if LESSOPEN starts with two vertical bars, the
1093 exit status of the script becomes meaningful. If the exit status is
1094 zero, the output is considered to be replacement text, even if it
1095 empty. If the exit status is nonzero, any output is ignored and the
1096 original file is used. For compatibility with previous versions of
1097 less, if LESSOPEN starts with only one vertical bar, the exit status of
1098 the preprocessor is ignored.
1099 When an input pipe is used, a LESSCLOSE postprocessor can be used, but
1101 it is usually not necessary since there is no replacement file to clean
1102 up. In this case, the replacement file name passed to the LESSCLOSE
1103 postprocessor is "-".
1104 For compatibility with previous versions of less, the input preproces‐
1106 sor or pipe is not used if less is viewing standard input. However, if
1107 the first character of LESSOPEN is a dash (-), the input preprocessor
1108 is used on standard input as well as other files. In this case, the
1109 dash is not considered to be part of the preprocessor command. If
1110 standard input is being viewed, the input preprocessor is passed a file
1111 name consisting of a single dash. Similarly, if the first two charac‐
1112 ters of LESSOPEN are vertical bar and dash (|-) or two vertical bars
1113 and a dash (||-), the input pipe is used on standard input as well as
1114 other files. Again, in this case the dash is not considered to be part
1115 of the input pipe command.
1116 There are used following files to set up default preprocessor:
1118 /etc/profile.d/less.sh
1119 /etc/profile.d/less.csh
1120 These files set up /usr/bin/lesspipe.sh as a default filter. An user
1121 defined filter can be specified in ~/.lessfilter. This file should have
1122 an execute bit set and accept only one parameter, which represents a
1123 filename. If the user defined filter process the file, zero should be
1124 returned. Otherwise ~/.lessfilter tries to handle the file.
1125
1128 There are three types of characters in the input file:
1129 normal characters
1131 can be displayed directly to the screen.
1132 control characters
1134 should not be displayed directly, but are expected to be found
1135 in ordinary text files (such as backspace and tab).
1136 binary characters
1138 should not be displayed directly and are not expected to be
1139 found in text files.
1140 A "character set" is simply a description of which characters are to be
1142 considered normal, control, and binary. The LESSCHARSET environment
1143 variable may be used to select a character set. Possible values for
1144 LESSCHARSET are:
1145 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1147 with values between 32 and 126 are normal, and all others are
1148 binary.
1149 iso8859
1151 Selects an ISO 8859 character set. This is the same as ASCII,
1152 except characters between 160 and 255 are treated as normal
1153 characters.
1154 latin1 Same as iso8859.
1156 latin9 Same as iso8859.
1158 dos Selects a character set appropriate for MS-DOS.
1160 ebcdic Selects an EBCDIC character set.
1162 IBM-1047
1164 Selects an EBCDIC character set used by OS/390 Unix Services.
1165 This is the EBCDIC analogue of latin1. You get similar results
1166 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1167 environment.
1168 koi8-r Selects a Russian character set.
1170 next Selects a character set appropriate for NeXT computers.
1172 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1174 UTF-8 is special in that it supports multi-byte characters in
1175 the input file. It is the only character set that supports
1176 multi-byte characters.
1177 windows
1179 Selects a character set appropriate for Microsoft Windows (cp
1180 1251).
1181 In rare cases, it may be desired to tailor less to use a character set
1183 other than the ones definable by LESSCHARSET. In this case, the envi‐
1184 ronment variable LESSCHARDEF can be used to define a character set. It
1185 should be set to a string where each character in the string represents
1186 one character in the character set. The character "." is used for a
1187 normal character, "c" for control, and "b" for binary. A decimal num‐
1188 ber may be used for repetition. For example, "bccc4b." would mean
1189 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
1190 binary, and 8 is normal. All characters after the last are taken to be
1191 the same as the last, so characters 9 through 255 would be normal.
1192 (This is an example, and does not necessarily represent any real char‐
1193 acter set.)
1194 This table shows the value of LESSCHARDEF which is equivalent to each
1196 of the possible values for LESSCHARSET:
1197 ascii 8bcccbcc18b95.b
1199 dos 8bcccbcc12bc5b95.b.
1200 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1201 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1202 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1203 191.b
1204 iso8859 8bcccbcc18b95.33b.
1205 koi8-r 8bcccbcc18b95.b128.
1206 latin1 8bcccbcc18b95.33b.
1207 next 8bcccbcc18b95.bb125.bb
1208 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1210 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
1211 LANG environment variables, then the default character set is utf-8.
1212 If that string is not found, but your system supports the setlocale
1214 interface, less will use setlocale to determine the character set.
1215 setlocale is controlled by setting the LANG or LC_CTYPE environment
1216 variables.
1217 Finally, if the setlocale interface is also not available, the default
1219 character set is latin1.
1220 Control and binary characters are displayed in standout (reverse
1222 video). Each such character is displayed in caret notation if possible
1223 (e.g. ^A for control-A). Caret notation is used only if inverting the
1224 0100 bit results in a normal printable character. Otherwise, the char‐
1225 acter is displayed as a hex number in angle brackets. This format can
1226 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1227 may begin with a "*" and one character to select the display attribute:
1228 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1229 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1230 attribute is assumed. The remainder of LESSBINFMT is a string which
1231 may include one printf-style escape sequence (a % followed by x, X, o,
1232 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1233 are displayed in underlined hexadecimal surrounded by brackets. The
1234 default if no LESSBINFMT is specified is "*s<%02X>". Warning: the
1235 result of expanding the character via LESSBINFMT must be less than 31
1236 characters.
1237 When the character set is utf-8, the LESSUTFBINFMT environment variable
1239 acts similarly to LESSBINFMT but it applies to Unicode code points that
1240 were successfully decoded but are unsuitable for display (e.g., unas‐
1241 signed code points). Its default value is "<U+%04lX>". Note that
1242 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1243 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1244 LESSBINFMT so its setting, if any, will have priority. Problematic
1245 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1246 complete but non-shortest form sequence, illegal octets, and stray
1247 trailing octets) are displayed individually using LESSBINFMT so as to
1248 facilitate diagnostic of how the UTF-8 file is ill-formed.
1249
1252 The -P option allows you to tailor the prompt to your preference. The
1253 string given to the -P option replaces the specified prompt string.
1254 Certain characters in the string are interpreted specially. The prompt
1255 mechanism is rather complicated to provide flexibility, but the ordi‐
1256 nary user need not understand the details of constructing personalized
1257 prompt strings.
1258 A percent sign followed by a single character is expanded according to
1260 what the following character is:
1261 %bX Replaced by the byte offset into the current input file. The b
1263 is followed by a single character (shown as X above) which spec‐
1264 ifies the line whose byte offset is to be used. If the charac‐
1265 ter is a "t", the byte offset of the top line in the display is
1266 used, an "m" means use the middle line, a "b" means use the bot‐
1267 tom line, a "B" means use the line just after the bottom line,
1268 and a "j" means use the "target" line, as specified by the -j
1269 option.
1270 %B Replaced by the size of the current input file.
1272 %c Replaced by the column number of the text appearing in the first
1274 column of the screen.
1275 %dX Replaced by the page number of a line in the input file. The
1277 line to be used is determined by the X, as with the %b option.
1278 %D Replaced by the number of pages in the input file, or equiva‐
1280 lently, the page number of the last line in the input file.
1281 %E Replaced by the name of the editor (from the VISUAL environment
1283 variable, or the EDITOR environment variable if VISUAL is not
1284 defined). See the discussion of the LESSEDIT feature below.
1285 %f Replaced by the name of the current input file.
1287 %F Replaced by the last component of the name of the current input
1289 file.
1290 %i Replaced by the index of the current file in the list of input
1292 files.
1293 %lX Replaced by the line number of a line in the input file. The
1295 line to be used is determined by the X, as with the %b option.
1296 %L Replaced by the line number of the last line in the input file.
1298 %m Replaced by the total number of input files.
1300 %pX Replaced by the percent into the current input file, based on
1302 byte offsets. The line used is determined by the X as with the
1303 %b option.
1304 %PX Replaced by the percent into the current input file, based on
1306 line numbers. The line used is determined by the X as with the
1307 %b option.
1308 %s Same as %B.
1310 %t Causes any trailing spaces to be removed. Usually used at the
1312 end of the string, but may appear anywhere.
1313 %x Replaced by the name of the next input file in the list.
1315 If any item is unknown (for example, the file size if input is a pipe),
1317 a question mark is printed instead.
1318 The format of the prompt string can be changed depending on certain
1320 conditions. A question mark followed by a single character acts like
1321 an "IF": depending on the following character, a condition is evalu‐
1322 ated. If the condition is true, any characters following the question
1323 mark and condition character, up to a period, are included in the
1324 prompt. If the condition is false, such characters are not included.
1325 A colon appearing between the question mark and the period can be used
1326 to establish an "ELSE": any characters between the colon and the period
1327 are included in the string if and only if the IF condition is false.
1328 Condition characters (which follow a question mark) may be:
1329 ?a True if any characters have been included in the prompt so far.
1331 ?bX True if the byte offset of the specified line is known.
1333 ?B True if the size of current input file is known.
1335 ?c True if the text is horizontally shifted (%c is not zero).
1337 ?dX True if the page number of the specified line is known.
1339 ?e True if at end-of-file.
1341 ?f True if there is an input filename (that is, if input is not a
1343 pipe).
1344 ?lX True if the line number of the specified line is known.
1346 ?L True if the line number of the last line in the file is known.
1348 ?m True if there is more than one input file.
1350 ?n True if this is the first prompt in a new input file.
1352 ?pX True if the percent into the current input file, based on byte
1354 offsets, of the specified line is known.
1355 ?PX True if the percent into the current input file, based on line
1357 numbers, of the specified line is known.
1358 ?s Same as "?B".
1360 ?x True if there is a next input file (that is, if the current
1362 input file is not the last one).
1363 Any characters other than the special ones (question mark, colon,
1365 period, percent, and backslash) become literally part of the prompt.
1366 Any of the special characters may be included in the prompt literally
1367 by preceding it with a backslash.
1368 Some examples:
1370 ?f%f:Standard input.
1372 This prompt prints the filename, if known; otherwise the string "Stan‐
1374 dard input".
1375 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1377 This prompt would print the filename, if known. The filename is fol‐
1379 lowed by the line number, if known, otherwise the percent if known,
1380 otherwise the byte offset if known. Otherwise, a dash is printed.
1381 Notice how each question mark has a matching period, and how the %
1382 after the %pt is included literally by escaping it with a backslash.
1383 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
1385 This prints the filename if this is the first prompt in a file, fol‐
1387 lowed by the "file N of N" message if there is more than one input
1388 file. Then, if we are at end-of-file, the string "(END)" is printed
1389 followed by the name of the next file, if there is one. Finally, any
1390 trailing spaces are truncated. This is the default prompt. For refer‐
1391 ence, here are the defaults for the other two prompts (-m and -M
1392 respectively). Each is broken into two lines here for readability
1393 only.
1394 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
1396 ?pB%pB\%:byte %bB?s/%s...%t
1397 ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
1399 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1400 And here is the default message produced by the = command:
1402 ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1404 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1405 The prompt expansion features are also used for another purpose: if an
1407 environment variable LESSEDIT is defined, it is used as the command to
1408 be executed when the v command is invoked. The LESSEDIT string is
1409 expanded in the same way as the prompt strings. The default value for
1410 LESSEDIT is:
1411 %E ?lm+%lm. %f
1413 Note that this expands to the editor name, followed by a + and the line
1415 number, followed by the file name. If your editor does not accept the
1416 "+linenumber" syntax, or has other differences in invocation syntax,
1417 the LESSEDIT variable can be changed to modify this default.
1418
1421 When the environment variable LESSSECURE is set to 1, less runs in a
1422 "secure" mode. This means these features are disabled:
1423 ! the shell command
1425 | the pipe command
1427 :e the examine command.
1429 v the editing command
1431 s -o log files
1433 -k use of lesskey files
1435 -t use of tags files
1437 metacharacters in filenames, such as *
1439 filename completion (TAB, ^L)
1441 Less can also be compiled to be permanently in "secure" mode.
1443
1446 If the environment variable LESS_IS_MORE is set to 1, or if the program
1447 is invoked via a file link named "more", less behaves (mostly) in con‐
1448 formance with the POSIX "more" command specification. In this mode,
1449 less behaves differently in these ways:
1450 The -e option works differently. If the -e option is not set, less
1452 behaves as if the -E option were set. If the -e option is set, less
1453 behaves as if the -e and -F options were set.
1454 The -m option works differently. If the -m option is not set, the
1456 medium prompt is used, and it is prefixed with the string "--More--".
1457 If the -m option is set, the short prompt is used.
1458 The -n option acts like the -z option. The normal behavior of the -n
1460 option is unavailable in this mode.
1461 The parameter to the -p option is taken to be a less command rather
1463 than a search pattern.
1464 The LESS environment variable is ignored, and the MORE environment
1466 variable is used in its place.
1467
1470 Environment variables may be specified either in the system environment
1471 as usual, or in a lesskey (1) file. If environment variables are
1472 defined in more than one place, variables defined in a local lesskey
1473 file take precedence over variables defined in the system environment,
1474 which take precedence over variables defined in the system-wide lesskey
1475 file.
1476 COLUMNS
1478 Sets the number of columns on the screen. Takes precedence over
1479 the number of columns specified by the TERM variable. (But if
1480 you have a windowing system which supports TIOCGWINSZ or
1481 WIOCGETD, the window system's idea of the screen size takes
1482 precedence over the LINES and COLUMNS environment variables.)
1483 EDITOR The name of the editor (used for the v command).
1485 HOME Name of the user's home directory (used to find a lesskey file
1487 on Unix and OS/2 systems).
1488 HOMEDRIVE, HOMEPATH
1490 Concatenation of the HOMEDRIVE and HOMEPATH environment vari‐
1491 ables is the name of the user's home directory if the HOME vari‐
1492 able is not set (only in the Windows version).
1493 INIT Name of the user's init directory (used to find a lesskey file
1495 on OS/2 systems).
1496 LANG Language for determining the character set.
1498 LC_CTYPE
1500 Language for determining the character set.
1501 LESS Options which are passed to less automatically.
1503 LESSANSIENDCHARS
1505 Characters which may end an ANSI color escape sequence (default
1506 "m").
1507 LESSANSIMIDCHARS
1509 Characters which may appear between the ESC character and the
1510 end character in an ANSI color escape sequence (default
1511 "0123456789;[?!"'#%()*+ ".
1512 LESSBINFMT
1514 Format for displaying non-printable, non-control characters.
1515 LESSCHARDEF
1517 Defines a character set.
1518 LESSCHARSET
1520 Selects a predefined character set.
1521 LESSCLOSE
1523 Command line to invoke the (optional) input-postprocessor.
1524 LESSECHO
1526 Name of the lessecho program (default "lessecho"). The lessecho
1527 program is needed to expand metacharacters, such as * and ?, in
1528 filenames on Unix systems.
1529 LESSEDIT
1531 Editor prototype string (used for the v command). See discus‐
1532 sion under PROMPTS.
1533 LESSGLOBALTAGS
1535 Name of the command used by the -t option to find global tags.
1536 Normally should be set to "global" if your system has the global
1537 (1) command. If not set, global tags are not used.
1538 LESSHISTFILE
1540 Name of the history file used to remember search commands and
1541 shell commands between invocations of less. If set to "-" or
1542 "/dev/null", a history file is not used. The default is
1543 "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
1544 Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1545 on OS/2 systems.
1546 LESSHISTSIZE
1548 The maximum number of commands to save in the history file. The
1549 default is 100.
1550 LESSKEY
1552 Name of the default lesskey(1) file.
1553 LESSKEY_SYSTEM
1555 Name of the default system-wide lesskey(1) file.
1556 LESSMETACHARS
1558 List of characters which are considered "metacharacters" by the
1559 shell.
1560 LESSMETAESCAPE
1562 Prefix which less will add before each metacharacter in a com‐
1563 mand sent to the shell. If LESSMETAESCAPE is an empty string,
1564 commands containing metacharacters will not be passed to the
1565 shell.
1566 LESSOPEN
1568 Command line to invoke the (optional) input-preprocessor.
1569 LESSSECURE
1571 Runs less in "secure" mode. See discussion under SECURITY.
1572 LESSSEPARATOR
1574 String to be appended to a directory name in filename comple‐
1575 tion.
1576 LESSUTFBINFMT
1578 Format for displaying non-printable Unicode code points.
1579 LESS_IS_MORE
1581 Emulate the more (1) command.
1582 LINES Sets the number of lines on the screen. Takes precedence over
1584 the number of lines specified by the TERM variable. (But if you
1585 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1586 the window system's idea of the screen size takes precedence
1587 over the LINES and COLUMNS environment variables.)
1588 MORE Options which are passed to less automatically when running in
1590 more compatible mode.
1591 PATH User's search path (used to find a lesskey file on MS-DOS and
1593 OS/2 systems).
1594 SHELL The shell used to execute the ! command, as well as to expand
1596 filenames.
1597 TERM The type of terminal on which less is being run.
1599 VISUAL The name of the editor (used for the v command).
1601
1604 lesskey(1)
1605
1608 Copyright (C) 1984-2012 Mark Nudelman
1609 less is part of the GNU project and is free software. You can redis‐
1611 tribute it and/or modify it under the terms of either (1) the GNU Gen‐
1612 eral Public License as published by the Free Software Foundation; or
1613 (2) the Less License. See the file README in the less distribution for
1614 more details regarding redistribution. You should have received a copy
1615 of the GNU General Public License along with the source for less; see
1616 the file COPYING. If not, write to the Free Software Foundation, 59
1617 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
1618 have received a copy of the Less License; see the file LICENSE.
1619 less is distributed in the hope that it will be useful, but WITHOUT ANY
1621 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT‐
1622 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
1623 more details.
1624
1627 Mark Nudelman
1628 Send bug reports or comments to <bug-less@gnu.org>
1629 See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
1630 of known bugs in less.
1631 For more information, see the less homepage at
1632 http://www.greenwoodsoftware.com/less.
1633 Version 458: 04 Apr 2013 LESS(1)