8 less - opposite of more
10 S
\bSY
\bYN
\bNO
\bOP
\bPS
\bSI
\bIS
\bS
11 l
\ble
\bes
\bss
\bs -
\b-?
\b?
12 l
\ble
\bes
\bss
\bs -
\b--
\b-h
\bhe
\bel
\blp
\bp
13 l
\ble
\bes
\bss
\bs -
\b-V
\bV
14 l
\ble
\bes
\bss
\bs -
\b--
\b-v
\bve
\ber
\brs
\bsi
\bio
\bon
\bn
15 l
\ble
\bes
\bss
\bs [
\b[-
\b-[
\b[+
\b+]
\b]a
\baB
\bBc
\bcC
\bCd
\bde
\beE
\bEf
\bfF
\bFg
\bgG
\bGi
\biI
\bIJ
\bJL
\bLm
\bmM
\bMn
\bnN
\bNq
\bqQ
\bQr
\brR
\bRs
\bsS
\bSu
\buU
\bUV
\bVw
\bwW
\bWX
\bX~
\b~]
\b]
16 [
\b[-
\b-b
\bb _
\bs_
\bp_
\ba_
\bc_
\be]
\b] [
\b[-
\b-h
\bh _
\bl_
\bi_
\bn_
\be_
\bs]
\b] [
\b[-
\b-j
\bj _
\bl_
\bi_
\bn_
\be]
\b] [
\b[-
\b-k
\bk _
\bk_
\be_
\by_
\bf_
\bi_
\bl_
\be]
\b]
17 [
\b[-
\b-{
\b{o
\boO
\bO}
\b} _
\bl_
\bo_
\bg_
\bf_
\bi_
\bl_
\be]
\b] [
\b[-
\b-p
\bp _
\bp_
\ba_
\bt_
\bt_
\be_
\br_
\bn]
\b] [
\b[-
\b-P
\bP _
\bp_
\br_
\bo_
\bm_
\bp_
\bt]
\b] [
\b[-
\b-t
\bt _
\bt_
\ba_
\bg]
\b]
18 [
\b[-
\b-T
\bT _
\bt_
\ba_
\bg_
\bs_
\bf_
\bi_
\bl_
\be]
\b] [
\b[-
\b-x
\bx _
\bt_
\ba_
\bb,
\b,.
\b..
\b..
\b.]
\b] [
\b[-
\b-y
\by _
\bl_
\bi_
\bn_
\be_
\bs]
\b] [
\b[-
\b-[
\b[z
\bz]
\b] _
\bl_
\bi_
\bn_
\be_
\bs]
\b]
19 [
\b[-
\b-#
\b# _
\bs_
\bh_
\bi_
\bf_
\bt]
\b] [
\b[+
\b+[
\b[+
\b+]
\b]_
\bc_
\bm_
\bd]
\b] [
\b[-
\b--
\b-]
\b] [
\b[_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be]
\b].
\b..
\b..
\b.
20 (See the OPTIONS section for alternate option syntax with
24 D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
25 _
\bL_
\be_
\bs_
\bs is a program similar to _
\bm_
\bo_
\br_
\be (1), but which allows
26 backward movement in the file as well as forward movement.
27 Also, _
\bl_
\be_
\bs_
\bs does not have to read the entire input file
28 before starting, so with large input files it starts up
29 faster than text editors like _
\bv_
\bi (1). _
\bL_
\be_
\bs_
\bs uses termcap
30 (or terminfo on some systems), so it can run on a variety
31 of terminals. There is even limited support for hardcopy
32 terminals. (On a hardcopy terminal, lines which should be
33 printed at the top of the screen are prefixed with a
36 Commands are based on both _
\bm_
\bo_
\br_
\be and _
\bv_
\bi_
\b. Commands may be
37 preceded by a decimal number, called N in the descriptions
38 below. The number is used by some commands, as indicated.
41 C
\bCO
\bOM
\bMM
\bMA
\bAN
\bND
\bDS
\bS
42 In the following descriptions, ^X means control-X. ESC
43 stands for the ESCAPE key; for example ESC-v means the two
44 character sequence "ESCAPE", then "v".
46 h or H Help: display a summary of these commands. If you
47 forget all the other commands, remember this one.
49 SPACE or ^V or f or ^F
50 Scroll forward N lines, default one window (see
51 option -z below). If N is more than the screen
52 size, only the final screenful is displayed. Warn
53 ing: some systems use ^V as a special literaliza
56 z Like SPACE, but if N is specified, it becomes the
60 Like SPACE, but scrolls a full screenful, even if
64 Version 381: 17 Jan 2003 1
73 it reaches end-of-file in the process.
75 RETURN or ^N or e or ^E or j or ^J
76 Scroll forward N lines, default 1. The entire N
77 lines are displayed, even if N is more than the
81 Scroll forward N lines, default one half of the
82 screen size. If N is specified, it becomes the new
83 default for subsequent d and u commands.
86 Scroll backward N lines, default one window (see
87 option -z below). If N is more than the screen
88 size, only the final screenful is displayed.
90 w Like ESC-v, but if N is specified, it becomes the
93 y or ^Y or ^P or k or ^K
94 Scroll backward N lines, default 1. The entire N
95 lines are displayed, even if N is more than the
96 screen size. Warning: some systems use ^Y as a
97 special job control character.
100 Scroll backward N lines, default one half of the
101 screen size. If N is specified, it becomes the new
102 default for subsequent d and u commands.
105 Scroll horizontally right N characters, default
106 half the screen width (see the -# option). If a
107 number N is specified, it becomes the default for
108 future RIGHTARROW and LEFTARROW commands. While
109 the text is scrolled, it acts as though the -S
110 option (chop lines) were in effect.
113 Scroll horizontally left N characters, default half
114 the screen width (see the -# option). If a number
115 N is specified, it becomes the default for future
116 RIGHTARROW and LEFTARROW commands.
121 R Repaint the screen, discarding any buffered input.
122 Useful if the file is changing while it is being
125 F Scroll forward, and keep trying to read when the
126 end of file is reached. Normally this command
130 Version 381: 17 Jan 2003 2
139 would be used when already at the end of the file.
140 It is a way to monitor the tail of a file which is
141 growing while it is being viewed. (The behavior is
142 similar to the "tail -f" command.)
145 Go to line N in the file, default 1 (beginning of
146 file). (Warning: this may be slow if N is large.)
149 Go to line N in the file, default the end of the
150 file. (Warning: this may be slow if N is large, or
151 if N is not specified and standard input, rather
152 than a file, is being read.)
154 p or % Go to a position N percent into the file. N should
155 be between 0 and 100.
157 { If a left curly bracket appears in the top line
158 displayed on the screen, the { command will go to
159 the matching right curly bracket. The matching
160 right curly bracket is positioned on the bottom
161 line of the screen. If there is more than one left
162 curly bracket on the top line, a number N may be
163 used to specify the N-th bracket on the line.
165 } If a right curly bracket appears in the bottom line
166 displayed on the screen, the } command will go to
167 the matching left curly bracket. The matching left
168 curly bracket is positioned on the top line of the
169 screen. If there is more than one right curly
170 bracket on the top line, a number N may be used to
171 specify the N-th bracket on the line.
173 ( Like {, but applies to parentheses rather than
176 ) Like }, but applies to parentheses rather than
179 [ Like {, but applies to square brackets rather than
182 ] Like }, but applies to square brackets rather than
185 ESC-^F Followed by two characters, acts like {, but uses
186 the two characters as open and close brackets,
187 respectively. For example, "ESC ^F < >" could be
188 used to go forward to the > which matches the < in
189 the top displayed line.
191 ESC-^B Followed by two characters, acts like }, but uses
192 the two characters as open and close brackets,
196 Version 381: 17 Jan 2003 3
205 respectively. For example, "ESC ^B < >" could be
206 used to go backward to the < which matches the > in
207 the bottom displayed line.
209 m Followed by any lowercase letter, marks the current
210 position with that letter.
212 ' (Single quote.) Followed by any lowercase letter,
213 returns to the position which was previously marked
214 with that letter. Followed by another single
215 quote, returns to the position at which the last
216 "large" movement command was executed. Followed by
217 a ^ or $, jumps to the beginning or end of the file
218 respectively. Marks are preserved when a new file
219 is examined, so the ' command can be used to switch
222 ^X^X Same as single quote.
225 Search forward in the file for the N-th line con
226 taining the pattern. N defaults to 1. The pattern
227 is a regular expression, as recognized by _
\be_
\bd_
\b. The
228 search starts at the second line displayed (but see
229 the -a and -j options, which change this).
231 Certain characters are special if entered at the
232 beginning of the pattern; they modify the type of
233 search rather than become part of the pattern:
236 Search for lines which do NOT match the pat
240 Search multiple files. That is, if the
241 search reaches the END of the current file
242 without finding a match, the search contin
243 ues in the next file in the command line
247 Begin the search at the first line of the
248 FIRST file in the command line list, regard
249 less of what is currently displayed on the
250 screen or the settings of the -a or -j
253 ^K Highlight any text which matches the pattern
254 on the current screen, but don't move to the
255 first match (KEEP current position).
257 ^R Don't interpret regular expression metachar
258 acters; that is, do a simple textual
262 Version 381: 17 Jan 2003 4
274 Search backward in the file for the N-th line con
275 taining the pattern. The search starts at the line
276 immediately before the top line displayed.
278 Certain characters are special as in the / command:
281 Search for lines which do NOT match the pat
285 Search multiple files. That is, if the
286 search reaches the beginning of the current
287 file without finding a match, the search
288 continues in the previous file in the com
292 Begin the search at the last line of the
293 last file in the command line list, regard
294 less of what is currently displayed on the
295 screen or the settings of the -a or -j
298 ^K As in forward searches.
300 ^R As in forward searches.
308 n Repeat previous search, for N-th line containing
309 the last pattern. If the previous search was modi
310 fied by ^N, the search is made for the N-th line
311 NOT containing the pattern. If the previous search
312 was modified by ^E, the search continues in the
313 next (or previous) file if not satisfied in the
314 current file. If the previous search was modified
315 by ^R, the search is done without using regular
316 expressions. There is no effect if the previous
317 search was modified by ^F or ^K.
319 N Repeat previous search, but in the reverse direc
322 ESC-n Repeat previous search, but crossing file bound
323 aries. The effect is as if the previous search
328 Version 381: 17 Jan 2003 5
337 ESC-N Repeat previous search, but in the reverse direc
338 tion and crossing file boundaries.
340 ESC-u Undo search highlighting. Turn off highlighting of
341 strings matching the current search pattern. If
342 highlighting is already off because of a previous
343 ESC-u command, turn highlighting back on. Any
344 search command will also turn highlighting back on.
345 (Highlighting can also be disabled by toggling the
346 -G option; in that case search commands do not turn
347 highlighting back on.)
350 Examine a new file. If the filename is missing,
351 the "current" file (see the :n and :p commands
352 below) from the list of files in the command line
353 is re-examined. A percent sign (%) in the filename
354 is replaced by the name of the current file. A
355 pound sign (#) is replaced by the name of the pre
356 viously examined file. However, two consecutive
357 percent signs are simply replaced with a single
358 percent sign. This allows you to enter a filename
359 that contains a percent sign in the name. Simi
360 larly, two consecutive pound signs are replaced
361 with a single pound sign. The filename is inserted
362 into the command line list of files so that it can
363 be seen by subsequent :n and :p commands. If the
364 filename consists of several files, they are all
365 inserted into the list of files and the first one
366 is examined. If the filename contains one or more
367 spaces, the entire filename should be enclosed in
368 double quotes (also see the -" option).
371 Same as :e. Warning: some systems use ^V as a spe
372 cial literalization character. On such systems,
373 you may not be able to use ^V.
375 :n Examine the next file (from the list of files given
376 in the command line). If a number N is specified,
377 the N-th next file is examined.
379 :p Examine the previous file in the command line list.
380 If a number N is specified, the N-th previous file
383 :x Examine the first file in the command line list.
384 If a number N is specified, the N-th file in the
387 :d Remove the current file from the list of files.
389 t Go to the next tag, if there were more than one
390 matches for the current tag. See the -t option for
394 Version 381: 17 Jan 2003 6
403 more details about tags.
405 T Go to the previous tag, if there were more than one
406 matches for the current tag.
409 Prints some information about the file being
410 viewed, including its name and the line number and
411 byte offset of the bottom line being displayed. If
412 possible, it also prints the length of the file,
413 the number of lines in the file and the percent of
414 the file above the last displayed line.
416 - Followed by one of the command line option letters
417 (see OPTIONS below), this will change the setting
418 of that option and print a message describing the
419 new setting. If a ^P (CONTROL-P) is entered imme
420 diately after the dash, the setting of the option
421 is changed but no message is printed. If the
422 option letter has a numeric value (such as -b or
423 -h), or a string value (such as -P or -t), a new
424 value may be entered after the option letter. If
425 no new value is entered, a message describing the
426 current setting is printed and nothing is changed.
428 -- Like the - command, but takes a long option name
429 (see OPTIONS below) rather than a single option
430 letter. You must press RETURN after typing the
431 option name. A ^P immediately after the second
432 dash suppresses printing of a message describing
433 the new setting, as in the - command.
435 -+ Followed by one of the command line option letters
436 this will reset the option to its default setting
437 and print a message describing the new setting.
438 (The "-+_
\bX" command does the same thing as "-+_
\bX" on
439 the command line.) This does not work for string-
442 --+ Like the -+ command, but takes a long option name
443 rather than a single option letter.
445 -! Followed by one of the command line option letters,
446 this will reset the option to the "opposite" of its
447 default setting and print a message describing the
448 new setting. This does not work for numeric or
449 string-valued options.
451 --! Like the -! command, but takes a long option name
452 rather than a single option letter.
454 _ (Underscore.) Followed by one of the command line
455 option letters, this will print a message describ
456 ing the current setting of that option. The
460 Version 381: 17 Jan 2003 7
469 setting of the option is not changed.
471 __ (Double underscore.) Like the _ (underscore) com
472 mand, but takes a long option name rather than a
473 single option letter. You must press RETURN after
474 typing the option name.
476 +cmd Causes the specified cmd to be executed each time a
477 new file is examined. For example, +G causes _
\bl_
\be_
\bs_
\bs
478 to initially display each file starting at the end
479 rather than the beginning.
481 V Prints the version number of _
\bl_
\be_
\bs_
\bs being run.
483 q or Q or :q or :Q or ZZ
484 Exits _
\bl_
\be_
\bs_
\bs_
\b.
486 The following four commands may or may not be valid,
487 depending on your particular installation.
490 v Invokes an editor to edit the current file being
491 viewed. The editor is taken from the environment
492 variable VISUAL if defined, or EDITOR if VISUAL is
493 not defined, or defaults to "vi" if neither VISUAL
494 nor EDITOR is defined. See also the discussion of
495 LESSEDIT under the section on PROMPTS below.
498 Invokes a shell to run the shell-command given. A
499 percent sign (%) in the command is replaced by the
500 name of the current file. A pound sign (#) is
501 replaced by the name of the previously examined
502 file. "!!" repeats the last shell command. "!"
503 with no shell command simply invokes a shell. On
504 Unix systems, the shell is taken from the environ
505 ment variable SHELL, or defaults to "sh". On MS-
506 DOS and OS/2 systems, the shell is the normal com
510 <m> represents any mark letter. Pipes a section of
511 the input file to the given shell command. The
512 section of the file to be piped is between the
513 first line on the current screen and the position
514 marked by the letter. <m> may also be ^ or $ to
515 indicate beginning or end of file respectively. If
516 <m> is . or newline, the current screen is piped.
519 Save the input to a file. This only works if the
520 input is a pipe, not an ordinary file.
526 Version 381: 17 Jan 2003 8
535 O
\bOP
\bPT
\bTI
\bIO
\bON
\bNS
\bS
536 Command line options are described below. Most options
537 may be changed while _
\bl_
\be_
\bs_
\bs is running, via the "-" command.
539 Most options may be given in one of two forms: either a
540 dash followed by a single letter, or two dashes followed
541 by a long option name. A long option name may be abbrevi
542 ated as long as the abbreviation is unambiguous. For
543 example, --quit-at-eof may be abbreviated --quit, but not
544 --qui, since both --quit-at-eof and --quiet begin with
545 --qui. Some long option names are in uppercase, such as
546 --QUIT-AT-EOF, as distinct from --quit-at-eof. Such
547 option names need only have their first letter capital
548 ized; the remainder of the name may be in either case.
549 For example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
551 Options are also taken from the environment variable
552 "LESS". For example, to avoid typing "less -options ..."
553 each time _
\bl_
\be_
\bs_
\bs is invoked, you might tell _
\bc_
\bs_
\bh_
\b:
555 setenv LESS "-options"
557 or if you use _
\bs_
\bh_
\b:
559 LESS="-options"; export LESS
561 On MS-DOS, you don't need the quotes, but you should
562 replace any percent signs in the options string by double
565 The environment variable is parsed before the command
566 line, so command line options override the LESS environ
567 ment variable. If an option appears in the LESS variable,
568 it can be reset to its default value on the command line
569 by beginning the command line option with "-+".
571 For options like -P or -D which take a following string, a
572 dollar sign ($) must be used to signal the end of the
573 string. For example, to set two -D options on MS-DOS, you
574 must have a dollar sign between them, like this:
580 This option displays a summary of the commands
581 accepted by _
\bl_
\be_
\bs_
\bs (the same as the h command).
582 (Depending on how your shell interprets the ques
583 tion mark, it may be necessary to quote the ques
584 tion mark, thus: "-\?".)
586 -a or --search-skip-screen
587 Causes searches to start after the last line dis
588 played on the screen, thus skipping all lines
592 Version 381: 17 Jan 2003 9
601 displayed on the screen. By default, searches
602 start at the second line on the screen (or after
603 the last found line; see the -j option).
605 -b_
\bn or --buffers=_
\bn
606 Specifies the amount of buffer space _
\bl_
\be_
\bs_
\bs will use
607 for each file, in units of kilobytes (1024 bytes).
608 By default 64K of buffer space is used for each
609 file (unless the file is a pipe; see the -B
610 option). The -b option specifies instead that _
\bn
611 kilobytes of buffer space should be used for each
612 file. If _
\bn is -1, buffer space is unlimited; that
613 is, the entire file is read into memory.
616 By default, when data is read from a pipe, buffers
617 are allocated automatically as needed. If a large
618 amount of data is read from the pipe, this can
619 cause a large amount of memory to be allocated.
620 The -B option disables this automatic allocation of
621 buffers for pipes, so that only 64K (or the amount
622 of space specified by the -b option) is used for
623 the pipe. Warning: use of -B can result in erro
624 neous display, since only the most recently viewed
625 part of the file is kept in memory; any earlier
629 Causes full screen repaints to be painted from the
630 top line down. By default, full screen repaints
631 are done by scrolling from the bottom of the
635 The -C option is like -c, but the screen is cleared
636 before it is repainted.
639 The -d option suppresses the error message normally
640 displayed if the terminal is dumb; that is, lacks
641 some important capability, such as the ability to
642 clear the screen or scroll backward. The -d option
643 does not otherwise change the behavior of _
\bl_
\be_
\bs_
\bs on a
646 -Dx
\bx_
\bc_
\bo_
\bl_
\bo_
\br or --color=x
\bx_
\bc_
\bo_
\bl_
\bo_
\br
647 [MS-DOS only] Sets the color of the text displayed.
648 x
\bx is a single character which selects the type of
649 text whose color is being set: n=normal, s=stand
650 out, d=bold, u=underlined, k=blink. _
\bc_
\bo_
\bl_
\bo_
\br is a
651 pair of numbers separated by a period. The first
652 number selects the foreground color and the second
653 selects the background color of the text. A single
654 number _
\bN is the same as _
\bN_
\b._
\b0.
658 Version 381: 17 Jan 2003 10
668 Causes _
\bl_
\be_
\bs_
\bs to automatically exit the second time
669 it reaches end-of-file. By default, the only way
670 to exit _
\bl_
\be_
\bs_
\bs is via the "q" command.
673 Causes _
\bl_
\be_
\bs_
\bs to automatically exit the first time it
677 Forces non-regular files to be opened. (A non-reg
678 ular file is a directory or a device special file.)
679 Also suppresses the warning message when a binary
680 file is opened. By default, _
\bl_
\be_
\bs_
\bs will refuse to
681 open non-regular files.
683 -F or --quit-if-one-screen
684 Causes _
\bl_
\be_
\bs_
\bs to automatically exit if the entire
685 file can be displayed on the first screen.
687 -g or --hilite-search
688 Normally, _
\bl_
\be_
\bs_
\bs will highlight ALL strings which
689 match the last search command. The -g option
690 changes this behavior to highlight only the partic
691 ular string which was found by the last search com
692 mand. This can cause _
\bl_
\be_
\bs_
\bs to run somewhat faster
695 -G or --HILITE-SEARCH
696 The -G option suppresses all highlighting of
697 strings found by search commands.
699 -h_
\bn or ---max-back-scroll=_
\bn
700 Specifies a maximum number of lines to scroll back
701 ward. If it is necessary to scroll backward more
702 than _
\bn lines, the screen is repainted in a forward
703 direction instead. (If the terminal does not have
704 the ability to scroll backward, -h0 is implied.)
707 Causes searches to ignore case; that is, uppercase
708 and lowercase are considered identical. This
709 option is ignored if any uppercase letters appear
710 in the search pattern; in other words, if a pattern
711 contains uppercase letters, then that search does
715 Like -i, but searches ignore case even if the pat
716 tern contains uppercase letters.
718 -j_
\bn or --jump-target=_
\bn
719 Specifies a line on the screen where the "target"
720 line is to be positioned. A target line is the
724 Version 381: 17 Jan 2003 11
733 object of a text search, tag search, jump to a line
734 number, jump to a file percentage, or jump to a
735 marked position. The screen line is specified by a
736 number: the top line on the screen is 1, the next
737 is 2, and so on. The number may be negative to
738 specify a line relative to the bottom of the
739 screen: the bottom line on the screen is -1, the
740 second to the bottom is -2, and so on. If the -j
741 option is used, searches begin at the line immedi
742 ately after the target line. For example, if "-j4"
743 is used, the target line is the fourth line on the
744 screen, so searches begin at the fifth line on the
747 -J or --status-column
748 Displays a status column at the left edge of the
749 screen. The status column shows the lines that
750 matched the current search. The status column is
751 also used if the -w or -W option is in effect.
753 -k_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be or --lesskey-file=_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be
754 Causes _
\bl_
\be_
\bs_
\bs to open and interpret the named file as
755 a _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by (1) file. Multiple -k options may be
756 specified. If the LESSKEY or LESSKEY_SYSTEM envi
757 ronment variable is set, or if a lesskey file is
758 found in a standard place (see KEY BINDINGS), it is
759 also used as a _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by file.
762 Ignore the LESSOPEN environment variable (see the
763 INPUT PREPROCESSOR section below). This option can
764 be set from within _
\bl_
\be_
\bs_
\bs, but it will apply only to
765 files opened subsequently, not to the file which is
769 Causes _
\bl_
\be_
\bs_
\bs to prompt verbosely (like _
\bm_
\bo_
\br_
\be), with
770 the percent into the file. By default, _
\bl_
\be_
\bs_
\bs
771 prompts with a colon.
774 Causes _
\bl_
\be_
\bs_
\bs to prompt even more verbosely than
778 Suppresses line numbers. The default (to use line
779 numbers) may cause _
\bl_
\be_
\bs_
\bs to run more slowly in some
780 cases, especially with a very large input file.
781 Suppressing line numbers with the -n option will
782 avoid this problem. Using line numbers means: the
783 line number will be displayed in the verbose prompt
784 and in the = command, and the v command will pass
785 the current line number to the editor (see also the
786 discussion of LESSEDIT in PROMPTS below).
790 Version 381: 17 Jan 2003 12
800 Causes a line number to be displayed at the begin
801 ning of each line in the display.
803 -o_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be or --log-file=_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be
804 Causes _
\bl_
\be_
\bs_
\bs to copy its input to the named file as
805 it is being viewed. This applies only when the
806 input file is a pipe, not an ordinary file. If the
807 file already exists, _
\bl_
\be_
\bs_
\bs will ask for confirmation
808 before overwriting it.
810 -O_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be or --LOG-FILE=_
\bf_
\bi_
\bl_
\be_
\bn_
\ba_
\bm_
\be
811 The -O option is like -o, but it will overwrite an
812 existing file without asking for confirmation.
814 If no log file has been specified, the -o and -O
815 options can be used from within _
\bl_
\be_
\bs_
\bs to specify a
816 log file. Without a file name, they will simply
817 report the name of the log file. The "s" command
818 is equivalent to specifying -o from within _
\bl_
\be_
\bs_
\bs_
\b.
820 -p_
\bp_
\ba_
\bt_
\bt_
\be_
\br_
\bn or --pattern=_
\bp_
\ba_
\bt_
\bt_
\be_
\br_
\bn
821 The -p option on the command line is equivalent to
822 specifying +/_
\bp_
\ba_
\bt_
\bt_
\be_
\br_
\bn; that is, it tells _
\bl_
\be_
\bs_
\bs to
823 start at the first occurrence of _
\bp_
\ba_
\bt_
\bt_
\be_
\br_
\bn in the
826 -P_
\bp_
\br_
\bo_
\bm_
\bp_
\bt or --prompt=_
\bp_
\br_
\bo_
\bm_
\bp_
\bt
827 Provides a way to tailor the three prompt styles to
828 your own preference. This option would normally be
829 put in the LESS environment variable, rather than
830 being typed in with each _
\bl_
\be_
\bs_
\bs command. Such an
831 option must either be the last option in the LESS
832 variable, or be terminated by a dollar sign. -Ps
833 followed by a string changes the default (short)
834 prompt to that string. -Pm changes the medium (-m)
835 prompt. -PM changes the long (-M) prompt. -Ph
836 changes the prompt for the help screen. -P=
837 changes the message printed by the = command. -Pw
838 changes the message printed while waiting for data
839 (in the F command). All prompt strings consist of
840 a sequence of letters and special escape sequences.
841 See the section on PROMPTS for more details.
843 -q or --quiet or --silent
844 Causes moderately "quiet" operation: the terminal
845 bell is not rung if an attempt is made to scroll
846 past the end of the file or before the beginning of
847 the file. If the terminal has a "visual bell", it
848 is used instead. The bell will be rung on certain
849 other errors, such as typing an invalid character.
850 The default is to ring the terminal bell in all
856 Version 381: 17 Jan 2003 13
865 -Q or --QUIET or --SILENT
866 Causes totally "quiet" operation: the terminal bell
869 -r or --raw-control-chars
870 Causes "raw" control characters to be displayed.
871 The default is to display control characters using
872 the caret notation; for example, a control-A (octal
873 001) is displayed as "^A". Warning: when the -r
874 option is used, _
\bl_
\be_
\bs_
\bs cannot keep track of the
875 actual appearance of the screen (since this depends
876 on how the screen responds to each type of control
877 character). Thus, various display problems may
878 result, such as long lines being split in the wrong
881 -R or --RAW-CONTROL-CHARS
882 Like -r, but tries to keep track of the screen
883 appearance where possible. This works only if the
884 input consists of normal text and possibly some
885 ANSI "color" escape sequences, which are sequences
890 where the "..." is zero or more characters other
891 than "m". For the purpose of keeping track of
892 screen appearance, all control characters and all
893 ANSI color escape sequences are assumed to not move
894 the cursor. You can make _
\bl_
\be_
\bs_
\bs think that charac
895 ters other than "m" can end ANSI color escape
896 sequences by setting the environment variable
897 LESSANSIENDCHARS to the list of characters which
898 can end a color escape sequence.
900 -s or --squeeze-blank-lines
901 Causes consecutive blank lines to be squeezed into
902 a single blank line. This is useful when viewing
903 _
\bn_
\br_
\bo_
\bf_
\bf output.
905 -S or --chop-long-lines
906 Causes lines longer than the screen width to be
907 chopped rather than folded. That is, the portion
908 of a long line that does not fit in the screen
909 width is not shown. The default is to fold long
910 lines; that is, display the remainder on the next
913 -t_
\bt_
\ba_
\bg or --tag=_
\bt_
\ba_
\bg
914 The -t option, followed immediately by a TAG, will
915 edit the file containing that tag. For this to
916 work, tag information must be available; for exam
917 ple, there may be a file in the current directory
918 called "tags", which was previously built by _
\bc_
\bt_
\ba_
\bg_
\bs
922 Version 381: 17 Jan 2003 14
931 (1) or an equivalent command. If the environment
932 variable LESSGLOBALTAGS is set, it is taken to be
933 the name of a command compatible with _
\bg_
\bl_
\bo_
\bb_
\ba_
\bl (1),
934 and that command is executed to find the tag. (See
935 http://www.gnu.org/software/global/global.html).
936 The -t option may also be specified from within
937 _
\bl_
\be_
\bs_
\bs (using the - command) as a way of examining a
938 new file. The command ":t" is equivalent to speci
939 fying -t from within _
\bl_
\be_
\bs_
\bs_
\b.
941 -T_
\bt_
\ba_
\bg_
\bs_
\bf_
\bi_
\bl_
\be or --tag-file=_
\bt_
\ba_
\bg_
\bs_
\bf_
\bi_
\bl_
\be
942 Specifies a tags file to be used instead of "tags".
944 -u or --underline-special
945 Causes backspaces and carriage returns to be
946 treated as printable characters; that is, they are
947 sent to the terminal when they appear in the input.
949 -U or --UNDERLINE-SPECIAL
950 Causes backspaces, tabs and carriage returns to be
951 treated as control characters; that is, they are
952 handled as specified by the -r option.
954 By default, if neither -u nor -U is given,
955 backspaces which appear adjacent to an underscore
956 character are treated specially: the underlined
957 text is displayed using the terminal's hardware
958 underlining capability. Also, backspaces which
959 appear between two identical characters are treated
960 specially: the overstruck text is printed using the
961 terminal's hardware boldface capability. Other
962 backspaces are deleted, along with the preceding
963 character. Carriage returns immediately followed
964 by a newline are deleted. other carriage returns
965 are handled as specified by the -r option. Text
966 which is overstruck or underlined can be searched
967 for if neither -u nor -U is in effect.
970 Displays the version number of _
\bl_
\be_
\bs_
\bs_
\b.
972 -w or --hilite-unread
973 Temporarily highlights the first "new" line after a
974 forward movement of a full page. The first "new"
975 line is the line immediately following the line
976 previously at the bottom of the screen. Also high
977 lights the target line after a g or p command. The
978 highlight is removed at the next command which
979 causes movement. The entire line is highlighted,
980 unless the -J option is in effect, in which case
981 only the status column is highlighted.
983 -W or --HILITE-UNREAD
984 Like -w, but temporarily highlights the first new
988 Version 381: 17 Jan 2003 15
997 line after any forward movement command larger than
1000 -x_
\bn,... or --tabs=_
\bn,...
1001 Sets tab stops. If only one _
\bn is specified, tab
1002 stops are set at multiples of _
\bn. If multiple val
1003 ues separated by commas are specified, tab stops
1004 are set at those positions, and then continue with
1005 the same spacing as the last two. For example,
1006 _
\b-_
\bx_
\b9_
\b,_
\b1_
\b7 will set tabs at positions 9, 17, 25, 33,
1007 etc. The default for _
\bn is 8.
1010 Disables sending the termcap initialization and
1011 deinitialization strings to the terminal. This is
1012 sometimes desirable if the deinitialization string
1013 does something unnecessary, like clearing the
1017 Disables sending the keypad initialization and
1018 deinitialization strings to the terminal. This is
1019 sometimes useful if the keypad strings make the
1020 numeric keypad behave in an undesirable manner.
1022 -y_
\bn or --max-forw-scroll=_
\bn
1023 Specifies a maximum number of lines to scroll for
1024 ward. If it is necessary to scroll forward more
1025 than _
\bn lines, the screen is repainted instead. The
1026 -c or -C option may be used to repaint from the top
1027 of the screen if desired. By default, any forward
1028 movement causes scrolling.
1030 -[z]_
\bn or --window=_
\bn
1031 Changes the default scrolling window size to _
\bn
1032 lines. The default is one screenful. The z and w
1033 commands can also be used to change the window
1034 size. The "z" may be omitted for compatibility
1035 with _
\bm_
\bo_
\br_
\be_
\b. If the number _
\bn is negative, it indi
1036 cates _
\bn lines less than the current screen size.
1037 For example, if the screen is 24 lines, _
\b-_
\bz_
\b-_
\b4 sets
1038 the scrolling window to 20 lines. If the screen is
1039 resized to 40 lines, the scrolling window automati
1040 cally changes to 36 lines.
1042 -_
\b"_
\bc_
\bc or --quotes=_
\bc_
\bc
1043 Changes the filename quoting character. This may
1044 be necessary if you are trying to name a file which
1045 contains both spaces and quote characters. Fol
1046 lowed by a single character, this changes the quote
1047 character to that character. Filenames containing
1048 a space should then be surrounded by that character
1049 rather than by double quotes. Followed by two
1050 characters, changes the open quote to the first
1054 Version 381: 17 Jan 2003 16
1063 character, and the close quote to the second char
1064 acter. Filenames containing a space should then be
1065 preceded by the open quote character and followed
1066 by the close quote character. Note that even after
1067 the quote characters are changed, this option
1068 remains -" (a dash followed by a double quote).
1071 Normally lines after end of file are displayed as a
1072 single tilde (~). This option causes lines after
1073 end of file to be displayed as blank lines.
1076 Specifies the default number of positions to scroll
1077 horizontally in the RIGHTARROW and LEFTARROW com
1078 mands. If the number specified is zero, it sets
1079 the default number of positions to one half of the
1082 -- A command line argument of "--" marks the end of
1083 option arguments. Any arguments following this are
1084 interpreted as filenames. This can be useful when
1085 viewing a file whose name begins with a "-" or "+".
1087 + If a command line option begins with +
\b+, the remain
1088 der of that option is taken to be an initial com
1089 mand to _
\bl_
\be_
\bs_
\bs_
\b. For example, +G tells _
\bl_
\be_
\bs_
\bs to start
1090 at the end of the file rather than the beginning,
1091 and +/xyz tells it to start at the first occurrence
1092 of "xyz" in the file. As a special case, +<number>
1093 acts like +<number>g; that is, it starts the dis
1094 play at the specified line number (however, see the
1095 caveat under the "g" command above). If the option
1096 starts with ++, the initial command applies to
1097 every file being viewed, not just the first one.
1098 The + command described previously may also be used
1099 to set (or change) an initial command for every
1103 L
\bLI
\bIN
\bNE
\bE E
\bED
\bDI
\bIT
\bTI
\bIN
\bNG
\bG
1104 When entering command line at the bottom of the screen
1105 (for example, a filename for the :e command, or the pat
1106 tern for a search command), certain keys can be used to
1107 manipulate the command line. Most commands have an alter
1108 nate form in [ brackets ] which can be used if a key does
1109 not exist on a particular keyboard. (The bracketed forms
1110 do not work in the MS-DOS version.) Any of these special
1111 keys may be entered literally by preceding it with the
1112 "literal" character, either ^V or ^A. A backslash itself
1113 may also be entered literally by entering two backslashes.
1116 Move the cursor one space to the left.
1120 Version 381: 17 Jan 2003 17
1129 RIGHTARROW [ ESC-l ]
1130 Move the cursor one space to the right.
1132 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
1133 (That is, CONTROL and LEFTARROW simultaneously.)
1134 Move the cursor one word to the left.
1136 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
1137 (That is, CONTROL and RIGHTARROW simultaneously.)
1138 Move the cursor one word to the right.
1141 Move the cursor to the beginning of the line.
1144 Move the cursor to the end of the line.
1147 Delete the character to the left of the cursor, or
1148 cancel the command if the command line is empty.
1151 Delete the character under the cursor.
1153 ^BACKSPACE [ ESC-BACKSPACE ]
1154 (That is, CONTROL and BACKSPACE simultaneously.)
1155 Delete the word to the left of the cursor.
1157 ^DELETE [ ESC-X or ESC-DELETE ]
1158 (That is, CONTROL and DELETE simultaneously.)
1159 Delete the word under the cursor.
1162 Retrieve the previous command line.
1165 Retrieve the next command line.
1167 TAB Complete the partial filename to the left of the
1168 cursor. If it matches more than one filename, the
1169 first match is entered into the command line.
1170 Repeated TABs will cycle thru the other matching
1171 filenames. If the completed filename is a direc
1172 tory, a "/" is appended to the filename. (On MS-
1173 DOS systems, a "\" is appended.) The environment
1174 variable LESSSEPARATOR can be used to specify a
1175 different character to append to a directory name.
1178 Like, TAB, but cycles in the reverse direction thru
1179 the matching filenames.
1181 ^L Complete the partial filename to the left of the
1182 cursor. If it matches more than one filename, all
1186 Version 381: 17 Jan 2003 18
1195 matches are entered into the command line (if they
1198 ^U (Unix and OS/2) or ESC (MS-DOS)
1199 Delete the entire command line, or cancel the com
1200 mand if the command line is empty. If you have
1201 changed your line-kill character in Unix to some
1202 thing other than ^U, that character is used instead
1206 K
\bKE
\bEY
\bY B
\bBI
\bIN
\bND
\bDI
\bIN
\bNG
\bGS
\bS
1207 You may define your own _
\bl_
\be_
\bs_
\bs commands by using the program
1208 _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by (1) to create a lesskey file. This file specifies
1209 a set of command keys and an action associated with each
1210 key. You may also use _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by to change the line-editing
1211 keys (see LINE EDITING), and to set environment variables.
1212 If the environment variable LESSKEY is set, _
\bl_
\be_
\bs_
\bs uses that
1213 as the name of the lesskey file. Otherwise, _
\bl_
\be_
\bs_
\bs looks in
1214 a standard place for the lesskey file: On Unix systems,
1215 _
\bl_
\be_
\bs_
\bs looks for a lesskey file called "$HOME/.less". On
1216 MS-DOS and Windows systems, _
\bl_
\be_
\bs_
\bs looks for a lesskey file
1217 called "$HOME/_less", and if it is not found there, then
1218 looks for a lesskey file called "_less" in any directory
1219 specified in the PATH environment variable. On OS/2 sys
1220 tems, _
\bl_
\be_
\bs_
\bs looks for a lesskey file called
1221 "$HOME/less.ini", and if it is not found, then looks for a
1222 lesskey file called "less.ini" in any directory specified
1223 in the INIT environment variable, and if it not found
1224 there, then looks for a lesskey file called "less.ini" in
1225 any directory specified in the PATH environment variable.
1226 See the _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by manual page for more details.
1228 A system-wide lesskey file may also be set up to provide
1229 key bindings. If a key is defined in both a local lesskey
1230 file and in the system-wide file, key bindings in the
1231 local file take precedence over those in the system-wide
1232 file. If the environment variable LESSKEY_SYSTEM is set,
1233 _
\bl_
\be_
\bs_
\bs uses that as the name of the system-wide lesskey
1234 file. Otherwise, _
\bl_
\be_
\bs_
\bs looks in a standard place for the
1235 system-wide lesskey file: On Unix systems, the system-wide
1236 lesskey file is /usr/local/etc/sysless. (However, if _
\bl_
\be_
\bs_
\bs
1237 was built with a different sysconf directory than
1238 /usr/local/etc, that directory is where the sysless file
1239 is found.) On MS-DOS and Windows systems, the system-wide
1240 lesskey file is c:\_sysless. On OS/2 systems, the system-
1241 wide lesskey file is c:\sysless.ini.
1244 I
\bIN
\bNP
\bPU
\bUT
\bT P
\bPR
\bRE
\bEP
\bPR
\bRO
\bOC
\bCE
\bES
\bSS
\bSO
\bOR
\bR
1245 You may define an "input preprocessor" for _
\bl_
\be_
\bs_
\bs_
\b. Before
1246 _
\bl_
\be_
\bs_
\bs opens a file, it first gives your input preprocessor
1247 a chance to modify the way the contents of the file are
1248 displayed. An input preprocessor is simply an executable
1252 Version 381: 17 Jan 2003 19
1261 program (or shell script), which writes the contents of
1262 the file to a different file, called the replacement file.
1263 The contents of the replacement file are then displayed in
1264 place of the contents of the original file. However, it
1265 will appear to the user as if the original file is opened;
1266 that is, _
\bl_
\be_
\bs_
\bs will display the original filename as the
1267 name of the current file.
1269 An input preprocessor receives one command line argument,
1270 the original filename, as entered by the user. It should
1271 create the replacement file, and when finished, print the
1272 name of the replacement file to its standard output. If
1273 the input preprocessor does not output a replacement file
1274 name, _
\bl_
\be_
\bs_
\bs uses the original file, as normal. The input
1275 preprocessor is not called when viewing standard input.
1276 To set up an input preprocessor, set the LESSOPEN environ
1277 ment variable to a command line which will invoke your
1278 input preprocessor. This command line should include one
1279 occurrence of the string "%s", which will be replaced by
1280 the filename when the input preprocessor command is
1283 When _
\bl_
\be_
\bs_
\bs closes a file opened in such a way, it will call
1284 another program, called the input postprocessor, which may
1285 perform any desired clean-up action (such as deleting the
1286 replacement file created by LESSOPEN). This program
1287 receives two command line arguments, the original filename
1288 as entered by the user, and the name of the replacement
1289 file. To set up an input postprocessor, set the LESSCLOSE
1290 environment variable to a command line which will invoke
1291 your input postprocessor. It may include two occurrences
1292 of the string "%s"; the first is replaced with the origi
1293 nal name of the file and the second with the name of the
1294 replacement file, which was output by LESSOPEN.
1296 For example, on many Unix systems, these two scripts will
1297 allow you to keep files in compressed format, but still
1298 let _
\bl_
\be_
\bs_
\bs view them directly:
1303 *.Z) uncompress -c $1 >/tmp/less.$$ 2>/dev/null
1304 if [ -s /tmp/less.$$ ]; then
1318 Version 381: 17 Jan 2003 20
1327 To use these scripts, put them both where they can be exe
1328 cuted and set LESSOPEN="lessopen.sh %s", and
1329 LESSCLOSE="lessclose.sh %s %s". More complex LESSOPEN and
1330 LESSCLOSE scripts may be written to accept other types of
1331 compressed files, and so on.
1333 It is also possible to set up an input preprocessor to
1334 pipe the file data directly to _
\bl_
\be_
\bs_
\bs_
\b, rather than putting
1335 the data into a replacement file. This avoids the need to
1336 decompress the entire file before starting to view it. An
1337 input preprocessor that works this way is called an input
1338 pipe. An input pipe, instead of writing the name of a
1339 replacement file on its standard output, writes the entire
1340 contents of the replacement file on its standard output.
1341 If the input pipe does not write any characters on its
1342 standard output, then there is no replacement file and
1343 _
\bl_
\be_
\bs_
\bs uses the original file, as normal. To use an input
1344 pipe, make the first character in the LESSOPEN environment
1345 variable a vertical bar (|) to signify that the input pre
1346 processor is an input pipe.
1348 For example, on many Unix systems, this script will work
1349 like the previous example scripts:
1354 *.Z) uncompress -c $1 2>/dev/null
1358 To use this script, put it where it can be executed and
1359 set LESSOPEN="|lesspipe.sh %s". When an input pipe is
1360 used, a LESSCLOSE postprocessor can be used, but it is
1361 usually not necessary since there is no replacement file
1362 to clean up. In this case, the replacement file name
1363 passed to the LESSCLOSE postprocessor is "-".
1366 N
\bNA
\bAT
\bTI
\bIO
\bON
\bNA
\bAL
\bL C
\bCH
\bHA
\bAR
\bRA
\bAC
\bCT
\bTE
\bER
\bR S
\bSE
\bET
\bTS
\bS
1367 There are three types of characters in the input file:
1370 can be displayed directly to the screen.
1373 should not be displayed directly, but are expected
1374 to be found in ordinary text files (such as
1378 should not be displayed directly and are not
1379 expected to be found in text files.
1384 Version 381: 17 Jan 2003 21
1393 A "character set" is simply a description of which charac
1394 ters are to be considered normal, control, and binary.
1395 The LESSCHARSET environment variable may be used to select
1396 a character set. Possible values for LESSCHARSET are:
1398 ascii BS, TAB, NL, CR, and formfeed are control charac
1399 ters, all chars with values between 32 and 126 are
1400 normal, and all others are binary.
1403 Selects an ISO 8859 character set. This is the
1404 same as ASCII, except characters between 160 and
1405 255 are treated as normal characters.
1407 latin1 Same as iso8859.
1409 latin9 Same as iso8859.
1411 dos Selects a character set appropriate for MS-DOS.
1413 ebcdic Selects an EBCDIC character set.
1416 Selects an EBCDIC character set used by OS/390 Unix
1417 Services. This is the EBCDIC analogue of latin1.
1418 You get similar results by setting either LESS
1419 CHARSET=IBM-1047 or LC_CTYPE=en_US in your environ
1422 koi8-r Selects a Russian character set.
1424 next Selects a character set appropriate for NeXT com
1427 utf-8 Selects the UTF-8 encoding of the ISO 10646 charac
1430 In special cases, it may be desired to tailor _
\bl_
\be_
\bs_
\bs to use
1431 a character set other than the ones definable by LESS
1432 CHARSET. In this case, the environment variable LESS
1433 CHARDEF can be used to define a character set. It should
1434 be set to a string where each character in the string rep
1435 resents one character in the character set. The character
1436 "." is used for a normal character, "c" for control, and
1437 "b" for binary. A decimal number may be used for repeti
1438 tion. For example, "bccc4b." would mean character 0 is
1439 binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are binary,
1440 and 8 is normal. All characters after the last are taken
1441 to be the same as the last, so characters 9 through 255
1442 would be normal. (This is an example, and does not neces
1443 sarily represent any real character set.)
1445 This table shows the value of LESSCHARDEF which is equiva
1446 lent to each of the possible values for LESSCHARSET:
1450 Version 381: 17 Jan 2003 22
1459 ascii 8bcccbcc18b95.b
1460 dos 8bcccbcc12bc5b95.b.
1461 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1462 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1463 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1465 iso8859 8bcccbcc18b95.33b.
1466 koi8-r 8bcccbcc18b95.b128.
1467 latin1 8bcccbcc18b95.33b.
1468 next 8bcccbcc18b95.bb125.bb
1470 If neither LESSCHARSET nor LESSCHARDEF is set, but the
1471 string "UTF-8" is found in the LC_ALL, LC_TYPE or LANG
1472 environment variables, then the default character set is
1475 If that string is not found, but your system supports the
1476 _
\bs_
\be_
\bt_
\bl_
\bo_
\bc_
\ba_
\bl_
\be interface, _
\bl_
\be_
\bs_
\bs will use setlocale to determine
1477 the character set. setlocale is controlled by setting the
1478 LANG or LC_CTYPE environment variables.
1480 Finally, if the _
\bs_
\be_
\bt_
\bl_
\bo_
\bc_
\ba_
\bl_
\be interface is also not available,
1481 the default character set is latin1.
1483 Control and binary characters are displayed in standout
1484 (reverse video). Each such character is displayed in
1485 caret notation if possible (e.g. ^A for control-A). Caret
1486 notation is used only if inverting the 0100 bit results in
1487 a normal printable character. Otherwise, the character is
1488 displayed as a hex number in angle brackets. This format
1489 can be changed by setting the LESSBINFMT environment vari
1490 able. LESSBINFMT may begin with a "*" and one character
1491 to select the display attribute: "*k" is blinking, "*d" is
1492 bold, "*u" is underlined, "*s" is standout, and "*n" is
1493 normal. If LESSBINFMT does not begin with a "*", normal
1494 attribute is assumed. The remainder of LESSBINFMT is a
1495 string which may include one printf-style escape sequence
1496 (a % followed by x, X, o, d, etc.). For example, if LESS
1497 BINFMT is "*u[%x]", binary characters are displayed in
1498 underlined hexadecimal surrounded by brackets. The
1499 default if no LESSBINFMT is specified is "*s<%X>".
1502 P
\bPR
\bRO
\bOM
\bMP
\bPT
\bTS
\bS
1503 The -P option allows you to tailor the prompt to your
1504 preference. The string given to the -P option replaces
1505 the specified prompt string. Certain characters in the
1506 string are interpreted specially. The prompt mechanism is
1507 rather complicated to provide flexibility, but the ordi
1508 nary user need not understand the details of constructing
1509 personalized prompt strings.
1511 A percent sign followed by a single character is expanded
1512 according to what the following character is:
1516 Version 381: 17 Jan 2003 23
1525 %b_
\bX Replaced by the byte offset into the current input
1526 file. The b is followed by a single character
1527 (shown as _
\bX above) which specifies the line whose
1528 byte offset is to be used. If the character is a
1529 "t", the byte offset of the top line in the display
1530 is used, an "m" means use the middle line, a "b"
1531 means use the bottom line, a "B" means use the line
1532 just after the bottom line, and a "j" means use the
1533 "target" line, as specified by the -j option.
1535 %B Replaced by the size of the current input file.
1537 %c Replaced by the column number of the text appearing
1538 in the first column of the screen.
1540 %d_
\bX Replaced by the page number of a line in the input
1541 file. The line to be used is determined by the _
\bX,
1542 as with the %b option.
1544 %D Replaced by the number of pages in the input file,
1545 or equivalently, the page number of the last line
1548 %E Replaced by the name of the editor (from the VISUAL
1549 environment variable, or the EDITOR environment
1550 variable if VISUAL is not defined). See the dis
1551 cussion of the LESSEDIT feature below.
1553 %f Replaced by the name of the current input file.
1555 %i Replaced by the index of the current file in the
1556 list of input files.
1558 %l_
\bX Replaced by the line number of a line in the input
1559 file. The line to be used is determined by the _
\bX,
1560 as with the %b option.
1562 %L Replaced by the line number of the last line in the
1565 %m Replaced by the total number of input files.
1567 %p_
\bX Replaced by the percent into the current input
1568 file, based on byte offsets. The line used is
1569 determined by the _
\bX as with the %b option.
1571 %P_
\bX Replaced by the percent into the current input
1572 file, based on line numbers. The line used is
1573 determined by the _
\bX as with the %b option.
1577 %t Causes any trailing spaces to be removed. Usually
1578 used at the end of the string, but may appear
1582 Version 381: 17 Jan 2003 24
1593 %x Replaced by the name of the next input file in the
1596 If any item is unknown (for example, the file size if
1597 input is a pipe), a question mark is printed instead.
1599 The format of the prompt string can be changed depending
1600 on certain conditions. A question mark followed by a sin
1601 gle character acts like an "IF": depending on the follow
1602 ing character, a condition is evaluated. If the condition
1603 is true, any characters following the question mark and
1604 condition character, up to a period, are included in the
1605 prompt. If the condition is false, such characters are
1606 not included. A colon appearing between the question mark
1607 and the period can be used to establish an "ELSE": any
1608 characters between the colon and the period are included
1609 in the string if and only if the IF condition is false.
1610 Condition characters (which follow a question mark) may
1613 ?a True if any characters have been included in the
1616 ?b_
\bX True if the byte offset of the specified line is
1619 ?B True if the size of current input file is known.
1621 ?c True if the text is horizontally shifted (%c is not
1624 ?d_
\bX True if the page number of the specified line is
1627 ?e True if at end-of-file.
1629 ?f True if there is an input filename (that is, if
1630 input is not a pipe).
1632 ?l_
\bX True if the line number of the specified line is
1635 ?L True if the line number of the last line in the
1638 ?m True if there is more than one input file.
1640 ?n True if this is the first prompt in a new input
1643 ?p_
\bX True if the percent into the current input file,
1644 based on byte offsets, of the specified line is
1648 Version 381: 17 Jan 2003 25
1659 ?P_
\bX True if the percent into the current input file,
1660 based on line numbers, of the specified line is
1665 ?x True if there is a next input file (that is, if the
1666 current input file is not the last one).
1668 Any characters other than the special ones (question mark,
1669 colon, period, percent, and backslash) become literally
1670 part of the prompt. Any of the special characters may be
1671 included in the prompt literally by preceding it with a
1676 ?f%f:Standard input.
1678 This prompt prints the filename, if known; otherwise the
1679 string "Standard input".
1681 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1683 This prompt would print the filename, if known. The file
1684 name is followed by the line number, if known, otherwise
1685 the percent if known, otherwise the byte offset if known.
1686 Otherwise, a dash is printed. Notice how each question
1687 mark has a matching period, and how the % after the %pt is
1688 included literally by escaping it with a backslash.
1690 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
1692 This prints the filename if this is the first prompt in a
1693 file, followed by the "file N of N" message if there is
1694 more than one input file. Then, if we are at end-of-file,
1695 the string "(END)" is printed followed by the name of the
1696 next file, if there is one. Finally, any trailing spaces
1697 are truncated. This is the default prompt. For refer
1698 ence, here are the defaults for the other two prompts (-m
1699 and -M respectively). Each is broken into two lines here
1700 for readability only.
1702 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
1703 ?pB%pB\%:byte %bB?s/%s...%t
1705 ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
1706 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1708 And here is the default message produced by the = command:
1710 ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1714 Version 381: 17 Jan 2003 26
1723 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1725 The prompt expansion features are also used for another
1726 purpose: if an environment variable LESSEDIT is defined,
1727 it is used as the command to be executed when the v com
1728 mand is invoked. The LESSEDIT string is expanded in the
1729 same way as the prompt strings. The default value for
1734 Note that this expands to the editor name, followed by a +
1735 and the line number, followed by the file name. If your
1736 editor does not accept the "+linenumber" syntax, or has
1737 other differences in invocation syntax, the LESSEDIT vari
1738 able can be changed to modify this default.
1741 S
\bSE
\bEC
\bCU
\bUR
\bRI
\bIT
\bTY
\bY
1742 When the environment variable LESSSECURE is set to 1, _
\bl_
\be_
\bs_
\bs
1743 runs in a "secure" mode. This means these features are
1750 :e the examine command.
1752 v the editing command
1756 -k use of lesskey files
1758 -t use of tags files
1760 metacharacters in filenames, such as *
1762 filename completion (TAB, ^L)
1764 Less can also be compiled to be permanently in "secure"
1768 E
\bEN
\bNV
\bVI
\bIR
\bRO
\bON
\bNM
\bME
\bEN
\bNT
\bT V
\bVA
\bAR
\bRI
\bIA
\bAB
\bBL
\bLE
\bES
\bS
1769 Environment variables may be specified either in the sys
1770 tem environment as usual, or in a _
\bl_
\be_
\bs_
\bs_
\bk_
\be_
\by (1) file. If
1771 environment variables are defined in more than one place,
1772 variables defined in a local lesskey file take precedence
1773 over variables defined in the system environment, which
1774 take precedence over variables defined in the system-wide
1780 Version 381: 17 Jan 2003 27
1790 Sets the number of columns on the screen. Takes
1791 precedence over the number of columns specified by
1792 the TERM variable. (But if you have a windowing
1793 system which supports TIOCGWINSZ or WIOCGETD, the
1794 window system's idea of the screen size takes
1795 precedence over the LINES and COLUMNS environment
1798 EDITOR The name of the editor (used for the v command).
1800 HOME Name of the user's home directory (used to find a
1801 lesskey file on Unix and OS/2 systems).
1804 Concatenation of the HOMEDRIVE and HOMEPATH envi
1805 ronment variables is the name of the user's home
1806 directory if the HOME variable is not set (only in
1807 the Windows version).
1809 INIT Name of the user's init directory (used to find a
1810 lesskey file on OS/2 systems).
1812 LANG Language for determining the character set.
1815 Language for determining the character set.
1817 LESS Options which are passed to _
\bl_
\be_
\bs_
\bs automatically.
1820 Characters which are assumed to end an ANSI color
1821 escape sequence (default "m").
1824 Format for displaying non-printable, non-control
1828 Defines a character set.
1831 Selects a predefined character set.
1834 Command line to invoke the (optional) input-post
1838 Name of the lessecho program (default "lessecho").
1839 The lessecho program is needed to expand metachar
1840 acters, such as * and ?, in filenames on Unix sys
1846 Version 381: 17 Jan 2003 28
1856 Editor prototype string (used for the v command).
1857 See discussion under PROMPTS.
1860 Name of the command used by the -t option to find
1861 global tags. Normally should be set to "global" if
1862 your system has the _
\bg_
\bl_
\bo_
\bb_
\ba_
\bl (1) command. If not
1863 set, global tags are not used.
1866 Name of the default lesskey(1) file.
1869 Name of the default system-wide lesskey(1) file.
1872 List of characters which are considered "metachar
1873 acters" by the shell.
1876 Prefix which less will add before each metacharac
1877 ter in a command sent to the shell. If LESS
1878 METAESCAPE is an empty string, commands containing
1879 metacharacters will not be passed to the shell.
1882 Command line to invoke the (optional) input-prepro
1886 Runs less in "secure" mode. See discussion under
1890 String to be appended to a directory name in file
1893 LINES Sets the number of lines on the screen. Takes
1894 precedence over the number of lines specified by
1895 the TERM variable. (But if you have a windowing
1896 system which supports TIOCGWINSZ or WIOCGETD, the
1897 window system's idea of the screen size takes
1898 precedence over the LINES and COLUMNS environment
1901 PATH User's search path (used to find a lesskey file on
1902 MS-DOS and OS/2 systems).
1904 SHELL The shell used to execute the ! command, as well as
1905 to expand filenames.
1907 TERM The type of terminal on which _
\bl_
\be_
\bs_
\bs is being run.
1912 Version 381: 17 Jan 2003 29
1921 VISUAL The name of the editor (used for the v command).
1924 S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
1928 W
\bWA
\bAR
\bRN
\bNI
\bIN
\bNG
\bGS
\bS
1929 The = command and prompts (unless changed by -P) report
1930 the line numbers of the lines at the top and bottom of the
1931 screen, but the byte and percent of the line after the one
1932 at the bottom of the screen.
1934 If the :e command is used to name more than one file, and
1935 one of the named files has been viewed previously, the new
1936 files may be entered into the list in an unexpected order.
1938 On certain older terminals (the so-called "magic cookie"
1939 terminals), search highlighting will cause an erroneous
1940 display. On such terminals, search highlighting is dis
1941 abled by default to avoid possible problems.
1943 In certain cases, when search highlighting is enabled and
1944 a search pattern begins with a ^, more text than the
1945 matching string may be highlighted. (This problem does
1946 not occur when less is compiled to use the POSIX regular
1947 expression package.)
1949 When viewing text containing ANSI color escape sequences
1950 using the -R option, searching will not find text contain
1951 ing an embedded escape sequence. Also, search highlight
1952 ing may change the color of some of the text which follows
1953 the highlighted text.
1955 On some systems, _
\bs_
\be_
\bt_
\bl_
\bo_
\bc_
\ba_
\bl_
\be claims that ASCII characters 0
1956 thru 31 are control characters rather than binary charac
1957 ters. This causes _
\bl_
\be_
\bs_
\bs to treat some binary files as
1958 ordinary, non-binary files. To workaround this problem,
1959 set the environment variable LESSCHARSET to "ascii" (or
1960 whatever character set is appropriate).
1962 See http://www.greenwoodsoftware.com/less for the latest
1963 list of known bugs in this version of less.
1966 C
\bCO
\bOP
\bPY
\bYR
\bRI
\bIG
\bGH
\bHT
\bT
1967 Copyright (C) 2002 Mark Nudelman
1969 less is part of the GNU project and is free software. You
1970 can redistribute it and/or modify it under the terms of
1971 either (1) the GNU General Public License as published by
1972 the Free Software Foundation; or (2) the Less License.
1973 See the file README in the less distribution for more
1974 details regarding redistribution. You should have
1978 Version 381: 17 Jan 2003 30
1987 received a copy of the GNU General Public License along
1988 with the source for less; see the file COPYING. If not,
1989 write to the Free Software Foundation, 59 Temple Place,
1990 Suite 330, Boston, MA 02111-1307, USA. You should also
1991 have received a copy of the Less License; see the file
1994 less is distributed in the hope that it will be useful,
1995 but WITHOUT ANY WARRANTY; without even the implied war
1996 ranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR
1997 POSE. See the GNU General Public License for more
2001 A
\bAU
\bUT
\bTH
\bHO
\bOR
\bR
2002 Mark Nudelman <markn@greenwoodsoftware.com>
2003 Send bug reports or comments to the above address or to
2005 For more information, see the less homepage at
2006 http://www.greenwoodsoftware.com/less.
2044 Version 381: 17 Jan 2003 31