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 [-[+]aBcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
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 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 g or < or ESC-<
111 Go to line N in the file, default 1 (beginning of file). (Warn‐
112 ing: this may be slow if N is large.)
113 G or > or ESC->
115 Go to line N in the file, default the end of the file. (Warn‐
116 ing: this may be slow if N is large, or if N is not specified
117 and standard input, rather than a file, is being read.)
118 p or % Go to a position N percent into the file. N should be between 0
120 and 100.
121 { If a left curly bracket appears in the top line displayed on the
123 screen, the { command will go to the matching right curly
124 bracket. The matching right curly bracket is positioned on the
125 bottom line of the screen. If there is more than one left curly
126 bracket on the top line, a number N may be used to specify the
127 N-th bracket on the line.
128 } If a right curly bracket appears in the bottom line displayed on
130 the screen, the } command will go to the matching left curly
131 bracket. The matching left curly bracket is positioned on the
132 top line of the screen. If there is more than one right curly
133 bracket on the top line, a number N may be used to specify the
134 N-th bracket on the line.
135 ( Like {, but applies to parentheses rather than curly brackets.
137 ) Like }, but applies to parentheses rather than curly brackets.
139 [ Like {, but applies to square brackets rather than curly brack‐
141 ets.
142 ] Like }, but applies to square brackets rather than curly brack‐
144 ets.
145 ESC-^F Followed by two characters, acts like {, but uses the two char‐
147 acters as open and close brackets, respectively. For example,
148 "ESC ^F < >" could be used to go forward to the > which matches
149 the < in the top displayed line.
150 ESC-^B Followed by two characters, acts like }, but uses the two char‐
152 acters as open and close brackets, respectively. For example,
153 "ESC ^B < >" could be used to go backward to the < which matches
154 the > in the bottom displayed line.
155 m Followed by any lowercase letter, marks the current position
157 with that letter.
158 ' (Single quote.) Followed by any lowercase letter, returns to
160 the position which was previously marked with that letter. Fol‐
161 lowed by another single quote, returns to the position at which
162 the last "large" movement command was executed. Followed by a ^
163 or $, jumps to the beginning or end of the file respectively.
164 Marks are preserved when a new file is examined, so the ' com‐
165 mand can be used to switch between input files.
166 ^X^X Same as single quote.
168 /pattern
170 Search forward in the file for the N-th line containing the pat‐
171 tern. N defaults to 1. The pattern is a regular expression, as
172 recognized by the regular expression library supplied by your
173 system. The search starts at the second line displayed (but see
174 the -a and -j options, which change this).
175 Certain characters are special if entered at the beginning of
177 the pattern; they modify the type of search rather than become
178 part of the pattern:
179 ^N or !
181 Search for lines which do NOT match the pattern.
182 ^E or *
184 Search multiple files. That is, if the search reaches
185 the END of the current file without finding a match, the
186 search continues in the next file in the command line
187 list.
188 ^F or @
190 Begin the search at the first line of the FIRST file in
191 the command line list, regardless of what is currently
192 displayed on the screen or the settings of the -a or -j
193 options.
194 ^K Highlight any text which matches the pattern on the cur‐
196 rent screen, but don't move to the first match (KEEP cur‐
197 rent position).
198 ^R Don't interpret regular expression metacharacters; that
200 is, do a simple textual comparison.
201 ?pattern
203 Search backward in the file for the N-th line containing the
204 pattern. The search starts at the line immediately before the
205 top line displayed.
206 Certain characters are special as in the / command:
208 ^N or !
210 Search for lines which do NOT match the pattern.
211 ^E or *
213 Search multiple files. That is, if the search reaches
214 the beginning of the current file without finding a
215 match, the search continues in the previous file in the
216 command line list.
217 ^F or @
219 Begin the search at the last line of the last file in the
220 command line list, regardless of what is currently dis‐
221 played on the screen or the settings of the -a or -j
222 options.
223 ^K As in forward searches.
225 ^R As in forward searches.
227 ESC-/pattern
229 Same as "/*".
230 ESC-?pattern
232 Same as "?*".
233 n Repeat previous search, for N-th line containing the last pat‐
235 tern. If the previous search was modified by ^N, the search is
236 made for the N-th line NOT containing the pattern. If the pre‐
237 vious search was modified by ^E, the search continues in the
238 next (or previous) file if not satisfied in the current file.
239 If the previous search was modified by ^R, the search is done
240 without using regular expressions. There is no effect if the
241 previous search was modified by ^F or ^K.
242 N Repeat previous search, but in the reverse direction.
244 ESC-n Repeat previous search, but crossing file boundaries. The
246 effect is as if the previous search were modified by *.
247 ESC-N Repeat previous search, but in the reverse direction and cross‐
249 ing file boundaries.
250 ESC-u Undo search highlighting. Turn off highlighting of strings
252 matching the current search pattern. If highlighting is already
253 off because of a previous ESC-u command, turn highlighting back
254 on. Any search command will also turn highlighting back on.
255 (Highlighting can also be disabled by toggling the -G option; in
256 that case search commands do not turn highlighting back on.)
257 :e [filename]
259 Examine a new file. If the filename is missing, the "current"
260 file (see the :n and :p commands below) from the list of files
261 in the command line is re-examined. A percent sign (%) in the
262 filename is replaced by the name of the current file. A pound
263 sign (#) is replaced by the name of the previously examined
264 file. However, two consecutive percent signs are simply
265 replaced with a single percent sign. This allows you to enter a
266 filename that contains a percent sign in the name. Similarly,
267 two consecutive pound signs are replaced with a single pound
268 sign. The filename is inserted into the command line list of
269 files so that it can be seen by subsequent :n and :p commands.
270 If the filename consists of several files, they are all inserted
271 into the list of files and the first one is examined. If the
272 filename contains one or more spaces, the entire filename should
273 be enclosed in double quotes (also see the -" option).
274 ^X^V or E
276 Same as :e. Warning: some systems use ^V as a special literal‐
277 ization character. On such systems, you may not be able to use
278 ^V.
279 :n Examine the next file (from the list of files given in the com‐
281 mand line). If a number N is specified, the N-th next file is
282 examined.
283 :p Examine the previous file in the command line list. If a number
285 N is specified, the N-th previous file is examined.
286 :x Examine the first file in the command line list. If a number N
288 is specified, the N-th file in the list is examined.
289 :d Remove the current file from the list of files.
291 t Go to the next tag, if there were more than one matches for the
293 current tag. See the -t option for more details about tags.
294 T Go to the previous tag, if there were more than one matches for
296 the current tag.
297 = or ^G or :f
299 Prints some information about the file being viewed, including
300 its name and the line number and byte offset of the bottom line
301 being displayed. If possible, it also prints the length of the
302 file, the number of lines in the file and the percent of the
303 file above the last displayed line.
304 - Followed by one of the command line option letters (see OPTIONS
306 below), this will change the setting of that option and print a
307 message describing the new setting. If a ^P (CONTROL-P) is
308 entered immediately after the dash, the setting of the option is
309 changed but no message is printed. If the option letter has a
310 numeric value (such as -b or -h), or a string value (such as -P
311 or -t), a new value may be entered after the option letter. If
312 no new value is entered, a message describing the current set‐
313 ting is printed and nothing is changed.
314 -- Like the - command, but takes a long option name (see OPTIONS
316 below) rather than a single option letter. You must press
317 RETURN after typing the option name. A ^P immediately after the
318 second dash suppresses printing of a message describing the new
319 setting, as in the - command.
320 -+ Followed by one of the command line option letters this will
322 reset the option to its default setting and print a message
323 describing the new setting. (The "-+X" command does the same
324 thing as "-+X" on the command line.) This does not work for
325 string-valued options.
326 --+ Like the -+ command, but takes a long option name rather than a
328 single option letter.
329 -! Followed by one of the command line option letters, this will
331 reset the option to the "opposite" of its default setting and
332 print a message describing the new setting. This does not work
333 for numeric or string-valued options.
334 --! Like the -! command, but takes a long option name rather than a
336 single option letter.
337 _ (Underscore.) Followed by one of the command line option let‐
339 ters, this will print a message describing the current setting
340 of that option. The setting of the option is not changed.
341 __ (Double underscore.) Like the _ (underscore) command, but takes
343 a long option name rather than a single option letter. You must
344 press RETURN after typing the option name.
345 +cmd Causes the specified cmd to be executed each time a new file is
347 examined. For example, +G causes less to initially display each
348 file starting at the end rather than the beginning.
349 V Prints the version number of less being run.
351 q or Q or :q or :Q or ZZ
353 Exits less.
354 The following four commands may or may not be valid, depending on your
356 particular installation.
357 v Invokes an editor to edit the current file being viewed. The
359 editor is taken from the environment variable VISUAL if defined,
360 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei‐
361 ther VISUAL nor EDITOR is defined. See also the discussion of
362 LESSEDIT under the section on PROMPTS below.
363 ! shell-command
365 Invokes a shell to run the shell-command given. A percent sign
366 (%) in the command is replaced by the name of the current file.
367 A pound sign (#) is replaced by the name of the previously exam‐
368 ined file. "!!" repeats the last shell command. "!" with no
369 shell command simply invokes a shell. On Unix systems, the
370 shell is taken from the environment variable SHELL, or defaults
371 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
372 command processor.
373 | <m> shell-command
375 <m> represents any mark letter. Pipes a section of the input
376 file to the given shell command. The section of the file to be
377 piped is between the first line on the current screen and the
378 position marked by the letter. <m> may also be ^ or $ to indi‐
379 cate beginning or end of file respectively. If <m> is . or new‐
380 line, the current screen is piped.
381 s filename
383 Save the input to a file. This only works if the input is a
384 pipe, not an ordinary file.
385
387 Command line options are described below. Most options may be changed
388 while less is running, via the "-" command.
389 Most options may be given in one of two forms: either a dash followed
391 by a single letter, or two dashes followed by a long option name. A
392 long option name may be abbreviated as long as the abbreviation is
393 unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
394 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
395 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
396 from --quit-at-eof. Such option names need only have their first let‐
397 ter capitalized; the remainder of the name may be in either case. For
398 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
399 Options are also taken from the environment variable "LESS". For exam‐
401 ple, to avoid typing "less -options ..." each time less is invoked, you
402 might tell csh:
403 setenv LESS "-options"
405 or if you use sh:
407 LESS="-options"; export LESS
409 On MS-DOS, you don't need the quotes, but you should replace any per‐
411 cent signs in the options string by double percent signs.
412 The environment variable is parsed before the command line, so command
414 line options override the LESS environment variable. If an option
415 appears in the LESS variable, it can be reset to its default value on
416 the command line by beginning the command line option with "-+".
417 For options like -P or -D which take a following string, a dollar sign
419 ($) must be used to signal the end of the string. For example, to set
420 two -D options on MS-DOS, you must have a dollar sign between them,
421 like this:
422 LESS="-Dn9.1$-Ds4.1"
424 -? or --help
427 This option displays a summary of the commands accepted by less
428 (the same as the h command). (Depending on how your shell
429 interprets the question mark, it may be necessary to quote the
430 question mark, thus: "-\?".)
431 -a or --search-skip-screen
433 Causes searches to start after the last line displayed on the
434 screen, thus skipping all lines displayed on the screen. By
435 default, searches start at the second line on the screen (or
436 after the last found line; see the -j option).
437 -bn or --buffers=n
439 Specifies the amount of buffer space less will use for each
440 file, in units of kilobytes (1024 bytes). By default 64K of
441 buffer space is used for each file (unless the file is a pipe;
442 see the -B option). The -b option specifies instead that n
443 kilobytes of buffer space should be used for each file. If n is
444 -1, buffer space is unlimited; that is, the entire file is read
445 into memory.
446 -B or --auto-buffers
448 By default, when data is read from a pipe, buffers are allocated
449 automatically as needed. If a large amount of data is read from
450 the pipe, this can cause a large amount of memory to be allo‐
451 cated. The -B option disables this automatic allocation of buf‐
452 fers for pipes, so that only 64K (or the amount of space speci‐
453 fied by the -b option) is used for the pipe. Warning: use of -B
454 can result in erroneous display, since only the most recently
455 viewed part of the file is kept in memory; any earlier data is
456 lost.
457 -c or --clear-screen
459 Causes full screen repaints to be painted from the top line
460 down. By default, full screen repaints are done by scrolling
461 from the bottom of the screen.
462 -C or --CLEAR-SCREEN
464 The -C option is like -c, but the screen is cleared before it is
465 repainted.
466 -d or --dumb
468 The -d option suppresses the error message normally displayed if
469 the terminal is dumb; that is, lacks some important capability,
470 such as the ability to clear the screen or scroll backward. The
471 -d option does not otherwise change the behavior of less on a
472 dumb terminal.
473 -Dxcolor or --color=xcolor
475 [MS-DOS only] Sets the color of the text displayed. x is a sin‐
476 gle character which selects the type of text whose color is
477 being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
478 color is a pair of numbers separated by a period. The first
479 number selects the foreground color and the second selects the
480 background color of the text. A single number N is the same as
481 N.0.
482 -e or --quit-at-eof
484 Causes less to automatically exit the second time it reaches
485 end-of-file. By default, the only way to exit less is via the
486 "q" command.
487 -E or --QUIT-AT-EOF
489 Causes less to automatically exit the first time it reaches end-
490 of-file.
491 -f or --force
493 Forces non-regular files to be opened. (A non-regular file is a
494 directory or a device special file.) Also suppresses the warn‐
495 ing message when a binary file is opened. By default, less will
496 refuse to open non-regular files.
497 -F or --quit-if-one-screen
499 Causes less to automatically exit if the entire file can be dis‐
500 played on the first screen.
501 -g or --hilite-search
503 Normally, less will highlight ALL strings which match the last
504 search command. The -g option changes this behavior to high‐
505 light only the particular string which was found by the last
506 search command. This can cause less to run somewhat faster than
507 the default.
508 -G or --HILITE-SEARCH
510 The -G option suppresses all highlighting of strings found by
511 search commands.
512 -hn or --max-back-scroll=n
514 Specifies a maximum number of lines to scroll backward. If it
515 is necessary to scroll backward more than n lines, the screen is
516 repainted in a forward direction instead. (If the terminal does
517 not have the ability to scroll backward, -h0 is implied.)
518 -i or --ignore-case
520 Causes searches to ignore case; that is, uppercase and lowercase
521 are considered identical. This option is ignored if any upper‐
522 case letters appear in the search pattern; in other words, if a
523 pattern contains uppercase letters, then that search does not
524 ignore case.
525 -I or --IGNORE-CASE
527 Like -i, but searches ignore case even if the pattern contains
528 uppercase letters.
529 -jn or --jump-target=n
531 Specifies a line on the screen where the "target" line is to be
532 positioned. A target line is the object of a text search, tag
533 search, jump to a line number, jump to a file percentage, or
534 jump to a marked position. The screen line is specified by a
535 number: the top line on the screen is 1, the next is 2, and so
536 on. The number may be negative to specify a line relative to
537 the bottom of the screen: the bottom line on the screen is -1,
538 the second to the bottom is -2, and so on. If the -j option is
539 used, searches begin at the line immediately after the target
540 line. For example, if "-j4" is used, the target line is the
541 fourth line on the screen, so searches begin at the fifth line
542 on the screen.
543 -J or --status-column
545 Displays a status column at the left edge of the screen. The
546 status column shows the lines that matched the current search.
547 The status column is also used if the -w or -W option is in
548 effect.
549 -kfilename or --lesskey-file=filename
551 Causes less to open and interpret the named file as a lesskey
552 (1) file. Multiple -k options may be specified. If the LESSKEY
553 or LESSKEY_SYSTEM environment variable is set, or if a lesskey
554 file is found in a standard place (see KEY BINDINGS), it is also
555 used as a lesskey file.
556 -K or --quit-on-intr
558 Causes less to exit immediately when an interrupt character
559 (usually ^C) is typed. Normally, an interrupt character causes
560 less to stop whatever it is doing and return to its command
561 prompt.
562 -L or --no-lessopen
564 Ignore the LESSOPEN environment variable (see the INPUT PRE‐
565 PROCESSOR section below). This option can be set from within
566 less, but it will apply only to files opened subsequently, not
567 to the file which is currently open.
568 -m or --long-prompt
570 Causes less to prompt verbosely (like more), with the percent
571 into the file. By default, less prompts with a colon.
572 -M or --LONG-PROMPT
574 Causes less to prompt even more verbosely than more.
575 -n or --line-numbers
577 Suppresses line numbers. The default (to use line numbers) may
578 cause less to run more slowly in some cases, especially with a
579 very large input file. Suppressing line numbers with the -n
580 option will avoid this problem. Using line numbers means: the
581 line number will be displayed in the verbose prompt and in the =
582 command, and the v command will pass the current line number to
583 the editor (see also the discussion of LESSEDIT in PROMPTS
584 below).
585 -N or --LINE-NUMBERS
587 Causes a line number to be displayed at the beginning of each
588 line in the display.
589 -ofilename or --log-file=filename
591 Causes less to copy its input to the named file as it is being
592 viewed. This applies only when the input file is a pipe, not an
593 ordinary file. If the file already exists, less will ask for
594 confirmation before overwriting it.
595 -Ofilename or --LOG-FILE=filename
597 The -O option is like -o, but it will overwrite an existing file
598 without asking for confirmation.
599 If no log file has been specified, the -o and -O options can be
601 used from within less to specify a log file. Without a file
602 name, they will simply report the name of the log file. The "s"
603 command is equivalent to specifying -o from within less.
604 -ppattern or --pattern=pattern
606 The -p option on the command line is equivalent to specifying
607 +/pattern; that is, it tells less to start at the first occur‐
608 rence of pattern in the file.
609 -Pprompt or --prompt=prompt
611 Provides a way to tailor the three prompt styles to your own
612 preference. This option would normally be put in the LESS envi‐
613 ronment variable, rather than being typed in with each less com‐
614 mand. Such an option must either be the last option in the LESS
615 variable, or be terminated by a dollar sign. -Ps followed by a
616 string changes the default (short) prompt to that string. -Pm
617 changes the medium (-m) prompt. -PM changes the long (-M)
618 prompt. -Ph changes the prompt for the help screen. -P=
619 changes the message printed by the = command. -Pw changes the
620 message printed while waiting for data (in the F command). All
621 prompt strings consist of a sequence of letters and special
622 escape sequences. See the section on PROMPTS for more details.
623 -q or --quiet or --silent
625 Causes moderately "quiet" operation: the terminal bell is not
626 rung if an attempt is made to scroll past the end of the file or
627 before the beginning of the file. If the terminal has a "visual
628 bell", it is used instead. The bell will be rung on certain
629 other errors, such as typing an invalid character. The default
630 is to ring the terminal bell in all such cases.
631 -Q or --QUIET or --SILENT
633 Causes totally "quiet" operation: the terminal bell is never
634 rung.
635 -r or --raw-control-chars
637 Causes "raw" control characters to be displayed. The default is
638 to display control characters using the caret notation; for
639 example, a control-A (octal 001) is displayed as "^A". Warning:
640 when the -r option is used, less cannot keep track of the actual
641 appearance of the screen (since this depends on how the screen
642 responds to each type of control character). Thus, various dis‐
643 play problems may result, such as long lines being split in the
644 wrong place.
645 -R or --RAW-CONTROL-CHARS
647 Like -r, but only ANSI "color" escape sequences are output in
648 "raw" form. Unlike -r, the screen appearance is maintained cor‐
649 rectly in most cases. ANSI "color" escape sequences are
650 sequences of the form:
651 ESC [ ... m
653 where the "..." is zero or more color specification characters
655 For the purpose of keeping track of screen appearance, ANSI
656 color escape sequences are assumed to not move the cursor. You
657 can make less think that characters other than "m" can end ANSI
658 color escape sequences by setting the environment variable
659 LESSANSIENDCHARS to the list of characters which can end a color
660 escape sequence. And you can make less think that characters
661 other than the standard ones may appear between the ESC and the
662 m by setting the environment variable LESSANSIMIDCHARS to the
663 list of characters which can appear.
664 -s or --squeeze-blank-lines
666 Causes consecutive blank lines to be squeezed into a single
667 blank line. This is useful when viewing nroff output.
668 -S or --chop-long-lines
670 Causes lines longer than the screen width to be chopped rather
671 than folded. That is, the portion of a long line that does not
672 fit in the screen width is not shown. The default is to fold
673 long lines; that is, display the remainder on the next line.
674 -ttag or --tag=tag
676 The -t option, followed immediately by a TAG, will edit the file
677 containing that tag. For this to work, tag information must be
678 available; for example, there may be a file in the current
679 directory called "tags", which was previously built by ctags (1)
680 or an equivalent command. If the environment variable LESSGLOB‐
681 ALTAGS is set, it is taken to be the name of a command compati‐
682 ble with global (1), and that command is executed to find the
683 tag. (See http://www.gnu.org/software/global/global.html). The
684 -t option may also be specified from within less (using the -
685 command) as a way of examining a new file. The command ":t" is
686 equivalent to specifying -t from within less.
687 -Ttagsfile or --tag-file=tagsfile
689 Specifies a tags file to be used instead of "tags".
690 -u or --underline-special
692 Causes backspaces and carriage returns to be treated as print‐
693 able characters; that is, they are sent to the terminal when
694 they appear in the input.
695 -U or --UNDERLINE-SPECIAL
697 Causes backspaces, tabs and carriage returns to be treated as
698 control characters; that is, they are handled as specified by
699 the -r option.
700 By default, if neither -u nor -U is given, backspaces which
702 appear adjacent to an underscore character are treated spe‐
703 cially: the underlined text is displayed using the terminal's
704 hardware underlining capability. Also, backspaces which appear
705 between two identical characters are treated specially: the
706 overstruck text is printed using the terminal's hardware bold‐
707 face capability. Other backspaces are deleted, along with the
708 preceding character. Carriage returns immediately followed by a
709 newline are deleted. other carriage returns are handled as
710 specified by the -r option. Text which is overstruck or under‐
711 lined can be searched for if neither -u nor -U is in effect.
712 -V or --version
714 Displays the version number of less.
715 -w or --hilite-unread
717 Temporarily highlights the first "new" line after a forward
718 movement of a full page. The first "new" line is the line imme‐
719 diately following the line previously at the bottom of the
720 screen. Also highlights the target line after a g or p command.
721 The highlight is removed at the next command which causes move‐
722 ment. The entire line is highlighted, unless the -J option is
723 in effect, in which case only the status column is highlighted.
724 -W or --HILITE-UNREAD
726 Like -w, but temporarily highlights the first new line after any
727 forward movement command larger than one line.
728 -xn,... or --tabs=n,...
730 Sets tab stops. If only one n is specified, tab stops are set
731 at multiples of n. If multiple values separated by commas are
732 specified, tab stops are set at those positions, and then con‐
733 tinue with the same spacing as the last two. For example,
734 -x9,17 will set tabs at positions 9, 17, 25, 33, etc. The
735 default for n is 8.
736 -X or --no-init
738 Disables sending the termcap initialization and deinitialization
739 strings to the terminal. This is sometimes desirable if the
740 deinitialization string does something unnecessary, like clear‐
741 ing the screen.
742 --no-keypad
744 Disables sending the keypad initialization and deinitialization
745 strings to the terminal. This is sometimes useful if the keypad
746 strings make the numeric keypad behave in an undesirable manner.
747 -yn or --max-forw-scroll=n
749 Specifies a maximum number of lines to scroll forward. If it is
750 necessary to scroll forward more than n lines, the screen is
751 repainted instead. The -c or -C option may be used to repaint
752 from the top of the screen if desired. By default, any forward
753 movement causes scrolling.
754 -[z]n or --window=n
756 Changes the default scrolling window size to n lines. The
757 default is one screenful. The z and w commands can also be used
758 to change the window size. The "z" may be omitted for compati‐
759 bility with more. If the number n is negative, it indicates n
760 lines less than the current screen size. For example, if the
761 screen is 24 lines, -z-4 sets the scrolling window to 20 lines.
762 If the screen is resized to 40 lines, the scrolling window auto‐
763 matically changes to 36 lines.
764 -"cc or --quotes=cc
766 Changes the filename quoting character. This may be necessary
767 if you are trying to name a file which contains both spaces and
768 quote characters. Followed by a single character, this changes
769 the quote character to that character. Filenames containing a
770 space should then be surrounded by that character rather than by
771 double quotes. Followed by two characters, changes the open
772 quote to the first character, and the close quote to the second
773 character. Filenames containing a space should then be preceded
774 by the open quote character and followed by the close quote
775 character. Note that even after the quote characters are
776 changed, this option remains -" (a dash followed by a double
777 quote).
778 -~ or --tilde
780 Normally lines after end of file are displayed as a single tilde
781 (~). This option causes lines after end of file to be displayed
782 as blank lines.
783 -# or --shift
785 Specifies the default number of positions to scroll horizontally
786 in the RIGHTARROW and LEFTARROW commands. If the number speci‐
787 fied is zero, it sets the default number of positions to one
788 half of the screen width.
789 -- A command line argument of "--" marks the end of option argu‐
791 ments. Any arguments following this are interpreted as file‐
792 names. This can be useful when viewing a file whose name begins
793 with a "-" or "+".
794 + If a command line option begins with +, the remainder of that
796 option is taken to be an initial command to less. For example,
797 +G tells less to start at the end of the file rather than the
798 beginning, and +/xyz tells it to start at the first occurrence
799 of "xyz" in the file. As a special case, +<number> acts like
800 +<number>g; that is, it starts the display at the specified line
801 number (however, see the caveat under the "g" command above).
802 If the option starts with ++, the initial command applies to
803 every file being viewed, not just the first one. The + command
804 described previously may also be used to set (or change) an ini‐
805 tial command for every file.
806
809 When entering command line at the bottom of the screen (for example, a
810 filename for the :e command, or the pattern for a search command), cer‐
811 tain keys can be used to manipulate the command line. Most commands
812 have an alternate form in [ brackets ] which can be used if a key does
813 not exist on a particular keyboard. (The bracketed forms do not work
814 in the MS-DOS version.) Any of these special keys may be entered lit‐
815 erally by preceding it with the "literal" character, either ^V or ^A.
816 A backslash itself may also be entered literally by entering two back‐
817 slashes.
818 LEFTARROW [ ESC-h ]
820 Move the cursor one space to the left.
821 RIGHTARROW [ ESC-l ]
823 Move the cursor one space to the right.
824 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
826 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur‐
827 sor one word to the left.
828 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
830 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur‐
831 sor one word to the right.
832 HOME [ ESC-0 ]
834 Move the cursor to the beginning of the line.
835 END [ ESC-$ ]
837 Move the cursor to the end of the line.
838 BACKSPACE
840 Delete the character to the left of the cursor, or cancel the
841 command if the command line is empty.
842 DELETE or [ ESC-x ]
844 Delete the character under the cursor.
845 ^BACKSPACE [ ESC-BACKSPACE ]
847 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
848 word to the left of the cursor.
849 ^DELETE [ ESC-X or ESC-DELETE ]
851 (That is, CONTROL and DELETE simultaneously.) Delete the word
852 under the cursor.
853 UPARROW [ ESC-k ]
855 Retrieve the previous command line.
856 DOWNARROW [ ESC-j ]
858 Retrieve the next command line.
859 TAB Complete the partial filename to the left of the cursor. If it
861 matches more than one filename, the first match is entered into
862 the command line. Repeated TABs will cycle thru the other
863 matching filenames. If the completed filename is a directory, a
864 "/" is appended to the filename. (On MS-DOS systems, a "\" is
865 appended.) The environment variable LESSSEPARATOR can be used
866 to specify a different character to append to a directory name.
867 BACKTAB [ ESC-TAB ]
869 Like, TAB, but cycles in the reverse direction thru the matching
870 filenames.
871 ^L Complete the partial filename to the left of the cursor. If it
873 matches more than one filename, all matches are entered into the
874 command line (if they fit).
875 ^U (Unix and OS/2) or ESC (MS-DOS)
877 Delete the entire command line, or cancel the command if the
878 command line is empty. If you have changed your line-kill char‐
879 acter in Unix to something other than ^U, that character is used
880 instead of ^U.
881
884 You may define your own less commands by using the program lesskey (1)
885 to create a lesskey file. This file specifies a set of command keys
886 and an action associated with each key. You may also use lesskey to
887 change the line-editing keys (see LINE EDITING), and to set environment
888 variables. If the environment variable LESSKEY is set, less uses that
889 as the name of the lesskey file. Otherwise, less looks in a standard
890 place for the lesskey file: On Unix systems, less looks for a lesskey
891 file called "$HOME/.less". On MS-DOS and Windows systems, less looks
892 for a lesskey file called "$HOME/_less", and if it is not found there,
893 then looks for a lesskey file called "_less" in any directory specified
894 in the PATH environment variable. On OS/2 systems, less looks for a
895 lesskey file called "$HOME/less.ini", and if it is not found, then
896 looks for a lesskey file called "less.ini" in any directory specified
897 in the INIT environment variable, and if it not found there, then looks
898 for a lesskey file called "less.ini" in any directory specified in the
899 PATH environment variable. See the lesskey manual page for more
900 details.
901 A system-wide lesskey file may also be set up to provide key bindings.
903 If a key is defined in both a local lesskey file and in the system-wide
904 file, key bindings in the local file take precedence over those in the
905 system-wide file. If the environment variable LESSKEY_SYSTEM is set,
906 less uses that as the name of the system-wide lesskey file. Otherwise,
907 less looks in a standard place for the system-wide lesskey file: On
908 Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
909 (However, if less was built with a different sysconf directory than
910 /usr/local/etc, that directory is where the sysless file is found.) On
911 MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys‐
912 less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
913
916 You may define an "input preprocessor" for less. Before less opens a
917 file, it first gives your input preprocessor a chance to modify the way
918 the contents of the file are displayed. An input preprocessor is sim‐
919 ply an executable program (or shell script), which writes the contents
920 of the file to a different file, called the replacement file. The con‐
921 tents of the replacement file are then displayed in place of the con‐
922 tents of the original file. However, it will appear to the user as if
923 the original file is opened; that is, less will display the original
924 filename as the name of the current file.
925 An input preprocessor receives one command line argument, the original
927 filename, as entered by the user. It should create the replacement
928 file, and when finished, print the name of the replacement file to its
929 standard output. If the input preprocessor does not output a replace‐
930 ment filename, less uses the original file, as normal. The input pre‐
931 processor is not called when viewing standard input. To set up an
932 input preprocessor, set the LESSOPEN environment variable to a command
933 line which will invoke your input preprocessor. This command line
934 should include one occurrence of the string "%s", which will be
935 replaced by the filename when the input preprocessor command is
936 invoked.
937 When less closes a file opened in such a way, it will call another pro‐
939 gram, called the input postprocessor, which may perform any desired
940 clean-up action (such as deleting the replacement file created by
941 LESSOPEN). This program receives two command line arguments, the orig‐
942 inal filename as entered by the user, and the name of the replacement
943 file. To set up an input postprocessor, set the LESSCLOSE environment
944 variable to a command line which will invoke your input postprocessor.
945 It may include two occurrences of the string "%s"; the first is
946 replaced with the original name of the file and the second with the
947 name of the replacement file, which was output by LESSOPEN.
948 For example, on many Unix systems, these two scripts will allow you to
950 keep files in compressed format, but still let less view them directly:
951 lessopen.sh:
953 #! /bin/sh
954 case "$1" in
955 *.Z) uncompress -
956 if [ -s /tmp/less.$$ ]; then
957 echo /tmp/less.$$
958 else
959 rm -f /tmp/less.$$
960 fi
961 ;;
962 esac
963 lessclose.sh:
965 #! /bin/sh
966 rm $2
967 To use these scripts, put them both where they can be executed and set
969 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
970 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
971 types of compressed files, and so on.
972 It is also possible to set up an input preprocessor to pipe the file
974 data directly to less, rather than putting the data into a replacement
975 file. This avoids the need to decompress the entire file before start‐
976 ing to view it. An input preprocessor that works this way is called an
977 input pipe. An input pipe, instead of writing the name of a replace‐
978 ment file on its standard output, writes the entire contents of the
979 replacement file on its standard output. If the input pipe does not
980 write any characters on its standard output, then there is no replace‐
981 ment file and less uses the original file, as normal. To use an input
982 pipe, make the first character in the LESSOPEN environment variable a
983 vertical bar (|) to signify that the input preprocessor is an input
984 pipe.
985 For example, on many Unix systems, this script will work like the pre‐
987 vious example scripts:
988 lesspipe.sh:
990 #! /bin/sh
991 case "$1" in
992 *.Z) uncompress -c $1 2>/dev/null
993 ;;
994 esac
995 To use this script, put it where it can be executed and set
997 LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE
998 postprocessor can be used, but it is usually not necessary since there
999 is no replacement file to clean up. In this case, the replacement file
1000 name passed to the LESSCLOSE postprocessor is "-".
1001
1004 There are three types of characters in the input file:
1005 normal characters
1007 can be displayed directly to the screen.
1008 control characters
1010 should not be displayed directly, but are expected to be found
1011 in ordinary text files (such as backspace and tab).
1012 binary characters
1014 should not be displayed directly and are not expected to be
1015 found in text files.
1016 A "character set" is simply a description of which characters are to be
1018 considered normal, control, and binary. The LESSCHARSET environment
1019 variable may be used to select a character set. Possible values for
1020 LESSCHARSET are:
1021 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1023 with values between 32 and 126 are normal, and all others are
1024 binary.
1025 iso8859
1027 Selects an ISO 8859 character set. This is the same as ASCII,
1028 except characters between 160 and 255 are treated as normal
1029 characters.
1030 latin1 Same as iso8859.
1032 latin9 Same as iso8859.
1034 dos Selects a character set appropriate for MS-DOS.
1036 ebcdic Selects an EBCDIC character set.
1038 IBM-1047
1040 Selects an EBCDIC character set used by OS/390 Unix Services.
1041 This is the EBCDIC analogue of latin1. You get similar results
1042 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1043 environment.
1044 koi8-r Selects a Russian character set.
1046 next Selects a character set appropriate for NeXT computers.
1048 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1050 windows
1052 Selects a character set appropriate for Microsoft Windows (cp
1053 1251).
1054 In special cases, it may be desired to tailor less to use a character
1056 set other than the ones definable by LESSCHARSET. In this case, the
1057 environment variable LESSCHARDEF can be used to define a character set.
1058 It should be set to a string where each character in the string repre‐
1059 sents one character in the character set. The character "." is used
1060 for a normal character, "c" for control, and "b" for binary. A decimal
1061 number may be used for repetition. For example, "bccc4b." would mean
1062 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
1063 binary, and 8 is normal. All characters after the last are taken to be
1064 the same as the last, so characters 9 through 255 would be normal.
1065 (This is an example, and does not necessarily represent any real char‐
1066 acter set.)
1067 This table shows the value of LESSCHARDEF which is equivalent to each
1069 of the possible values for LESSCHARSET:
1070 ascii 8bcccbcc18b95.b
1072 dos 8bcccbcc12bc5b95.b.
1073 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1074 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1075 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1076 191.b
1077 iso8859 8bcccbcc18b95.33b.
1078 koi8-r 8bcccbcc18b95.b128.
1079 latin1 8bcccbcc18b95.33b.
1080 next 8bcccbcc18b95.bb125.bb
1081 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1083 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_TYPE or
1084 LANG environment variables, then the default character set is utf-8.
1085 If that string is not found, but your system supports the setlocale
1087 interface, less will use setlocale to determine the character set.
1088 setlocale is controlled by setting the LANG or LC_CTYPE environment
1089 variables.
1090 Finally, if the setlocale interface is also not available, the default
1092 character set is latin1.
1093 Control and binary characters are displayed in standout (reverse
1095 video). Each such character is displayed in caret notation if possible
1096 (e.g. ^A for control-A). Caret notation is used only if inverting the
1097 0100 bit results in a normal printable character. Otherwise, the char‐
1098 acter is displayed as a hex number in angle brackets. This format can
1099 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1100 may begin with a "*" and one character to select the display attribute:
1101 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1102 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1103 attribute is assumed. The remainder of LESSBINFMT is a string which
1104 may include one printf-style escape sequence (a % followed by x, X, o,
1105 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1106 are displayed in underlined hexadecimal surrounded by brackets. The
1107 default if no LESSBINFMT is specified is "*s<%X>". The default if no
1108 LESSBINFMT is specified is "*s<%02X>". Warning: the result of expand‐
1109 ing the character via LESSBINFMT must be less than 31 characters.
1110 When the character set is utf-8, the LESSUTFBINFMT environment variable
1112 acts similarly to LESSBINFMT but it applies to Unicode code points that
1113 were successfully decoded but are unsuitable for display (e.g., unas‐
1114 signed code points). Its default value is "<U+%04lX>". Note that
1115 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1116 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1117 LESSBINFMT so its setting, if any, will have priority. Problematic
1118 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1119 complete but non-shortest form sequence, illegal octets, and stray
1120 trailing octets) are displayed individually using LESSBINFMT so as to
1121 facilitate diagnostic of how the UTF-8 file is ill-formed.
1122
1125 The -P option allows you to tailor the prompt to your preference. The
1126 string given to the -P option replaces the specified prompt string.
1127 Certain characters in the string are interpreted specially. The prompt
1128 mechanism is rather complicated to provide flexibility, but the ordi‐
1129 nary user need not understand the details of constructing personalized
1130 prompt strings.
1131 A percent sign followed by a single character is expanded according to
1133 what the following character is:
1134 %bX Replaced by the byte offset into the current input file. The b
1136 is followed by a single character (shown as X above) which spec‐
1137 ifies the line whose byte offset is to be used. If the charac‐
1138 ter is a "t", the byte offset of the top line in the display is
1139 used, an "m" means use the middle line, a "b" means use the bot‐
1140 tom line, a "B" means use the line just after the bottom line,
1141 and a "j" means use the "target" line, as specified by the -j
1142 option.
1143 %B Replaced by the size of the current input file.
1145 %c Replaced by the column number of the text appearing in the first
1147 column of the screen.
1148 %dX Replaced by the page number of a line in the input file. The
1150 line to be used is determined by the X, as with the %b option.
1151 %D Replaced by the number of pages in the input file, or equiva‐
1153 lently, the page number of the last line in the input file.
1154 %E Replaced by the name of the editor (from the VISUAL environment
1156 variable, or the EDITOR environment variable if VISUAL is not
1157 defined). See the discussion of the LESSEDIT feature below.
1158 %f Replaced by the name of the current input file.
1160 %i Replaced by the index of the current file in the list of input
1162 files.
1163 %lX Replaced by the line number of a line in the input file. The
1165 line to be used is determined by the X, as with the %b option.
1166 %L Replaced by the line number of the last line in the input file.
1168 %m Replaced by the total number of input files.
1170 %pX Replaced by the percent into the current input file, based on
1172 byte offsets. The line used is determined by the X as with the
1173 %b option.
1174 %PX Replaced by the percent into the current input file, based on
1176 line numbers. The line used is determined by the X as with the
1177 %b option.
1178 %s Same as %B.
1180 %t Causes any trailing spaces to be removed. Usually used at the
1182 end of the string, but may appear anywhere.
1183 %x Replaced by the name of the next input file in the list.
1185 If any item is unknown (for example, the file size if input is a pipe),
1187 a question mark is printed instead.
1188 The format of the prompt string can be changed depending on certain
1190 conditions. A question mark followed by a single character acts like
1191 an "IF": depending on the following character, a condition is evalu‐
1192 ated. If the condition is true, any characters following the question
1193 mark and condition character, up to a period, are included in the
1194 prompt. If the condition is false, such characters are not included.
1195 A colon appearing between the question mark and the period can be used
1196 to establish an "ELSE": any characters between the colon and the period
1197 are included in the string if and only if the IF condition is false.
1198 Condition characters (which follow a question mark) may be:
1199 ?a True if any characters have been included in the prompt so far.
1201 ?bX True if the byte offset of the specified line is known.
1203 ?B True if the size of current input file is known.
1205 ?c True if the text is horizontally shifted (%c is not zero).
1207 ?dX True if the page number of the specified line is known.
1209 ?e True if at end-of-file.
1211 ?f True if there is an input filename (that is, if input is not a
1213 pipe).
1214 ?lX True if the line number of the specified line is known.
1216 ?L True if the line number of the last line in the file is known.
1218 ?m True if there is more than one input file.
1220 ?n True if this is the first prompt in a new input file.
1222 ?pX True if the percent into the current input file, based on byte
1224 offsets, of the specified line is known.
1225 ?PX True if the percent into the current input file, based on line
1227 numbers, of the specified line is known.
1228 ?s Same as "?B".
1230 ?x True if there is a next input file (that is, if the current
1232 input file is not the last one).
1233 Any characters other than the special ones (question mark, colon,
1235 period, percent, and backslash) become literally part of the prompt.
1236 Any of the special characters may be included in the prompt literally
1237 by preceding it with a backslash.
1238 Some examples:
1240 ?f%f:Standard input.
1242 This prompt prints the filename, if known; otherwise the string "Stan‐
1244 dard input".
1245 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1247 This prompt would print the filename, if known. The filename is fol‐
1249 lowed by the line number, if known, otherwise the percent if known,
1250 otherwise the byte offset if known. Otherwise, a dash is printed.
1251 Notice how each question mark has a matching period, and how the %
1252 after the %pt is included literally by escaping it with a backslash.
1253 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
1255 This prints the filename if this is the first prompt in a file, fol‐
1257 lowed by the "file N of N" message if there is more than one input
1258 file. Then, if we are at end-of-file, the string "(END)" is printed
1259 followed by the name of the next file, if there is one. Finally, any
1260 trailing spaces are truncated. This is the default prompt. For refer‐
1261 ence, here are the defaults for the other two prompts (-m and -M
1262 respectively). Each is broken into two lines here for readability
1263 only.
1264 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
1266 ?pB%pB\%:byte %bB?s/%s...%t
1267 ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
1269 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1270 And here is the default message produced by the = command:
1272 ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1274 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1275 The prompt expansion features are also used for another purpose: if an
1277 environment variable LESSEDIT is defined, it is used as the command to
1278 be executed when the v command is invoked. The LESSEDIT string is
1279 expanded in the same way as the prompt strings. The default value for
1280 LESSEDIT is:
1281 %E ?lm+%lm. %f
1283 Note that this expands to the editor name, followed by a + and the line
1285 number, followed by the file name. If your editor does not accept the
1286 "+linenumber" syntax, or has other differences in invocation syntax,
1287 the LESSEDIT variable can be changed to modify this default.
1288
1291 When the environment variable LESSSECURE is set to 1, less runs in a
1292 "secure" mode. This means these features are disabled:
1293 ! the shell command
1295 | the pipe command
1297 :e the examine command.
1299 v the editing command
1301 s -o log files
1303 -k use of lesskey files
1305 -t use of tags files
1307 metacharacters in filenames, such as *
1309 filename completion (TAB, ^L)
1311 Less can also be compiled to be permanently in "secure" mode.
1313
1316 Environment variables may be specified either in the system environment
1317 as usual, or in a lesskey (1) file. If environment variables are
1318 defined in more than one place, variables defined in a local lesskey
1319 file take precedence over variables defined in the system environment,
1320 which take precedence over variables defined in the system-wide lesskey
1321 file.
1322 COLUMNS
1324 Sets the number of columns on the screen. Takes precedence over
1325 the number of columns specified by the TERM variable. (But if
1326 you have a windowing system which supports TIOCGWINSZ or
1327 WIOCGETD, the window system's idea of the screen size takes
1328 precedence over the LINES and COLUMNS environment variables.)
1329 EDITOR The name of the editor (used for the v command).
1331 HOME Name of the user's home directory (used to find a lesskey file
1333 on Unix and OS/2 systems).
1334 HOMEDRIVE, HOMEPATH
1336 Concatenation of the HOMEDRIVE and HOMEPATH environment vari‐
1337 ables is the name of the user's home directory if the HOME vari‐
1338 able is not set (only in the Windows version).
1339 INIT Name of the user's init directory (used to find a lesskey file
1341 on OS/2 systems).
1342 LANG Language for determining the character set.
1344 LC_CTYPE
1346 Language for determining the character set.
1347 LESS Options which are passed to less automatically.
1349 LESSANSIENDCHARS
1351 Characters which may end an ANSI color escape sequence (default
1352 "m").
1353 LESSANSIMIDCHARS
1355 Characters which may appear between the ESC character and the
1356 end character in an ANSI color escape sequence (default
1357 "0123456789;[?!"'#%()*+ ".
1358 LESSBINFMT
1360 Format for displaying non-printable, non-control characters.
1361 LESSCHARDEF
1363 Defines a character set.
1364 LESSCHARSET
1366 Selects a predefined character set.
1367 LESSCLOSE
1369 Command line to invoke the (optional) input-postprocessor.
1370 LESSECHO
1372 Name of the lessecho program (default "lessecho"). The lessecho
1373 program is needed to expand metacharacters, such as * and ?, in
1374 filenames on Unix systems.
1375 LESSEDIT
1377 Editor prototype string (used for the v command). See discus‐
1378 sion under PROMPTS.
1379 LESSGLOBALTAGS
1381 Name of the command used by the -t option to find global tags.
1382 Normally should be set to "global" if your system has the global
1383 (1) command. If not set, global tags are not used.
1384 LESSHISTFILE
1386 Name of the history file used to remember search commands and
1387 shell commands between invocations of less. If set to "-", a
1388 history file is not used. The default is "$HOME/.lesshst" on
1389 Unix systems, "$HOME/_lesshst" on DOS and Windows systems, or
1390 "$HOME/lesshst.ini" or "$INIT/lesshst.ini" on OS/2 systems.
1391 LESSHISTSIZE
1393 The maximum number of commands to save in the history file. The
1394 default is 100.
1395 LESSKEY
1397 Name of the default lesskey(1) file.
1398 LESSKEY_SYSTEM
1400 Name of the default system-wide lesskey(1) file.
1401 LESSMETACHARS
1403 List of characters which are considered "metacharacters" by the
1404 shell.
1405 LESSMETAESCAPE
1407 Prefix which less will add before each metacharacter in a com‐
1408 mand sent to the shell. If LESSMETAESCAPE is an empty string,
1409 commands containing metacharacters will not be passed to the
1410 shell.
1411 LESSOPEN
1413 Command line to invoke the (optional) input-preprocessor.
1414 LESSSECURE
1416 Runs less in "secure" mode. See discussion under SECURITY.
1417 LESSSEPARATOR
1419 String to be appended to a directory name in filename comple‐
1420 tion.
1421 LESSUTFBINFMT
1423 Format for displaying non-printable Unicode code points.
1424 LINES Sets the number of lines on the screen. Takes precedence over
1426 the number of lines specified by the TERM variable. (But if you
1427 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1428 the window system's idea of the screen size takes precedence
1429 over the LINES and COLUMNS environment variables.)
1430 PATH User's search path (used to find a lesskey file on MS-DOS and
1432 OS/2 systems).
1433 SHELL The shell used to execute the ! command, as well as to expand
1435 filenames.
1436 TERM The type of terminal on which less is being run.
1438 VISUAL The name of the editor (used for the v command).
1440
1443 lesskey(1)
1444
1447 The = command and prompts (unless changed by -P) report the line num‐
1448 bers of the lines at the top and bottom of the screen, but the byte and
1449 percent of the line after the one at the bottom of the screen.
1450 If the :e command is used to name more than one file, and one of the
1452 named files has been viewed previously, the new files may be entered
1453 into the list in an unexpected order.
1454 On certain older terminals (the so-called "magic cookie" terminals),
1456 search highlighting will cause an erroneous display. On such termi‐
1457 nals, search highlighting is disabled by default to avoid possible
1458 problems.
1459 In certain cases, when search highlighting is enabled and a search pat‐
1461 tern begins with a ^, more text than the matching string may be high‐
1462 lighted. (This problem does not occur when less is compiled to use the
1463 POSIX regular expression package.)
1464 When viewing text containing ANSI color escape sequences using the -R
1466 option, searching will not find text containing an embedded escape
1467 sequence. Also, search highlighting may change the color of some of
1468 the text which follows the highlighted text.
1469 On some systems, setlocale claims that ASCII characters 0 thru 31 are
1471 control characters rather than binary characters. This causes less to
1472 treat some binary files as ordinary, non-binary files. To workaround
1473 this problem, set the environment variable LESSCHARSET to "ascii" (or
1474 whatever character set is appropriate).
1475 This manual is too long.
1477 See http://www.greenwoodsoftware.com/less for the list of known bugs in
1479 all versions of less.
1480
1483 Copyright (C) 1984-2005 Mark Nudelman
1484 less is part of the GNU project and is free software. You can redis‐
1486 tribute it and/or modify it under the terms of either (1) the GNU Gen‐
1487 eral Public License as published by the Free Software Foundation; or
1488 (2) the Less License. See the file README in the less distribution for
1489 more details regarding redistribution. You should have received a copy
1490 of the GNU General Public License along with the source for less; see
1491 the file COPYING. If not, write to the Free Software Foundation, 59
1492 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
1493 have received a copy of the Less License; see the file LICENSE.
1494 less is distributed in the hope that it will be useful, but WITHOUT ANY
1496 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT‐
1497 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
1498 more details.
1499
1502 Mark Nudelman <markn@greenwoodsoftware.com>
1503 Send bug reports or comments to the above address or to bug-
1504 less@gnu.org.
1505 For more information, see the less homepage at http://www.greenwood‐
1506 software.com/less.
1507 Version 394: 03 Dec 2005 LESS(1)