1 LESS(1) General Commands Manual LESS(1)
6 less - opposite of more
12 \e[1mless --version
\e[0m
13 \e[1mless [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
\e[0m
14 \e[1m[-b
\e[4m
\e[22mspace
\e[24m
\e[1m] [-h
\e[4m
\e[22mlines
\e[24m
\e[1m] [-j
\e[4m
\e[22mline
\e[24m
\e[1m] [-k
\e[4m
\e[22mkeyfile
\e[24m
\e[1m]
\e[0m
15 \e[1m[-{oO}
\e[4m
\e[22mlogfile
\e[24m
\e[1m] [-p
\e[4m
\e[22mpattern
\e[24m
\e[1m] [-P
\e[4m
\e[22mprompt
\e[24m
\e[1m] [-t
\e[4m
\e[22mtag
\e[24m
\e[1m]
\e[0m
16 \e[1m[-T
\e[4m
\e[22mtagsfile
\e[24m
\e[1m] [-x
\e[4m
\e[22mtab
\e[24m
\e[1m,...] [-y
\e[4m
\e[22mlines
\e[24m
\e[1m] [-[z]
\e[4m
\e[22mlines
\e[24m
\e[1m]
\e[0m
17 \e[1m[-#
\e[4m
\e[22mshift
\e[24m
\e[1m] [+[+]
\e[4m
\e[22mcmd
\e[24m
\e[1m] [--] [
\e[4m
\e[22mfilename
\e[24m
\e[1m]...
\e[0m
18 (See the OPTIONS section for alternate option syntax with long option
23 \e[4mLess
\e[24m is a program similar to
\e[4mmore
\e[24m (1), but which allows backward move-
24 ment in the file as well as forward movement. Also,
\e[4mless
\e[24m does not have
25 to read the entire input file before starting, so with large input
26 files it starts up faster than text editors like
\e[4mvi
\e[24m (1).
\e[4mLess
\e[24m uses
27 termcap (or terminfo on some systems), so it can run on a variety of
28 terminals. There is even limited support for hardcopy terminals. (On
29 a hardcopy terminal, lines which should be printed at the top of the
30 screen are prefixed with a caret.)
32 Commands are based on both
\e[4mmore
\e[24m and
\e[4mvi.
\e[24m Commands may be preceded by a
33 decimal number, called N in the descriptions below. The number is used
34 by some commands, as indicated.
38 In the following descriptions, ^X means control-X. ESC stands for the
39 ESCAPE key; for example ESC-v means the two character sequence
42 h or H Help: display a summary of these commands. If you forget all
43 the other commands, remember this one.
45 SPACE or ^V or f or ^F
46 Scroll forward N lines, default one window (see option -z
47 below). If N is more than the screen size, only the final
48 screenful is displayed. Warning: some systems use ^V as a spe-
49 cial literalization character.
51 z Like SPACE, but if N is specified, it becomes the new window
55 Like SPACE, but scrolls a full screenful, even if it reaches
56 end-of-file in the process.
58 ENTER or RETURN or ^N or e or ^E or j or ^J
59 Scroll forward N lines, default 1. The entire N lines are dis-
60 played, even if N is more than the screen size.
63 Scroll forward N lines, default one half of the screen size. If
64 N is specified, it becomes the new default for subsequent d and
68 Scroll backward N lines, default one window (see option -z
69 below). If N is more than the screen size, only the final
70 screenful is displayed.
72 w Like ESC-v, but if N is specified, it becomes the new window
75 y or ^Y or ^P or k or ^K
76 Scroll backward N lines, default 1. The entire N lines are dis-
77 played, even if N is more than the screen size. Warning: some
78 systems use ^Y as a special job control character.
81 Scroll backward N lines, default one half of the screen size.
82 If N is specified, it becomes the new default for subsequent d
86 Scroll horizontally right N characters, default half the screen
87 width (see the -# option). If a number N is specified, it
88 becomes the default for future RIGHTARROW and LEFTARROW com-
89 mands. While the text is scrolled, it acts as though the -S
90 option (chop lines) were in effect.
93 Scroll horizontally left N characters, default half the screen
94 width (see the -# option). If a number N is specified, it
95 becomes the default for future RIGHTARROW and LEFTARROW com-
101 R Repaint the screen, discarding any buffered input. Useful if
102 the file is changing while it is being viewed.
104 F Scroll forward, and keep trying to read when the end of file is
105 reached. Normally this command would be used when already at
106 the end of the file. It is a way to monitor the tail of a file
107 which is growing while it is being viewed. (The behavior is
108 similar to the "tail -f" command.)
110 ESC-F Like F, but as soon as a line is found which matches the last
111 search pattern, the terminal bell is rung and forward scrolling
115 Go to line N in the file, default 1 (beginning of file). (Warn-
116 ing: this may be slow if N is large.)
119 Go to line N in the file, default the end of the file. (Warn-
120 ing: this may be slow if N is large, or if N is not specified
121 and standard input, rather than a file, is being read.)
123 ESC-G Same as G, except if no number N is specified and the input is
124 standard input, goes to the last line which is currently
127 p or % Go to a position N percent into the file. N should be between 0
128 and 100, and may contain a decimal point.
130 P Go to the line containing byte offset N in the file.
132 { If a left curly bracket appears in the top line displayed on the
133 screen, the { command will go to the matching right curly
134 bracket. The matching right curly bracket is positioned on the
135 bottom line of the screen. If there is more than one left curly
136 bracket on the top line, a number N may be used to specify the
137 N-th bracket on the line.
139 } If a right curly bracket appears in the bottom line displayed on
140 the screen, the } command will go to the matching left curly
141 bracket. The matching left curly bracket is positioned on the
142 top line of the screen. If there is more than one right curly
143 bracket on the top line, a number N may be used to specify the
144 N-th bracket on the line.
146 ( Like {, but applies to parentheses rather than curly brackets.
148 ) Like }, but applies to parentheses rather than curly brackets.
150 [ Like {, but applies to square brackets rather than curly brack-
153 ] Like }, but applies to square brackets rather than curly brack-
156 ESC-^F Followed by two characters, acts like {, but uses the two char-
157 acters as open and close brackets, respectively. For example,
158 "ESC ^F < >" could be used to go forward to the > which matches
159 the < in the top displayed line.
161 ESC-^B Followed by two characters, acts like }, but uses the two char-
162 acters as open and close brackets, respectively. For example,
163 "ESC ^B < >" could be used to go backward to the < which matches
164 the > in the bottom displayed line.
166 m Followed by any lowercase letter, marks the current position
169 ' (Single quote.) Followed by any lowercase letter, returns to
170 the position which was previously marked with that letter. Fol-
171 lowed by another single quote, returns to the position at which
172 the last "large" movement command was executed. Followed by a ^
173 or $, jumps to the beginning or end of the file respectively.
174 Marks are preserved when a new file is examined, so the ' com-
175 mand can be used to switch between input files.
177 ^X^X Same as single quote.
180 Search forward in the file for the N-th line containing the pat-
181 tern. N defaults to 1. The pattern is a regular expression, as
182 recognized by the regular expression library supplied by your
183 system. The search starts at the first line displayed (but see
184 the -a and -j options, which change this).
186 Certain characters are special if entered at the beginning of
187 the pattern; they modify the type of search rather than become
191 Search for lines which do NOT match the pattern.
194 Search multiple files. That is, if the search reaches
195 the END of the current file without finding a match, the
196 search continues in the next file in the command line
200 Begin the search at the first line of the FIRST file in
201 the command line list, regardless of what is currently
202 displayed on the screen or the settings of the -a or -j
205 ^K Highlight any text which matches the pattern on the cur-
206 rent screen, but don't move to the first match (KEEP cur-
209 ^R Don't interpret regular expression metacharacters; that
210 is, do a simple textual comparison.
213 Search backward in the file for the N-th line containing the
214 pattern. The search starts at the line immediately before the
217 Certain characters are special as in the / command:
220 Search for lines which do NOT match the pattern.
223 Search multiple files. That is, if the search reaches
224 the beginning of the current file without finding a
225 match, the search continues in the previous file in the
229 Begin the search at the last line of the last file in the
230 command line list, regardless of what is currently dis-
231 played on the screen or the settings of the -a or -j
234 ^K As in forward searches.
236 ^R As in forward searches.
244 n Repeat previous search, for N-th line containing the last pat-
245 tern. If the previous search was modified by ^N, the search is
246 made for the N-th line NOT containing the pattern. If the pre-
247 vious search was modified by ^E, the search continues in the
248 next (or previous) file if not satisfied in the current file.
249 If the previous search was modified by ^R, the search is done
250 without using regular expressions. There is no effect if the
251 previous search was modified by ^F or ^K.
253 N Repeat previous search, but in the reverse direction.
255 ESC-n Repeat previous search, but crossing file boundaries. The
256 effect is as if the previous search were modified by *.
258 ESC-N Repeat previous search, but in the reverse direction and cross-
261 ESC-u Undo search highlighting. Turn off highlighting of strings
262 matching the current search pattern. If highlighting is already
263 off because of a previous ESC-u command, turn highlighting back
264 on. Any search command will also turn highlighting back on.
265 (Highlighting can also be disabled by toggling the -G option; in
266 that case search commands do not turn highlighting back on.)
269 Display only lines which match the pattern; lines which do not
270 match the pattern are not displayed. If pattern is empty (if
271 you type & immediately followed by ENTER), any filtering is
272 turned off, and all lines are displayed. While filtering is in
273 effect, an ampersand is displayed at the beginning of the
274 prompt, as a reminder that some lines in the file may be hidden.
276 Certain characters are special as in the / command:
279 Display only lines which do NOT match the pattern.
281 ^R Don't interpret regular expression metacharacters; that
282 is, do a simple textual comparison.
285 Examine a new file. If the filename is missing, the "current"
286 file (see the :n and :p commands below) from the list of files
287 in the command line is re-examined. A percent sign (%) in the
288 filename is replaced by the name of the current file. A pound
289 sign (#) is replaced by the name of the previously examined
290 file. However, two consecutive percent signs are simply
291 replaced with a single percent sign. This allows you to enter a
292 filename that contains a percent sign in the name. Similarly,
293 two consecutive pound signs are replaced with a single pound
294 sign. The filename is inserted into the command line list of
295 files so that it can be seen by subsequent :n and :p commands.
296 If the filename consists of several files, they are all inserted
297 into the list of files and the first one is examined. If the
298 filename contains one or more spaces, the entire filename should
299 be enclosed in double quotes (also see the -" option).
302 Same as :e. Warning: some systems use ^V as a special literal-
303 ization character. On such systems, you may not be able to use
306 :n Examine the next file (from the list of files given in the com-
307 mand line). If a number N is specified, the N-th next file is
310 :p Examine the previous file in the command line list. If a number
311 N is specified, the N-th previous file is examined.
313 :x Examine the first file in the command line list. If a number N
314 is specified, the N-th file in the list is examined.
316 :d Remove the current file from the list of files.
318 t Go to the next tag, if there were more than one matches for the
319 current tag. See the -t option for more details about tags.
321 T Go to the previous tag, if there were more than one matches for
325 Prints some information about the file being viewed, including
326 its name and the line number and byte offset of the bottom line
327 being displayed. If possible, it also prints the length of the
328 file, the number of lines in the file and the percent of the
329 file above the last displayed line.
331 - Followed by one of the command line option letters (see OPTIONS
332 below), this will change the setting of that option and print a
333 message describing the new setting. If a ^P (CONTROL-P) is
334 entered immediately after the dash, the setting of the option is
335 changed but no message is printed. If the option letter has a
336 numeric value (such as -b or -h), or a string value (such as -P
337 or -t), a new value may be entered after the option letter. If
338 no new value is entered, a message describing the current set-
339 ting is printed and nothing is changed.
341 -- Like the - command, but takes a long option name (see OPTIONS
342 below) rather than a single option letter. You must press ENTER
343 or RETURN after typing the option name. A ^P immediately after
344 the second dash suppresses printing of a message describing the
345 new setting, as in the - command.
347 -+ Followed by one of the command line option letters this will
348 reset the option to its default setting and print a message
349 describing the new setting. (The "-+
\e[4mX
\e[24m" command does the same
350 thing as "-+
\e[4mX
\e[24m" on the command line.) This does not work for
351 string-valued options.
353 --+ Like the -+ command, but takes a long option name rather than a
354 single option letter.
356 -! Followed by one of the command line option letters, this will
357 reset the option to the "opposite" of its default setting and
358 print a message describing the new setting. This does not work
359 for numeric or string-valued options.
361 --! Like the -! command, but takes a long option name rather than a
362 single option letter.
364 _ (Underscore.) Followed by one of the command line option let-
365 ters, this will print a message describing the current setting
366 of that option. The setting of the option is not changed.
368 __ (Double underscore.) Like the _ (underscore) command, but takes
369 a long option name rather than a single option letter. You must
370 press ENTER or RETURN after typing the option name.
372 +cmd Causes the specified cmd to be executed each time a new file is
373 examined. For example, +G causes
\e[4mless
\e[24m to initially display each
374 file starting at the end rather than the beginning.
376 V Prints the version number of
\e[4mless
\e[24m being run.
378 q or Q or :q or :Q or ZZ
379 Exits
\e[4mless.
\e[0m
381 The following four commands may or may not be valid, depending on your
382 particular installation.
384 v Invokes an editor to edit the current file being viewed. The
385 editor is taken from the environment variable VISUAL if defined,
386 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei-
387 ther VISUAL nor EDITOR is defined. See also the discussion of
388 LESSEDIT under the section on PROMPTS below.
391 Invokes a shell to run the shell-command given. A percent sign
392 (%) in the command is replaced by the name of the current file.
393 A pound sign (#) is replaced by the name of the previously exam-
394 ined file. "!!" repeats the last shell command. "!" with no
395 shell command simply invokes a shell. On Unix systems, the
396 shell is taken from the environment variable SHELL, or defaults
397 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
401 <m> represents any mark letter. Pipes a section of the input
402 file to the given shell command. The section of the file to be
403 piped is between the first line on the current screen and the
404 position marked by the letter. <m> may also be ^ or $ to indi-
405 cate beginning or end of file respectively. If <m> is . or new-
406 line, the current screen is piped.
409 Save the input to a file. This only works if the input is a
410 pipe, not an ordinary file.
413 Command line options are described below. Most options may be changed
414 while
\e[4mless
\e[24m is running, via the "-" command.
416 Most options may be given in one of two forms: either a dash followed
417 by a single letter, or two dashes followed by a long option name. A
418 long option name may be abbreviated as long as the abbreviation is
419 unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
420 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
421 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
422 from --quit-at-eof. Such option names need only have their first let-
423 ter capitalized; the remainder of the name may be in either case. For
424 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
426 Options are also taken from the environment variable "LESS". For exam-
427 ple, to avoid typing "less -options ..." each time
\e[4mless
\e[24m is invoked, you
428 might tell
\e[4mcsh:
\e[0m
430 setenv LESS "-options"
432 or if you use
\e[4msh:
\e[0m
434 LESS="-options"; export LESS
436 On MS-DOS, you don't need the quotes, but you should replace any per-
437 cent signs in the options string by double percent signs.
439 The environment variable is parsed before the command line, so command
440 line options override the LESS environment variable. If an option
441 appears in the LESS variable, it can be reset to its default value on
442 the command line by beginning the command line option with "-+".
444 Some options like -k or -D require a string to follow the option let-
445 ter. The string for that option is considered to end when a dollar
446 sign ($) is found. For example, you can set two -D options on MS-DOS
451 If the --use-backslash option appears earlier in the options, then a
452 dollar sign or backslash may be included literally in an option string
453 by preceding it with a backslash. If the --use-backslash option is not
454 in effect, then backslashes are not treated specially, and there is no
455 way to include a dollar sign in the option string.
458 This option displays a summary of the commands accepted by
\e[4mless
\e[0m
459 (the same as the h command). (Depending on how your shell
460 interprets the question mark, it may be necessary to quote the
461 question mark, thus: "-\?".)
463 -a or --search-skip-screen
464 By default, forward searches start at the top of the displayed
465 screen and backwards searches start at the bottom of the dis-
466 played screen (except for repeated searches invoked by the n or
467 N commands, which start after or before the "target" line
468 respectively; see the -j option for more about the target line).
469 The -a option causes forward searches to instead start at the
470 bottom of the screen and backward searches to start at the top
471 of the screen, thus skipping all lines displayed on the screen.
473 -A or --SEARCH-SKIP-SCREEN
474 Causes all forward searches (not just non-repeated searches) to
475 start just after the target line, and all backward searches to
476 start just before the target line. Thus, forward searches will
477 skip part of the displayed screen (from the first line up to and
478 including the target line). Similarly backwards searches will
479 skip the displayed screen from the last line up to and including
480 the target line. This was the default behavior in less versions
483 -b
\e[4mn
\e[24m or --buffers=
\e[4mn
\e[0m
484 Specifies the amount of buffer space
\e[4mless
\e[24m will use for each
485 file, in units of kilobytes (1024 bytes). By default 64 K of
486 buffer space is used for each file (unless the file is a pipe;
487 see the -B option). The -b option specifies instead that
\e[4mn
\e[0m
488 kilobytes of buffer space should be used for each file. If
\e[4mn
\e[24m is
489 -1, buffer space is unlimited; that is, the entire file can be
493 By default, when data is read from a pipe, buffers are allocated
494 automatically as needed. If a large amount of data is read from
495 the pipe, this can cause a large amount of memory to be allo-
496 cated. The -B option disables this automatic allocation of buf-
497 fers for pipes, so that only 64 K (or the amount of space speci-
498 fied by the -b option) is used for the pipe. Warning: use of -B
499 can result in erroneous display, since only the most recently
500 viewed part of the piped data is kept in memory; any earlier
504 Causes full screen repaints to be painted from the top line
505 down. By default, full screen repaints are done by scrolling
506 from the bottom of the screen.
509 Same as -c, for compatibility with older versions of
\e[4mless.
\e[0m
512 The -d option suppresses the error message normally displayed if
513 the terminal is dumb; that is, lacks some important capability,
514 such as the ability to clear the screen or scroll backward. The
515 -d option does not otherwise change the behavior of
\e[4mless
\e[24m on a
518 -D
\e[1mx
\e[4m
\e[22mcolor
\e[24m or --color=
\e[1mx
\e[4m
\e[22mcolor
\e[0m
519 [MS-DOS only] Sets the color of the text displayed.
\e[1mx
\e[22mis a sin-
520 gle character which selects the type of text whose color is
521 being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
522 \e[4mcolor
\e[24m is a pair of numbers separated by a period. The first
523 number selects the foreground color and the second selects the
524 background color of the text. A single number
\e[4mN
\e[24m is the same as
525 \e[4mN.M
\e[24m, where
\e[4mM
\e[24m is the normal background color.
529 Causes
\e[4mless
\e[24m to automatically exit the second time it reaches
530 end-of-file. By default, the only way to exit
\e[4mless
\e[24m is via the
534 Causes
\e[4mless
\e[24m to automatically exit the first time it reaches end-
538 Forces non-regular files to be opened. (A non-regular file is a
539 directory or a device special file.) Also suppresses the warn-
540 ing message when a binary file is opened. By default,
\e[4mless
\e[24m will
541 refuse to open non-regular files. Note that some operating sys-
542 tems will not allow directories to be read, even if -f is set.
544 -F or --quit-if-one-screen
545 Causes
\e[4mless
\e[24m to automatically exit if the entire file can be dis-
546 played on the first screen.
548 -g or --hilite-search
549 Normally,
\e[4mless
\e[24m will highlight ALL strings which match the last
550 search command. The -g option changes this behavior to high-
551 light only the particular string which was found by the last
552 search command. This can cause
\e[4mless
\e[24m to run somewhat faster than
555 -G or --HILITE-SEARCH
556 The -G option suppresses all highlighting of strings found by
559 -h
\e[4mn
\e[24m or --max-back-scroll=
\e[4mn
\e[0m
560 Specifies a maximum number of lines to scroll backward. If it
561 is necessary to scroll backward more than
\e[4mn
\e[24m lines, the screen is
562 repainted in a forward direction instead. (If the terminal does
563 not have the ability to scroll backward, -h0 is implied.)
566 Causes searches to ignore case; that is, uppercase and lowercase
567 are considered identical. This option is ignored if any upper-
568 case letters appear in the search pattern; in other words, if a
569 pattern contains uppercase letters, then that search does not
573 Like -i, but searches ignore case even if the pattern contains
576 -j
\e[4mn
\e[24m or --jump-target=
\e[4mn
\e[0m
577 Specifies a line on the screen where the "target" line is to be
578 positioned. The target line is the line specified by any com-
579 mand to search for a pattern, jump to a line number, jump to a
580 file percentage or jump to a tag. The screen line may be speci-
581 fied by a number: the top line on the screen is 1, the next is
582 2, and so on. The number may be negative to specify a line rel-
583 ative to the bottom of the screen: the bottom line on the screen
584 is -1, the second to the bottom is -2, and so on. Alternately,
585 the screen line may be specified as a fraction of the height of
586 the screen, starting with a decimal point: .5 is in the middle
587 of the screen, .3 is three tenths down from the first line, and
588 so on. If the line is specified as a fraction, the actual line
589 number is recalculated if the terminal window is resized, so
590 that the target line remains at the specified fraction of the
591 screen height. If any form of the -j option is used, repeated
592 forward searches (invoked with "n" or "N") begin at the line
593 immediately after the target line, and repeated backward
594 searches begin at the target line, unless changed by -a or -A.
595 For example, if "-j4" is used, the target line is the fourth
596 line on the screen, so forward searches begin at the fifth line
597 on the screen. However nonrepeated searches (invoked with "/"
598 or "?") always begin at the start or end of the current screen
601 -J or --status-column
602 Displays a status column at the left edge of the screen. The
603 status column shows the lines that matched the current search.
604 The status column is also used if the -w or -W option is in
607 -k
\e[4mfilename
\e[24m or --lesskey-file=
\e[4mfilename
\e[0m
608 Causes
\e[4mless
\e[24m to open and interpret the named file as a
\e[4mlesskey
\e[0m
609 (1) file. Multiple -k options may be specified. If the LESSKEY
610 or LESSKEY_SYSTEM environment variable is set, or if a lesskey
611 file is found in a standard place (see KEY BINDINGS), it is also
612 used as a
\e[4mlesskey
\e[24m file.
615 Causes
\e[4mless
\e[24m to exit immediately (with status 2) when an inter-
616 rupt character (usually ^C) is typed. Normally, an interrupt
617 character causes
\e[4mless
\e[24m to stop whatever it is doing and return to
618 its command prompt. Note that use of this option makes it
619 impossible to return to the command prompt from the "F" command.
622 Ignore the LESSOPEN environment variable (see the INPUT PRE-
623 PROCESSOR section below). This option can be set from within
624 \e[4mless
\e[24m, but it will apply only to files opened subsequently, not
625 to the file which is currently open.
628 Causes
\e[4mless
\e[24m to prompt verbosely (like
\e[4mmore
\e[24m), with the percent
629 into the file. By default,
\e[4mless
\e[24m prompts with a colon.
632 Causes
\e[4mless
\e[24m to prompt even more verbosely than
\e[4mmore.
\e[0m
635 Suppresses line numbers. The default (to use line numbers) may
636 cause
\e[4mless
\e[24m to run more slowly in some cases, especially with a
637 very large input file. Suppressing line numbers with the -n
638 option will avoid this problem. Using line numbers means: the
639 line number will be displayed in the verbose prompt and in the =
640 command, and the v command will pass the current line number to
641 the editor (see also the discussion of LESSEDIT in PROMPTS
645 Causes a line number to be displayed at the beginning of each
648 -o
\e[4mfilename
\e[24m or --log-file=
\e[4mfilename
\e[0m
649 Causes
\e[4mless
\e[24m to copy its input to the named file as it is being
650 viewed. This applies only when the input file is a pipe, not an
651 ordinary file. If the file already exists,
\e[4mless
\e[24m will ask for
652 confirmation before overwriting it.
654 -O
\e[4mfilename
\e[24m or --LOG-FILE=
\e[4mfilename
\e[0m
655 The -O option is like -o, but it will overwrite an existing file
656 without asking for confirmation.
658 If no log file has been specified, the -o and -O options can be
659 used from within
\e[4mless
\e[24m to specify a log file. Without a file
660 name, they will simply report the name of the log file. The "s"
661 command is equivalent to specifying -o from within
\e[4mless.
\e[0m
663 -p
\e[4mpattern
\e[24m or --pattern=
\e[4mpattern
\e[0m
664 The -p option on the command line is equivalent to specifying
665 +/
\e[4mpattern
\e[24m; that is, it tells
\e[4mless
\e[24m to start at the first occur-
666 rence of
\e[4mpattern
\e[24m in the file.
668 -P
\e[4mprompt
\e[24m or --prompt=
\e[4mprompt
\e[0m
669 Provides a way to tailor the three prompt styles to your own
670 preference. This option would normally be put in the LESS envi-
671 ronment variable, rather than being typed in with each
\e[4mless
\e[24m com-
672 mand. Such an option must either be the last option in the LESS
673 variable, or be terminated by a dollar sign.
674 -Ps followed by a string changes the default (short) prompt to
676 -Pm changes the medium (-m) prompt.
677 -PM changes the long (-M) prompt.
678 -Ph changes the prompt for the help screen.
679 -P= changes the message printed by the = command.
680 -Pw changes the message printed while waiting for data (in the
681 F command). All prompt strings consist of a sequence of letters
682 and special escape sequences. See the section on PROMPTS for
685 -q or --quiet or --silent
686 Causes moderately "quiet" operation: the terminal bell is not
687 rung if an attempt is made to scroll past the end of the file or
688 before the beginning of the file. If the terminal has a "visual
689 bell", it is used instead. The bell will be rung on certain
690 other errors, such as typing an invalid character. The default
691 is to ring the terminal bell in all such cases.
693 -Q or --QUIET or --SILENT
694 Causes totally "quiet" operation: the terminal bell is never
697 -r or --raw-control-chars
698 Causes "raw" control characters to be displayed. The default is
699 to display control characters using the caret notation; for
700 example, a control-A (octal 001) is displayed as "^A". Warning:
701 when the -r option is used,
\e[4mless
\e[24m cannot keep track of the actual
702 appearance of the screen (since this depends on how the screen
703 responds to each type of control character). Thus, various dis-
704 play problems may result, such as long lines being split in the
707 -R or --RAW-CONTROL-CHARS
708 Like -r, but only ANSI "color" escape sequences are output in
709 "raw" form. Unlike -r, the screen appearance is maintained cor-
710 rectly in most cases. ANSI "color" escape sequences are
711 sequences of the form:
715 where the "..." is zero or more color specification characters
716 For the purpose of keeping track of screen appearance, ANSI
717 color escape sequences are assumed to not move the cursor. You
718 can make
\e[4mless
\e[24m think that characters other than "m" can end ANSI
719 color escape sequences by setting the environment variable
720 LESSANSIENDCHARS to the list of characters which can end a color
721 escape sequence. And you can make
\e[4mless
\e[24m think that characters
722 other than the standard ones may appear between the ESC and the
723 m by setting the environment variable LESSANSIMIDCHARS to the
724 list of characters which can appear.
726 -s or --squeeze-blank-lines
727 Causes consecutive blank lines to be squeezed into a single
728 blank line. This is useful when viewing
\e[4mnroff
\e[24m output.
730 -S or --chop-long-lines
731 Causes lines longer than the screen width to be chopped (trun-
732 cated) rather than wrapped. That is, the portion of a long line
733 that does not fit in the screen width is not shown. The default
734 is to wrap long lines; that is, display the remainder on the
737 -t
\e[4mtag
\e[24m or --tag=
\e[4mtag
\e[0m
738 The -t option, followed immediately by a TAG, will edit the file
739 containing that tag. For this to work, tag information must be
740 available; for example, there may be a file in the current
741 directory called "tags", which was previously built by
\e[4mctags
\e[24m (1)
742 or an equivalent command. If the environment variable LESSGLOB-
743 ALTAGS is set, it is taken to be the name of a command compati-
744 ble with
\e[4mglobal
\e[24m (1), and that command is executed to find the
745 tag. (See http://www.gnu.org/software/global/global.html). The
746 -t option may also be specified from within
\e[4mless
\e[24m (using the -
747 command) as a way of examining a new file. The command ":t" is
748 equivalent to specifying -t from within
\e[4mless.
\e[0m
750 -T
\e[4mtagsfile
\e[24m or --tag-file=
\e[4mtagsfile
\e[0m
751 Specifies a tags file to be used instead of "tags".
753 -u or --underline-special
754 Causes backspaces and carriage returns to be treated as print-
755 able characters; that is, they are sent to the terminal when
756 they appear in the input.
758 -U or --UNDERLINE-SPECIAL
759 Causes backspaces, tabs and carriage returns to be treated as
760 control characters; that is, they are handled as specified by
763 By default, if neither -u nor -U is given, backspaces which
764 appear adjacent to an underscore character are treated spe-
765 cially: the underlined text is displayed using the terminal's
766 hardware underlining capability. Also, backspaces which appear
767 between two identical characters are treated specially: the
768 overstruck text is printed using the terminal's hardware bold-
769 face capability. Other backspaces are deleted, along with the
770 preceding character. Carriage returns immediately followed by a
771 newline are deleted. Other carriage returns are handled as
772 specified by the -r option. Text which is overstruck or under-
773 lined can be searched for if neither -u nor -U is in effect.
776 Displays the version number of
\e[4mless.
\e[0m
778 -w or --hilite-unread
779 Temporarily highlights the first "new" line after a forward
780 movement of a full page. The first "new" line is the line imme-
781 diately following the line previously at the bottom of the
782 screen. Also highlights the target line after a g or p command.
783 The highlight is removed at the next command which causes move-
784 ment. The entire line is highlighted, unless the -J option is
785 in effect, in which case only the status column is highlighted.
787 -W or --HILITE-UNREAD
788 Like -w, but temporarily highlights the first new line after any
789 forward movement command larger than one line.
791 -x
\e[4mn
\e[24m,... or --tabs=
\e[4mn
\e[24m,...
792 Sets tab stops. If only one
\e[4mn
\e[24m is specified, tab stops are set
793 at multiples of
\e[4mn
\e[24m. If multiple values separated by commas are
794 specified, tab stops are set at those positions, and then con-
795 tinue with the same spacing as the last two. For example,
796 \e[4m-x9,17
\e[24m will set tabs at positions 9, 17, 25, 33, etc. The
797 default for
\e[4mn
\e[24m is 8.
800 Disables sending the termcap initialization and deinitialization
801 strings to the terminal. This is sometimes desirable if the
802 deinitialization string does something unnecessary, like clear-
805 -y
\e[4mn
\e[24m or --max-forw-scroll=
\e[4mn
\e[0m
806 Specifies a maximum number of lines to scroll forward. If it is
807 necessary to scroll forward more than
\e[4mn
\e[24m lines, the screen is
808 repainted instead. The -c or -C option may be used to repaint
809 from the top of the screen if desired. By default, any forward
810 movement causes scrolling.
812 -[z]
\e[4mn
\e[24m or --window=
\e[4mn
\e[0m
813 Changes the default scrolling window size to
\e[4mn
\e[24m lines. The
814 default is one screenful. The z and w commands can also be used
815 to change the window size. The "z" may be omitted for compati-
816 bility with some versions of
\e[4mmore.
\e[24m If the number
\e[4mn
\e[24m is negative,
817 it indicates
\e[4mn
\e[24m lines less than the current screen size. For
818 example, if the screen is 24 lines,
\e[4m-z-4
\e[24m sets the scrolling win-
819 dow to 20 lines. If the screen is resized to 40 lines, the
820 scrolling window automatically changes to 36 lines.
822 -
\e[4m"cc
\e[24m or --quotes=
\e[4mcc
\e[0m
823 Changes the filename quoting character. This may be necessary
824 if you are trying to name a file which contains both spaces and
825 quote characters. Followed by a single character, this changes
826 the quote character to that character. Filenames containing a
827 space should then be surrounded by that character rather than by
828 double quotes. Followed by two characters, changes the open
829 quote to the first character, and the close quote to the second
830 character. Filenames containing a space should then be preceded
831 by the open quote character and followed by the close quote
832 character. Note that even after the quote characters are
833 changed, this option remains -" (a dash followed by a double
837 Normally lines after end of file are displayed as a single tilde
838 (~). This option causes lines after end of file to be displayed
842 Specifies the default number of positions to scroll horizontally
843 in the RIGHTARROW and LEFTARROW commands. If the number speci-
844 fied is zero, it sets the default number of positions to one
845 half of the screen width. Alternately, the number may be speci-
846 fied as a fraction of the width of the screen, starting with a
847 decimal point: .5 is half of the screen width, .3 is three
848 tenths of the screen width, and so on. If the number is speci-
849 fied as a fraction, the actual number of scroll positions is
850 recalculated if the terminal window is resized, so that the
851 actual scroll remains at the specified fraction of the screen
855 Normally, if the input file is renamed while an F command is
856 executing,
\e[4mless
\e[24m will continue to display the contents of the
857 original file despite its name change. If --follow-name is
858 specified, during an F command
\e[4mless
\e[24m will periodically attempt to
859 reopen the file by name. If the reopen succeeds and the file is
860 a different file from the original (which means that a new file
861 has been created with the same name as the original (now
862 renamed) file),
\e[4mless
\e[24m will display the contents of that new file.
865 Disables sending the keypad initialization and deinitialization
866 strings to the terminal. This is sometimes useful if the keypad
867 strings make the numeric keypad behave in an undesirable manner.
870 This option changes the interpretations of options which follow
871 this one. After the --use-backslash option, any backslash in an
872 option string is removed and the following character is taken
873 literally. This allows a dollar sign to be included in option
876 -- A command line argument of "--" marks the end of option argu-
877 ments. Any arguments following this are interpreted as file-
878 names. This can be useful when viewing a file whose name begins
881 + If a command line option begins with
\e[1m+
\e[22m, the remainder of that
882 option is taken to be an initial command to
\e[4mless.
\e[24m For example,
883 +G tells
\e[4mless
\e[24m to start at the end of the file rather than the
884 beginning, and +/xyz tells it to start at the first occurrence
885 of "xyz" in the file. As a special case, +<number> acts like
886 +<number>g; that is, it starts the display at the specified line
887 number (however, see the caveat under the "g" command above).
888 If the option starts with ++, the initial command applies to
889 every file being viewed, not just the first one. The + command
890 described previously may also be used to set (or change) an ini-
891 tial command for every file.
894 \e[1mLINE EDITING
\e[0m
895 When entering command line at the bottom of the screen (for example, a
896 filename for the :e command, or the pattern for a search command), cer-
897 tain keys can be used to manipulate the command line. Most commands
898 have an alternate form in [ brackets ] which can be used if a key does
899 not exist on a particular keyboard. (Note that the forms beginning
900 with ESC do not work in some MS-DOS and Windows systems because ESC is
901 the line erase character.) Any of these special keys may be entered
902 literally by preceding it with the "literal" character, either ^V or
903 ^A. A backslash itself may also be entered literally by entering two
907 Move the cursor one space to the left.
910 Move the cursor one space to the right.
912 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
913 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur-
914 sor one word to the left.
916 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
917 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur-
918 sor one word to the right.
921 Move the cursor to the beginning of the line.
924 Move the cursor to the end of the line.
927 Delete the character to the left of the cursor, or cancel the
928 command if the command line is empty.
931 Delete the character under the cursor.
933 ^BACKSPACE [ ESC-BACKSPACE ]
934 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
935 word to the left of the cursor.
937 ^DELETE [ ESC-X or ESC-DELETE ]
938 (That is, CONTROL and DELETE simultaneously.) Delete the word
942 Retrieve the previous command line. If you first enter some
943 text and then press UPARROW, it will retrieve the previous com-
944 mand which begins with that text.
947 Retrieve the next command line. If you first enter some text
948 and then press DOWNARROW, it will retrieve the next command
949 which begins with that text.
951 TAB Complete the partial filename to the left of the cursor. If it
952 matches more than one filename, the first match is entered into
953 the command line. Repeated TABs will cycle thru the other
954 matching filenames. If the completed filename is a directory, a
955 "/" is appended to the filename. (On MS-DOS systems, a "\" is
956 appended.) The environment variable LESSSEPARATOR can be used
957 to specify a different character to append to a directory name.
960 Like, TAB, but cycles in the reverse direction thru the matching
963 ^L Complete the partial filename to the left of the cursor. If it
964 matches more than one filename, all matches are entered into the
965 command line (if they fit).
967 ^U (Unix and OS/2) or ESC (MS-DOS)
968 Delete the entire command line, or cancel the command if the
969 command line is empty. If you have changed your line-kill char-
970 acter in Unix to something other than ^U, that character is used
973 ^G Delete the entire command line and return to the main prompt.
976 \e[1mKEY BINDINGS
\e[0m
977 You may define your own
\e[4mless
\e[24m commands by using the program
\e[4mlesskey
\e[24m (1)
978 to create a lesskey file. This file specifies a set of command keys
979 and an action associated with each key. You may also use
\e[4mlesskey
\e[24m to
980 change the line-editing keys (see LINE EDITING), and to set environment
981 variables. If the environment variable LESSKEY is set,
\e[4mless
\e[24m uses that
982 as the name of the lesskey file. Otherwise,
\e[4mless
\e[24m looks in a standard
983 place for the lesskey file: On Unix systems,
\e[4mless
\e[24m looks for a lesskey
984 file called "$HOME/.less". On MS-DOS and Windows systems,
\e[4mless
\e[24m looks
985 for a lesskey file called "$HOME/_less", and if it is not found there,
986 then looks for a lesskey file called "_less" in any directory specified
987 in the PATH environment variable. On OS/2 systems,
\e[4mless
\e[24m looks for a
988 lesskey file called "$HOME/less.ini", and if it is not found, then
989 looks for a lesskey file called "less.ini" in any directory specified
990 in the INIT environment variable, and if it not found there, then looks
991 for a lesskey file called "less.ini" in any directory specified in the
992 PATH environment variable. See the
\e[4mlesskey
\e[24m manual page for more
995 A system-wide lesskey file may also be set up to provide key bindings.
996 If a key is defined in both a local lesskey file and in the system-wide
997 file, key bindings in the local file take precedence over those in the
998 system-wide file. If the environment variable LESSKEY_SYSTEM is set,
999 \e[4mless
\e[24m uses that as the name of the system-wide lesskey file. Otherwise,
1000 \e[4mless
\e[24m looks in a standard place for the system-wide lesskey file: On
1001 Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
1002 (However, if
\e[4mless
\e[24m was built with a different sysconf directory than
1003 /usr/local/etc, that directory is where the sysless file is found.) On
1004 MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys-
1005 less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
1008 \e[1mINPUT PREPROCESSOR
\e[0m
1009 You may define an "input preprocessor" for
\e[4mless.
\e[24m Before
\e[4mless
\e[24m opens a
1010 file, it first gives your input preprocessor a chance to modify the way
1011 the contents of the file are displayed. An input preprocessor is sim-
1012 ply an executable program (or shell script), which writes the contents
1013 of the file to a different file, called the replacement file. The con-
1014 tents of the replacement file are then displayed in place of the con-
1015 tents of the original file. However, it will appear to the user as if
1016 the original file is opened; that is,
\e[4mless
\e[24m will display the original
1017 filename as the name of the current file.
1019 An input preprocessor receives one command line argument, the original
1020 filename, as entered by the user. It should create the replacement
1021 file, and when finished, print the name of the replacement file to its
1022 standard output. If the input preprocessor does not output a replace-
1023 ment filename,
\e[4mless
\e[24m uses the original file, as normal. The input pre-
1024 processor is not called when viewing standard input. To set up an
1025 input preprocessor, set the LESSOPEN environment variable to a command
1026 line which will invoke your input preprocessor. This command line
1027 should include one occurrence of the string "%s", which will be
1028 replaced by the filename when the input preprocessor command is
1031 When
\e[4mless
\e[24m closes a file opened in such a way, it will call another pro-
1032 gram, called the input postprocessor, which may perform any desired
1033 clean-up action (such as deleting the replacement file created by
1034 LESSOPEN). This program receives two command line arguments, the orig-
1035 inal filename as entered by the user, and the name of the replacement
1036 file. To set up an input postprocessor, set the LESSCLOSE environment
1037 variable to a command line which will invoke your input postprocessor.
1038 It may include two occurrences of the string "%s"; the first is
1039 replaced with the original name of the file and the second with the
1040 name of the replacement file, which was output by LESSOPEN.
1042 For example, on many Unix systems, these two scripts will allow you to
1043 keep files in compressed format, but still let
\e[4mless
\e[24m view them directly:
1048 *.Z) uncompress -c $1 >/tmp/less.$$ 2>/dev/null
1049 if [ -s /tmp/less.$$ ]; then
1061 To use these scripts, put them both where they can be executed and set
1062 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
1063 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
1064 types of compressed files, and so on.
1066 It is also possible to set up an input preprocessor to pipe the file
1067 data directly to
\e[4mless,
\e[24m rather than putting the data into a replacement
1068 file. This avoids the need to decompress the entire file before start-
1069 ing to view it. An input preprocessor that works this way is called an
1070 input pipe. An input pipe, instead of writing the name of a replace-
1071 ment file on its standard output, writes the entire contents of the
1072 replacement file on its standard output. If the input pipe does not
1073 write any characters on its standard output, then there is no replace-
1074 ment file and
\e[4mless
\e[24m uses the original file, as normal. To use an input
1075 pipe, make the first character in the LESSOPEN environment variable a
1076 vertical bar (|) to signify that the input preprocessor is an input
1079 For example, on many Unix systems, this script will work like the pre-
1080 vious example scripts:
1085 *.Z) uncompress -c $1 2>/dev/null
1091 To use this script, put it where it can be executed and set
1092 LESSOPEN="|lesspipe.sh %s".
1094 Note that a preprocessor cannot output an empty file, since that is
1095 interpreted as meaning there is no replacement, and the original file
1096 is used. To avoid this, if LESSOPEN starts with two vertical bars, the
1097 exit status of the script becomes meaningful. If the exit status is
1098 zero, the output is considered to be replacement text, even if it
1099 empty. If the exit status is nonzero, any output is ignored and the
1100 original file is used. For compatibility with previous versions of
1101 \e[4mless,
\e[24m if LESSOPEN starts with only one vertical bar, the exit status of
1102 the preprocessor is ignored.
1104 When an input pipe is used, a LESSCLOSE postprocessor can be used, but
1105 it is usually not necessary since there is no replacement file to clean
1106 up. In this case, the replacement file name passed to the LESSCLOSE
1107 postprocessor is "-".
1109 For compatibility with previous versions of
\e[4mless,
\e[24m the input preproces-
1110 sor or pipe is not used if
\e[4mless
\e[24m is viewing standard input. However, if
1111 the first character of LESSOPEN is a dash (-), the input preprocessor
1112 is used on standard input as well as other files. In this case, the
1113 dash is not considered to be part of the preprocessor command. If
1114 standard input is being viewed, the input preprocessor is passed a file
1115 name consisting of a single dash. Similarly, if the first two charac-
1116 ters of LESSOPEN are vertical bar and dash (|-) or two vertical bars
1117 and a dash (||-), the input pipe is used on standard input as well as
1118 other files. Again, in this case the dash is not considered to be part
1119 of the input pipe command.
1122 \e[1mNATIONAL CHARACTER SETS
\e[0m
1123 There are three types of characters in the input file:
1126 can be displayed directly to the screen.
1129 should not be displayed directly, but are expected to be found
1130 in ordinary text files (such as backspace and tab).
1133 should not be displayed directly and are not expected to be
1134 found in text files.
1136 A "character set" is simply a description of which characters are to be
1137 considered normal, control, and binary. The LESSCHARSET environment
1138 variable may be used to select a character set. Possible values for
1141 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1142 with values between 32 and 126 are normal, and all others are
1146 Selects an ISO 8859 character set. This is the same as ASCII,
1147 except characters between 160 and 255 are treated as normal
1150 latin1 Same as iso8859.
1152 latin9 Same as iso8859.
1154 dos Selects a character set appropriate for MS-DOS.
1156 ebcdic Selects an EBCDIC character set.
1159 Selects an EBCDIC character set used by OS/390 Unix Services.
1160 This is the EBCDIC analogue of latin1. You get similar results
1161 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1164 koi8-r Selects a Russian character set.
1166 next Selects a character set appropriate for NeXT computers.
1168 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1169 UTF-8 is special in that it supports multi-byte characters in
1170 the input file. It is the only character set that supports
1171 multi-byte characters.
1174 Selects a character set appropriate for Microsoft Windows (cp
1177 In rare cases, it may be desired to tailor
\e[4mless
\e[24m to use a character set
1178 other than the ones definable by LESSCHARSET. In this case, the envi-
1179 ronment variable LESSCHARDEF can be used to define a character set. It
1180 should be set to a string where each character in the string represents
1181 one character in the character set. The character "." is used for a
1182 normal character, "c" for control, and "b" for binary. A decimal num-
1183 ber may be used for repetition. For example, "bccc4b." would mean
1184 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
1185 binary, and 8 is normal. All characters after the last are taken to be
1186 the same as the last, so characters 9 through 255 would be normal.
1187 (This is an example, and does not necessarily represent any real char-
1190 This table shows the value of LESSCHARDEF which is equivalent to each
1191 of the possible values for LESSCHARSET:
1193 ascii 8bcccbcc18b95.b
1194 dos 8bcccbcc12bc5b95.b.
1195 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1196 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1197 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1199 iso8859 8bcccbcc18b95.33b.
1200 koi8-r 8bcccbcc18b95.b128.
1201 latin1 8bcccbcc18b95.33b.
1202 next 8bcccbcc18b95.bb125.bb
1204 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1205 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
1206 LANG environment variables, then the default character set is utf-8.
1208 If that string is not found, but your system supports the
\e[4msetlocale
\e[0m
1209 interface,
\e[4mless
\e[24m will use setlocale to determine the character set.
1210 setlocale is controlled by setting the LANG or LC_CTYPE environment
1213 Finally, if the
\e[4msetlocale
\e[24m interface is also not available, the default
1214 character set is latin1.
1216 Control and binary characters are displayed in standout (reverse
1217 video). Each such character is displayed in caret notation if possible
1218 (e.g. ^A for control-A). Caret notation is used only if inverting the
1219 0100 bit results in a normal printable character. Otherwise, the char-
1220 acter is displayed as a hex number in angle brackets. This format can
1221 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1222 may begin with a "*" and one character to select the display attribute:
1223 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1224 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1225 attribute is assumed. The remainder of LESSBINFMT is a string which
1226 may include one printf-style escape sequence (a % followed by x, X, o,
1227 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1228 are displayed in underlined hexadecimal surrounded by brackets. The
1229 default if no LESSBINFMT is specified is "*s<%02X>". Warning: the
1230 result of expanding the character via LESSBINFMT must be less than 31
1233 When the character set is utf-8, the LESSUTFBINFMT environment variable
1234 acts similarly to LESSBINFMT but it applies to Unicode code points that
1235 were successfully decoded but are unsuitable for display (e.g., unas-
1236 signed code points). Its default value is "<U+%04lX>". Note that
1237 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1238 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1239 LESSBINFMT so its setting, if any, will have priority. Problematic
1240 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1241 complete but non-shortest form sequence, illegal octets, and stray
1242 trailing octets) are displayed individually using LESSBINFMT so as to
1243 facilitate diagnostic of how the UTF-8 file is ill-formed.
1247 The -P option allows you to tailor the prompt to your preference. The
1248 string given to the -P option replaces the specified prompt string.
1249 Certain characters in the string are interpreted specially. The prompt
1250 mechanism is rather complicated to provide flexibility, but the ordi-
1251 nary user need not understand the details of constructing personalized
1254 A percent sign followed by a single character is expanded according to
1255 what the following character is:
1257 %b
\e[4mX
\e[24m Replaced by the byte offset into the current input file. The b
1258 is followed by a single character (shown as
\e[4mX
\e[24m above) which spec-
1259 ifies the line whose byte offset is to be used. If the charac-
1260 ter is a "t", the byte offset of the top line in the display is
1261 used, an "m" means use the middle line, a "b" means use the bot-
1262 tom line, a "B" means use the line just after the bottom line,
1263 and a "j" means use the "target" line, as specified by the -j
1266 %B Replaced by the size of the current input file.
1268 %c Replaced by the column number of the text appearing in the first
1269 column of the screen.
1271 %d
\e[4mX
\e[24m Replaced by the page number of a line in the input file. The
1272 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1274 %D Replaced by the number of pages in the input file, or equiva-
1275 lently, the page number of the last line in the input file.
1277 %E Replaced by the name of the editor (from the VISUAL environment
1278 variable, or the EDITOR environment variable if VISUAL is not
1279 defined). See the discussion of the LESSEDIT feature below.
1281 %f Replaced by the name of the current input file.
1283 %F Replaced by the last component of the name of the current input
1286 %i Replaced by the index of the current file in the list of input
1289 %l
\e[4mX
\e[24m Replaced by the line number of a line in the input file. The
1290 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1292 %L Replaced by the line number of the last line in the input file.
1294 %m Replaced by the total number of input files.
1296 %p
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1297 byte offsets. The line used is determined by the
\e[4mX
\e[24m as with the
1300 %P
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1301 line numbers. The line used is determined by the
\e[4mX
\e[24m as with the
1306 %t Causes any trailing spaces to be removed. Usually used at the
1307 end of the string, but may appear anywhere.
1309 %T Normally expands to the word "file". However if viewing files
1310 via a tags list using the -t option, it expands to the word
1313 %x Replaced by the name of the next input file in the list.
1315 If any item is unknown (for example, the file size if input is a pipe),
1316 a question mark is printed instead.
1318 The format of the prompt string can be changed depending on certain
1319 conditions. A question mark followed by a single character acts like
1320 an "IF": depending on the following character, a condition is evalu-
1321 ated. If the condition is true, any characters following the question
1322 mark and condition character, up to a period, are included in the
1323 prompt. If the condition is false, such characters are not included.
1324 A colon appearing between the question mark and the period can be used
1325 to establish an "ELSE": any characters between the colon and the period
1326 are included in the string if and only if the IF condition is false.
1327 Condition characters (which follow a question mark) may be:
1329 ?a True if any characters have been included in the prompt so far.
1331 ?b
\e[4mX
\e[24m True if the byte offset of the specified line is known.
1333 ?B True if the size of current input file is known.
1335 ?c True if the text is horizontally shifted (%c is not zero).
1337 ?d
\e[4mX
\e[24m True if the page number of the specified line is known.
1339 ?e True if at end-of-file.
1341 ?f True if there is an input filename (that is, if input is not a
1344 ?l
\e[4mX
\e[24m True if the line number of the specified line is known.
1346 ?L True if the line number of the last line in the file is known.
1348 ?m True if there is more than one input file.
1350 ?n True if this is the first prompt in a new input file.
1352 ?p
\e[4mX
\e[24m True if the percent into the current input file, based on byte
1353 offsets, of the specified line is known.
1355 ?P
\e[4mX
\e[24m True if the percent into the current input file, based on line
1356 numbers, of the specified line is known.
1360 ?x True if there is a next input file (that is, if the current
1361 input file is not the last one).
1363 Any characters other than the special ones (question mark, colon,
1364 period, percent, and backslash) become literally part of the prompt.
1365 Any of the special characters may be included in the prompt literally
1366 by preceding it with a backslash.
1370 ?f%f:Standard input.
1372 This prompt prints the filename, if known; otherwise the string "Stan-
1375 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1377 This prompt would print the filename, if known. The filename is fol-
1378 lowed by the line number, if known, otherwise the percent if known,
1379 otherwise the byte offset if known. Otherwise, a dash is printed.
1380 Notice how each question mark has a matching period, and how the %
1381 after the %pt is included literally by escaping it with a backslash.
1383 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x..%t";
1385 This prints the filename if this is the first prompt in a file, fol-
1386 lowed by the "file N of N" message if there is more than one input
1387 file. Then, if we are at end-of-file, the string "(END)" is printed
1388 followed by the name of the next file, if there is one. Finally, any
1389 trailing spaces are truncated. This is the default prompt. For refer-
1390 ence, here are the defaults for the other two prompts (-m and -M
1391 respectively). Each is broken into two lines here for readability
1394 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x.:
1395 ?pB%pB\%:byte %bB?s/%s...%t
1397 ?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :
1398 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1400 And here is the default message produced by the = command:
1402 ?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .
1403 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1405 The prompt expansion features are also used for another purpose: if an
1406 environment variable LESSEDIT is defined, it is used as the command to
1407 be executed when the v command is invoked. The LESSEDIT string is
1408 expanded in the same way as the prompt strings. The default value for
1413 Note that this expands to the editor name, followed by a + and the line
1414 number, followed by the file name. If your editor does not accept the
1415 "+linenumber" syntax, or has other differences in invocation syntax,
1416 the LESSEDIT variable can be changed to modify this default.
1420 When the environment variable LESSSECURE is set to 1,
\e[4mless
\e[24m runs in a
1421 "secure" mode. This means these features are disabled:
1427 :e the examine command.
1429 v the editing command
1433 -k use of lesskey files
1435 -t use of tags files
1437 metacharacters in filenames, such as *
1439 filename completion (TAB, ^L)
1441 Less can also be compiled to be permanently in "secure" mode.
1444 \e[1mCOMPATIBILITY WITH MORE
\e[0m
1445 If the environment variable LESS_IS_MORE is set to 1, or if the program
1446 is invoked via a file link named "more",
\e[4mless
\e[24m behaves (mostly) in con-
1447 formance with the POSIX "more" command specification. In this mode,
1448 less behaves differently in these ways:
1450 The -e option works differently. If the -e option is not set,
\e[4mless
\e[0m
1451 behaves as if the -e option were set. If the -e option is set,
\e[4mless
\e[0m
1452 behaves as if the -E option were set.
1454 The -m option works differently. If the -m option is not set, the
1455 medium prompt is used, and it is prefixed with the string "--More--".
1456 If the -m option is set, the short prompt is used.
1458 The -n option acts like the -z option. The normal behavior of the -n
1459 option is unavailable in this mode.
1461 The parameter to the -p option is taken to be a
\e[4mless
\e[24m command rather
1462 than a search pattern.
1464 The LESS environment variable is ignored, and the MORE environment
1465 variable is used in its place.
1468 \e[1mENVIRONMENT VARIABLES
\e[0m
1469 Environment variables may be specified either in the system environment
1470 as usual, or in a
\e[4mlesskey
\e[24m (1) file. If environment variables are
1471 defined in more than one place, variables defined in a local lesskey
1472 file take precedence over variables defined in the system environment,
1473 which take precedence over variables defined in the system-wide lesskey
1477 Sets the number of columns on the screen. Takes precedence over
1478 the number of columns specified by the TERM variable. (But if
1479 you have a windowing system which supports TIOCGWINSZ or
1480 WIOCGETD, the window system's idea of the screen size takes
1481 precedence over the LINES and COLUMNS environment variables.)
1483 EDITOR The name of the editor (used for the v command).
1485 HOME Name of the user's home directory (used to find a lesskey file
1486 on Unix and OS/2 systems).
1489 Concatenation of the HOMEDRIVE and HOMEPATH environment vari-
1490 ables is the name of the user's home directory if the HOME vari-
1491 able is not set (only in the Windows version).
1493 INIT Name of the user's init directory (used to find a lesskey file
1496 LANG Language for determining the character set.
1499 Language for determining the character set.
1501 LESS Options which are passed to
\e[4mless
\e[24m automatically.
1504 Characters which may end an ANSI color escape sequence (default
1508 Characters which may appear between the ESC character and the
1509 end character in an ANSI color escape sequence (default
1510 "0123456789:;[?!"'#%()*+ ".
1513 Format for displaying non-printable, non-control characters.
1516 Defines a character set.
1519 Selects a predefined character set.
1522 Command line to invoke the (optional) input-postprocessor.
1525 Name of the lessecho program (default "lessecho"). The lessecho
1526 program is needed to expand metacharacters, such as * and ?, in
1527 filenames on Unix systems.
1530 Editor prototype string (used for the v command). See discus-
1534 Name of the command used by the -t option to find global tags.
1535 Normally should be set to "global" if your system has the
\e[4mglobal
\e[0m
1536 (1) command. If not set, global tags are not used.
1539 Name of the history file used to remember search commands and
1540 shell commands between invocations of
\e[4mless.
\e[24m If set to "-" or
1541 "/dev/null", a history file is not used. The default is
1542 "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
1543 Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1547 The maximum number of commands to save in the history file. The
1551 Name of the default lesskey(1) file.
1554 Name of the default system-wide lesskey(1) file.
1557 List of characters which are considered "metacharacters" by the
1561 Prefix which less will add before each metacharacter in a com-
1562 mand sent to the shell. If LESSMETAESCAPE is an empty string,
1563 commands containing metacharacters will not be passed to the
1567 Command line to invoke the (optional) input-preprocessor.
1570 Runs less in "secure" mode. See discussion under SECURITY.
1573 String to be appended to a directory name in filename comple-
1577 Format for displaying non-printable Unicode code points.
1580 Emulate the
\e[4mmore
\e[24m (1) command.
1582 LINES Sets the number of lines on the screen. Takes precedence over
1583 the number of lines specified by the TERM variable. (But if you
1584 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1585 the window system's idea of the screen size takes precedence
1586 over the LINES and COLUMNS environment variables.)
1588 MORE Options which are passed to
\e[4mless
\e[24m automatically when running in
1589 \e[4mmore
\e[24m compatible mode.
1591 PATH User's search path (used to find a lesskey file on MS-DOS and
1594 SHELL The shell used to execute the ! command, as well as to expand
1597 TERM The type of terminal on which
\e[4mless
\e[24m is being run.
1599 VISUAL The name of the editor (used for the v command).
1607 Copyright (C) 1984-2014 Mark Nudelman
1609 less is part of the GNU project and is free software. You can redis-
1610 tribute it and/or modify it under the terms of either (1) the GNU Gen-
1611 eral Public License as published by the Free Software Foundation; or
1612 (2) the Less License. See the file README in the less distribution for
1613 more details regarding redistribution. You should have received a copy
1614 of the GNU General Public License along with the source for less; see
1615 the file COPYING. If not, write to the Free Software Foundation, 59
1616 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
1617 have received a copy of the Less License; see the file LICENSE.
1619 less is distributed in the hope that it will be useful, but WITHOUT ANY
1620 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT-
1621 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
1627 Send bug reports or comments to <bug-less@gnu.org>
1628 See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
1629 of known bugs in less.
1630 For more information, see the less homepage at
1631 http://www.greenwoodsoftware.com/less.
1635 Version 466: 23 Aug 2014 LESS(1)
projects / platform / upstream / less.git / blob