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.)
111 Go to line N in the file, default 1 (beginning of file). (Warn-
112 ing: this may be slow if N is large.)
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.)
119 p or % Go to a position N percent into the file. N should be between 0
120 and 100, and may contain a decimal point.
122 P Go to the line containing byte offset N in the file.
124 { If a left curly bracket appears in the top line displayed on the
125 screen, the { command will go to the matching right curly
126 bracket. The matching right curly bracket is positioned on the
127 bottom line of the screen. If there is more than one left curly
128 bracket on the top line, a number N may be used to specify the
129 N-th bracket on the line.
131 } If a right curly bracket appears in the bottom line displayed on
132 the screen, the } command will go to the matching left curly
133 bracket. The matching left curly bracket is positioned on the
134 top line of the screen. If there is more than one right curly
135 bracket on the top line, a number N may be used to specify the
136 N-th bracket on the line.
138 ( Like {, but applies to parentheses rather than curly brackets.
140 ) Like }, but applies to parentheses rather than curly brackets.
142 [ Like {, but applies to square brackets rather than curly brack-
145 ] Like }, but applies to square brackets rather than curly brack-
148 ESC-^F Followed by two characters, acts like {, but uses the two char-
149 acters as open and close brackets, respectively. For example,
150 "ESC ^F < >" could be used to go forward to the > which matches
151 the < in the top displayed line.
153 ESC-^B Followed by two characters, acts like }, but uses the two char-
154 acters as open and close brackets, respectively. For example,
155 "ESC ^B < >" could be used to go backward to the < which matches
156 the > in the bottom displayed line.
158 m Followed by any lowercase letter, marks the current position
161 ' (Single quote.) Followed by any lowercase letter, returns to
162 the position which was previously marked with that letter. Fol-
163 lowed by another single quote, returns to the position at which
164 the last "large" movement command was executed. Followed by a ^
165 or $, jumps to the beginning or end of the file respectively.
166 Marks are preserved when a new file is examined, so the ' com-
167 mand can be used to switch between input files.
169 ^X^X Same as single quote.
172 Search forward in the file for the N-th line containing the pat-
173 tern. N defaults to 1. The pattern is a regular expression, as
174 recognized by the regular expression library supplied by your
175 system. The search starts at the first line displayed (but see
176 the -a and -j options, which change this).
178 Certain characters are special if entered at the beginning of
179 the pattern; they modify the type of search rather than become
183 Search for lines which do NOT match the pattern.
186 Search multiple files. That is, if the search reaches
187 the END of the current file without finding a match, the
188 search continues in the next file in the command line
192 Begin the search at the first line of the FIRST file in
193 the command line list, regardless of what is currently
194 displayed on the screen or the settings of the -a or -j
197 ^K Highlight any text which matches the pattern on the cur-
198 rent screen, but don't move to the first match (KEEP cur-
201 ^R Don't interpret regular expression metacharacters; that
202 is, do a simple textual comparison.
205 Search backward in the file for the N-th line containing the
206 pattern. The search starts at the line immediately before the
209 Certain characters are special as in the / command:
212 Search for lines which do NOT match the pattern.
215 Search multiple files. That is, if the search reaches
216 the beginning of the current file without finding a
217 match, the search continues in the previous file in the
221 Begin the search at the last line of the last file in the
222 command line list, regardless of what is currently dis-
223 played on the screen or the settings of the -a or -j
226 ^K As in forward searches.
228 ^R As in forward searches.
236 n Repeat previous search, for N-th line containing the last pat-
237 tern. If the previous search was modified by ^N, the search is
238 made for the N-th line NOT containing the pattern. If the pre-
239 vious search was modified by ^E, the search continues in the
240 next (or previous) file if not satisfied in the current file.
241 If the previous search was modified by ^R, the search is done
242 without using regular expressions. There is no effect if the
243 previous search was modified by ^F or ^K.
245 N Repeat previous search, but in the reverse direction.
247 ESC-n Repeat previous search, but crossing file boundaries. The
248 effect is as if the previous search were modified by *.
250 ESC-N Repeat previous search, but in the reverse direction and cross-
253 ESC-u Undo search highlighting. Turn off highlighting of strings
254 matching the current search pattern. If highlighting is already
255 off because of a previous ESC-u command, turn highlighting back
256 on. Any search command will also turn highlighting back on.
257 (Highlighting can also be disabled by toggling the -G option; in
258 that case search commands do not turn highlighting back on.)
261 Display only lines which match the pattern; lines which do not
262 match the pattern are not displayed. If pattern is empty (if
263 you type & immediately followed by ENTER), any filtering is
264 turned off, and all lines are displayed. While filtering is in
265 effect, an ampersand is displayed at the beginning of the
266 prompt, as a reminder that some lines in the file may be hidden.
268 Certain characters are special as in the / command:
271 Display only lines which do NOT match the pattern.
273 ^R Don't interpret regular expression metacharacters; that
274 is, do a simple textual comparison.
277 Examine a new file. If the filename is missing, the "current"
278 file (see the :n and :p commands below) from the list of files
279 in the command line is re-examined. A percent sign (%) in the
280 filename is replaced by the name of the current file. A pound
281 sign (#) is replaced by the name of the previously examined
282 file. However, two consecutive percent signs are simply
283 replaced with a single percent sign. This allows you to enter a
284 filename that contains a percent sign in the name. Similarly,
285 two consecutive pound signs are replaced with a single pound
286 sign. The filename is inserted into the command line list of
287 files so that it can be seen by subsequent :n and :p commands.
288 If the filename consists of several files, they are all inserted
289 into the list of files and the first one is examined. If the
290 filename contains one or more spaces, the entire filename should
291 be enclosed in double quotes (also see the -" option).
294 Same as :e. Warning: some systems use ^V as a special literal-
295 ization character. On such systems, you may not be able to use
298 :n Examine the next file (from the list of files given in the com-
299 mand line). If a number N is specified, the N-th next file is
302 :p Examine the previous file in the command line list. If a number
303 N is specified, the N-th previous file is examined.
305 :x Examine the first file in the command line list. If a number N
306 is specified, the N-th file in the list is examined.
308 :d Remove the current file from the list of files.
310 t Go to the next tag, if there were more than one matches for the
311 current tag. See the -t option for more details about tags.
313 T Go to the previous tag, if there were more than one matches for
317 Prints some information about the file being viewed, including
318 its name and the line number and byte offset of the bottom line
319 being displayed. If possible, it also prints the length of the
320 file, the number of lines in the file and the percent of the
321 file above the last displayed line.
323 - Followed by one of the command line option letters (see OPTIONS
324 below), this will change the setting of that option and print a
325 message describing the new setting. If a ^P (CONTROL-P) is
326 entered immediately after the dash, the setting of the option is
327 changed but no message is printed. If the option letter has a
328 numeric value (such as -b or -h), or a string value (such as -P
329 or -t), a new value may be entered after the option letter. If
330 no new value is entered, a message describing the current set-
331 ting is printed and nothing is changed.
333 -- Like the - command, but takes a long option name (see OPTIONS
334 below) rather than a single option letter. You must press ENTER
335 or RETURN after typing the option name. A ^P immediately after
336 the second dash suppresses printing of a message describing the
337 new setting, as in the - command.
339 -+ Followed by one of the command line option letters this will
340 reset the option to its default setting and print a message
341 describing the new setting. (The "-+
\e[4mX
\e[24m" command does the same
342 thing as "-+
\e[4mX
\e[24m" on the command line.) This does not work for
343 string-valued options.
345 --+ Like the -+ command, but takes a long option name rather than a
346 single option letter.
348 -! Followed by one of the command line option letters, this will
349 reset the option to the "opposite" of its default setting and
350 print a message describing the new setting. This does not work
351 for numeric or string-valued options.
353 --! Like the -! command, but takes a long option name rather than a
354 single option letter.
356 _ (Underscore.) Followed by one of the command line option let-
357 ters, this will print a message describing the current setting
358 of that option. The setting of the option is not changed.
360 __ (Double underscore.) Like the _ (underscore) command, but takes
361 a long option name rather than a single option letter. You must
362 press ENTER or RETURN after typing the option name.
364 +cmd Causes the specified cmd to be executed each time a new file is
365 examined. For example, +G causes
\e[4mless
\e[24m to initially display each
366 file starting at the end rather than the beginning.
368 V Prints the version number of
\e[4mless
\e[24m being run.
370 q or Q or :q or :Q or ZZ
371 Exits
\e[4mless.
\e[0m
373 The following four commands may or may not be valid, depending on your
374 particular installation.
376 v Invokes an editor to edit the current file being viewed. The
377 editor is taken from the environment variable VISUAL if defined,
378 or EDITOR if VISUAL is not defined, or defaults to "vi" if nei-
379 ther VISUAL nor EDITOR is defined. See also the discussion of
380 LESSEDIT under the section on PROMPTS below.
383 Invokes a shell to run the shell-command given. A percent sign
384 (%) in the command is replaced by the name of the current file.
385 A pound sign (#) is replaced by the name of the previously exam-
386 ined file. "!!" repeats the last shell command. "!" with no
387 shell command simply invokes a shell. On Unix systems, the
388 shell is taken from the environment variable SHELL, or defaults
389 to "sh". On MS-DOS and OS/2 systems, the shell is the normal
393 <m> represents any mark letter. Pipes a section of the input
394 file to the given shell command. The section of the file to be
395 piped is between the first line on the current screen and the
396 position marked by the letter. <m> may also be ^ or $ to indi-
397 cate beginning or end of file respectively. If <m> is . or new-
398 line, the current screen is piped.
401 Save the input to a file. This only works if the input is a
402 pipe, not an ordinary file.
405 Command line options are described below. Most options may be changed
406 while
\e[4mless
\e[24m is running, via the "-" command.
408 Most options may be given in one of two forms: either a dash followed
409 by a single letter, or two dashes followed by a long option name. A
410 long option name may be abbreviated as long as the abbreviation is
411 unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
412 not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
413 long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
414 from --quit-at-eof. Such option names need only have their first let-
415 ter capitalized; the remainder of the name may be in either case. For
416 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
418 Options are also taken from the environment variable "LESS". For exam-
419 ple, to avoid typing "less -options ..." each time
\e[4mless
\e[24m is invoked, you
420 might tell
\e[4mcsh:
\e[0m
422 setenv LESS "-options"
424 or if you use
\e[4msh:
\e[0m
426 LESS="-options"; export LESS
428 On MS-DOS, you don't need the quotes, but you should replace any per-
429 cent signs in the options string by double percent signs.
431 The environment variable is parsed before the command line, so command
432 line options override the LESS environment variable. If an option
433 appears in the LESS variable, it can be reset to its default value on
434 the command line by beginning the command line option with "-+".
436 For options like -P or -D which take a following string, a dollar sign
437 ($) must be used to signal the end of the string. For example, to set
438 two -D options on MS-DOS, you must have a dollar sign between them,
445 This option displays a summary of the commands accepted by
\e[4mless
\e[0m
446 (the same as the h command). (Depending on how your shell
447 interprets the question mark, it may be necessary to quote the
448 question mark, thus: "-\?".)
450 -a or --search-skip-screen
451 By default, forward searches start at the top of the displayed
452 screen and backwards searches start at the bottom of the dis-
453 played screen (except for repeated searches invoked by the n or
454 N commands, which start after or before the "target" line
455 respectively; see the -j option for more about the target line).
456 The -a option causes forward searches to instead start at the
457 bottom of the screen and backward searches to start at the top
458 of the screen, thus skipping all lines displayed on the screen.
460 -A or --SEARCH-SKIP-SCREEN
461 Causes all forward searches (not just non-repeated searches) to
462 start just after the target line, and all backward searches to
463 start just before the target line. Thus, forward searches will
464 skip part of the displayed screen (from the first line up to and
465 including the target line). Similarly backwards searches will
466 skip the displayed screen from the last line up to and including
467 the target line. This was the default behavior in less versions
470 -b
\e[4mn
\e[24m or --buffers=
\e[4mn
\e[0m
471 Specifies the amount of buffer space
\e[4mless
\e[24m will use for each
472 file, in units of kilobytes (1024 bytes). By default 64K of
473 buffer space is used for each file (unless the file is a pipe;
474 see the -B option). The -b option specifies instead that
\e[4mn
\e[0m
475 kilobytes of buffer space should be used for each file. If
\e[4mn
\e[24m is
476 -1, buffer space is unlimited; that is, the entire file can be
480 By default, when data is read from a pipe, buffers are allocated
481 automatically as needed. If a large amount of data is read from
482 the pipe, this can cause a large amount of memory to be allo-
483 cated. The -B option disables this automatic allocation of buf-
484 fers for pipes, so that only 64K (or the amount of space speci-
485 fied by the -b option) is used for the pipe. Warning: use of -B
486 can result in erroneous display, since only the most recently
487 viewed part of the piped data is kept in memory; any earlier
491 Causes full screen repaints to be painted from the top line
492 down. By default, full screen repaints are done by scrolling
493 from the bottom of the screen.
496 Same as -c, for compatibility with older versions of
\e[4mless.
\e[0m
499 The -d option suppresses the error message normally displayed if
500 the terminal is dumb; that is, lacks some important capability,
501 such as the ability to clear the screen or scroll backward. The
502 -d option does not otherwise change the behavior of
\e[4mless
\e[24m on a
505 -D
\e[1mx
\e[4m
\e[22mcolor
\e[24m or --color=
\e[1mx
\e[4m
\e[22mcolor
\e[0m
506 [MS-DOS only] Sets the color of the text displayed.
\e[1mx
\e[22mis a sin-
507 gle character which selects the type of text whose color is
508 being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
509 \e[4mcolor
\e[24m is a pair of numbers separated by a period. The first
510 number selects the foreground color and the second selects the
511 background color of the text. A single number
\e[4mN
\e[24m is the same as
512 \e[4mN.M
\e[24m, where
\e[4mM
\e[24m is the normal background color.
516 Causes
\e[4mless
\e[24m to automatically exit the second time it reaches
517 end-of-file. By default, the only way to exit
\e[4mless
\e[24m is via the
521 Causes
\e[4mless
\e[24m to automatically exit the first time it reaches end-
525 Forces non-regular files to be opened. (A non-regular file is a
526 directory or a device special file.) Also suppresses the warn-
527 ing message when a binary file is opened. By default,
\e[4mless
\e[24m will
528 refuse to open non-regular files. Note that some operating sys-
529 tems will not allow directories to be read, even if -f is set.
531 -F or --quit-if-one-screen
532 Causes
\e[4mless
\e[24m to automatically exit if the entire file can be dis-
533 played on the first screen.
535 -g or --hilite-search
536 Normally,
\e[4mless
\e[24m will highlight ALL strings which match the last
537 search command. The -g option changes this behavior to high-
538 light only the particular string which was found by the last
539 search command. This can cause
\e[4mless
\e[24m to run somewhat faster than
542 -G or --HILITE-SEARCH
543 The -G option suppresses all highlighting of strings found by
546 -h
\e[4mn
\e[24m or --max-back-scroll=
\e[4mn
\e[0m
547 Specifies a maximum number of lines to scroll backward. If it
548 is necessary to scroll backward more than
\e[4mn
\e[24m lines, the screen is
549 repainted in a forward direction instead. (If the terminal does
550 not have the ability to scroll backward, -h0 is implied.)
553 Causes searches to ignore case; that is, uppercase and lowercase
554 are considered identical. This option is ignored if any upper-
555 case letters appear in the search pattern; in other words, if a
556 pattern contains uppercase letters, then that search does not
560 Like -i, but searches ignore case even if the pattern contains
563 -j
\e[4mn
\e[24m or --jump-target=
\e[4mn
\e[0m
564 Specifies a line on the screen where the "target" line is to be
565 positioned. The target line is the line specified by any com-
566 mand to search for a pattern, jump to a line number, jump to a
567 file percentage or jump to a tag. The screen line may be speci-
568 fied by a number: the top line on the screen is 1, the next is
569 2, and so on. The number may be negative to specify a line rel-
570 ative to the bottom of the screen: the bottom line on the screen
571 is -1, the second to the bottom is -2, and so on. Alternately,
572 the screen line may be specified as a fraction of the height of
573 the screen, starting with a decimal point: .5 is in the middle
574 of the screen, .3 is three tenths down from the first line, and
575 so on. If the line is specified as a fraction, the actual line
576 number is recalculated if the terminal window is resized, so
577 that the target line remains at the specified fraction of the
578 screen height. If any form of the -j option is used, forward
579 searches begin at the line immediately after the target line,
580 and backward searches begin at the target line, unless changed
581 by -a or -A. For example, if "-j4" is used, the target line is
582 the fourth line on the screen, so forward searches begin at the
583 fifth line on the screen.
585 -J or --status-column
586 Displays a status column at the left edge of the screen. The
587 status column shows the lines that matched the current search.
588 The status column is also used if the -w or -W option is in
591 -k
\e[4mfilename
\e[24m or --lesskey-file=
\e[4mfilename
\e[0m
592 Causes
\e[4mless
\e[24m to open and interpret the named file as a
\e[4mlesskey
\e[0m
593 (1) file. Multiple -k options may be specified. If the LESSKEY
594 or LESSKEY_SYSTEM environment variable is set, or if a lesskey
595 file is found in a standard place (see KEY BINDINGS), it is also
596 used as a
\e[4mlesskey
\e[24m file.
599 Causes
\e[4mless
\e[24m to exit immediately (with status 2) when an inter-
600 rupt character (usually ^C) is typed. Normally, an interrupt
601 character causes
\e[4mless
\e[24m to stop whatever it is doing and return to
602 its command prompt. Note that use of this option makes it
603 impossible to return to the command prompt from the "F" command.
606 Ignore the LESSOPEN environment variable (see the INPUT PRE-
607 PROCESSOR section below). This option can be set from within
608 \e[4mless
\e[24m, but it will apply only to files opened subsequently, not
609 to the file which is currently open.
612 Causes
\e[4mless
\e[24m to prompt verbosely (like
\e[4mmore
\e[24m), with the percent
613 into the file. By default,
\e[4mless
\e[24m prompts with a colon.
616 Causes
\e[4mless
\e[24m to prompt even more verbosely than
\e[4mmore.
\e[0m
619 Suppresses line numbers. The default (to use line numbers) may
620 cause
\e[4mless
\e[24m to run more slowly in some cases, especially with a
621 very large input file. Suppressing line numbers with the -n
622 option will avoid this problem. Using line numbers means: the
623 line number will be displayed in the verbose prompt and in the =
624 command, and the v command will pass the current line number to
625 the editor (see also the discussion of LESSEDIT in PROMPTS
629 Causes a line number to be displayed at the beginning of each
632 -o
\e[4mfilename
\e[24m or --log-file=
\e[4mfilename
\e[0m
633 Causes
\e[4mless
\e[24m to copy its input to the named file as it is being
634 viewed. This applies only when the input file is a pipe, not an
635 ordinary file. If the file already exists,
\e[4mless
\e[24m will ask for
636 confirmation before overwriting it.
638 -O
\e[4mfilename
\e[24m or --LOG-FILE=
\e[4mfilename
\e[0m
639 The -O option is like -o, but it will overwrite an existing file
640 without asking for confirmation.
642 If no log file has been specified, the -o and -O options can be
643 used from within
\e[4mless
\e[24m to specify a log file. Without a file
644 name, they will simply report the name of the log file. The "s"
645 command is equivalent to specifying -o from within
\e[4mless.
\e[0m
647 -p
\e[4mpattern
\e[24m or --pattern=
\e[4mpattern
\e[0m
648 The -p option on the command line is equivalent to specifying
649 +/
\e[4mpattern
\e[24m; that is, it tells
\e[4mless
\e[24m to start at the first occur-
650 rence of
\e[4mpattern
\e[24m in the file.
652 -P
\e[4mprompt
\e[24m or --prompt=
\e[4mprompt
\e[0m
653 Provides a way to tailor the three prompt styles to your own
654 preference. This option would normally be put in the LESS envi-
655 ronment variable, rather than being typed in with each
\e[4mless
\e[24m com-
656 mand. Such an option must either be the last option in the LESS
657 variable, or be terminated by a dollar sign. -Ps followed by a
658 string changes the default (short) prompt to that string. -Pm
659 changes the medium (-m) prompt. -PM changes the long (-M)
660 prompt. -Ph changes the prompt for the help screen. -P=
661 changes the message printed by the = command. -Pw changes the
662 message printed while waiting for data (in the F command). All
663 prompt strings consist of a sequence of letters and special
664 escape sequences. See the section on PROMPTS for more details.
666 -q or --quiet or --silent
667 Causes moderately "quiet" operation: the terminal bell is not
668 rung if an attempt is made to scroll past the end of the file or
669 before the beginning of the file. If the terminal has a "visual
670 bell", it is used instead. The bell will be rung on certain
671 other errors, such as typing an invalid character. The default
672 is to ring the terminal bell in all such cases.
674 -Q or --QUIET or --SILENT
675 Causes totally "quiet" operation: the terminal bell is never
678 -r or --raw-control-chars
679 Causes "raw" control characters to be displayed. The default is
680 to display control characters using the caret notation; for
681 example, a control-A (octal 001) is displayed as "^A". Warning:
682 when the -r option is used,
\e[4mless
\e[24m cannot keep track of the actual
683 appearance of the screen (since this depends on how the screen
684 responds to each type of control character). Thus, various dis-
685 play problems may result, such as long lines being split in the
688 -R or --RAW-CONTROL-CHARS
689 Like -r, but only ANSI "color" escape sequences are output in
690 "raw" form. Unlike -r, the screen appearance is maintained cor-
691 rectly in most cases. ANSI "color" escape sequences are
692 sequences of the form:
696 where the "..." is zero or more color specification characters
697 For the purpose of keeping track of screen appearance, ANSI
698 color escape sequences are assumed to not move the cursor. You
699 can make
\e[4mless
\e[24m think that characters other than "m" can end ANSI
700 color escape sequences by setting the environment variable
701 LESSANSIENDCHARS to the list of characters which can end a color
702 escape sequence. And you can make
\e[4mless
\e[24m think that characters
703 other than the standard ones may appear between the ESC and the
704 m by setting the environment variable LESSANSIMIDCHARS to the
705 list of characters which can appear.
707 -s or --squeeze-blank-lines
708 Causes consecutive blank lines to be squeezed into a single
709 blank line. This is useful when viewing
\e[4mnroff
\e[24m output.
711 -S or --chop-long-lines
712 Causes lines longer than the screen width to be chopped rather
713 than folded. That is, the portion of a long line that does not
714 fit in the screen width is not shown. The default is to fold
715 long lines; that is, display the remainder on the next line.
717 -t
\e[4mtag
\e[24m or --tag=
\e[4mtag
\e[0m
718 The -t option, followed immediately by a TAG, will edit the file
719 containing that tag. For this to work, tag information must be
720 available; for example, there may be a file in the current
721 directory called "tags", which was previously built by
\e[4mctags
\e[24m (1)
722 or an equivalent command. If the environment variable LESSGLOB-
723 ALTAGS is set, it is taken to be the name of a command compati-
724 ble with
\e[4mglobal
\e[24m (1), and that command is executed to find the
725 tag. (See http://www.gnu.org/software/global/global.html). The
726 -t option may also be specified from within
\e[4mless
\e[24m (using the -
727 command) as a way of examining a new file. The command ":t" is
728 equivalent to specifying -t from within
\e[4mless.
\e[0m
730 -T
\e[4mtagsfile
\e[24m or --tag-file=
\e[4mtagsfile
\e[0m
731 Specifies a tags file to be used instead of "tags".
733 -u or --underline-special
734 Causes backspaces and carriage returns to be treated as print-
735 able characters; that is, they are sent to the terminal when
736 they appear in the input.
738 -U or --UNDERLINE-SPECIAL
739 Causes backspaces, tabs and carriage returns to be treated as
740 control characters; that is, they are handled as specified by
743 By default, if neither -u nor -U is given, backspaces which
744 appear adjacent to an underscore character are treated spe-
745 cially: the underlined text is displayed using the terminal's
746 hardware underlining capability. Also, backspaces which appear
747 between two identical characters are treated specially: the
748 overstruck text is printed using the terminal's hardware bold-
749 face capability. Other backspaces are deleted, along with the
750 preceding character. Carriage returns immediately followed by a
751 newline are deleted. other carriage returns are handled as
752 specified by the -r option. Text which is overstruck or under-
753 lined can be searched for if neither -u nor -U is in effect.
756 Displays the version number of
\e[4mless.
\e[0m
758 -w or --hilite-unread
759 Temporarily highlights the first "new" line after a forward
760 movement of a full page. The first "new" line is the line imme-
761 diately following the line previously at the bottom of the
762 screen. Also highlights the target line after a g or p command.
763 The highlight is removed at the next command which causes move-
764 ment. The entire line is highlighted, unless the -J option is
765 in effect, in which case only the status column is highlighted.
767 -W or --HILITE-UNREAD
768 Like -w, but temporarily highlights the first new line after any
769 forward movement command larger than one line.
771 -x
\e[4mn
\e[24m,... or --tabs=
\e[4mn
\e[24m,...
772 Sets tab stops. If only one
\e[4mn
\e[24m is specified, tab stops are set
773 at multiples of
\e[4mn
\e[24m. If multiple values separated by commas are
774 specified, tab stops are set at those positions, and then con-
775 tinue with the same spacing as the last two. For example,
776 \e[4m-x9,17
\e[24m will set tabs at positions 9, 17, 25, 33, etc. The
777 default for
\e[4mn
\e[24m is 8.
780 Disables sending the termcap initialization and deinitialization
781 strings to the terminal. This is sometimes desirable if the
782 deinitialization string does something unnecessary, like clear-
785 -y
\e[4mn
\e[24m or --max-forw-scroll=
\e[4mn
\e[0m
786 Specifies a maximum number of lines to scroll forward. If it is
787 necessary to scroll forward more than
\e[4mn
\e[24m lines, the screen is
788 repainted instead. The -c or -C option may be used to repaint
789 from the top of the screen if desired. By default, any forward
790 movement causes scrolling.
792 -[z]
\e[4mn
\e[24m or --window=
\e[4mn
\e[0m
793 Changes the default scrolling window size to
\e[4mn
\e[24m lines. The
794 default is one screenful. The z and w commands can also be used
795 to change the window size. The "z" may be omitted for compati-
796 bility with some versions of
\e[4mmore.
\e[24m If the number
\e[4mn
\e[24m is negative,
797 it indicates
\e[4mn
\e[24m lines less than the current screen size. For
798 example, if the screen is 24 lines,
\e[4m-z-4
\e[24m sets the scrolling win-
799 dow to 20 lines. If the screen is resized to 40 lines, the
800 scrolling window automatically changes to 36 lines.
802 -
\e[4m"cc
\e[24m or --quotes=
\e[4mcc
\e[0m
803 Changes the filename quoting character. This may be necessary
804 if you are trying to name a file which contains both spaces and
805 quote characters. Followed by a single character, this changes
806 the quote character to that character. Filenames containing a
807 space should then be surrounded by that character rather than by
808 double quotes. Followed by two characters, changes the open
809 quote to the first character, and the close quote to the second
810 character. Filenames containing a space should then be preceded
811 by the open quote character and followed by the close quote
812 character. Note that even after the quote characters are
813 changed, this option remains -" (a dash followed by a double
817 Normally lines after end of file are displayed as a single tilde
818 (~). This option causes lines after end of file to be displayed
822 Specifies the default number of positions to scroll horizontally
823 in the RIGHTARROW and LEFTARROW commands. If the number speci-
824 fied is zero, it sets the default number of positions to one
825 half of the screen width. Alternately, the number may be speci-
826 fied as a fraction of the width of the screen, starting with a
827 decimal point: .5 is half of the screen width, .3 is three
828 tenths of the screen width, and so on. If the number is speci-
829 fied as a fraction, the actual number of scroll positions is
830 recalculated if the terminal window is resized, so that the
831 actual scroll remains at the specified fraction of the screen
835 Disables sending the keypad initialization and deinitialization
836 strings to the terminal. This is sometimes useful if the keypad
837 strings make the numeric keypad behave in an undesirable manner.
840 Normally, if the input file is renamed while an F command is
841 executing,
\e[4mless
\e[24m will continue to display the contents of the
842 original file despite its name change. If --follow-name is
843 specified, during an F command
\e[4mless
\e[24m will periodically attempt to
844 reopen the file by name. If the reopen succeeds and the file is
845 a different file from the original (which means that a new file
846 has been created with the same name as the original (now
847 renamed) file),
\e[4mless
\e[24m will display the contents of that new file.
849 -- A command line argument of "--" marks the end of option argu-
850 ments. Any arguments following this are interpreted as file-
851 names. This can be useful when viewing a file whose name begins
854 + If a command line option begins with
\e[1m+
\e[22m, the remainder of that
855 option is taken to be an initial command to
\e[4mless.
\e[24m For example,
856 +G tells
\e[4mless
\e[24m to start at the end of the file rather than the
857 beginning, and +/xyz tells it to start at the first occurrence
858 of "xyz" in the file. As a special case, +<number> acts like
859 +<number>g; that is, it starts the display at the specified line
860 number (however, see the caveat under the "g" command above).
861 If the option starts with ++, the initial command applies to
862 every file being viewed, not just the first one. The + command
863 described previously may also be used to set (or change) an ini-
864 tial command for every file.
867 \e[1mLINE EDITING
\e[0m
868 When entering command line at the bottom of the screen (for example, a
869 filename for the :e command, or the pattern for a search command), cer-
870 tain keys can be used to manipulate the command line. Most commands
871 have an alternate form in [ brackets ] which can be used if a key does
872 not exist on a particular keyboard. (Note that the forms beginning
873 with ESC do not work in some MS-DOS and Windows systems because ESC is
874 the line erase character.) Any of these special keys may be entered
875 literally by preceding it with the "literal" character, either ^V or
876 ^A. A backslash itself may also be entered literally by entering two
880 Move the cursor one space to the left.
883 Move the cursor one space to the right.
885 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
886 (That is, CONTROL and LEFTARROW simultaneously.) Move the cur-
887 sor one word to the left.
889 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
890 (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur-
891 sor one word to the right.
894 Move the cursor to the beginning of the line.
897 Move the cursor to the end of the line.
900 Delete the character to the left of the cursor, or cancel the
901 command if the command line is empty.
904 Delete the character under the cursor.
906 ^BACKSPACE [ ESC-BACKSPACE ]
907 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
908 word to the left of the cursor.
910 ^DELETE [ ESC-X or ESC-DELETE ]
911 (That is, CONTROL and DELETE simultaneously.) Delete the word
915 Retrieve the previous command line.
918 Retrieve the next command line.
920 TAB Complete the partial filename to the left of the cursor. If it
921 matches more than one filename, the first match is entered into
922 the command line. Repeated TABs will cycle thru the other
923 matching filenames. If the completed filename is a directory, a
924 "/" is appended to the filename. (On MS-DOS systems, a "\" is
925 appended.) The environment variable LESSSEPARATOR can be used
926 to specify a different character to append to a directory name.
929 Like, TAB, but cycles in the reverse direction thru the matching
932 ^L Complete the partial filename to the left of the cursor. If it
933 matches more than one filename, all matches are entered into the
934 command line (if they fit).
936 ^U (Unix and OS/2) or ESC (MS-DOS)
937 Delete the entire command line, or cancel the command if the
938 command line is empty. If you have changed your line-kill char-
939 acter in Unix to something other than ^U, that character is used
942 ^G Delete the entire command line and return to the main prompt.
945 \e[1mKEY BINDINGS
\e[0m
946 You may define your own
\e[4mless
\e[24m commands by using the program
\e[4mlesskey
\e[24m (1)
947 to create a lesskey file. This file specifies a set of command keys
948 and an action associated with each key. You may also use
\e[4mlesskey
\e[24m to
949 change the line-editing keys (see LINE EDITING), and to set environment
950 variables. If the environment variable LESSKEY is set,
\e[4mless
\e[24m uses that
951 as the name of the lesskey file. Otherwise,
\e[4mless
\e[24m looks in a standard
952 place for the lesskey file: On Unix systems,
\e[4mless
\e[24m looks for a lesskey
953 file called "$HOME/.less". On MS-DOS and Windows systems,
\e[4mless
\e[24m looks
954 for a lesskey file called "$HOME/_less", and if it is not found there,
955 then looks for a lesskey file called "_less" in any directory specified
956 in the PATH environment variable. On OS/2 systems,
\e[4mless
\e[24m looks for a
957 lesskey file called "$HOME/less.ini", and if it is not found, then
958 looks for a lesskey file called "less.ini" in any directory specified
959 in the INIT environment variable, and if it not found there, then looks
960 for a lesskey file called "less.ini" in any directory specified in the
961 PATH environment variable. See the
\e[4mlesskey
\e[24m manual page for more
964 A system-wide lesskey file may also be set up to provide key bindings.
965 If a key is defined in both a local lesskey file and in the system-wide
966 file, key bindings in the local file take precedence over those in the
967 system-wide file. If the environment variable LESSKEY_SYSTEM is set,
968 \e[4mless
\e[24m uses that as the name of the system-wide lesskey file. Otherwise,
969 \e[4mless
\e[24m looks in a standard place for the system-wide lesskey file: On
970 Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
971 (However, if
\e[4mless
\e[24m was built with a different sysconf directory than
972 /usr/local/etc, that directory is where the sysless file is found.) On
973 MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys-
974 less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
977 \e[1mINPUT PREPROCESSOR
\e[0m
978 You may define an "input preprocessor" for
\e[4mless.
\e[24m Before
\e[4mless
\e[24m opens a
979 file, it first gives your input preprocessor a chance to modify the way
980 the contents of the file are displayed. An input preprocessor is sim-
981 ply an executable program (or shell script), which writes the contents
982 of the file to a different file, called the replacement file. The con-
983 tents of the replacement file are then displayed in place of the con-
984 tents of the original file. However, it will appear to the user as if
985 the original file is opened; that is,
\e[4mless
\e[24m will display the original
986 filename as the name of the current file.
988 An input preprocessor receives one command line argument, the original
989 filename, as entered by the user. It should create the replacement
990 file, and when finished, print the name of the replacement file to its
991 standard output. If the input preprocessor does not output a replace-
992 ment filename,
\e[4mless
\e[24m uses the original file, as normal. The input pre-
993 processor is not called when viewing standard input. To set up an
994 input preprocessor, set the LESSOPEN environment variable to a command
995 line which will invoke your input preprocessor. This command line
996 should include one occurrence of the string "%s", which will be
997 replaced by the filename when the input preprocessor command is
1000 When
\e[4mless
\e[24m closes a file opened in such a way, it will call another pro-
1001 gram, called the input postprocessor, which may perform any desired
1002 clean-up action (such as deleting the replacement file created by
1003 LESSOPEN). This program receives two command line arguments, the orig-
1004 inal filename as entered by the user, and the name of the replacement
1005 file. To set up an input postprocessor, set the LESSCLOSE environment
1006 variable to a command line which will invoke your input postprocessor.
1007 It may include two occurrences of the string "%s"; the first is
1008 replaced with the original name of the file and the second with the
1009 name of the replacement file, which was output by LESSOPEN.
1011 For example, on many Unix systems, these two scripts will allow you to
1012 keep files in compressed format, but still let
\e[4mless
\e[24m view them directly:
1018 if [ -s /tmp/less.$$ ]; then
1030 To use these scripts, put them both where they can be executed and set
1031 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
1032 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
1033 types of compressed files, and so on.
1035 It is also possible to set up an input preprocessor to pipe the file
1036 data directly to
\e[4mless,
\e[24m rather than putting the data into a replacement
1037 file. This avoids the need to decompress the entire file before start-
1038 ing to view it. An input preprocessor that works this way is called an
1039 input pipe. An input pipe, instead of writing the name of a replace-
1040 ment file on its standard output, writes the entire contents of the
1041 replacement file on its standard output. If the input pipe does not
1042 write any characters on its standard output, then there is no replace-
1043 ment file and
\e[4mless
\e[24m uses the original file, as normal. To use an input
1044 pipe, make the first character in the LESSOPEN environment variable a
1045 vertical bar (|) to signify that the input preprocessor is an input
1048 For example, on many Unix systems, this script will work like the pre-
1049 vious example scripts:
1054 *.Z) uncompress -c $1 2>/dev/null
1058 To use this script, put it where it can be executed and set
1059 LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE
1060 postprocessor can be used, but it is usually not necessary since there
1061 is no replacement file to clean up. In this case, the replacement file
1062 name passed to the LESSCLOSE postprocessor is "-".
1064 For compatibility with previous versions of
\e[4mless,
\e[24m the input preproces-
1065 sor or pipe is not used if
\e[4mless
\e[24m is viewing standard input. However, if
1066 the first character of LESSOPEN is a dash (-), the input preprocessor
1067 is used on standard input as well as other files. In this case, the
1068 dash is not considered to be part of the preprocessor command. If
1069 standard input is being viewed, the input preprocessor is passed a file
1070 name consisting of a single dash. Similarly, if the first two charac-
1071 ters of LESSOPEN are vertical bar and dash (|-), the input pipe is used
1072 on standard input as well as other files. Again, in this case the dash
1073 is not considered to be part of the input pipe command.
1076 \e[1mNATIONAL CHARACTER SETS
\e[0m
1077 There are three types of characters in the input file:
1080 can be displayed directly to the screen.
1083 should not be displayed directly, but are expected to be found
1084 in ordinary text files (such as backspace and tab).
1087 should not be displayed directly and are not expected to be
1088 found in text files.
1090 A "character set" is simply a description of which characters are to be
1091 considered normal, control, and binary. The LESSCHARSET environment
1092 variable may be used to select a character set. Possible values for
1095 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
1096 with values between 32 and 126 are normal, and all others are
1100 Selects an ISO 8859 character set. This is the same as ASCII,
1101 except characters between 160 and 255 are treated as normal
1104 latin1 Same as iso8859.
1106 latin9 Same as iso8859.
1108 dos Selects a character set appropriate for MS-DOS.
1110 ebcdic Selects an EBCDIC character set.
1113 Selects an EBCDIC character set used by OS/390 Unix Services.
1114 This is the EBCDIC analogue of latin1. You get similar results
1115 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
1118 koi8-r Selects a Russian character set.
1120 next Selects a character set appropriate for NeXT computers.
1122 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
1123 UTF-8 is special in that it supports multi-byte characters in
1124 the input file. It is the only character set that supports
1125 multi-byte characters.
1128 Selects a character set appropriate for Microsoft Windows (cp
1131 In rare cases, it may be desired to tailor
\e[4mless
\e[24m to use a character set
1132 other than the ones definable by LESSCHARSET. In this case, the envi-
1133 ronment variable LESSCHARDEF can be used to define a character set. It
1134 should be set to a string where each character in the string represents
1135 one character in the character set. The character "." is used for a
1136 normal character, "c" for control, and "b" for binary. A decimal num-
1137 ber may be used for repetition. For example, "bccc4b." would mean
1138 character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
1139 binary, and 8 is normal. All characters after the last are taken to be
1140 the same as the last, so characters 9 through 255 would be normal.
1141 (This is an example, and does not necessarily represent any real char-
1144 This table shows the value of LESSCHARDEF which is equivalent to each
1145 of the possible values for LESSCHARSET:
1147 ascii 8bcccbcc18b95.b
1148 dos 8bcccbcc12bc5b95.b.
1149 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1150 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1151 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1153 iso8859 8bcccbcc18b95.33b.
1154 koi8-r 8bcccbcc18b95.b128.
1155 latin1 8bcccbcc18b95.33b.
1156 next 8bcccbcc18b95.bb125.bb
1158 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
1159 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
1160 LANG environment variables, then the default character set is utf-8.
1162 If that string is not found, but your system supports the
\e[4msetlocale
\e[0m
1163 interface,
\e[4mless
\e[24m will use setlocale to determine the character set.
1164 setlocale is controlled by setting the LANG or LC_CTYPE environment
1167 Finally, if the
\e[4msetlocale
\e[24m interface is also not available, the default
1168 character set is latin1.
1170 Control and binary characters are displayed in standout (reverse
1171 video). Each such character is displayed in caret notation if possible
1172 (e.g. ^A for control-A). Caret notation is used only if inverting the
1173 0100 bit results in a normal printable character. Otherwise, the char-
1174 acter is displayed as a hex number in angle brackets. This format can
1175 be changed by setting the LESSBINFMT environment variable. LESSBINFMT
1176 may begin with a "*" and one character to select the display attribute:
1177 "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1178 and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
1179 attribute is assumed. The remainder of LESSBINFMT is a string which
1180 may include one printf-style escape sequence (a % followed by x, X, o,
1181 d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
1182 are displayed in underlined hexadecimal surrounded by brackets. The
1183 default if no LESSBINFMT is specified is "*s<%02X>". Warning: the
1184 result of expanding the character via LESSBINFMT must be less than 31
1187 When the character set is utf-8, the LESSUTFBINFMT environment variable
1188 acts similarly to LESSBINFMT but it applies to Unicode code points that
1189 were successfully decoded but are unsuitable for display (e.g., unas-
1190 signed code points). Its default value is "<U+%04lX>". Note that
1191 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
1192 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
1193 LESSBINFMT so its setting, if any, will have priority. Problematic
1194 octets in a UTF-8 file (octets of a truncated sequence, octets of a
1195 complete but non-shortest form sequence, illegal octets, and stray
1196 trailing octets) are displayed individually using LESSBINFMT so as to
1197 facilitate diagnostic of how the UTF-8 file is ill-formed.
1201 The -P option allows you to tailor the prompt to your preference. The
1202 string given to the -P option replaces the specified prompt string.
1203 Certain characters in the string are interpreted specially. The prompt
1204 mechanism is rather complicated to provide flexibility, but the ordi-
1205 nary user need not understand the details of constructing personalized
1208 A percent sign followed by a single character is expanded according to
1209 what the following character is:
1211 %b
\e[4mX
\e[24m Replaced by the byte offset into the current input file. The b
1212 is followed by a single character (shown as
\e[4mX
\e[24m above) which spec-
1213 ifies the line whose byte offset is to be used. If the charac-
1214 ter is a "t", the byte offset of the top line in the display is
1215 used, an "m" means use the middle line, a "b" means use the bot-
1216 tom line, a "B" means use the line just after the bottom line,
1217 and a "j" means use the "target" line, as specified by the -j
1220 %B Replaced by the size of the current input file.
1222 %c Replaced by the column number of the text appearing in the first
1223 column of the screen.
1225 %d
\e[4mX
\e[24m Replaced by the page number of a line in the input file. The
1226 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1228 %D Replaced by the number of pages in the input file, or equiva-
1229 lently, the page number of the last line in the input file.
1231 %E Replaced by the name of the editor (from the VISUAL environment
1232 variable, or the EDITOR environment variable if VISUAL is not
1233 defined). See the discussion of the LESSEDIT feature below.
1235 %f Replaced by the name of the current input file.
1237 %F Replaced by the last component of the name of the current input
1240 %i Replaced by the index of the current file in the list of input
1243 %l
\e[4mX
\e[24m Replaced by the line number of a line in the input file. The
1244 line to be used is determined by the
\e[4mX
\e[24m, as with the %b option.
1246 %L Replaced by the line number of the last line in the input file.
1248 %m Replaced by the total number of input files.
1250 %p
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1251 byte offsets. The line used is determined by the
\e[4mX
\e[24m as with the
1254 %P
\e[4mX
\e[24m Replaced by the percent into the current input file, based on
1255 line numbers. The line used is determined by the
\e[4mX
\e[24m as with the
1260 %t Causes any trailing spaces to be removed. Usually used at the
1261 end of the string, but may appear anywhere.
1263 %x Replaced by the name of the next input file in the list.
1265 If any item is unknown (for example, the file size if input is a pipe),
1266 a question mark is printed instead.
1268 The format of the prompt string can be changed depending on certain
1269 conditions. A question mark followed by a single character acts like
1270 an "IF": depending on the following character, a condition is evalu-
1271 ated. If the condition is true, any characters following the question
1272 mark and condition character, up to a period, are included in the
1273 prompt. If the condition is false, such characters are not included.
1274 A colon appearing between the question mark and the period can be used
1275 to establish an "ELSE": any characters between the colon and the period
1276 are included in the string if and only if the IF condition is false.
1277 Condition characters (which follow a question mark) may be:
1279 ?a True if any characters have been included in the prompt so far.
1281 ?b
\e[4mX
\e[24m True if the byte offset of the specified line is known.
1283 ?B True if the size of current input file is known.
1285 ?c True if the text is horizontally shifted (%c is not zero).
1287 ?d
\e[4mX
\e[24m True if the page number of the specified line is known.
1289 ?e True if at end-of-file.
1291 ?f True if there is an input filename (that is, if input is not a
1294 ?l
\e[4mX
\e[24m True if the line number of the specified line is known.
1296 ?L True if the line number of the last line in the file is known.
1298 ?m True if there is more than one input file.
1300 ?n True if this is the first prompt in a new input file.
1302 ?p
\e[4mX
\e[24m True if the percent into the current input file, based on byte
1303 offsets, of the specified line is known.
1305 ?P
\e[4mX
\e[24m True if the percent into the current input file, based on line
1306 numbers, of the specified line is known.
1310 ?x True if there is a next input file (that is, if the current
1311 input file is not the last one).
1313 Any characters other than the special ones (question mark, colon,
1314 period, percent, and backslash) become literally part of the prompt.
1315 Any of the special characters may be included in the prompt literally
1316 by preceding it with a backslash.
1320 ?f%f:Standard input.
1322 This prompt prints the filename, if known; otherwise the string "Stan-
1325 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
1327 This prompt would print the filename, if known. The filename is fol-
1328 lowed by the line number, if known, otherwise the percent if known,
1329 otherwise the byte offset if known. Otherwise, a dash is printed.
1330 Notice how each question mark has a matching period, and how the %
1331 after the %pt is included literally by escaping it with a backslash.
1333 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
1335 This prints the filename if this is the first prompt in a file, fol-
1336 lowed by the "file N of N" message if there is more than one input
1337 file. Then, if we are at end-of-file, the string "(END)" is printed
1338 followed by the name of the next file, if there is one. Finally, any
1339 trailing spaces are truncated. This is the default prompt. For refer-
1340 ence, here are the defaults for the other two prompts (-m and -M
1341 respectively). Each is broken into two lines here for readability
1344 ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
1345 ?pB%pB\%:byte %bB?s/%s...%t
1347 ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
1348 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
1350 And here is the default message produced by the = command:
1352 ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
1353 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
1355 The prompt expansion features are also used for another purpose: if an
1356 environment variable LESSEDIT is defined, it is used as the command to
1357 be executed when the v command is invoked. The LESSEDIT string is
1358 expanded in the same way as the prompt strings. The default value for
1363 Note that this expands to the editor name, followed by a + and the line
1364 number, followed by the file name. If your editor does not accept the
1365 "+linenumber" syntax, or has other differences in invocation syntax,
1366 the LESSEDIT variable can be changed to modify this default.
1370 When the environment variable LESSSECURE is set to 1,
\e[4mless
\e[24m runs in a
1371 "secure" mode. This means these features are disabled:
1377 :e the examine command.
1379 v the editing command
1383 -k use of lesskey files
1385 -t use of tags files
1387 metacharacters in filenames, such as *
1389 filename completion (TAB, ^L)
1391 Less can also be compiled to be permanently in "secure" mode.
1394 \e[1mCOMPATIBILITY WITH MORE
\e[0m
1395 If the environment variable LESS_IS_MORE is set to 1, or if the program
1396 is invoked via a file link named "more",
\e[4mless
\e[24m behaves (mostly) in con-
1397 formance with the POSIX "more" command specification. In this mode,
1398 less behaves differently in these ways:
1400 The -e option works differently. If the -e option is not set,
\e[4mless
\e[0m
1401 behaves as if the -E option were set. If the -e option is set,
\e[4mless
\e[0m
1402 behaves as if the -e and -F options were set.
1404 The -m option works differently. If the -m option is not set, the
1405 medium prompt is used, and it is prefixed with the string "--More--".
1406 If the -m option is set, the short prompt is used.
1408 The -n option acts like the -z option. The normal behavior of the -n
1409 option is unavailable in this mode.
1411 The parameter to the -p option is taken to be a
\e[4mless
\e[24m command rather
1412 than a search pattern.
1414 The LESS environment variable is ignored, and the MORE environment
1415 variable is used in its place.
1418 \e[1mENVIRONMENT VARIABLES
\e[0m
1419 Environment variables may be specified either in the system environment
1420 as usual, or in a
\e[4mlesskey
\e[24m (1) file. If environment variables are
1421 defined in more than one place, variables defined in a local lesskey
1422 file take precedence over variables defined in the system environment,
1423 which take precedence over variables defined in the system-wide lesskey
1427 Sets the number of columns on the screen. Takes precedence over
1428 the number of columns specified by the TERM variable. (But if
1429 you have a windowing system which supports TIOCGWINSZ or
1430 WIOCGETD, the window system's idea of the screen size takes
1431 precedence over the LINES and COLUMNS environment variables.)
1433 EDITOR The name of the editor (used for the v command).
1435 HOME Name of the user's home directory (used to find a lesskey file
1436 on Unix and OS/2 systems).
1439 Concatenation of the HOMEDRIVE and HOMEPATH environment vari-
1440 ables is the name of the user's home directory if the HOME vari-
1441 able is not set (only in the Windows version).
1443 INIT Name of the user's init directory (used to find a lesskey file
1446 LANG Language for determining the character set.
1449 Language for determining the character set.
1451 LESS Options which are passed to
\e[4mless
\e[24m automatically.
1454 Characters which may end an ANSI color escape sequence (default
1458 Characters which may appear between the ESC character and the
1459 end character in an ANSI color escape sequence (default
1460 "0123456789;[?!"'#%()*+ ".
1463 Format for displaying non-printable, non-control characters.
1466 Defines a character set.
1469 Selects a predefined character set.
1472 Command line to invoke the (optional) input-postprocessor.
1475 Name of the lessecho program (default "lessecho"). The lessecho
1476 program is needed to expand metacharacters, such as * and ?, in
1477 filenames on Unix systems.
1480 Editor prototype string (used for the v command). See discus-
1484 Name of the command used by the -t option to find global tags.
1485 Normally should be set to "global" if your system has the
\e[4mglobal
\e[0m
1486 (1) command. If not set, global tags are not used.
1489 Name of the history file used to remember search commands and
1490 shell commands between invocations of
\e[4mless.
\e[24m If set to "-" or
1491 "/dev/null", a history file is not used. The default is
1492 "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
1493 Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1497 The maximum number of commands to save in the history file. The
1501 Name of the default lesskey(1) file.
1504 Name of the default system-wide lesskey(1) file.
1507 List of characters which are considered "metacharacters" by the
1511 Prefix which less will add before each metacharacter in a com-
1512 mand sent to the shell. If LESSMETAESCAPE is an empty string,
1513 commands containing metacharacters will not be passed to the
1517 Command line to invoke the (optional) input-preprocessor.
1520 Runs less in "secure" mode. See discussion under SECURITY.
1523 String to be appended to a directory name in filename comple-
1527 Format for displaying non-printable Unicode code points.
1530 Emulate the
\e[4mmore
\e[24m (1) command.
1532 LINES Sets the number of lines on the screen. Takes precedence over
1533 the number of lines specified by the TERM variable. (But if you
1534 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1535 the window system's idea of the screen size takes precedence
1536 over the LINES and COLUMNS environment variables.)
1538 PATH User's search path (used to find a lesskey file on MS-DOS and
1541 SHELL The shell used to execute the ! command, as well as to expand
1544 TERM The type of terminal on which
\e[4mless
\e[24m is being run.
1546 VISUAL The name of the editor (used for the v command).
1554 Copyright (C) 1984-2011 Mark Nudelman
1556 less is part of the GNU project and is free software. You can redis-
1557 tribute it and/or modify it under the terms of either (1) the GNU Gen-
1558 eral Public License as published by the Free Software Foundation; or
1559 (2) the Less License. See the file README in the less distribution for
1560 more details regarding redistribution. You should have received a copy
1561 of the GNU General Public License along with the source for less; see
1562 the file COPYING. If not, write to the Free Software Foundation, 59
1563 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
1564 have received a copy of the Less License; see the file LICENSE.
1566 less is distributed in the hope that it will be useful, but WITHOUT ANY
1567 WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT-
1568 NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
1573 Mark Nudelman <markn@greenwoodsoftware.com>
1574 Send bug reports or comments to the above address or to bug-
1576 See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
1577 of known bugs in less.
1578 For more information, see the less homepage at
1579 http://www.greenwoodsoftware.com/less.
1583 Version 444: 09 Jun 2011 LESS(1)