Annotation of src/usr.bin/less/less.1, Revision 1.25
1.25 ! nicm 1: .\" $OpenBSD: less.1,v 1.24 2011/09/16 19:57:30 jmc Exp $
1.1 millert 2: .\"
1.23 shadchin 3: .\" Copyright (C) 1984-2011 Mark Nudelman
1.1 millert 4: .\"
1.5 millert 5: .\" Redistribution and use in source and binary forms, with or without
6: .\" modification, are permitted provided that the following conditions
7: .\" are met:
8: .\" 1. Redistributions of source code must retain the above copyright
9: .\" notice, this list of conditions and the following disclaimer.
10: .\" 2. Redistributions in binary form must reproduce the above copyright
1.7 jmc 11: .\" notice in the documentation and/or other materials provided with
1.5 millert 12: .\" the distribution.
1.1 millert 13: .\"
1.5 millert 14: .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
15: .\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.7 jmc 16: .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
1.5 millert 17: .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE
1.7 jmc 18: .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19: .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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21: .\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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1.5 millert 24: .\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.1 millert 25: .\"
1.24 jmc 26: .Dd $Mdocdate: September 16 2011 $
1.1 millert 27: .Dt LESS 1
28: .Os
29: .Sh NAME
30: .Nm less , more
1.11 jmc 31: .Nd view files
1.1 millert 32: .Sh SYNOPSIS
1.18 jmc 33: .Nm less \*(Ba more
1.6 jmc 34: .Fl \&?
1.18 jmc 35: .Nm less \*(Ba more
1.1 millert 36: .Fl -help
1.18 jmc 37: .Nm less \*(Ba more
1.1 millert 38: .Fl V
1.18 jmc 39: .Nm less \*(Ba more
1.1 millert 40: .Fl -version
1.18 jmc 41: .Nm less \*(Ba more
1.1 millert 42: .Bk -words
1.24 jmc 43: .Op Fl Oo Cm + Oc Ns Cm AaBCcdEeFfGgIiJKLMmNnQqRrSsUuVWwX~
1.1 millert 44: .Op Fl b Ar space
45: .Op Fl h Ar lines
46: .Op Fl j Ar line
47: .Op Fl k Ar keyfile
1.12 jmc 48: .Op Fl O | o Ar logfile
49: .Op Fl P Ar prompt
1.1 millert 50: .Op Fl p Ar pattern
1.12 jmc 51: .Op Fl T Ar tagsfile
1.1 millert 52: .Op Fl t Ar tag
53: .Op Fl x Ar tab,...
54: .Op Fl y Ar lines
1.18 jmc 55: .Op Fl Oo Cm z Oc Ar lines
1.1 millert 56: .Op Fl # Ar shift
1.18 jmc 57: .Xo Oo Cm \&+ Ns Oo Ns Cm \&+ Ns
1.1 millert 58: .Oc Ar cmd
59: .Oc
60: .Xc
61: .Op Fl -
62: .Op Ar filename ...
63: .Ek
64: .\" (See the
65: .\" .Sx OPTIONS
66: .\" section for alternate option syntax with long option names.)
67: .Sh DESCRIPTION
68: .Nm
69: is a program similar to the traditional
70: .Xr more 1 ,
71: but which allows backward movement in the file as well as forward movement.
72: Also,
73: .Nm
74: does not have to read the entire input file before starting,
75: so with large input files it starts up faster than text editors like
76: .Xr vi 1 .
77: .Nm
78: uses termcap (or terminfo on some systems),
79: so it can run on a variety of terminals.
80: There is even limited support for hardcopy terminals.
81: (On a hardcopy terminal, lines which should be printed at the top
82: of the screen are prefixed with a caret.)
83: .Pp
84: This version of
85: .Nm
86: also acts as
87: .Xr more 1
88: if it is called as
89: .Nm more .
90: In this mode, the differences are in the prompt and that
91: .Nm more
92: exits by default when it gets to the end of the file.
93: Commands are based on both traditional
94: .Nm more
95: and
96: .Xr vi 1 .
97: Commands may be preceded by a decimal number,
98: called N in the descriptions below.
99: The number is used by some commands, as indicated.
100: .Sh COMMANDS
101: In the following descriptions, ^X means control-X.
102: ESC stands for the ESCAPE key; for example ESC-v means the
103: two character sequence "ESCAPE", then "v".
104: .Bl -tag -width XXXX
105: .It Ic h | H
106: Help: display a summary of these commands.
107: If you forget all the other commands, remember this one.
108: .It Ic SPACE | ^V | f | ^F
109: Scroll forward N lines, default one window (see option -z below).
110: If N is more than the screen size, only the final screenful is displayed.
111: Warning: some systems use ^V as a special literalization character.
112: .It Ic z
113: Like SPACE, but if N is specified, it becomes the new window size.
114: .It Ic ESC-SPACE
1.23 shadchin 115: Like SPACE, but scrolls a full screenful, even if it reaches
1.1 millert 116: end-of-file in the process.
1.23 shadchin 117: .It Ic ENTER | RETURN | ^N | e | ^E | j | ^J
1.1 millert 118: Scroll forward N lines, default 1.
119: The entire N lines are displayed, even if N is more than the screen size.
120: .It Ic d | ^D
121: Scroll forward N lines, default one half of the screen size.
122: If N is specified, it becomes the new default for subsequent d and u commands.
123: .It Ic b | ^B | ESC-v
124: Scroll backward N lines, default one window (see option -z below).
125: If N is more than the screen size, only the final screenful is displayed.
126: .It Ic w
127: Like ESC-v, but if N is specified, it becomes the new window size.
1.22 jmc 128: .It Ic y | ^Y | ^P | k | ^K
1.1 millert 129: Scroll backward N lines, default 1.
130: The entire N lines are displayed, even if N is more than the screen size.
131: Warning: some systems use ^Y as a special job control character.
132: .It Ic u | ^U
133: Scroll backward N lines, default one half of the screen size.
134: If N is specified, it becomes the new default for subsequent d and u commands.
135: .It Ic ESC-) | RIGHTARROW
136: Scroll horizontally right N characters, default half the screen width
137: (see the -# option).
138: If a number N is specified, it becomes the default for future
139: RIGHTARROW and LEFTARROW commands.
140: While the text is scrolled, it acts as though the -S option (chop lines)
141: were in effect.
142: .It Ic ESC-( | LEFTARROW
143: Scroll horizontally left N
144: characters, default half the screen width (see the -# option).
145: If a number N is specified, it becomes the default for future
146: RIGHTARROW and LEFTARROW commands.
147: .It Ic r | ^R | ^L
148: Repaint the screen.
149: .It Ic R
150: Repaint the screen, discarding any buffered input.
151: Useful if the file is changing while it is being viewed.
152: .It Ic F
153: Scroll forward, and keep trying to read when the end of file is reached.
154: Normally this command would be used when already at the end of the file.
155: It is a way to monitor the tail of a file which is growing
156: while it is being viewed.
157: (The behavior is similar to the "tail -f" command.)
158: .It Ic g | < | ESC-<
159: Go to line N in the file, default 1 (beginning of file).
160: (Warning: this may be slow if N is large.)
161: .It Ic G | > | ESC->
162: Go to line N in the file, default the end of the file.
163: (Warning: this may be slow if N is large,
164: or if N is not specified and standard input, rather than a file,
165: is being read.)
166: .It Ic p | %
167: Go to a position N percent into the file.
1.23 shadchin 168: N should be between 0 and 100, and may contain a decimal point.
169: .It Ic P
170: Go to the line containing byte offset N in the file.
1.1 millert 171: .It Ic {
172: If a left curly bracket appears in the top line displayed
173: on the screen, the { command will go to the matching right curly bracket.
174: The matching right curly bracket is positioned on the bottom
175: line of the screen.
176: If there is more than one left curly bracket on the top line, a number N
177: may be used to specify the N-th bracket on the line.
178: .It Ic }
179: If a right curly bracket appears in the bottom line displayed on the screen,
180: the } command will go to the matching left curly bracket.
181: The matching left curly bracket is positioned on the top
182: line of the screen.
183: If there is more than one right curly bracket on the top line,
184: a number N may be used to specify the N-th bracket on the line.
185: .It Ic \&(
186: Like {, but applies to parentheses rather than curly brackets.
187: .It Ic \&)
188: Like }, but applies to parentheses rather than curly brackets.
189: .It Ic \&[
190: Like {, but applies to square brackets rather than curly brackets.
191: .It Ic \&]
192: Like }, but applies to square brackets rather than curly brackets.
193: .It Ic ESC-^F
194: Followed by two characters, acts like {,
195: but uses the two characters as open and close brackets, respectively.
196: For example, "ESC ^F < >" could be used to
197: go forward to the > which matches the < in the top displayed line.
198: .It Ic ESC-^B
199: Followed by two characters, acts like },
200: but uses the two characters as open and close brackets, respectively.
201: For example, "ESC ^B < >" could be used to
202: go backward to the < which matches the > in the bottom displayed line.
203: .It Ic m
204: Followed by any lowercase letter, marks the current position with that letter.
205: .It Ic '
206: (Single quote.)
207: Followed by any lowercase letter, returns to the position which
208: was previously marked with that letter.
209: Followed by another single quote, returns to the position at
210: which the last "large" movement command was executed.
211: Followed by a ^ or $, jumps to the beginning or end of the file respectively.
212: Marks are preserved when a new file is examined,
213: so the ' command can be used to switch between input files.
214: .It Ic ^X^X
215: Same as single quote.
216: .It Ic /pattern
217: Search forward in the file for the N-th line containing the pattern.
218: N defaults to 1.
219: The pattern is a regular expression, as recognized by
1.23 shadchin 220: the regular expression library supplied by your system.
221: The search starts at the first line displayed
1.1 millert 222: (but see the -a and -j options, which change this).
223: .Pp
224: Certain characters are special if entered at the beginning of the pattern;
225: they modify the type of search rather than become part of the pattern:
226: .Bl -tag -width Ds
1.6 jmc 227: .It Ic ^N | \&!
1.1 millert 228: Search for lines which do NOT match the pattern.
229: .It Ic ^E | *
230: Search multiple files.
231: That is, if the search reaches the END of the current file
232: without finding a match,
233: the search continues in the next file in the command line list.
234: .It Ic ^F | @
235: Begin the search at the first line of the FIRST file
236: in the command line list,
237: regardless of what is currently displayed on the screen
238: or the settings of the -a or -j options.
239: .It Ic ^K
240: Highlight any text which matches the pattern on the current screen,
241: but don't move to the first match (KEEP current position).
242: .It Ic ^R
243: Don't interpret regular expression metacharacters;
244: that is, do a simple textual comparison.
245: .El
246: .It Ic ?pattern
247: Search backward in the file for the N-th line containing the pattern.
248: The search starts at the line immediately before the top line displayed.
249: .Pp
250: Certain characters are special, as in the / command:
251: .Bl -tag -width Ds
1.6 jmc 252: .It Ic ^N | \&!
1.1 millert 253: Search for lines which do NOT match the pattern.
254: .It Ic ^E | *
255: Search multiple files.
256: That is, if the search reaches the beginning of the current file
257: without finding a match,
258: the search continues in the previous file in the command line list.
259: .It Ic ^F | @
260: Begin the search at the last line of the last file
261: in the command line list,
262: regardless of what is currently displayed on the screen
263: or the settings of the -a or -j options.
264: .It Ic ^K
265: As in forward searches.
266: .It Ic ^R
267: As in forward searches.
268: .El
269: .It Ic ESC-/pattern
270: Same as "/*".
271: .It Ic ESC-?pattern
272: Same as "?*".
273: .It Ic n
274: Repeat previous search, for N-th line containing the last pattern.
275: If the previous search was modified by ^N, the search is made for the
276: N-th line NOT containing the pattern.
277: If the previous search was modified by ^E, the search continues
278: in the next (or previous) file if not satisfied in the current file.
279: If the previous search was modified by ^R, the search is done
280: without using regular expressions.
281: There is no effect if the previous search was modified by ^F or ^K.
282: .It Ic N
283: Repeat previous search, but in the reverse direction.
284: .It Ic ESC-n
285: Repeat previous search, but crossing file boundaries.
286: The effect is as if the previous search were modified by *.
287: .It Ic ESC-N
288: Repeat previous search, but in the reverse direction
289: and crossing file boundaries.
290: .It Ic ESC-u
291: Undo search highlighting.
292: Turn off highlighting of strings matching the current search pattern.
293: If highlighting is already off because of a previous ESC-u command,
294: turn highlighting back on.
295: Any search command will also turn highlighting back on.
296: (Highlighting can also be disabled by toggling the -G option;
297: in that case search commands do not turn highlighting back on.)
1.23 shadchin 298: .It Ic &pattern
299: Display only lines which match the pattern;
300: lines which do not match the pattern are not displayed.
301: If pattern is empty (if you type & immediately followed by ENTER),
302: any filtering is turned off, and all lines are displayed.
303: While filtering is in effect, an ampersand is displayed at the
304: beginning of the prompt,
305: as a reminder that some lines in the file may be hidden.
306: .Pp
307: Certain characters are special as in the / command:
308: .Bl -tag -width Ds
309: .It Ic ^N | !
310: Display only lines which do NOT match the pattern.
311: .It Ic ^R
312: Don't interpret regular expression metacharacters;
313: that is, do a simple textual comparison.
314: .El
1.1 millert 315: .It Ic :e Op Ar filename
316: Examine a new file.
317: If the filename is missing, the "current" file (see the :n and :p commands
318: below) from the list of files in the command line is re-examined.
319: A percent sign (%) in the filename is replaced by the name of the
320: current file.
321: A pound sign (#) is replaced by the name of the previously examined file.
322: However, two consecutive percent signs are simply
323: replaced with a single percent sign.
324: This allows you to enter a filename that contains a percent sign
325: in the name.
326: Similarly, two consecutive pound signs are replaced with a single pound sign.
327: The filename is inserted into the command line list of files
328: so that it can be seen by subsequent :n and :p commands.
329: If the filename consists of several files, they are all inserted into
330: the list of files and the first one is examined.
331: If the filename contains one or more spaces,
332: the entire filename should be enclosed in double quotes
333: (also see the -" option).
334: .It Ic ^X^V | E
335: Same as :e.
336: Warning: some systems use ^V as a special literalization character.
337: On such systems, you may not be able to use ^V.
338: .It Ic :n
339: Examine the next file (from the list of files given in the command line).
340: If a number N is specified, the N-th next file is examined.
341: .It Ic :p
342: Examine the previous file in the command line list.
343: If a number N is specified, the N-th previous file is examined.
344: .It Ic :t
345: Go to the specified tag.
346: .It Ic :x
347: Examine the first file in the command line list.
348: If a number N is specified, the N-th file in the list is examined.
349: .It Ic :d
350: Remove the current file from the list of files.
351: .It Ic t
352: Go to the next tag, if there were more than one matches for the current tag.
353: See the \-t option for more details about tags.
354: .It Ic T
355: Go to the previous tag, if there were more than one matches for the current tag.
356: .It Ic = | ^G | :f
357: Prints some information about the file being viewed, including its name
358: and the line number and byte offset of the bottom line being displayed.
359: If possible, it also prints the length of the file,
360: the number of lines in the file
361: and the percent of the file above the last displayed line.
362: .It Ic \-
363: Followed by one of the command line option letters (see
364: .Sx OPTIONS
365: below),
366: this will change the setting of that option
367: and print a message describing the new setting.
368: If a ^P (CONTROL-P) is entered immediately after the dash,
369: the setting of the option is changed but no message is printed.
370: If the option letter has a numeric value (such as -b or -h),
371: or a string value (such as -P or -t),
372: a new value may be entered after the option letter.
373: If no new value is entered, a message describing
374: the current setting is printed and nothing is changed.
375: .It Ic \-\-
376: Like the \- command, but takes a long option name (see
377: .Sx OPTIONS
378: below)
379: rather than a single option letter.
1.23 shadchin 380: You must press ENTER or RETURN after typing the option name.
1.1 millert 381: A ^P immediately after the second dash suppresses printing of a
382: message describing the new setting, as in the \- command.
383: .It Ic \-+
384: Followed by one of the command line option letters this will reset the
385: option to its default setting and print a message describing the new setting.
386: (The "\-+X" command does the same thing as "\-+X" on the command line.)
387: This does not work for string-valued options.
388: .It Ic \-\-+
389: Like the \-+ command, but takes a long option name
390: rather than a single option letter.
391: .It Ic \-!
392: Followed by one of the command line option letters, this will reset the
393: option to the "opposite" of its default setting and print a message
394: describing the new setting.
395: This does not work for numeric or string-valued options.
396: .It Ic \-\-!
397: Like the \-! command, but takes a long option name
398: rather than a single option letter.
399: .It Ic _
400: (Underscore.)
401: Followed by one of the command line option letters,
402: this will print a message describing the current setting of that option.
403: The setting of the option is not changed.
404: .It Ic __
405: (Double underscore.)
406: Like the _ (underscore) command, but takes a long option name
407: rather than a single option letter.
1.23 shadchin 408: You must press ENTER or RETURN after typing the option name.
1.1 millert 409: .It Ic +cmd
410: Causes the specified cmd to be executed each time a new file is examined.
411: For example, +G causes
412: .Nm
413: to initially display each file starting at the end rather than the beginning.
414: .It Ic V
415: Prints the version number of
416: .Nm
417: being run.
1.22 jmc 418: .It Ic q | Q | :q | :Q | ZZ
1.1 millert 419: Exits
420: .Nm less .
421: .El
422: .Pp
423: The following
424: four
425: commands may or may not be valid, depending on your particular installation.
426: .Bl -tag -width XXXX
427: .It Ic v
428: Invokes an editor to edit the current file being viewed.
429: The editor is taken from the environment variable
430: .Ev VISUAL ,
431: if defined,
432: or
433: .Ev EDITOR
434: if
435: .Ev VISUAL
436: is not defined,
437: or defaults to "vi" if neither
438: .Ev VISUAL
439: nor
440: .Ev EDITOR
441: is defined.
442: See also the discussion of LESSEDIT under the section on
443: .Sx PROMPTS
444: below.
1.6 jmc 445: .It Ic \&! Ar shell-command
1.1 millert 446: Invokes a shell to run the shell-command given.
447: A percent sign (%) in the command is replaced by the name of the current file.
448: A pound sign (#) is replaced by the name of the previously examined file.
449: "!!" repeats the last shell command.
450: "!" with no shell command simply invokes a shell.
451: The shell is taken from the environment variable
452: .Ev SHELL ,
453: or defaults to "sh".
454: .\" On MS-DOS and OS/2 systems, the shell is the normal command processor.
1.22 jmc 455: .It Ic | <m> Ar shell-command
1.1 millert 456: <m> represents any mark letter.
457: Pipes a section of the input file to the given shell command.
458: The section of the file to be piped is between the first line on
459: the current screen and the position marked by the letter.
460: <m> may also be ^ or $ to indicate beginning or end of file respectively.
461: If <m> is . or newline, the current screen is piped.
462: .It Ic s Ar filename
463: Save the input to a file.
464: This only works if the input is a pipe, not an ordinary file.
465: .El
466: .Sh OPTIONS
467: Command line options are described below.
468: Most options may be changed while
469: .Nm
470: is running, via the "\-" command.
471: .Pp
472: Most options may be given in one of two forms:
473: either a dash followed by a single letter, or two dashes followed by a
474: long option name.
475: A long option name may be abbreviated as long as the abbreviation is
476: unambiguous.
477: For example, --quit-at-eof may be abbreviated --quit, but not
478: --qui, since both --quit-at-eof and --quiet begin with --qui.
479: Some long option names are in uppercase, such as --QUIT-AT-EOF, as
480: distinct from --quit-at-eof.
481: Such option names need only have their first letter capitalized;
482: the remainder of the name may be in either case.
483: For example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
484: .Pp
485: Options are also taken from the environment variable
486: .Ev LESS
487: if the command is
488: .Nm less ,
489: or from the environment variable
490: .Ev MORE
491: if the command is
492: .Nm more .
493: For example, to avoid typing "less -options ..." each time
494: .Nm
495: is invoked, you might tell
496: .Xr csh 1 :
497: .Pp
498: .Dl setenv LESS "-options"
499: .Pp
500: or if you use
501: .Xr sh 1 :
502: .Pp
503: .Dl LESS="-options"; export LESS
504: .Pp
505: .\" On MS-DOS, you don't need the quotes, but you should replace any
506: .\" percent signs in the options string by double percent signs.
507: .\" .Pp
508: The environment variable is parsed before the command line,
509: so command line options override the
510: .Ev LESS
511: environment variable.
512: If an option appears in the
513: .Ev LESS
514: variable, it can be reset to its default value on the command line by
515: beginning the command line option with "\-+".
516: .Pp
517: For options like -P which take a following string,
518: a dollar sign ($) must be used to signal the end of the string.
519: For example, to separate a prompt value from any other options
520: with dollar sign between them:
521: .Pp
522: .Dl LESS="-Ps--More--$-C -e"
523: .Bl -tag -width XXXX
1.6 jmc 524: .It Fl \&? | -help
1.1 millert 525: This option displays a summary of the commands accepted by
526: .Nm
527: (the same as the h command).
528: (Depending on how your shell interprets the question mark,
529: it may be necessary to quote the question mark, thus: "-\e?".)
1.23 shadchin 530: .It Fl A | -SEARCH-SKIP-SCREEN
531: Causes all forward searches (not just non-repeated searches)
532: to start just after the target line, and all backward searches
533: to start just before the target line.
534: Thus, forward searches will skip part of the displayed screen
535: (from the first line up to and including the target line).
536: Similarly backwards searches will skip the displayed screen
537: from the last line up to and including the target line.
538: This was the default behavior in less versions prior to 441.
1.1 millert 539: .It Fl a | -search-skip-screen
1.23 shadchin 540: By default, forward searches start at the top of the displayed screen
541: and backwards searches start at the bottom of the displayed screen
542: (except for repeated searches invoked by the n or N commands,
543: which start after or before the "target" line respectively;
544: see the -j option for more about the target line).
545: The -a option causes forward searches to instead start at
546: the bottom of the screen
547: and backward searches to start at the top of the screen,
1.1 millert 548: thus skipping all lines displayed on the screen.
1.12 jmc 549: .It Fl B | -auto-buffers
550: By default, when data is read from a pipe,
551: buffers are allocated automatically as needed.
552: If a large amount of data is read from the pipe, this can cause
553: a large amount of memory to be allocated.
554: The -B option disables this automatic allocation of buffers for pipes,
555: so that only 64K (or the amount of space specified by the -b option)
556: is used for the pipe.
557: Warning: use of -B can result in erroneous display, since only the
1.23 shadchin 558: most recently viewed part of the piped data is kept in memory;
1.12 jmc 559: any earlier data is lost.
1.1 millert 560: .It Xo
561: .Fl b Ns Ar n |
1.8 jmc 562: .Fl -buffers Ns = Ns Ar n
1.1 millert 563: .Xc
564: Specifies the amount of buffer space
565: .Nm
566: will use for each file, in units of kilobytes (1024 bytes).
567: By default 64K of buffer space is used for each file
568: (unless the file is a pipe; see the -B option).
569: The -b option specifies instead that n kilobytes of
570: buffer space should be used for each file.
571: If n is -1, buffer space is unlimited; that is,
1.23 shadchin 572: the entire file can be read into memory.
1.12 jmc 573: .It Fl C | -CLEAR-SCREEN
1.23 shadchin 574: Same as -c, for compatibility with older versions of
575: .Nm less .
1.1 millert 576: .It Fl c | -clear-screen
577: Causes full screen repaints to be painted from the top line down.
578: By default,
579: full screen repaints are done by scrolling from the bottom of the screen.
580: .It Fl d | -dumb No (less only)
581: The -d option suppresses the error message
582: normally displayed if the terminal is dumb;
583: that is, lacks some important capability,
584: such as the ability to clear the screen or scroll backward.
585: The -d option does not otherwise change the behavior of
586: .Nm
587: on a dumb terminal.
588: This option is on by default when invoked as
589: .Nm more .
590: .It Fl d No (more only)
591: The -d option causes the default prompt to include the
592: basic directions ``[Press space to continue, 'q' to quit.]''.
593: The -d option also causes the message ``[Press 'h' for instructions.]'' to be
594: displayed when an invalid command is entered (normally, the bell is rung).
595: This option is useful in environments where users may not be experienced
596: with pagers.
597: .\" .It Fl Dxcolor or --color=xcolor"
598: .\" [MS-DOS only]
599: .\" Sets the color of the text displayed.
600: .\" x is a single character which selects the type of text whose color is
601: .\" being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
602: .\" color is a pair of numbers separated by a period.
603: .\" The first number selects the foreground color and the second selects
604: .\" the background color of the text.
1.23 shadchin 605: .\" A single number N is the same as N.M,
606: .\" where M is the normal background color.
1.12 jmc 607: .It Fl E | -QUIT-AT-EOF
608: Causes
609: .Nm
610: to automatically exit the first time it reaches end-of-file.
1.1 millert 611: .It Fl e | -quit-at-eof
612: Causes
613: .Nm
614: to automatically exit the second time it reaches end-of-file.
615: By default, the only way to exit
616: .Nm
617: is via the "q" command.
1.12 jmc 618: .It Fl F | -quit-if-one-screen
1.1 millert 619: Causes
620: .Nm
1.12 jmc 621: to automatically exit if the entire file can be displayed on the first screen.
1.1 millert 622: .It Fl f | -force
623: Forces non-regular files to be opened.
624: (A non-regular file is a directory or a device special file.)
625: Also suppresses the warning message when a binary file is opened.
626: By default,
627: .Nm
628: will refuse to open non-regular files.
1.12 jmc 629: .It Fl G | -HILITE-SEARCH
630: The -G option suppresses all highlighting of strings found by search commands.
1.1 millert 631: .It Fl g | -hilite-search
632: Normally,
633: .Nm
634: will highlight ALL strings which match the last search command.
635: The -g option changes this behavior to highlight only the particular string
636: which was found by the last search command.
637: This can cause
638: .Nm
639: to run somewhat faster than the default.
640: .It Xo
641: .Fl h Ns Ar n |
1.8 jmc 642: .Fl -max-back-scroll Ns = Ns Ar n
1.1 millert 643: .Xc
644: Specifies a maximum number of lines to scroll backward.
645: If it is necessary to scroll backward more than n lines,
646: the screen is repainted in a forward direction instead.
647: (If the terminal does not have the ability to scroll backward, -h0 is implied.)
1.12 jmc 648: .It Fl I | -IGNORE-CASE
649: Like -i, but searches ignore case even if the pattern contains uppercase
650: letters.
1.1 millert 651: .It Fl i | -ignore-case
652: Causes searches to ignore case; that is,
653: uppercase and lowercase are considered identical.
654: This option is ignored if any uppercase letters appear in the search pattern;
655: in other words,
656: if a pattern contains uppercase letters, then that search does not ignore case.
1.12 jmc 657: .It Fl J | -status-column
658: Displays a status column at the left edge of the screen.
659: The status column shows the lines that matched the current search.
660: The status column is also used if the -w or -W option is in effect.
1.1 millert 661: .It Xo
662: .Fl j Ns Ar n |
1.8 jmc 663: .Fl -jump-target Ns = Ns Ar n
1.1 millert 664: .Xc
665: Specifies a line on the screen where the "target" line is to be positioned.
1.23 shadchin 666: The target line is the line specified by any command to
667: search for a pattern, jump to a line number,
668: jump to a file percentage or jump to a tag.
669: The screen line may be specified by a number: the top line on the screen
1.1 millert 670: is 1, the next is 2, and so on.
671: The number may be negative to specify a line relative to the bottom
672: of the screen: the bottom line on the screen is -1, the second
673: to the bottom is -2, and so on.
1.23 shadchin 674: Alternately, the screen line may be specified as a fraction of the height
675: of the screen, starting with a decimal point: .5 is in the middle of the
676: screen, .3 is three tenths down from the first line, and so on.
677: If the line is specified as a fraction, the actual line number
678: is recalculated if the terminal window is resized, so that the
679: target line remains at the specified fraction of the screen height.
1.24 jmc 680: If any form of the -j option is used,
1.23 shadchin 681: forward searches begin at the line immediately after the target line,
682: and backward searches begin at the target line,
683: unless changed by -a or -A.
1.1 millert 684: For example, if "-j4" is used, the target line is the
1.23 shadchin 685: fourth line on the screen, so forward searches begin at the fifth line
686: on the screen.
687: .It Fl K | -quit-on-intr
688: Causes
689: .Nm
690: to exit immediately (with status 2)
691: when an interrupt character (usually ^C) is typed.
692: Normally, an interrupt character causes
693: .Nm
694: to stop whatever it is doing and return to its command prompt.
1.24 jmc 695: Note that use of this option makes it impossible to return to the
1.23 shadchin 696: command prompt from the "F" command.
1.1 millert 697: .It Xo
698: .Fl k Ns Ar filename |
1.8 jmc 699: .Fl -lesskey-file Ns = Ns Ar filename
1.1 millert 700: .Xc
701: Causes
702: .Nm
703: to open and interpret the named file as a
704: .Xr lesskey 1
705: file.
706: Multiple -k options may be specified.
707: If the
708: .Ev LESSKEY
709: or
710: .Ev LESSKEY_SYSTEM
711: environment variable is set, or if a lesskey file is found in a standard place
712: (see
713: .Sx KEY BINDINGS ) ,
714: it is also used as a lesskey file.
715: .It Fl L | -no-lessopen
716: Ignore the
717: .Ev LESSOPEN
718: environment variable (see the
719: .Sx INPUT PREPROCESSOR
720: section below).
721: This option can be set from within
722: .Nm less ,
723: but it will apply only to files opened subsequently, not to the
724: file which is currently open.
725: When invoked as
726: .Nm more ,
727: the
728: .Ev LESSOPEN
729: environment variable is ignored by default.
1.12 jmc 730: .It Fl M | -LONG-PROMPT
731: Causes
732: .Nm
733: to prompt even more verbosely than
734: .Nm more .
1.1 millert 735: .It Fl m | -long-prompt
736: Causes
737: .Nm
738: to prompt verbosely (like more), with the percent into the file.
739: By default,
740: .Nm
741: prompts with a colon.
1.12 jmc 742: .It Fl N | -LINE-NUMBERS
743: Causes a line number to be displayed at the beginning of each line in the
744: display.
1.1 millert 745: .It Fl n | -line-numbers
746: Suppresses line numbers.
747: The default (to use line numbers) may cause
748: .Nm
749: to run more slowly in some cases, especially with a very large input file.
750: Suppressing line numbers with the -n option will avoid this problem.
751: Using line numbers means: the line number will be displayed in the verbose
752: prompt and in the = command, and the v command will pass the current line
753: number to the editor (see also the discussion of LESSEDIT in
754: .Sx PROMPTS
755: below).
756: .It Xo
757: .Fl O Ns Ar filename |
1.8 jmc 758: .Fl -LOG-FILE Ns = Ns Ar filename
1.1 millert 759: .Xc
760: The -O option is like -o, but it will overwrite an existing
761: file without asking for confirmation.
762: .Pp
763: If no log file has been specified,
764: the -o and -O options can be used from within
765: .Nm
766: to specify a log file.
767: Without a file name, they will simply report the name of the log file.
768: The "s" command is equivalent to specifying -o from within
769: .Nm less .
770: .It Xo
1.12 jmc 771: .Fl o Ns Ar filename |
772: .Fl -log-file Ns = Ns Ar filename
1.1 millert 773: .Xc
1.12 jmc 774: Causes
775: .Nm
776: to copy its input to the named file as it is being viewed.
777: This applies only when the input file is a pipe, not an ordinary file.
778: If the file already exists,
1.1 millert 779: .Nm
1.12 jmc 780: will ask for confirmation before overwriting it.
1.1 millert 781: .It Xo
782: .Fl P Ns Ar prompt |
1.8 jmc 783: .Fl -prompt Ns = Ns Ar prompt
1.1 millert 784: .Xc
785: Provides a way to tailor the three prompt styles to your own preference.
786: This option would normally be put in the
787: .Ev LESS
788: environment variable, rather than being typed in with each
789: .Nm
790: command.
791: Such an option must either be the last option in the
792: .Ev LESS
793: variable, or be terminated by a dollar sign.
794: -Ps followed by a string changes the default (short) prompt to that string.
795: -Pm changes the medium (-m) prompt.
796: -PM changes the long (-M) prompt.
797: -Ph changes the prompt for the help screen.
798: -P= changes the message printed by the = command.
799: -Pw changes the message printed while waiting for data (in the F command).
800: All prompt strings consist of a sequence of letters and special escape
801: sequences.
802: See the section on
803: .Sx PROMPTS
804: for more details.
1.12 jmc 805: .It Xo
806: .Fl p Ns Ar pattern |
807: .Fl -pattern Ns = Ns Ar pattern
808: .Xc
809: The -p option on the command line is equivalent to specifying +/pattern;
810: that is, it tells
811: .Nm
812: to start at the first occurrence of pattern in the file.
813: .It Fl Q | -QUIET | -SILENT
814: Causes totally "quiet" operation: the terminal bell is never rung.
1.1 millert 815: .It Fl q | -quiet | -silent
816: Causes moderately "quiet" operation:
817: the terminal bell is not rung if an attempt is made to scroll past the end
818: of the file or before the beginning of the file.
819: If the terminal has a "visual bell", it is used instead.
820: The bell will be rung on certain other errors,
821: such as typing an invalid character.
822: The default is to ring the terminal bell in all such cases.
823: .It Fl R | -RAW-CONTROL-CHARS
1.23 shadchin 824: Like -r, but only ANSI "color" escape sequences are output in "raw" form.
825: Unlike -r, the screen appearance is maintained correctly in most cases.
826: ANSI "color" escape sequences are sequences of the form:
1.1 millert 827: .Pp
1.18 jmc 828: .Dl ESC \&[ ... m
1.1 millert 829: .Pp
1.23 shadchin 830: where the "..." is zero or more color specification characters.
1.1 millert 831: For the purpose of keeping track of screen appearance,
1.23 shadchin 832: ANSI color escape sequences are assumed to not move the cursor.
1.1 millert 833: You can make
834: .Nm
835: think that characters other than "m" can end ANSI color escape sequences
836: by setting the environment variable
837: .Ev LESSANSIENDCHARS
838: to the list of characters which can end a color escape sequence.
1.23 shadchin 839: And you can make
840: .Nm
841: think that characters other than the standard ones may appear between
842: the ESC and the m by setting the environment variable
843: .Ev LESSANSIMIDCHARS
844: to the list of characters which can appear.
1.12 jmc 845: .It Fl r | -raw-control-chars
846: Causes "raw" control characters to be displayed.
847: The default is to display control characters using the caret notation;
848: for example, a control-A (octal 001) is displayed as "^A".
849: Warning: when the -r option is used,
850: .Nm
851: cannot keep track of the actual appearance of the screen
852: (since this depends on how the screen responds to
853: each type of control character).
854: Thus, various display problems may result,
855: such as long lines being split in the wrong place.
1.1 millert 856: .It Fl S | -chop-long-lines
857: Causes lines longer than the screen width to be chopped rather than folded.
858: That is, the portion of a long line that does not fit in
859: the screen width is not shown.
860: The default is to fold long lines; that is, display the remainder
861: on the next line.
1.12 jmc 862: .It Fl s | -squeeze-blank-lines
863: Causes consecutive blank lines to be squeezed into a single blank line.
864: .It Xo
865: .Fl T Ns Ar tagsfile |
866: .Fl -tag-file Ns = Ns Ar tagsfile
867: .Xc
868: Specifies a tags file to be used instead of "tags".
1.1 millert 869: .It Xo
870: .Fl t Ns Ar tag |
1.8 jmc 871: .Fl -tag Ns = Ns Ar tag
1.1 millert 872: .Xc
873: The -t option, followed immediately by a TAG,
874: will edit the file containing that tag.
875: For this to work, tag information must be available;
876: for example, there may be a file in the current directory called "tags",
877: which was previously built by
878: .Xr ctags 1
879: or an equivalent command.
880: If the environment variable
881: .Ev LESSGLOBALTAGS
882: is set, it is taken to be the name of a command compatible with
883: .Xr global ,
884: and that command is executed to find the tag.
885: (See http://www.gnu.org/software/global/global.html).
886: The -t option may also be specified from within
887: .Nm
888: (using the \- command) as a way of examining a new file.
889: The command ":t" is equivalent to specifying -t from within
890: .Nm less .
891: .It Fl U | -UNDERLINE-SPECIAL
892: Causes backspaces, tabs and carriage returns to be
893: treated as control characters;
894: that is, they are handled as specified by the -r option.
895: .Pp
896: By default, if neither -u nor -U is given, backspaces which appear adjacent
897: to an underscore character are treated specially:
898: the underlined text is displayed
899: using the terminal's hardware underlining capability.
900: Also, backspaces which appear between two identical characters
901: are treated specially:
902: the overstruck text is printed
903: using the terminal's hardware boldface capability.
904: Other backspaces are deleted, along with the preceding character.
905: Carriage returns immediately followed by a newline are deleted.
906: Other carriage returns are handled as specified by the -r option.
907: Text which is overstruck or underlined can be searched for
908: if neither -u nor -U is in effect.
1.12 jmc 909: .It Fl u | -underline-special
910: Causes backspaces and carriage returns to be treated as printable characters;
911: that is, they are sent to the terminal when they appear in the input.
1.1 millert 912: .It Fl V | -version
913: Displays the version number of
914: .Nm less .
1.12 jmc 915: .It Fl W | -HILITE-UNREAD
916: Like -w, but temporarily highlights the first new line after any
917: forward movement command larger than one line.
1.1 millert 918: .It Fl w | -hilite-unread
919: Temporarily highlights the first "new" line after a forward movement
920: of a full page.
921: The first "new" line is the line immediately following the line previously
922: at the bottom of the screen.
923: Also highlights the target line after a g or p command.
924: The highlight is removed at the next command which causes movement.
925: The entire line is highlighted, unless the -J option is in effect,
926: in which case only the status column is highlighted.
1.12 jmc 927: .It Fl X | -no-init
928: Disables sending the termcap initialization and deinitialization strings
929: to the terminal.
930: This is sometimes desirable if the deinitialization string does
931: something unnecessary, like clearing the screen.
1.1 millert 932: .It Xo
933: .Fl x Ns Ar n,... |
1.8 jmc 934: .Fl -tabs Ns = Ns Ar n,...
1.1 millert 935: .Xc
936: Sets tab stops.
937: If only one n is specified, tab stops are set at multiples of n.
938: If multiple values separated by commas are specified, tab stops are set at
939: those positions, and then continue with the same spacing as the last two.
940: For example, -x9,17 will set tabs at positions 9, 17, 25, 33, etc.
941: The default for n is 8.
942: .It Xo
943: .Fl y Ns Ar n |
1.8 jmc 944: .Fl -max-forw-scroll Ns = Ns Ar n
1.1 millert 945: .Xc
946: Specifies a maximum number of lines to scroll forward.
947: If it is necessary to scroll forward more than n lines,
948: the screen is repainted instead.
949: The -c or -C option may be used to repaint from the top of
950: the screen if desired.
951: By default, any forward movement causes scrolling.
952: .It Xo
953: .Fl Oo Cm z Oc Ns Ar n |
1.8 jmc 954: .Fl -window Ns = Ns Ar n
1.1 millert 955: .Xc
956: Changes the default scrolling window size to n lines.
957: The default is one screenful.
958: The z and w commands can also be used to change the window size.
1.23 shadchin 959: The "z" may be omitted for compatibility with some versions of
1.1 millert 960: .Nm more .
961: If the number
962: .Ar n
963: is negative, it indicates
964: .Ar n
965: lines less than the current screen size.
966: For example, if the screen is 24 lines, -z-4 sets the
967: scrolling window to 20 lines.
968: If the screen is resized to 40 lines,
969: the scrolling window automatically changes to 36 lines.
1.23 shadchin 970: .It Fl -follow-name
971: Normally, if the input file is renamed while an F command is executing,
972: .Nm
973: will continue to display the contents of the original file despite
974: its name change.
975: If --follow-name is specified, during an F command
976: .Nm
977: will periodically attempt to reopen the file by name.
978: If the reopen succeeds and the file is a different file from the original
979: (which means that a new file has been created
980: with the same name as the original (now renamed) file),
981: .Nm
982: will display the contents of that new file.
1.12 jmc 983: .It Fl -no-keypad
984: Disables sending the keypad initialization and deinitialization strings
985: to the terminal.
986: This is sometimes useful if the keypad strings make the numeric
987: keypad behave in an undesirable manner.
1.1 millert 988: .It Xo
989: .Ar -cc |
1.8 jmc 990: .Fl -quotes Ns = Ns Ar cc
1.1 millert 991: .Xc
992: Changes the filename quoting character.
993: This may be necessary if you are trying to name a file
994: which contains both spaces and quote characters.
995: Followed by a single character, this changes the quote character to that
996: character.
997: Filenames containing a space should then be surrounded by that character
998: rather than by double quotes.
999: Followed by two characters, changes the open quote to the first character,
1000: and the close quote to the second character.
1001: Filenames containing a space should then be preceded by the open quote
1002: character and followed by the close quote character.
1003: Note that even after the quote characters are changed, this option
1004: remains -" (a dash followed by a double quote).
1005: .It Fl ~ | -tilde
1006: Normally lines after end of file are displayed as a single tilde (~).
1007: This option causes lines after end of file to be displayed as blank lines.
1008: .It Fl # | -shift
1009: Specifies the default number of positions to scroll horizontally
1010: in the RIGHTARROW and LEFTARROW commands.
1011: If the number specified is zero, it sets the default number of
1012: positions to one half of the screen width.
1.23 shadchin 1013: Alternately, the number may be specified as a fraction of the width
1014: of the screen, starting with a decimal point: .5 is half of the
1015: screen width, .3 is three tenths of the screen width, and so on.
1016: If the number is specified as a fraction, the actual number of
1017: scroll positions is recalculated if the terminal window is resized,
1018: so that the actual scroll remains at the specified fraction
1019: of the screen width.
1.1 millert 1020: .It Fl -
1021: A command line argument of "--" marks the end of option arguments.
1022: Any arguments following this are interpreted as filenames.
1023: This can be useful when viewing a file whose name begins with a "-" or "+".
1024: .It Cm +
1025: If a command line option begins with +,
1026: the remainder of that option is taken to be an initial command to
1027: .Nm less .
1028: For example, +G tells
1029: .Nm
1030: to start at the end of the file rather than the beginning,
1031: and +/xyz tells it to start at the first occurrence of "xyz" in the file.
1032: As a special case, +<number> acts like +<number>g;
1033: that is, it starts the display at the specified line number
1034: (however, see the caveat under the "g" command above).
1035: If the option starts with ++, the initial command applies to
1036: every file being viewed, not just the first one.
1037: The + command described previously
1038: may also be used to set (or change) an initial command for every file.
1039: .El
1040: .Sh LINE EDITING
1041: When entering command line at the bottom of the screen
1042: (for example, a filename for the :e command,
1043: or the pattern for a search command),
1044: certain keys can be used to manipulate the command line.
1045: Most commands have an alternate form in [ brackets ] which can be used if
1046: a key does not exist on a particular keyboard.
1.23 shadchin 1047: .\" (Note that the forms beginning with ESC do not work
1048: .\" in some MS-DOS and Windows systems because ESC is the line erase character.)
1.1 millert 1049: Any of these special keys may be entered literally by preceding
1050: it with the "literal" character, either ^V or ^A.
1051: A backslash itself may also be entered literally by entering two backslashes.
1052: .Bl -tag -width Ds
1053: .It LEFTARROW [ ESC-h ]
1054: Move the cursor one space to the left.
1055: .It RIGHTARROW [ ESC-l ]
1056: Move the cursor one space to the right.
1057: .It ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
1058: (That is, CONTROL and LEFTARROW simultaneously.)
1059: Move the cursor one word to the left.
1060: .It ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
1061: (That is, CONTROL and RIGHTARROW simultaneously.)
1062: Move the cursor one word to the right.
1063: .It HOME [ ESC-0 ]
1064: Move the cursor to the beginning of the line.
1065: .It END [ ESC-$ ]
1066: Move the cursor to the end of the line.
1067: .It BACKSPACE
1068: Delete the character to the left of the cursor,
1069: or cancel the command if the command line is empty.
1070: .It DELETE or [ ESC-x ]
1071: Delete the character under the cursor.
1072: .It ^BACKSPACE [ ESC-BACKSPACE ]
1073: (That is, CONTROL and BACKSPACE simultaneously.)
1074: Delete the word to the left of the cursor.
1075: .It ^DELETE [ ESC-X or ESC-DELETE ]
1076: (That is, CONTROL and DELETE simultaneously.)
1077: Delete the word under the cursor.
1078: .It UPARROW [ ESC-k ]
1079: Retrieve the previous command line.
1080: .It DOWNARROW [ ESC-j ]
1081: Retrieve the next command line.
1082: .It TAB
1083: Complete the partial filename to the left of the cursor.
1084: If it matches more than one filename, the first match
1085: is entered into the command line.
1086: Repeated TABs will cycle through the other matching filenames.
1087: If the completed filename is a directory, a "/" is appended to the filename.
1088: .\" (On MS-DOS systems, a "\e" is appended.)
1089: The environment variable
1090: .Ev LESSSEPARATOR
1091: can be used to specify a different character to append to a directory name.
1092: .It BACKTAB [ ESC-TAB ]
1093: Like TAB, but cycles in the reverse direction through the matching filenames.
1094: .It ^L
1095: Complete the partial filename to the left of the cursor.
1096: If it matches more than one filename, all matches are entered into
1097: the command line (if they fit).
1098: .\" .It ^U (Unix and OS/2) or ESC (MS-DOS)
1099: .It ^U
1100: Delete the entire command line,
1101: or cancel the command if the command line is empty.
1102: If you have changed your line-kill character to something
1103: other than ^U, that character is used instead of ^U.
1.23 shadchin 1104: .It "^G"
1105: Delete the entire command line and return to the main prompt.
1.1 millert 1106: .El
1107: .Sh KEY BINDINGS
1108: You may define your own
1109: .Nm
1110: commands by using the program
1111: .Xr lesskey 1
1112: to create a lesskey file.
1113: This file specifies a set of command keys and an action
1114: associated with each key.
1115: You may also use lesskey
1116: to change the line-editing keys (see
1117: .Sx LINE EDITING ) ,
1118: and to set environment variables.
1119: If the environment variable
1120: .Ev LESSKEY
1121: is set,
1122: .Nm
1123: uses that as the name of the lesskey file.
1124: Otherwise,
1125: .Nm
1126: looks for a lesskey file called "$HOME/.less".
1127: .\" On MS-DOS and Windows systems,
1128: .\" .I less
1129: .\" looks for a lesskey file called "$HOME/_less", and if it is not found there,
1130: .\" then looks for a lesskey file called "_less" in any directory specified
1131: .\" in the PATH environment variable.
1132: .\" On OS/2 systems,
1133: .\" .I less
1134: .\" looks for a lesskey file called "$HOME/less.ini", and if it is not found,
1135: .\" then looks for a lesskey file called "less.ini" in any directory specified
1136: .\" in the INIT environment variable, and if it not found there,
1137: .\" then looks for a lesskey file called "less.ini" in any directory specified
1138: .\" in the PATH environment variable.
1139: See the
1140: .Xr lesskey 1
1141: manual page for more details.
1142: .Pp
1143: A system-wide lesskey file may also be set up to provide key bindings.
1144: If a key is defined in both a local lesskey file and in the
1145: system-wide file, key bindings in the local file take precedence over
1146: those in the system-wide file.
1147: If the environment variable
1148: .Ev LESSKEY_SYSTEM
1149: is set,
1150: .Nm
1151: uses that as the name of the system-wide lesskey file.
1152: Otherwise,
1153: .Nm
1154: looks in a standard place for the system-wide lesskey file:
1155: On
1156: .Ox ,
1157: the system-wide lesskey file is
1158: .Pa /etc/sysless .
1159: .\" On Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
1160: .\" (However, if
1161: .\" .Nm less
1162: .\" was built with a different sysconf directory than /usr/local/etc,
1163: .\" that directory is where the sysless file is found.)
1164: .\" On MS-DOS and Windows systems, the system-wide lesskey file is c:\e_sysless.
1165: .\" On OS/2 systems, the system-wide lesskey file is c:\esysless.ini.
1166: .Sh INPUT PREPROCESSOR
1167: You may define an "input preprocessor" for
1168: .Nm less .
1169: Before
1170: .Nm less
1171: opens a file, it first gives your input preprocessor a chance to modify the
1172: way the contents of the file are displayed.
1173: An input preprocessor is simply an executable program (or shell script),
1174: which writes the contents of the file to a different file,
1175: called the replacement file.
1176: The contents of the replacement file are then displayed
1177: in place of the contents of the original file.
1178: However, it will appear to the user as if the original file is opened;
1179: that is,
1180: .Nm less
1181: will display the original filename as the name of the current file.
1182: .Pp
1183: An input preprocessor receives one command line argument, the original filename,
1184: as entered by the user.
1185: It should create the replacement file, and when finished
1186: print the name of the replacement file to its standard output.
1187: If the input preprocessor does not output a replacement filename,
1188: .Nm
1189: uses the original file, as normal.
1190: The input preprocessor is not called when viewing standard input.
1191: To set up an input preprocessor, set the
1192: .Ev LESSOPEN
1193: environment variable to a command line which will invoke your
1194: input preprocessor.
1195: This command line should include one occurrence of the string "%s",
1196: which will be replaced by the filename
1197: when the input preprocessor command is invoked.
1198: .Pp
1199: When
1200: .Nm
1201: closes a file opened in such a way, it will call another program,
1202: called the input postprocessor,
1203: which may perform any desired clean-up action (such as deleting the
1204: replacement file created by
1205: .Ev LESSOPEN ) .
1206: This program receives two command line arguments, the original filename
1207: as entered by the user, and the name of the replacement file.
1208: To set up an input postprocessor, set the
1209: .Ev LESSCLOSE
1210: environment variable to a command line which will invoke your
1211: input postprocessor.
1212: It may include two occurrences of the string "%s";
1213: the first is replaced with the original name of the file and the second
1214: with the name of the replacement file, which was output by
1215: .Ev LESSOPEN .
1216: .Pp
1217: For example, these two scripts will allow you
1218: to keep files in compressed format, but still let
1219: .Nm
1220: view them directly:
1221: .Pp
1222: lessopen.sh:
1223: .Bd -literal -offset indent
1224: #! /bin/sh
1225: case "$1" in
1226: *.Z) uncompress -c $1 >/tmp/less.$$ 2>/dev/null
1227: if [ -s /tmp/less.$$ ]; then
1228: echo /tmp/less.$$
1229: else
1230: rm -f /tmp/less.$$
1231: fi
1232: ;;
1233: esac
1234: .Ed
1235: .Pp
1236: lessclose.sh:
1237: .Bd -literal -offset indent
1238: #! /bin/sh
1239: rm $2
1240: .Ed
1241: .Pp
1242: To use these scripts, put them both where they can be executed and
1243: set LESSOPEN="lessopen.sh\ %s", and LESSCLOSE="lessclose.sh\ %s\ %s".
1244: More complex LESSOPEN and LESSCLOSE scripts may be written
1245: to accept other types of compressed files, and so on.
1246: .Pp
1247: It is also possible to set up an input preprocessor to
1248: pipe the file data directly to
1249: .Nm less ,
1250: rather than putting the data into a replacement file.
1251: This avoids the need to decompress the entire file before starting to view it.
1252: An input preprocessor that works this way is called an input pipe.
1253: An input pipe, instead of writing the name of a replacement file on
1254: its standard output,
1255: writes the entire contents of the replacement file on its standard output.
1256: If the input pipe does not write any characters on its standard output,
1257: then there is no replacement file and
1258: .Nm
1259: uses the original file, as normal.
1260: To use an input pipe, make the first character in the
1261: .Ev LESSOPEN
1262: environment variable a vertical bar (|) to signify that the
1263: input preprocessor is an input pipe.
1264: .Pp
1265: For example, this script will work like the previous example scripts:
1266: .Pp
1267: lesspipe.sh:
1268: .Bd -literal -offset indent
1269: #! /bin/sh
1270: case "$1" in
1271: *.Z) uncompress -c $1 2>/dev/null
1272: ;;
1273: esac
1274: .Ed
1275: .Pp
1276: To use this script, put it where it can be executed and set
1277: LESSOPEN="|lesspipe.sh %s".
1278: When an input pipe is used, a LESSCLOSE postprocessor can be used,
1279: but it is usually not necessary since there is no replacement file to clean up.
1280: In this case, the replacement file name passed to the LESSCLOSE
1281: postprocessor is "-".
1.23 shadchin 1282: .Pp
1283: For compatibility with previous versions of
1284: .Nm less ,
1285: the input preprocessor or pipe is not used if
1286: .Nm
1287: is viewing standard input.
1288: However, if the first character of LESSOPEN is a dash (-),
1289: the input preprocessor is used on standard input as well as other files.
1290: In this case, the dash is not considered to be part of
1291: the preprocessor command.
1292: If standard input is being viewed, the input preprocessor is passed
1293: a file name consisting of a single dash.
1294: Similarly, if the first two characters of LESSOPEN are vertical bar and dash
1295: (|-), the input pipe is used on standard input as well as other files.
1296: Again, in this case the dash is not considered to be part of
1297: the input pipe command.
1.1 millert 1298: .Sh NATIONAL CHARACTER SETS
1299: There are three types of characters in the input file:
1300: .Bl -tag -width "control characters"
1301: .It normal characters
1302: Can be displayed directly to the screen.
1303: .It control characters
1304: Should not be displayed directly, but are expected to be found
1305: in ordinary text files (such as backspace and tab).
1306: .It binary characters
1307: Should not be displayed directly and are not expected to be found
1308: in text files.
1309: .El
1310: .Pp
1311: A "character set" is simply a description of which characters are to
1312: be considered normal, control, and binary.
1313: The
1314: .Ev LESSCHARSET
1315: environment variable may be used to select a character set.
1316: Possible values for
1317: .Ev LESSCHARSET
1318: are:
1319: .Bl -tag -width "IBM-1047"
1320: .It ascii
1321: BS, TAB, NL, CR, and formfeed are control characters,
1322: all chars with values between 32 and 126 are normal,
1323: and all others are binary.
1324: .It iso8859
1325: Selects an ISO 8859 character set.
1326: This is the same as ASCII, except characters between 160 and 255 are
1327: treated as normal characters.
1328: .It latin1
1329: Same as iso8859.
1330: .It latin9
1331: Same as iso8859.
1332: .It dos
1333: Selects a character set appropriate for MS-DOS.
1334: .It ebcdic
1335: Selects an EBCDIC character set.
1336: .It IBM-1047
1.17 sobrado 1337: Selects an EBCDIC character set used by OS/390
1338: .Ux
1339: Services.
1.1 millert 1340: This is the EBCDIC analogue of latin1.
1341: You get similar results by setting either LESSCHARSET=IBM-1047 or
1342: LC_CTYPE=en_US in your environment.
1343: .It koi8-r
1344: Selects a Russian character set.
1345: .It next
1346: Selects a character set appropriate for NeXT computers.
1347: .It utf-8
1348: Selects the UTF-8 encoding of the ISO 10646 character set.
1.23 shadchin 1349: UTF-8 is special in that it supports multi-byte characters in the input file.
1350: It is the only character set that supports multi-byte characters.
1351: .It windows
1352: Selects a character set appropriate for Microsoft Windows (cp 1251).
1.1 millert 1353: .El
1354: .Pp
1.23 shadchin 1355: In rare cases, it may be desired to tailor
1.1 millert 1356: .Nm
1357: to use a character set other than the ones definable by LESSCHARSET.
1358: In this case, the environment variable
1359: .Ev LESSCHARDEF
1360: can be used to define a character set.
1361: It should be set to a string where each character in the string represents
1362: one character in the character set.
1363: The character "." is used for a normal character, "c" for control,
1364: and "b" for binary.
1365: A decimal number may be used for repetition.
1366: For example, "bccc4b." would mean character 0 is binary,
1367: 1, 2 and 3 are control, 4, 5, 6 and 7 are binary, and 8 is normal.
1368: All characters after the last are taken to be the same as the last,
1369: so characters 9 through 255 would be normal.
1370: (This is an example, and does not necessarily
1371: represent any real character set.)
1372: .Pp
1373: This table shows the value of LESSCHARDEF which is equivalent
1374: to each of the possible values for LESSCHARSET:
1375: .Bd -literal -offset indent
1376: ascii 8bcccbcc18b95.b
1377: dos 8bcccbcc12bc5b95.b.
1378: ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1379: 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1380: IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1381: 191.b
1382: iso8859 8bcccbcc18b95.33b.
1383: koi8-r 8bcccbcc18b95.b128.
1384: latin1 8bcccbcc18b95.33b.
1385: next 8bcccbcc18b95.bb125.bb
1386: .Ed
1387: .Pp
1388: If neither LESSCHARSET nor LESSCHARDEF is set,
1.23 shadchin 1389: but any of the strings "UTF-8", "UTF8", "utf-8" or "utf8" is found in the
1.21 jmc 1390: .Ev LC_ALL , LC_CTYPE
1.1 millert 1391: or
1392: .Ev LANG
1393: environment variables, then the default character set is utf-8.
1394: .Pp
1395: If that string is not found, but your system supports the
1396: setlocale interface,
1397: .Nm
1398: will use setlocale to determine the character set.
1399: setlocale is controlled by setting the
1400: .Ev LANG
1401: or
1402: .Ev LC_CTYPE
1403: environment variables.
1404: .Pp
1405: Finally, if the
1406: setlocale interface is also not available, the default character set is latin1.
1407: .Pp
1408: Control and binary characters are displayed in standout (reverse video).
1409: Each such character is displayed in caret notation if possible
1410: (e.g. ^A for control-A).
1411: Caret notation is used only if inverting the 0100 bit results in a
1412: normal printable character.
1413: Otherwise, the character is displayed as a hex number in angle brackets.
1414: This format can be changed by setting the
1415: .Ev LESSBINFMT
1416: environment variable.
1417: LESSBINFMT may begin with a "*" and one character to select
1418: the display attribute:
1419: "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1420: and "*n" is normal.
1421: If LESSBINFMT does not begin with a "*", normal attribute is assumed.
1422: The remainder of LESSBINFMT is a string which may include one
1423: printf-style escape sequence (a % followed by x, X, o, d, etc.).
1424: For example, if LESSBINFMT is "*u[%x]", binary characters
1425: are displayed in underlined hexadecimal surrounded by brackets.
1.23 shadchin 1426: The default if no LESSBINFMT is specified is "*s<%02X>".
1427: Warning: the result of expanding the character via LESSBINFMT must
1428: be less than 31 characters.
1429: .Pp
1430: When the character set is utf-8, the
1431: .Ev LESSUTFBINFMT
1432: environment variable
1433: acts similarly to LESSBINFMT but it applies to Unicode code points
1434: that were successfully decoded but are unsuitable for display (e.g.,
1435: unassigned code points).
1436: Its default value is "<U+%04lX>".
1437: Note that LESSUTFBINFMT and LESSBINFMT share their display attribute
1438: setting ("*x") so specifying one will affect both;
1439: LESSUTFBINFMT is read after LESSBINFMT so its setting, if any,
1440: will have priority.
1441: Problematic octets in a UTF-8 file (octets of a truncated sequence,
1442: octets of a complete but non-shortest form sequence, illegal octets,
1443: and stray trailing octets)
1444: are displayed individually using LESSBINFMT so as to facilitate diagnostic
1445: of how the UTF-8 file is ill-formed.
1.1 millert 1446: .Sh PROMPTS
1447: The -P option allows you to tailor the prompt to your preference.
1448: The string given to the -P option replaces the specified prompt string.
1449: Certain characters in the string are interpreted specially.
1450: The prompt mechanism is rather complicated to provide flexibility,
1451: but the ordinary user need not understand the details of constructing
1452: personalized prompt strings.
1453: .Pp
1454: A percent sign followed by a single character is expanded
1455: according to what the following character is:
1456: .Bl -tag -width Ds
1457: .It %b Ns Ar X
1458: Replaced by the byte offset into the current input file.
1459: The b is followed by a single character (shown as
1460: .Ar X
1461: above) which specifies the line whose byte offset is to be used.
1462: If the character is a "t", the byte offset of the top line in the
1463: display is used,
1464: an "m" means use the middle line,
1465: a "b" means use the bottom line,
1466: a "B" means use the line just after the bottom line,
1467: and a "j" means use the "target" line, as specified by the -j option.
1.4 jmc 1468: .It \&%B
1.1 millert 1469: Replaced by the size of the current input file.
1470: .It %c
1471: Replaced by the column number of the text appearing in the first
1472: column of the screen.
1473: .It %d Ns Ar X
1474: Replaced by the page number of a line in the input file.
1475: The line to be used is determined by the
1476: .Ar X ,
1477: as with the %b option.
1.4 jmc 1478: .It \&%D
1.1 millert 1479: Replaced by the number of pages in the input file,
1480: or equivalently, the page number of the last line in the input file.
1481: .It %E
1482: Replaced by the name of the editor (from the
1483: .Ev VISUAL
1484: environment variable, or the
1485: .Ev EDITOR
1486: environment variable if
1487: .Ev VISUAL
1488: is not defined).
1489: See the discussion of the LESSEDIT feature below.
1490: .It %f
1491: Replaced by the name of the current input file.
1.23 shadchin 1492: .It %F
1493: Replaced by the last component of the name of the current input file.
1.1 millert 1494: .It %i
1495: Replaced by the index of the current file in the list of
1496: input files.
1497: .It %l Ns Ar X
1498: Replaced by the line number of a line in the input file.
1499: The line to be used is determined by the
1500: .Ar X ,
1501: as with the %b option.
1502: .It %L
1503: Replaced by the line number of the last line in the input file.
1504: .It %m
1505: Replaced by the total number of input files.
1506: .It %p Ns Ar X
1507: Replaced by the percent into the current input file, based on byte offsets.
1508: The line used is determined by the
1509: .Ar X ,
1510: as with the %b option.
1.4 jmc 1511: .It \&%P Ns Ar X
1.1 millert 1512: Replaced by the percent into the current input file, based on line numbers.
1513: The line used is determined by the
1514: .Ar X ,
1515: as with the %b option.
1516: .It %s
1517: Same as %B.
1518: .It %t
1519: Causes any trailing spaces to be removed.
1520: Usually used at the end of the string, but may appear anywhere.
1521: .It %x
1522: Replaced by the name of the next input file in the list.
1523: .El
1524: .Pp
1525: If any item is unknown (for example, the file size if input is a pipe),
1526: a question mark is printed instead.
1527: .Pp
1528: The format of the prompt string can be changed depending on certain conditions.
1529: A question mark followed by a single character acts like an "IF":
1530: depending on the following character, a condition is evaluated.
1531: If the condition is true, any characters following the question mark
1532: and condition character, up to a period, are included in the prompt.
1533: If the condition is false, such characters are not included.
1534: A colon appearing between the question mark and the
1535: period can be used to establish an "ELSE": any characters between
1536: the colon and the period are included in the string, if and only if
1537: the IF condition is false.
1538: Condition characters (which follow a question mark) may be:
1539: .Bl -tag -width Ds
1540: .It ?a
1541: True if any characters have been included in the prompt so far.
1542: .It ?b Ns Ar X
1543: True if the byte offset of the specified line is known.
1544: .It ?B
1545: True if the size of the current input file is known.
1546: .It ?c
1547: True if the text is horizontally shifted (%c is not zero).
1548: .It ?d Ns Ar X
1549: True if the page number of the specified line is known.
1550: .It ?e
1551: True if at end-of-file.
1552: .It ?f
1553: True if there is an input filename
1554: (that is, if input is not a pipe).
1555: .It ?l Ns Ar X
1556: True if the line number of the specified line is known.
1557: .It ?L
1558: True if the line number of the last line in the file is known.
1559: .It ?m
1560: True if there is more than one input file.
1561: .It ?n
1562: True if this is the first prompt in a new input file.
1563: .It ?p Ns Ar X
1564: True if the percent into the current input file, based on byte offsets,
1565: of the specified line is known.
1566: .It ?P Ns Ar X
1567: True if the percent into the current input file, based on line numbers,
1568: of the specified line is known.
1569: .It ?s
1570: Same as "?B".
1571: .It ?x
1572: True if there is a next input file
1573: (that is, if the current input file is not the last one).
1574: .El
1575: .Pp
1576: Any characters other than the special ones
1577: (question mark, colon, period, percent, and backslash)
1578: become literally part of the prompt.
1579: Any of the special characters may be included in the prompt literally
1580: by preceding it with a backslash.
1581: .Pp
1582: Some examples:
1583: .Pp
1584: .Dl ?f%f:Standard input.
1585: .Pp
1586: This prompt prints the filename, if known;
1587: otherwise the string "Standard input".
1588: .Pp
1589: .Dl ?f%f .?ltLine %lt:?pt%pt\e%:?btByte %bt:-...
1590: .Pp
1591: This prompt would print the filename, if known.
1592: The filename is followed by the line number, if known,
1593: otherwise the percent if known, otherwise the byte offset if known.
1594: Otherwise, a dash is printed.
1595: Notice how each question mark has a matching period,
1596: and how the % after the %pt
1597: is included literally by escaping it with a backslash.
1598: .Pp
1599: .Dl ?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x..%t
1600: .Pp
1601: This prints the filename if this is the first prompt in a file,
1602: followed by the "file N of N" message if there is more
1603: than one input file.
1604: Then, if we are at end-of-file, the string "(END)" is printed
1605: followed by the name of the next file, if there is one.
1606: Finally, any trailing spaces are truncated.
1607: This is the default prompt.
1608: For reference, here are the defaults for
1609: the other two prompts (-m and -M respectively).
1610: Each is broken into two lines here for readability only.
1611: .Bd -literal -offset indent
1.19 ray 1612: ?f%f\ .?m(file\ %i\ of\ %m)\ .?e(END)\ ?x-\ Next\e:\ %x.:
1.1 millert 1613: ?pB%pB\e%:byte\ %bB?s/%s...%t
1614:
1615: ?f%f\ .?n?m(file\ %i\ of\ %m)\ ..?ltlines\ %lt-%lb?L/%L.\ :
1616: byte\ %bB?s/%s.\ .?e(END)\ ?x-\ Next\e:\ %x.:?pB%pB\e%..%t
1617: .Ed
1618: .Pp
1619: And here is the default message produced by the = command:
1620: .Bd -literal -offset indent
1621: ?f%f\ .?m(file\ %i\ of\ %m)\ .?ltlines\ %lt-%lb?L/%L.\ .
1622: byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\e%..%t
1623: .Ed
1624: .Pp
1625: The prompt expansion features are also used for another purpose:
1626: if an environment variable
1627: .Ev LESSEDIT
1628: is defined, it is used as the command to be executed when the v command
1629: is invoked.
1630: The LESSEDIT string is expanded in the same way as the prompt strings.
1631: The default value for LESSEDIT is:
1632: .Pp
1633: .Dl %E\ ?lm+%lm.\ %f
1634: .Pp
1635: Note that this expands to the editor name, followed by a + and the
1636: line number, followed by the file name.
1637: If your editor does not accept the "+linenumber" syntax, or has other
1638: differences in invocation syntax, the
1639: .Ev LESSEDIT
1640: variable can be changed to modify this default.
1641: .Sh SECURITY
1642: When the environment variable
1643: .Ev LESSSECURE
1644: is set to 1,
1645: .Nm
1646: runs in a "secure" mode.
1647: This means these features are disabled:
1648: .Bl -tag -width Ds
1.6 jmc 1649: .It \&!
1.1 millert 1650: The shell command.
1651: .It |
1652: The pipe command.
1653: .It :e
1654: The examine command.
1655: .It v
1656: The editing command.
1657: .It s -o
1658: Log files.
1659: .It -k
1660: Use of lesskey files.
1661: .It -t
1662: Use of tags files.
1663: .It " "
1664: Metacharacters in filenames, such as "*".
1665: .It " "
1666: Filename completion (TAB, ^L).
1667: .El
1668: .Pp
1669: Less can also be compiled to be permanently in "secure" mode.
1.23 shadchin 1670: .Sh COMPATIBILITY WITH MORE
1671: If the environment variable
1672: .Ev LESS_IS_MORE
1673: is set to 1,
1674: or if the program is invoked via a file link named "more",
1675: .Nm
1676: behaves (mostly) in conformance with the POSIX "more" command specification.
1677: In this mode, less behaves differently in these ways:
1678: .Pp
1679: The -e option works differently.
1680: If the -e option is not set,
1681: .Nm
1682: behaves as if the -E option were set.
1683: If the -e option is set,
1684: .Nm
1685: behaves as if the -e and -F options were set.
1686: .Pp
1687: The -m option works differently.
1688: If the -m option is not set, the medium prompt is used.
1689: If the -m option is set, the short prompt is used.
1690: .Pp
1691: The -n option acts like the -z option.
1692: The normal behavior of the -n option is unavailable in this mode.
1693: .Pp
1694: The parameter to the -p option is taken to be a
1695: .Nm
1696: command rather than a search pattern.
1697: .Pp
1698: The
1699: .Ev LESS
1700: environment variable is ignored, and the
1701: .Ev MORE
1702: environment variable is used in its place.
1.3 jmc 1703: .Sh ENVIRONMENT
1.1 millert 1704: Environment variables may be specified either in the system environment
1705: as usual, or in a
1706: .Xr lesskey 1
1707: file.
1708: If environment variables are defined in more than one place,
1709: variables defined in a local lesskey file take precedence over
1710: variables defined in the system environment, which take precedence
1711: over variables defined in the system-wide lesskey file.
1712: .Bl -tag -width Ds
1713: .It Ev COLUMNS
1714: Sets the number of columns on the screen.
1715: Takes precedence over the number of columns specified by the TERM variable.
1716: (But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1717: the window system's idea of the screen size takes precedence over the
1718: LINES and COLUMNS environment variables.)
1719: .It Ev EDITOR
1720: The name of the editor (used for the v command).
1721: .It Ev HOME
1722: Name of the user's home directory
1723: (used to find a lesskey file).
1724: .\" .It Ev "HOMEDRIVE, HOMEPATH"
1725: .\" Concatenation of the HOMEDRIVE and HOMEPATH environment variables is
1726: .\" the name of the user's home directory if the HOME variable is not set
1727: .\" (only in the Windows version).
1728: .\" .It Ev INIT
1729: .\" Name of the user's init directory
1730: .\" (used to find a lesskey file on OS/2 systems).
1731: .It Ev LANG
1732: Language for determining the character set.
1733: .It Ev LC_CTYPE
1734: Language for determining the character set.
1735: .It Ev LESS
1736: Options which are passed to
1737: .Nm
1738: automatically.
1739: .It Ev LESSANSIENDCHARS
1.23 shadchin 1740: Characters which may end an ANSI color escape sequence
1.1 millert 1741: (default "m").
1.23 shadchin 1742: .It Ev LESSANSIMIDCHARS
1743: Characters which may appear between the ESC character and the
1744: end character in an ANSI color escape sequence
1745: (default "0123456789;[?!"'#%()*+\ ").
1.1 millert 1746: .It Ev LESSBINFMT
1747: Format for displaying non-printable, non-control characters.
1748: .It Ev LESSCHARDEF
1749: Defines a character set.
1750: .It Ev LESSCHARSET
1751: Selects a predefined character set.
1752: .It Ev LESSCLOSE
1753: Command line to invoke the (optional) input-postprocessor.
1754: .\" .It Ev LESSECHO
1755: .\" Name of the lessecho program (default "lessecho").
1756: .\" The lessecho program is needed to expand metacharacters, such as * and ?,
1757: .\" in filenames on Unix systems.
1758: .It Ev LESSEDIT
1759: Editor prototype string (used for the v command).
1760: See discussion under
1761: .Sx PROMPTS .
1762: .It Ev LESSGLOBALTAGS
1763: Name of the command used by the -t option to find global tags.
1764: Normally should be set to "global" if your system has the global command.
1765: If not set, global tags are not used.
1.23 shadchin 1766: .It Ev LESSHISTFILE
1767: Name of the history file used to remember search commands and
1768: shell commands between invocations of
1769: .Nm less .
1770: If set to "-" or "/dev/null", a history file is not used.
1.25 ! nicm 1771: The default is "-".
1.23 shadchin 1772: .\" The default is "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on
1.24 jmc 1773: .\" DOS and Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
1.23 shadchin 1774: .\" on OS/2 systems.
1775: .It Ev LESSHISTSIZE
1776: The maximum number of commands to save in the history file.
1777: The default is 100.
1.1 millert 1778: .It Ev LESSKEY
1779: Name of the default lesskey(1) file.
1780: .It Ev LESSKEY_SYSTEM
1781: Name of the default system-wide lesskey(1) file.
1782: .It Ev LESSMETACHARS
1783: List of characters which are considered "metacharacters" by the shell.
1784: .It Ev LESSMETAESCAPE
1785: Prefix which
1786: .Nm
1787: will add before each metacharacter in a command sent to the shell.
1788: If LESSMETAESCAPE is an empty string, commands containing
1789: metacharacters will not be passed to the shell.
1790: .It Ev LESSOPEN
1791: Command line to invoke the (optional) input-preprocessor.
1792: .It Ev LESSSECURE
1793: Runs less in "secure" mode.
1794: See discussion under
1795: .Sx SECURITY .
1796: .It Ev LESSSEPARATOR
1797: String to be appended to a directory name in filename completion.
1.23 shadchin 1798: .It Ev LESSUTFBINFMT
1799: Format for displaying non-printable Unicode code points.
1800: .It Ev LESS_IS_MORE
1801: Emulate the
1802: .Xr more 1
1803: command.
1.1 millert 1804: .It Ev LINES
1805: Sets the number of lines on the screen.
1806: Takes precedence over the number of lines specified by the TERM variable.
1807: (But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1808: the window system's idea of the screen size takes precedence over the
1809: LINES and COLUMNS environment variables.)
1810: .\" .It Ev PATH
1811: .\" User's search path (used to find a lesskey file
1812: .\" on MS-DOS and OS/2 systems).
1813: .It Ev SHELL
1814: The shell used to execute the ! command, as well as to expand filenames.
1815: .It Ev TERM
1816: The type of terminal on which
1817: .Nm
1818: is being run.
1819: .It Ev VISUAL
1820: The name of the editor (used for the v command).
1821: .El
1822: .Sh SEE ALSO
1823: .Xr lesskey 1
1.13 jmc 1824: .Sh STANDARDS
1825: The
1826: .Nm more
1827: utility is compliant with the
1.15 jmc 1828: .St -p1003.1-2008
1.16 jmc 1829: specification,
1830: though its presence is optional.
1.13 jmc 1831: .Pp
1832: The flags
1833: .Op Fl aBbCdEFfGghIJjkLMmNOoPQqRrSTUVWwXxyz~#
1834: are extensions to that specification.
1.7 jmc 1835: .Sh AUTHORS
1836: .An Mark Nudelman Aq markn@greenwoodsoftware.com
1837: .Pp
1838: Send bug reports or comments to the above address or to
1839: .Aq bug\-less@gnu.org .
1840: .Pp
1841: For more information, see the less homepage at
1842: .Pa http://www.greenwoodsoftware.com/less .
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