Annotation of src/usr.bin/less/less.1, Revision 1.51
1.51 ! tb 1: .\" $OpenBSD: less.1,v 1.50 2015/11/15 21:05:56 nicm Exp $
1.1 millert 2: .\"
1.32 shadchin 3: .\" Copyright (C) 1984-2012 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
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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
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1.51 ! tb 26: .Dd $Mdocdate: November 15 2015 $
1.1 millert 27: .Dt LESS 1
28: .Os
29: .Sh NAME
1.34 jmc 30: .Nm less
1.11 jmc 31: .Nd view files
1.1 millert 32: .Sh SYNOPSIS
1.34 jmc 33: .Nm less
34: .Op Fl #?~AaBCcdEeFfGgIiJKLMmNnQqRrSsUuVWwX
35: .Op Fl b Ar n
36: .Op Fl h Ar n
37: .Op Fl j Ar n
1.1 millert 38: .Op Fl k Ar keyfile
1.12 jmc 39: .Op Fl O | o Ar logfile
40: .Op Fl P Ar prompt
1.1 millert 41: .Op Fl p Ar pattern
1.12 jmc 42: .Op Fl T Ar tagsfile
1.1 millert 43: .Op Fl t Ar tag
1.45 jmc 44: .Op Fl x Ar n , Ns Ar ...
1.34 jmc 45: .Op Fl y Ar n
1.44 bentley 46: .Op Fl z Ar n
1.34 jmc 47: .Op Ar
1.1 millert 48: .Sh DESCRIPTION
49: .Nm
50: is a program similar to the traditional
51: .Xr more 1 ,
1.37 jmc 52: but with many more features.
53: It displays text one screenful at a time.
54: After showing each screenful, it prompts the user for a command.
55: When showing the last line of a file,
56: .Nm
57: displays a prompt indicating end of file and the name of the next file
58: to examine, if any.
59: It then waits for input from the user.
1.1 millert 60: .Pp
1.38 jmc 61: Commands are based on both traditional
62: .Xr more 1
63: and
64: .Xr vi 1 .
65: Commands may be preceded by a decimal number,
1.44 bentley 66: called
67: .Ar N
68: in the descriptions below.
1.38 jmc 69: The number is used by some commands, as indicated.
70: .Pp
1.1 millert 71: This version of
72: .Nm
73: also acts as
74: .Xr more 1
75: if it is called as
1.37 jmc 76: .Nm more ,
77: or if the
78: .Ev LESS_IS_MORE
79: environment variable is set.
80: The main differences between the two are summarized in the
81: .Sx COMPATIBILITY WITH MORE
82: section, below.
83: .Pp
1.1 millert 84: A long option name may be abbreviated as long as the abbreviation is
85: unambiguous.
86: Such option names need only have their first letter capitalized;
87: the remainder of the name may be in either case.
1.44 bentley 88: For example,
89: .Fl -Quit-at-eof
90: is equivalent to
91: .Fl -QUIT-AT-EOF .
1.1 millert 92: .Pp
1.36 jmc 93: The options are as follows:
1.1 millert 94: .Bl -tag -width XXXX
1.6 jmc 95: .It Fl \&? | -help
1.1 millert 96: This option displays a summary of the commands accepted by
97: .Nm
1.44 bentley 98: (the same as the
99: .Ic h
100: command).
1.1 millert 101: (Depending on how your shell interprets the question mark,
1.44 bentley 102: it may be necessary to quote the question mark, thus:
103: .Ql Fl Ns \e? . )
1.23 shadchin 104: .It Fl A | -SEARCH-SKIP-SCREEN
105: Causes all forward searches (not just non-repeated searches)
106: to start just after the target line, and all backward searches
107: to start just before the target line.
108: Thus, forward searches will skip part of the displayed screen
109: (from the first line up to and including the target line).
110: Similarly backwards searches will skip the displayed screen
111: from the last line up to and including the target line.
1.44 bentley 112: This was the default behavior in
113: .Nm
114: versions prior to 441.
1.1 millert 115: .It Fl a | -search-skip-screen
1.23 shadchin 116: By default, forward searches start at the top of the displayed screen
117: and backwards searches start at the bottom of the displayed screen
1.44 bentley 118: (except for repeated searches invoked by the
119: .Ic n
120: or
121: .Ic N
122: commands,
123: which start after or before the
124: .Dq target
125: line respectively; see the
126: .Fl j
127: option for more about the target line).
128: The
129: .Fl a
130: option causes forward searches to instead start at the bottom of the screen
1.23 shadchin 131: and backward searches to start at the top of the screen,
1.1 millert 132: thus skipping all lines displayed on the screen.
1.12 jmc 133: .It Fl B | -auto-buffers
134: By default, when data is read from a pipe,
135: buffers are allocated automatically as needed.
136: If a large amount of data is read from the pipe, this can cause
137: a large amount of memory to be allocated.
1.44 bentley 138: The
139: .Fl B
140: option disables this automatic allocation of buffers for pipes,
141: so that only 64K (or the amount of space specified by the
142: .Fl b
143: option) is used for the pipe.
144: .Sy Warning :
145: use of
146: .Fl B
147: can result in erroneous display, since only the
1.23 shadchin 148: most recently viewed part of the piped data is kept in memory;
1.12 jmc 149: any earlier data is lost.
1.44 bentley 150: .It Fl b Ar n | Fl -buffers Ns = Ns Ar n
1.1 millert 151: Specifies the amount of buffer space
152: .Nm
153: will use for each file, in units of kilobytes (1024 bytes).
154: By default 64K of buffer space is used for each file
1.44 bentley 155: (unless the file is a pipe; see the
156: .Fl B
157: option).
158: The
159: .Fl b
160: option specifies instead that
161: .Ar n
162: kilobytes of buffer space should be used for each file.
163: If
164: .Ar n
165: is -1, buffer space is unlimited; that is,
1.23 shadchin 166: the entire file can be read into memory.
1.12 jmc 167: .It Fl C | -CLEAR-SCREEN
1.44 bentley 168: Same as
169: .Fl c ,
170: for compatibility with older versions of
171: .Nm .
1.1 millert 172: .It Fl c | -clear-screen
1.27 jmc 173: Causes full screen repaints to be painted from the bottom of the screen.
174: By default, full screen repaints are done from the top line down
175: to avoid the position of the display being moved
1.26 nicm 176: when using interactive commands.
1.33 millert 177: .It Fl d | -dumb
1.44 bentley 178: The
179: .Fl d
180: option suppresses the error message normally displayed if the terminal is dumb;
181: that is, if the terminal lacks some important capability,
1.1 millert 182: such as the ability to clear the screen or scroll backward.
1.44 bentley 183: The
184: .Fl d
185: option does not otherwise change the behavior of
1.1 millert 186: .Nm
187: on a dumb terminal.
1.12 jmc 188: .It Fl E | -QUIT-AT-EOF
189: Causes
190: .Nm
191: to automatically exit the first time it reaches end-of-file.
1.1 millert 192: .It Fl e | -quit-at-eof
193: Causes
194: .Nm
195: to automatically exit the second time it reaches end-of-file.
196: By default, the only way to exit
197: .Nm
1.44 bentley 198: is via the
199: .Ic q
200: command.
1.12 jmc 201: .It Fl F | -quit-if-one-screen
1.1 millert 202: Causes
203: .Nm
1.12 jmc 204: to automatically exit if the entire file can be displayed on the first screen.
1.1 millert 205: .It Fl f | -force
206: Forces non-regular files to be opened.
207: (A non-regular file is a directory or a device special file.)
208: Also suppresses the warning message when a binary file is opened.
209: By default,
210: .Nm
211: will refuse to open non-regular files.
1.12 jmc 212: .It Fl G | -HILITE-SEARCH
1.44 bentley 213: The
214: .Fl G
215: option suppresses all highlighting of strings found by search commands.
1.1 millert 216: .It Fl g | -hilite-search
217: Normally,
218: .Nm
1.44 bentley 219: will highlight all strings which match the last search command.
220: The
221: .Fl g
222: option changes this behavior to highlight only the particular string
1.1 millert 223: which was found by the last search command.
224: This can cause
225: .Nm
226: to run somewhat faster than the default.
1.44 bentley 227: .It Fl h Ar n | Fl -max-back-scroll Ns = Ns Ar n
1.1 millert 228: Specifies a maximum number of lines to scroll backward.
229: If it is necessary to scroll backward more than n lines,
230: the screen is repainted in a forward direction instead.
1.44 bentley 231: (If the terminal does not have the ability to scroll backward,
232: .Sq Fl h Ns 0
233: is implied.)
1.12 jmc 234: .It Fl I | -IGNORE-CASE
1.44 bentley 235: Like
236: .Fl i ,
237: but searches ignore case even if the pattern contains uppercase
1.12 jmc 238: letters.
1.1 millert 239: .It Fl i | -ignore-case
240: Causes searches to ignore case; that is,
241: uppercase and lowercase are considered identical.
242: This option is ignored if any uppercase letters appear in the search pattern;
243: in other words,
244: if a pattern contains uppercase letters, then that search does not ignore case.
1.12 jmc 245: .It Fl J | -status-column
246: Displays a status column at the left edge of the screen.
247: The status column shows the lines that matched the current search.
1.44 bentley 248: The status column is also used if the
249: .Fl w
250: or
251: .Fl W
252: option is in effect.
253: .It Fl j Ar n | Fl -jump-target Ns = Ns Ar n
254: Specifies a line on the screen where the
255: .Dq target
256: line is to be positioned.
1.23 shadchin 257: The target line is the line specified by any command to
258: search for a pattern, jump to a line number,
259: jump to a file percentage or jump to a tag.
260: The screen line may be specified by a number: the top line on the screen
1.1 millert 261: is 1, the next is 2, and so on.
262: The number may be negative to specify a line relative to the bottom
263: of the screen: the bottom line on the screen is -1, the second
264: to the bottom is -2, and so on.
1.23 shadchin 265: Alternately, the screen line may be specified as a fraction of the height
266: of the screen, starting with a decimal point: .5 is in the middle of the
267: screen, .3 is three tenths down from the first line, and so on.
268: If the line is specified as a fraction, the actual line number
269: is recalculated if the terminal window is resized, so that the
270: target line remains at the specified fraction of the screen height.
1.44 bentley 271: If any form of the
272: .Fl j
273: option is used,
1.23 shadchin 274: forward searches begin at the line immediately after the target line,
275: and backward searches begin at the target line,
1.44 bentley 276: unless changed by
277: .Fl a
278: or
279: .Fl A .
280: For example, if
281: .Sq Fl j Ns 4
282: is used, the target line is the fourth line on the screen,
283: so forward searches begin at the fifth line on the screen.
1.23 shadchin 284: .It Fl K | -quit-on-intr
285: Causes
286: .Nm
1.44 bentley 287: to exit immediately (with status 2) when an interrupt character (usually
288: .Ic ^C )
289: is typed.
1.23 shadchin 290: Normally, an interrupt character causes
291: .Nm
292: to stop whatever it is doing and return to its command prompt.
1.24 jmc 293: Note that use of this option makes it impossible to return to the
1.44 bentley 294: command prompt from the
295: .Ic F
296: command.
297: .It Fl k Ar keyfile | Fl -lesskey-file Ns = Ns Ar keyfile
1.1 millert 298: Causes
299: .Nm
300: to open and interpret the named file as a
301: .Xr lesskey 1
302: file.
1.44 bentley 303: Multiple
304: .Fl k
305: options may be specified.
1.36 jmc 306: If the
307: .Ev LESSKEY
308: or
309: .Ev LESSKEY_SYSTEM
310: environment variable is set, or if a lesskey file is found in a standard place
311: (see
312: .Sx KEY BINDINGS ) ,
313: it is also used as a lesskey file.
314: .It Fl L | -no-lessopen
315: Ignore the
316: .Ev LESSOPEN
317: environment variable (see the
318: .Sx INPUT PREPROCESSOR
319: section below).
320: This option can be set from within
321: .Nm less ,
322: but it will apply only to files opened subsequently, not to the
323: file which is currently open.
324: .It Fl M | -LONG-PROMPT
325: Causes
326: .Nm
327: to prompt even more verbosely than
1.39 jmc 328: .Xr more 1 .
1.36 jmc 329: .It Fl m | -long-prompt
330: Causes
331: .Nm
1.39 jmc 332: to prompt verbosely, like
333: .Xr more 1 ,
334: with the percent into the file.
1.36 jmc 335: By default,
336: .Nm
337: prompts with a colon.
338: .It Fl N | -LINE-NUMBERS
339: Causes a line number to be displayed at the beginning of each line in the
340: display.
341: .It Fl n | -line-numbers
342: Suppresses line numbers.
343: The default (to use line numbers) may cause
344: .Nm
345: to run more slowly in some cases, especially with a very large input file.
1.44 bentley 346: Suppressing line numbers with the
347: .Fl n
348: option will avoid this problem.
1.36 jmc 349: Using line numbers means: the line number will be displayed in the verbose
1.44 bentley 350: prompt and in the
351: .Ic =
352: command, and the
353: .Ic v
354: command will pass the current line
355: number to the editor (see also the discussion of
356: .Ev LESSEDIT
357: in
1.36 jmc 358: .Sx PROMPTS
359: below).
1.44 bentley 360: .It Fl O Ar logfile | Fl -LOG-FILE Ns = Ns Ar logfile
361: The
362: .Fl O
363: option is like
364: .Fl o ,
365: but it will overwrite an existing file without asking for confirmation.
1.36 jmc 366: .Pp
367: If no log file has been specified,
1.44 bentley 368: the
369: .Fl o
370: and
371: .Fl O
372: options can be used from within
1.36 jmc 373: .Nm
374: to specify a log file.
375: Without a file name, they will simply report the name of the log file.
1.44 bentley 376: The
377: .Ic s
378: command is equivalent to specifying
379: .Fl o
380: from within
381: .Nm .
382: .It Fl o Ar logfile | Fl -log-file Ns = Ns Ar logfile
1.36 jmc 383: Causes
384: .Nm
385: to copy its input to the named file as it is being viewed.
386: This applies only when the input file is a pipe, not an ordinary file.
387: If the file already exists,
388: .Nm
389: will ask for confirmation before overwriting it.
1.44 bentley 390: .It Fl P Ar prompt | Fl -prompt Ns = Ns Ar prompt
1.36 jmc 391: Provides a way to tailor the three prompt styles to your own preference.
392: This option would normally be put in the
393: .Ev LESS
394: environment variable, rather than being typed in with each
395: .Nm
396: command.
397: Such an option must either be the last option in the
398: .Ev LESS
399: variable, or be terminated by a dollar sign.
1.44 bentley 400: .Bl -item
401: .It
402: .Fl Ps Ar string
403: changes the default (short) prompt to
404: .Ar string .
405: .It
406: .Fl Pm
407: changes the medium
408: .Pq Fl m
409: prompt.
410: .It
411: .Fl PM
412: changes the long
413: .Pq Fl M
414: prompt.
415: .It
416: .Fl Ph
417: changes the prompt for the help screen.
418: .It
419: .Fl P=
420: changes the message printed by the
421: .Ic =
422: command.
423: .It
424: .Fl Pw
425: changes the message printed while waiting for data (in the
426: .Ic F
427: command).
428: .El
1.36 jmc 429: All prompt strings consist of a sequence of letters and special escape
430: sequences.
431: See the section on
432: .Sx PROMPTS
433: for more details.
1.44 bentley 434: .It Fl p Ar pattern | Fl -pattern Ns = Ns Ar pattern
435: The
436: .Fl p
437: option on the command line is equivalent to specifying
438: .Cm +/ Ns Ar pattern ;
1.36 jmc 439: that is, it tells
440: .Nm
441: to start at the first occurrence of pattern in the file.
442: .It Fl Q | -QUIET | -SILENT
1.44 bentley 443: Causes totally quiet operation: the terminal bell is never rung.
1.36 jmc 444: .It Fl q | -quiet | -silent
1.44 bentley 445: Causes moderately quiet operation:
1.36 jmc 446: the terminal bell is not rung if an attempt is made to scroll past the end
447: of the file or before the beginning of the file.
1.44 bentley 448: If the terminal has a visual bell, it is used instead.
1.36 jmc 449: The bell will be rung on certain other errors,
450: such as typing an invalid character.
451: The default is to ring the terminal bell in all such cases.
452: .It Fl R | -RAW-CONTROL-CHARS
1.44 bentley 453: Like
454: .Fl r ,
455: but only ANSI color escape sequences are output in raw form.
456: Unlike
457: .Fl r ,
458: the screen appearance is maintained correctly in most cases.
459: ANSI color escape sequences are sequences of the form:
1.36 jmc 460: .Pp
461: .Dl ESC \&[ ... m
462: .Pp
1.44 bentley 463: where the
464: .Dq ...
465: is zero or more color specification characters.
1.36 jmc 466: For the purpose of keeping track of screen appearance,
467: ANSI color escape sequences are assumed to not move the cursor.
468: You can make
469: .Nm
1.44 bentley 470: think that characters other than
471: .Sq m
472: can end ANSI color escape sequences by setting the environment variable
1.36 jmc 473: .Ev LESSANSIENDCHARS
474: to the list of characters which can end a color escape sequence.
475: And you can make
476: .Nm
477: think that characters other than the standard ones may appear between
1.44 bentley 478: the
479: .Cm ESC
480: and the
481: .Cm m
482: by setting the environment variable
1.36 jmc 483: .Ev LESSANSIMIDCHARS
484: to the list of characters which can appear.
485: .It Fl r | -raw-control-chars
1.44 bentley 486: Causes raw control characters to be displayed.
1.36 jmc 487: The default is to display control characters using the caret notation;
1.44 bentley 488: for example, a control-A (octal 001) is displayed as
489: .Sq ^A .
490: .Sy Warning :
491: when the
492: .Fl r
493: option is used,
1.36 jmc 494: .Nm
495: cannot keep track of the actual appearance of the screen
496: (since this depends on how the screen responds to
497: each type of control character).
498: Thus, various display problems may result,
499: such as long lines being split in the wrong place.
500: .It Fl S | -chop-long-lines
501: Causes lines longer than the screen width to be
502: chopped (truncated) rather than wrapped.
503: That is, the portion of a long line that does not fit in
504: the screen width is not shown.
505: The default is to wrap long lines; that is, display the remainder
506: on the next line.
507: .It Fl s | -squeeze-blank-lines
508: Causes consecutive blank lines to be squeezed into a single blank line.
1.44 bentley 509: .It Fl T Ar tagsfile | Fl -tag-file Ns = Ns Ar tagsfile
510: Specifies a tags file to be used instead of
511: .Pa tags .
1.36 jmc 512: .It Xo
513: .Fl t Ar tag |
514: .Fl -tag Ns = Ns Ar tag
515: .Xc
1.44 bentley 516: The
517: .Fl t
518: option, followed immediately by a
519: .Ar tag ,
1.36 jmc 520: will edit the file containing that tag.
521: For this to work, tag information must be available;
1.44 bentley 522: for example, there may be a file in the current directory called
523: .Pa tags ,
1.36 jmc 524: which was previously built by
525: .Xr ctags 1
526: or an equivalent command.
1.44 bentley 527: The
528: .Fl t
529: option may also be specified from within
1.36 jmc 530: .Nm
1.44 bentley 531: (using the
532: .Ic -
533: command) as a way of examining a new file.
534: The command
535: .Ic :t
536: is equivalent to specifying
537: .Fl t
538: from within
539: .Nm .
1.36 jmc 540: .It Fl U | -UNDERLINE-SPECIAL
541: Causes backspaces, tabs and carriage returns to be
542: treated as control characters;
1.44 bentley 543: that is, they are handled as specified by the
544: .Fl r
545: option.
1.36 jmc 546: .Pp
1.44 bentley 547: By default, if neither
548: .Fl u
549: nor
550: .Fl U
551: is given, backspaces which appear adjacent
1.36 jmc 552: to an underscore character are treated specially:
553: the underlined text is displayed
554: using the terminal's hardware underlining capability.
555: Also, backspaces which appear between two identical characters
556: are treated specially:
557: the overstruck text is printed
558: using the terminal's hardware boldface capability.
559: Other backspaces are deleted, along with the preceding character.
560: Carriage returns immediately followed by a newline are deleted.
1.44 bentley 561: Other carriage returns are handled as specified by the
562: .Fl r
563: option.
1.36 jmc 564: Text which is overstruck or underlined can be searched for
1.44 bentley 565: if neither
566: .Fl u
567: nor
568: .Fl U
569: is in effect.
1.36 jmc 570: .It Fl u | -underline-special
571: Causes backspaces and carriage returns to be treated as printable characters;
572: that is, they are sent to the terminal when they appear in the input.
573: .It Fl V | -version
574: Displays the version number of
1.44 bentley 575: .Nm .
1.36 jmc 576: .It Fl W | -HILITE-UNREAD
1.44 bentley 577: Like
578: .Fl w ,
579: but temporarily highlights the first new line after any
1.36 jmc 580: forward movement command larger than one line.
581: .It Fl w | -hilite-unread
1.44 bentley 582: Temporarily highlights the first new line after a forward movement
1.36 jmc 583: of a full page.
1.44 bentley 584: The first new line is the line immediately following the line previously
1.36 jmc 585: at the bottom of the screen.
1.44 bentley 586: Also highlights the target line after a
587: .Ic g
588: or
589: .Ic p
590: command.
1.36 jmc 591: The highlight is removed at the next command which causes movement.
1.44 bentley 592: The entire line is highlighted, unless the
593: .Fl J
594: option is in effect,
1.36 jmc 595: in which case only the status column is highlighted.
596: .It Fl X | -no-init
597: Disables sending the termcap initialization and deinitialization strings
598: to the terminal.
599: This is sometimes desirable if the deinitialization string does
600: something unnecessary, like clearing the screen.
601: .It Xo
1.44 bentley 602: .Fl x Ar n , Ns Ar ... |
603: .Fl -tabs Ns = Ns Ar n , Ns Ar ...
1.36 jmc 604: .Xc
605: Sets tab stops.
1.44 bentley 606: If only one
607: .Ar n
608: is specified, tab stops are set at multiples of
609: .Ar n .
1.36 jmc 610: If multiple values separated by commas are specified, tab stops are set at
611: those positions, and then continue with the same spacing as the last two.
1.44 bentley 612: For example,
613: .Sq Fl x Ns 9,17
614: will set tabs at positions 9, 17, 25, 33, etc.
615: The default for
616: .Ar n
617: is 8.
618: .It Fl y Ar n | Fl -max-forw-scroll Ns = Ns Ar n
1.36 jmc 619: Specifies a maximum number of lines to scroll forward.
620: If it is necessary to scroll forward more than n lines,
621: the screen is repainted instead.
1.44 bentley 622: The
623: .Fl c
624: or
625: .Fl C
626: option may be used to repaint from the top of the screen if desired.
1.36 jmc 627: By default, any forward movement causes scrolling.
1.44 bentley 628: .It Fl z Ar n | Fl -window Ns = Ns Ar n
629: Changes the default scrolling window size to
630: .Ar n
631: lines.
1.36 jmc 632: The default is one screenful.
1.44 bentley 633: The
634: .Ic z
635: and
636: .Ic w
637: commands can also be used to change the window size.
638: The
639: .Cm z
640: may be omitted for compatibility with some versions of
1.39 jmc 641: .Xr more 1 .
1.36 jmc 642: If the number
643: .Ar n
644: is negative, it indicates
645: .Ar n
646: lines less than the current screen size.
1.44 bentley 647: For example, if the screen is 24 lines,
648: .Fl z Ns -4
649: sets the scrolling window to 20 lines.
1.36 jmc 650: If the screen is resized to 40 lines,
651: the scrolling window automatically changes to 36 lines.
652: .It Fl -follow-name
1.44 bentley 653: Normally, if the input file is renamed while an
654: .Ic F
655: command is executing,
1.1 millert 656: .Nm
1.36 jmc 657: will continue to display the contents of the original file despite
658: its name change.
1.44 bentley 659: If
660: .Fl -follow-name
661: is specified, during an
662: .Ic F
663: command
1.1 millert 664: .Nm
1.36 jmc 665: will periodically attempt to reopen the file by name.
666: If the reopen succeeds and the file is a different file from the original
667: (which means that a new file has been created
668: with the same name as the original (now renamed) file),
1.1 millert 669: .Nm
1.36 jmc 670: will display the contents of that new file.
671: .It Fl -no-keypad
672: Disables sending the keypad initialization and deinitialization strings
673: to the terminal.
674: This is sometimes useful if the keypad strings make the numeric
675: keypad behave in an undesirable manner.
676: .It Fl -use-backslash
677: This option changes the interpretations of options which follow this one.
1.44 bentley 678: After the
679: .Fl -use-backslash
680: option, any backslash in an option string is
1.36 jmc 681: removed and the following character is taken literally.
682: This allows a dollar sign to be included in option strings.
1.44 bentley 683: .It Fl \&" Ar cc | Fl -quotes Ns = Ns Ar cc
1.36 jmc 684: Changes the filename quoting character.
685: This may be necessary if you are trying to name a file
686: which contains both spaces and quote characters.
1.44 bentley 687: If
688: .Ar cc
689: is a single character, this changes the quote character to that character.
1.36 jmc 690: Filenames containing a space should then be surrounded by that character
691: rather than by double quotes.
1.44 bentley 692: If
693: .Ar cc
694: consists of two characters, this changes the open quote to the first character,
1.36 jmc 695: and the close quote to the second character.
696: Filenames containing a space should then be preceded by the open quote
697: character and followed by the close quote character.
698: Note that even after the quote characters are changed, this option
1.44 bentley 699: remains
700: .Fl \&"
701: (a dash followed by a double quote).
1.36 jmc 702: .It Fl ~ | -tilde
703: Normally lines after end of file are displayed as a single tilde (~).
704: This option causes lines after end of file to be displayed as blank lines.
705: .It Fl # | -shift
706: Specifies the default number of positions to scroll horizontally
707: in the RIGHTARROW and LEFTARROW commands.
708: If the number specified is zero, it sets the default number of
709: positions to one half of the screen width.
710: Alternately, the number may be specified as a fraction of the width
711: of the screen, starting with a decimal point: .5 is half of the
712: screen width, .3 is three tenths of the screen width, and so on.
713: If the number is specified as a fraction, the actual number of
714: scroll positions is recalculated if the terminal window is resized,
715: so that the actual scroll remains at the specified fraction
716: of the screen width.
717: .It Fl -
1.44 bentley 718: A command line argument of
719: .Fl -
720: marks the end of option arguments.
1.36 jmc 721: Any arguments following this are interpreted as filenames.
1.44 bentley 722: This can be useful when viewing a file whose name begins with a
723: .Sq -
724: or
725: .Sq + .
1.36 jmc 726: .It Cm +
727: If a command line option begins with +,
728: the remainder of that option is taken to be an initial command to
1.44 bentley 729: .Nm .
730: For example,
731: .Cm +G
732: tells
1.36 jmc 733: .Nm
734: to start at the end of the file rather than the beginning,
1.44 bentley 735: and
736: .Cm +/xyz
737: tells it to start at the first occurrence of
738: .Dq xyz
739: in the file.
740: As a special case,
741: .Cm + Ns Ar number
742: acts like
743: .Cm + Ns Ar number Ns g ;
1.36 jmc 744: that is, it starts the display at the specified line number
1.44 bentley 745: (however, see the caveat under the
746: .Ic g
747: command below).
748: If the option starts with
749: .Cm ++ ,
750: the initial command applies to every file being viewed, not just the first one.
751: The
752: .Cm +
753: command described previously
1.36 jmc 754: may also be used to set (or change) an initial command for every file.
755: .El
756: .Sh COMMANDS
757: In the following descriptions, ^X means control-X.
758: ESC stands for the ESCAPE key; for example ESC-v means the
759: two character sequence "ESCAPE", then "v".
760: .Bl -tag -width XXXX
761: .It Ic h | H
762: Help: display a summary of these commands.
763: If you forget all the other commands, remember this one.
764: .It Ic SPACE | ^V | f | ^F
1.44 bentley 765: Scroll forward N lines, default one window (see option
766: .Fl z
767: above).
1.36 jmc 768: If N is more than the screen size, only the final screenful is displayed.
769: Warning: some systems use ^V as a special literalization character.
770: .It Ic z
771: Like SPACE, but if N is specified, it becomes the new window size.
772: .It Ic ESC-SPACE
773: Like SPACE, but scrolls a full screenful, even if it reaches
774: end-of-file in the process.
775: .It Ic ENTER | RETURN | ^N | e | ^E | j | ^J
776: Scroll forward N lines, default 1.
777: The entire N lines are displayed, even if N is more than the screen size.
778: .It Ic d | ^D
779: Scroll forward N lines, default one half of the screen size.
780: If N is specified, it becomes the new default for subsequent d and u commands.
781: .It Ic b | ^B | ESC-v
1.44 bentley 782: Scroll backward N lines, default one window (see option
783: .Fl z
784: above).
1.36 jmc 785: If N is more than the screen size, only the final screenful is displayed.
786: .It Ic w
787: Like ESC-v, but if N is specified, it becomes the new window size.
788: .It Ic y | ^Y | ^P | k | ^K
789: Scroll backward N lines, default 1.
790: The entire N lines are displayed, even if N is more than the screen size.
791: Warning: some systems use ^Y as a special job control character.
792: .It Ic u | ^U
793: Scroll backward N lines, default one half of the screen size.
794: If N is specified, it becomes the new default for subsequent d and u commands.
795: .It Ic ESC-) | RIGHTARROW
796: Scroll horizontally right N characters, default half the screen width
1.44 bentley 797: (see the
798: .Fl #
799: option).
1.36 jmc 800: If a number N is specified, it becomes the default for future
801: RIGHTARROW and LEFTARROW commands.
1.44 bentley 802: While the text is scrolled, it acts as though the
803: .Fl S
804: option (chop lines) were in effect.
1.36 jmc 805: .It Ic ESC-( | LEFTARROW
806: Scroll horizontally left N
1.44 bentley 807: characters, default half the screen width (see the
808: .Fl #
809: option).
1.36 jmc 810: If a number N is specified, it becomes the default for future
811: RIGHTARROW and LEFTARROW commands.
812: .It Ic r | ^R | ^L
813: Repaint the screen.
814: .It Ic R
815: Repaint the screen, discarding any buffered input.
816: Useful if the file is changing while it is being viewed.
817: .It Ic F
818: Scroll forward, and keep trying to read when the end of file is reached.
819: Normally this command would be used when already at the end of the file.
820: It is a way to monitor the tail of a file which is growing
821: while it is being viewed.
822: (The behavior is similar to the "tail -f" command.)
823: .It Ic ESC-F
824: Like F, but as soon as a line is found which matches
825: the last search pattern, the terminal bell is rung
826: and forward scrolling stops.
827: .It Ic g | < | ESC-<
828: Go to line N in the file, default 1 (beginning of file).
829: (Warning: this may be slow if N is large.)
830: .It Ic G | > | ESC->
831: Go to line N in the file, default the end of the file.
832: (Warning: this may be slow if N is large,
833: or if N is not specified and standard input, rather than a file,
834: is being read.)
835: .It Ic p | %
836: Go to a position N percent into the file.
837: N should be between 0 and 100, and may contain a decimal point.
838: .It Ic P
839: Go to the line containing byte offset N in the file.
840: .It Ic {
841: If a left curly bracket appears in the top line displayed
842: on the screen, the { command will go to the matching right curly bracket.
843: The matching right curly bracket is positioned on the bottom
844: line of the screen.
845: If there is more than one left curly bracket on the top line, a number N
846: may be used to specify the N-th bracket on the line.
847: .It Ic }
848: If a right curly bracket appears in the bottom line displayed on the screen,
849: the } command will go to the matching left curly bracket.
850: The matching left curly bracket is positioned on the top
851: line of the screen.
852: If there is more than one right curly bracket on the top line,
853: a number N may be used to specify the N-th bracket on the line.
854: .It Ic \&(
855: Like {, but applies to parentheses rather than curly brackets.
856: .It Ic \&)
857: Like }, but applies to parentheses rather than curly brackets.
858: .It Ic \&[
859: Like {, but applies to square brackets rather than curly brackets.
860: .It Ic \&]
861: Like }, but applies to square brackets rather than curly brackets.
862: .It Ic ESC-^F
863: Followed by two characters, acts like {,
864: but uses the two characters as open and close brackets, respectively.
865: For example, "ESC ^F < >" could be used to
866: go forward to the > which matches the < in the top displayed line.
867: .It Ic ESC-^B
868: Followed by two characters, acts like },
869: but uses the two characters as open and close brackets, respectively.
870: For example, "ESC ^B < >" could be used to
871: go backward to the < which matches the > in the bottom displayed line.
872: .It Ic m
873: Followed by any lowercase letter, marks the current position with that letter.
874: .It Ic '
875: (Single quote.)
876: Followed by any lowercase letter, returns to the position which
877: was previously marked with that letter.
878: Followed by another single quote, returns to the position at
879: which the last "large" movement command was executed.
880: Followed by a ^ or $, jumps to the beginning or end of the file respectively.
881: Marks are preserved when a new file is examined,
882: so the ' command can be used to switch between input files.
883: .It Ic ^X^X
884: Same as single quote.
885: .It Ic /pattern
886: Search forward in the file for the N-th line containing the pattern.
887: N defaults to 1.
888: The pattern is a regular expression, as recognized by
889: the regular expression library supplied by your system.
890: The search starts at the first line displayed
1.44 bentley 891: (but see the
892: .Fl a
893: and
894: .Fl j
895: options, which change this).
1.1 millert 896: .Pp
1.36 jmc 897: Certain characters are special if entered at the beginning of the pattern;
898: they modify the type of search rather than become part of the pattern:
899: .Bl -tag -width Ds
900: .It Ic ^N | \&!
901: Search for lines which do NOT match the pattern.
902: .It Ic ^E | *
903: Search multiple files.
904: That is, if the search reaches the END of the current file
905: without finding a match,
906: the search continues in the next file in the command line list.
907: .It Ic ^F | @
908: Begin the search at the first line of the FIRST file
909: in the command line list,
910: regardless of what is currently displayed on the screen
1.44 bentley 911: or the settings of the
912: .Fl a
913: or
914: .Fl j
915: options.
1.36 jmc 916: .It Ic ^K
917: Highlight any text which matches the pattern on the current screen,
918: but don't move to the first match (KEEP current position).
919: .It Ic ^R
920: Don't interpret regular expression metacharacters;
921: that is, do a simple textual comparison.
922: .El
923: .It Ic ?pattern
924: Search backward in the file for the N-th line containing the pattern.
925: The search starts at the line immediately before the top line displayed.
1.1 millert 926: .Pp
1.36 jmc 927: Certain characters are special, as in the / command:
928: .Bl -tag -width Ds
929: .It Ic ^N | \&!
930: Search for lines which do NOT match the pattern.
931: .It Ic ^E | *
932: Search multiple files.
933: That is, if the search reaches the beginning of the current file
934: without finding a match,
935: the search continues in the previous file in the command line list.
936: .It Ic ^F | @
937: Begin the search at the last line of the last file
938: in the command line list,
939: regardless of what is currently displayed on the screen
1.44 bentley 940: or the settings of the
941: .Fl a
942: or
943: .Fl j
944: options.
1.36 jmc 945: .It Ic ^K
946: As in forward searches.
947: .It Ic ^R
948: As in forward searches.
949: .El
950: .It Ic ESC-/pattern
951: Same as "/*".
952: .It Ic ESC-?pattern
953: Same as "?*".
954: .It Ic n
955: Repeat previous search, for N-th line containing the last pattern.
956: If the previous search was modified by ^N, the search is made for the
957: N-th line NOT containing the pattern.
958: If the previous search was modified by ^E, the search continues
959: in the next (or previous) file if not satisfied in the current file.
960: If the previous search was modified by ^R, the search is done
961: without using regular expressions.
962: There is no effect if the previous search was modified by ^F or ^K.
963: .It Ic N
964: Repeat previous search, but in the reverse direction.
965: .It Ic ESC-n
966: Repeat previous search, but crossing file boundaries.
967: The effect is as if the previous search were modified by *.
968: .It Ic ESC-N
969: Repeat previous search, but in the reverse direction
970: and crossing file boundaries.
971: .It Ic ESC-u
972: Undo search highlighting.
973: Turn off highlighting of strings matching the current search pattern.
974: If highlighting is already off because of a previous ESC-u command,
975: turn highlighting back on.
976: Any search command will also turn highlighting back on.
1.44 bentley 977: (Highlighting can also be disabled by toggling the
978: .Fl G
979: option;
1.36 jmc 980: in that case search commands do not turn highlighting back on.)
981: .It Ic &pattern
982: Display only lines which match the pattern;
983: lines which do not match the pattern are not displayed.
984: If pattern is empty (if you type & immediately followed by ENTER),
985: any filtering is turned off, and all lines are displayed.
986: While filtering is in effect, an ampersand is displayed at the
987: beginning of the prompt,
988: as a reminder that some lines in the file may be hidden.
1.1 millert 989: .Pp
1.36 jmc 990: Certain characters are special as in the / command:
991: .Bl -tag -width Ds
992: .It Ic ^N | !
993: Display only lines which do NOT match the pattern.
994: .It Ic ^R
995: Don't interpret regular expression metacharacters;
996: that is, do a simple textual comparison.
997: .El
998: .It Ic :e Op Ar filename
999: Examine a new file.
1000: If the filename is missing, the "current" file (see the :n and :p commands
1001: below) from the list of files in the command line is re-examined.
1002: A percent sign (%) in the filename is replaced by the name of the
1003: current file.
1004: A pound sign (#) is replaced by the name of the previously examined file.
1005: However, two consecutive percent signs are simply
1006: replaced with a single percent sign.
1007: This allows you to enter a filename that contains a percent sign
1008: in the name.
1009: Similarly, two consecutive pound signs are replaced with a single pound sign.
1010: The filename is inserted into the command line list of files
1011: so that it can be seen by subsequent :n and :p commands.
1012: If the filename consists of several files, they are all inserted into
1013: the list of files and the first one is examined.
1014: If the filename contains one or more spaces,
1015: the entire filename should be enclosed in double quotes
1.44 bentley 1016: (also see the
1017: .Fl \&"
1018: option).
1.36 jmc 1019: .It Ic ^X^V | E
1020: Same as :e.
1021: Warning: some systems use ^V as a special literalization character.
1022: On such systems, you may not be able to use ^V.
1023: .It Ic :n
1024: Examine the next file (from the list of files given in the command line).
1025: If a number N is specified, the N-th next file is examined.
1026: .It Ic :p
1027: Examine the previous file in the command line list.
1028: If a number N is specified, the N-th previous file is examined.
1029: .It Ic :t
1030: Go to the specified tag.
1031: .It Ic :x
1032: Examine the first file in the command line list.
1033: If a number N is specified, the N-th file in the list is examined.
1034: .It Ic :d
1035: Remove the current file from the list of files.
1036: .It Ic t
1037: Go to the next tag, if there were more than one matches for the current tag.
1.44 bentley 1038: See the
1039: .Fl t
1040: option for more details about tags.
1.36 jmc 1041: .It Ic T
1042: Go to the previous tag, if there were more than one matches for the current tag.
1043: .It Ic = | ^G | :f
1044: Prints some information about the file being viewed, including its name
1045: and the line number and byte offset of the bottom line being displayed.
1046: If possible, it also prints the length of the file,
1047: the number of lines in the file
1048: and the percent of the file above the last displayed line.
1049: .It Ic \-
1050: Followed by one of the command line option letters (see
1.44 bentley 1051: .Sx DESCRIPTION
1052: above),
1.36 jmc 1053: this will change the setting of that option
1054: and print a message describing the new setting.
1055: If a ^P (CONTROL-P) is entered immediately after the dash,
1056: the setting of the option is changed but no message is printed.
1.44 bentley 1057: If the option letter has a numeric value (such as
1058: .Fl b
1059: or
1060: .Fl h ) ,
1061: or a string value (such as
1062: .Fl P
1063: or
1064: .Fl t ) ,
1.36 jmc 1065: a new value may be entered after the option letter.
1066: If no new value is entered, a message describing
1067: the current setting is printed and nothing is changed.
1068: .It Ic \-\-
1069: Like the \- command, but takes a long option name (see
1.44 bentley 1070: .Sx DESCRIPTION
1071: above)
1.36 jmc 1072: rather than a single option letter.
1073: You must press ENTER or RETURN after typing the option name.
1074: A ^P immediately after the second dash suppresses printing of a
1075: message describing the new setting, as in the \- command.
1076: .It Ic \-+
1077: Followed by one of the command line option letters this will reset the
1078: option to its default setting and print a message describing the new setting.
1.44 bentley 1079: (The "\-+X" command does the same thing as
1080: .Sq Fl + Ns X
1081: on the command line.)
1.36 jmc 1082: This does not work for string-valued options.
1083: .It Ic \-\-+
1084: Like the \-+ command, but takes a long option name
1085: rather than a single option letter.
1086: .It Ic \-!
1087: Followed by one of the command line option letters, this will reset the
1088: option to the "opposite" of its default setting and print a message
1089: describing the new setting.
1090: This does not work for numeric or string-valued options.
1091: .It Ic \-\-!
1092: Like the \-! command, but takes a long option name
1093: rather than a single option letter.
1094: .It Ic _
1095: (Underscore.)
1096: Followed by one of the command line option letters,
1097: this will print a message describing the current setting of that option.
1098: The setting of the option is not changed.
1099: .It Ic __
1100: (Double underscore.)
1101: Like the _ (underscore) command, but takes a long option name
1102: rather than a single option letter.
1103: You must press ENTER or RETURN after typing the option name.
1104: .It Ic +cmd
1105: Causes the specified cmd to be executed each time a new file is examined.
1106: For example, +G causes
1.23 shadchin 1107: .Nm
1.36 jmc 1108: to initially display each file starting at the end rather than the beginning.
1109: .It Ic V
1110: Prints the version number of
1.12 jmc 1111: .Nm
1.36 jmc 1112: being run.
1113: .It Ic q | Q | :q | :Q | ZZ
1114: Exits
1.1 millert 1115: .Nm less .
1.36 jmc 1116: .El
1.1 millert 1117: .Pp
1.36 jmc 1118: The following
1119: four
1120: commands may or may not be valid, depending on your particular installation.
1121: .Bl -tag -width XXXX
1122: .It Ic v
1123: Invokes an editor to edit the current file being viewed.
1124: The editor is taken from the environment variable
1125: .Ev VISUAL ,
1126: if defined,
1127: or
1128: .Ev EDITOR
1129: if
1130: .Ev VISUAL
1131: is not defined,
1132: or defaults to "vi" if neither
1133: .Ev VISUAL
1134: nor
1135: .Ev EDITOR
1136: is defined.
1137: See also the discussion of LESSEDIT under the section on
1138: .Sx PROMPTS
1139: below.
1140: .It Ic | <m> Ar shell-command
1141: <m> represents any mark letter.
1142: Pipes a section of the input file to the given shell command.
1143: The section of the file to be piped is between the first line on
1144: the current screen and the position marked by the letter.
1145: <m> may also be ^ or $ to indicate beginning or end of file respectively.
1146: If <m> is . or newline, the current screen is piped.
1147: .It Ic s Ar filename
1148: Save the input to a file.
1149: This only works if the input is a pipe, not an ordinary file.
1.1 millert 1150: .El
1151: .Sh LINE EDITING
1152: When entering command line at the bottom of the screen
1153: (for example, a filename for the :e command,
1154: or the pattern for a search command),
1155: certain keys can be used to manipulate the command line.
1156: Most commands have an alternate form in [ brackets ] which can be used if
1157: a key does not exist on a particular keyboard.
1158: Any of these special keys may be entered literally by preceding
1159: it with the "literal" character, either ^V or ^A.
1160: A backslash itself may also be entered literally by entering two backslashes.
1161: .Bl -tag -width Ds
1162: .It LEFTARROW [ ESC-h ]
1163: Move the cursor one space to the left.
1164: .It RIGHTARROW [ ESC-l ]
1165: Move the cursor one space to the right.
1166: .It ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
1167: (That is, CONTROL and LEFTARROW simultaneously.)
1168: Move the cursor one word to the left.
1169: .It ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
1170: (That is, CONTROL and RIGHTARROW simultaneously.)
1171: Move the cursor one word to the right.
1172: .It HOME [ ESC-0 ]
1173: Move the cursor to the beginning of the line.
1174: .It END [ ESC-$ ]
1175: Move the cursor to the end of the line.
1176: .It BACKSPACE
1177: Delete the character to the left of the cursor,
1178: or cancel the command if the command line is empty.
1179: .It DELETE or [ ESC-x ]
1180: Delete the character under the cursor.
1181: .It ^BACKSPACE [ ESC-BACKSPACE ]
1182: (That is, CONTROL and BACKSPACE simultaneously.)
1183: Delete the word to the left of the cursor.
1184: .It ^DELETE [ ESC-X or ESC-DELETE ]
1185: (That is, CONTROL and DELETE simultaneously.)
1186: Delete the word under the cursor.
1187: .It UPARROW [ ESC-k ]
1188: Retrieve the previous command line.
1.32 shadchin 1189: If you first enter some text and then press UPARROW,
1190: it will retrieve the previous command which begins with that text.
1.1 millert 1191: .It DOWNARROW [ ESC-j ]
1192: Retrieve the next command line.
1.32 shadchin 1193: If you first enter some text and then press DOWNARROW,
1194: it will retrieve the next command which begins with that text.
1.1 millert 1195: .It TAB
1196: Complete the partial filename to the left of the cursor.
1197: If it matches more than one filename, the first match
1198: is entered into the command line.
1199: Repeated TABs will cycle through the other matching filenames.
1200: If the completed filename is a directory, a "/" is appended to the filename.
1201: The environment variable
1202: .Ev LESSSEPARATOR
1203: can be used to specify a different character to append to a directory name.
1204: .It BACKTAB [ ESC-TAB ]
1205: Like TAB, but cycles in the reverse direction through the matching filenames.
1206: .It ^L
1207: Complete the partial filename to the left of the cursor.
1208: If it matches more than one filename, all matches are entered into
1209: the command line (if they fit).
1210: .It ^U
1211: Delete the entire command line,
1212: or cancel the command if the command line is empty.
1213: If you have changed your line-kill character to something
1214: other than ^U, that character is used instead of ^U.
1.23 shadchin 1215: .It "^G"
1216: Delete the entire command line and return to the main prompt.
1.1 millert 1217: .El
1218: .Sh KEY BINDINGS
1219: You may define your own
1220: .Nm
1221: commands by using the program
1222: .Xr lesskey 1
1223: to create a lesskey file.
1224: This file specifies a set of command keys and an action
1225: associated with each key.
1226: You may also use lesskey
1227: to change the line-editing keys (see
1228: .Sx LINE EDITING ) ,
1229: and to set environment variables.
1230: If the environment variable
1231: .Ev LESSKEY
1232: is set,
1233: .Nm
1234: uses that as the name of the lesskey file.
1235: Otherwise,
1236: .Nm
1237: looks for a lesskey file called "$HOME/.less".
1238: See the
1239: .Xr lesskey 1
1240: manual page for more details.
1241: .Pp
1242: A system-wide lesskey file may also be set up to provide key bindings.
1243: If a key is defined in both a local lesskey file and in the
1244: system-wide file, key bindings in the local file take precedence over
1245: those in the system-wide file.
1246: If the environment variable
1247: .Ev LESSKEY_SYSTEM
1248: is set,
1249: .Nm
1250: uses that as the name of the system-wide lesskey file.
1251: Otherwise,
1252: .Nm
1253: looks in a standard place for the system-wide lesskey file:
1254: On
1255: .Ox ,
1256: the system-wide lesskey file is
1257: .Pa /etc/sysless .
1258: .Sh INPUT PREPROCESSOR
1259: You may define an "input preprocessor" for
1260: .Nm less .
1261: Before
1262: .Nm less
1263: opens a file, it first gives your input preprocessor a chance to modify the
1264: way the contents of the file are displayed.
1265: An input preprocessor is simply an executable program (or shell script),
1266: which writes the contents of the file to a different file,
1267: called the replacement file.
1268: The contents of the replacement file are then displayed
1269: in place of the contents of the original file.
1270: However, it will appear to the user as if the original file is opened;
1271: that is,
1272: .Nm less
1273: will display the original filename as the name of the current file.
1274: .Pp
1275: An input preprocessor receives one command line argument, the original filename,
1276: as entered by the user.
1277: It should create the replacement file, and when finished
1278: print the name of the replacement file to its standard output.
1279: If the input preprocessor does not output a replacement filename,
1280: .Nm
1281: uses the original file, as normal.
1282: The input preprocessor is not called when viewing standard input.
1283: To set up an input preprocessor, set the
1284: .Ev LESSOPEN
1285: environment variable to a command line which will invoke your
1286: input preprocessor.
1287: This command line should include one occurrence of the string "%s",
1288: which will be replaced by the filename
1289: when the input preprocessor command is invoked.
1290: .Pp
1291: When
1292: .Nm
1293: closes a file opened in such a way, it will call another program,
1294: called the input postprocessor,
1295: which may perform any desired clean-up action (such as deleting the
1296: replacement file created by
1297: .Ev LESSOPEN ) .
1298: This program receives two command line arguments, the original filename
1299: as entered by the user, and the name of the replacement file.
1300: To set up an input postprocessor, set the
1301: .Ev LESSCLOSE
1302: environment variable to a command line which will invoke your
1303: input postprocessor.
1304: It may include two occurrences of the string "%s";
1305: the first is replaced with the original name of the file and the second
1306: with the name of the replacement file, which was output by
1307: .Ev LESSOPEN .
1308: .Pp
1309: For example, these two scripts will allow you
1310: to keep files in compressed format, but still let
1311: .Nm
1312: view them directly:
1313: .Pp
1314: lessopen.sh:
1315: .Bd -literal -offset indent
1316: #! /bin/sh
1317: case "$1" in
1318: *.Z) uncompress -c $1 >/tmp/less.$$ 2>/dev/null
1319: if [ -s /tmp/less.$$ ]; then
1320: echo /tmp/less.$$
1321: else
1322: rm -f /tmp/less.$$
1323: fi
1324: ;;
1325: esac
1326: .Ed
1327: .Pp
1328: lessclose.sh:
1329: .Bd -literal -offset indent
1330: #! /bin/sh
1331: rm $2
1332: .Ed
1333: .Pp
1334: To use these scripts, put them both where they can be executed and
1335: set LESSOPEN="lessopen.sh\ %s", and LESSCLOSE="lessclose.sh\ %s\ %s".
1336: More complex LESSOPEN and LESSCLOSE scripts may be written
1337: to accept other types of compressed files, and so on.
1338: .Pp
1339: It is also possible to set up an input preprocessor to
1340: pipe the file data directly to
1341: .Nm less ,
1342: rather than putting the data into a replacement file.
1343: This avoids the need to decompress the entire file before starting to view it.
1344: An input preprocessor that works this way is called an input pipe.
1345: An input pipe, instead of writing the name of a replacement file on
1346: its standard output,
1347: writes the entire contents of the replacement file on its standard output.
1348: If the input pipe does not write any characters on its standard output,
1349: then there is no replacement file and
1350: .Nm
1351: uses the original file, as normal.
1352: To use an input pipe, make the first character in the
1353: .Ev LESSOPEN
1354: environment variable a vertical bar (|) to signify that the
1355: input preprocessor is an input pipe.
1356: .Pp
1357: For example, this script will work like the previous example scripts:
1358: .Pp
1359: lesspipe.sh:
1360: .Bd -literal -offset indent
1361: #! /bin/sh
1362: case "$1" in
1363: *.Z) uncompress -c $1 2>/dev/null
1.32 shadchin 1364: *) exit 1
1.1 millert 1365: ;;
1366: esac
1.32 shadchin 1367: exit $?
1.1 millert 1368: .Ed
1369: .Pp
1370: To use this script, put it where it can be executed and set
1371: LESSOPEN="|lesspipe.sh %s".
1.32 shadchin 1372: .Pp
1373: Note that a preprocessor cannot output an empty file, since that
1374: is interpreted as meaning there is no replacement, and
1375: the original file is used.
1376: To avoid this, if
1377: .Ev LESSOPEN
1378: starts with two vertical bars,
1379: the exit status of the script becomes meaningful.
1380: If the exit status is zero, the output is considered to be
1381: replacement text, even if it empty.
1382: If the exit status is nonzero, any output is ignored and the
1383: original file is used.
1384: For compatibility with previous versions of
1385: .Nm less ,
1386: if
1387: .Ev LESSOPEN
1388: starts with only one vertical bar, the exit status
1389: of the preprocessor is ignored.
1390: .Pp
1.1 millert 1391: When an input pipe is used, a LESSCLOSE postprocessor can be used,
1392: but it is usually not necessary since there is no replacement file to clean up.
1393: In this case, the replacement file name passed to the LESSCLOSE
1394: postprocessor is "-".
1.23 shadchin 1395: .Pp
1396: For compatibility with previous versions of
1397: .Nm less ,
1398: the input preprocessor or pipe is not used if
1399: .Nm
1400: is viewing standard input.
1401: However, if the first character of LESSOPEN is a dash (-),
1402: the input preprocessor is used on standard input as well as other files.
1403: In this case, the dash is not considered to be part of
1404: the preprocessor command.
1405: If standard input is being viewed, the input preprocessor is passed
1406: a file name consisting of a single dash.
1407: Similarly, if the first two characters of LESSOPEN are vertical bar and dash
1.32 shadchin 1408: (|-) or two vertical bars and a dash (||-),
1409: the input pipe is used on standard input as well as other files.
1.23 shadchin 1410: Again, in this case the dash is not considered to be part of
1411: the input pipe command.
1.1 millert 1412: .Sh NATIONAL CHARACTER SETS
1413: There are three types of characters in the input file:
1414: .Bl -tag -width "control characters"
1415: .It normal characters
1416: Can be displayed directly to the screen.
1417: .It control characters
1418: Should not be displayed directly, but are expected to be found
1419: in ordinary text files (such as backspace and tab).
1420: .It binary characters
1421: Should not be displayed directly and are not expected to be found
1422: in text files.
1423: .El
1424: .Pp
1425: A "character set" is simply a description of which characters are to
1426: be considered normal, control, and binary.
1427: .Nm
1.51 ! tb 1428: will determine the character set to use from the environment (see
! 1429: .Xr locale 1 ) .
1.1 millert 1430: .Pp
1431: Control and binary characters are displayed in standout (reverse video).
1432: Each such character is displayed in caret notation if possible
1433: (e.g. ^A for control-A).
1434: Caret notation is used only if inverting the 0100 bit results in a
1435: normal printable character.
1436: Otherwise, the character is displayed as a hex number in angle brackets.
1437: This format can be changed by setting the
1438: .Ev LESSBINFMT
1439: environment variable.
1440: LESSBINFMT may begin with a "*" and one character to select
1441: the display attribute:
1442: "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1443: and "*n" is normal.
1444: If LESSBINFMT does not begin with a "*", normal attribute is assumed.
1445: The remainder of LESSBINFMT is a string which may include one
1446: printf-style escape sequence (a % followed by x, X, o, d, etc.).
1447: For example, if LESSBINFMT is "*u[%x]", binary characters
1448: are displayed in underlined hexadecimal surrounded by brackets.
1.23 shadchin 1449: The default if no LESSBINFMT is specified is "*s<%02X>".
1450: Warning: the result of expanding the character via LESSBINFMT must
1451: be less than 31 characters.
1452: .Pp
1453: When the character set is utf-8, the
1454: .Ev LESSUTFBINFMT
1455: environment variable
1456: acts similarly to LESSBINFMT but it applies to Unicode code points
1457: that were successfully decoded but are unsuitable for display (e.g.,
1458: unassigned code points).
1459: Its default value is "<U+%04lX>".
1460: Note that LESSUTFBINFMT and LESSBINFMT share their display attribute
1461: setting ("*x") so specifying one will affect both;
1462: LESSUTFBINFMT is read after LESSBINFMT so its setting, if any,
1463: will have priority.
1464: Problematic octets in a UTF-8 file (octets of a truncated sequence,
1465: octets of a complete but non-shortest form sequence, illegal octets,
1466: and stray trailing octets)
1467: are displayed individually using LESSBINFMT so as to facilitate diagnostic
1468: of how the UTF-8 file is ill-formed.
1.1 millert 1469: .Sh PROMPTS
1.44 bentley 1470: The
1471: .Fl P
1472: option allows you to tailor the prompt to your preference.
1473: The string given to the
1474: .Fl P
1475: option replaces the specified prompt string.
1.1 millert 1476: Certain characters in the string are interpreted specially.
1477: The prompt mechanism is rather complicated to provide flexibility,
1478: but the ordinary user need not understand the details of constructing
1479: personalized prompt strings.
1480: .Pp
1481: A percent sign followed by a single character is expanded
1482: according to what the following character is:
1483: .Bl -tag -width Ds
1484: .It %b Ns Ar X
1485: Replaced by the byte offset into the current input file.
1486: The b is followed by a single character (shown as
1487: .Ar X
1488: above) which specifies the line whose byte offset is to be used.
1489: If the character is a "t", the byte offset of the top line in the
1490: display is used,
1491: an "m" means use the middle line,
1492: a "b" means use the bottom line,
1493: a "B" means use the line just after the bottom line,
1.44 bentley 1494: and a "j" means use the "target" line, as specified by the
1495: .Fl j
1496: option.
1.4 jmc 1497: .It \&%B
1.1 millert 1498: Replaced by the size of the current input file.
1499: .It %c
1500: Replaced by the column number of the text appearing in the first
1501: column of the screen.
1502: .It %d Ns Ar X
1503: Replaced by the page number of a line in the input file.
1504: The line to be used is determined by the
1505: .Ar X ,
1506: as with the %b option.
1.4 jmc 1507: .It \&%D
1.1 millert 1508: Replaced by the number of pages in the input file,
1509: or equivalently, the page number of the last line in the input file.
1510: .It %E
1511: Replaced by the name of the editor (from the
1512: .Ev VISUAL
1513: environment variable, or the
1514: .Ev EDITOR
1515: environment variable if
1516: .Ev VISUAL
1517: is not defined).
1518: See the discussion of the LESSEDIT feature below.
1519: .It %f
1520: Replaced by the name of the current input file.
1.23 shadchin 1521: .It %F
1522: Replaced by the last component of the name of the current input file.
1.1 millert 1523: .It %i
1524: Replaced by the index of the current file in the list of
1525: input files.
1526: .It %l Ns Ar X
1527: Replaced by the line number of a line in the input file.
1528: The line to be used is determined by the
1529: .Ar X ,
1530: as with the %b option.
1531: .It %L
1532: Replaced by the line number of the last line in the input file.
1533: .It %m
1534: Replaced by the total number of input files.
1535: .It %p Ns Ar X
1536: Replaced by the percent into the current input file, based on byte offsets.
1537: The line used is determined by the
1538: .Ar X ,
1539: as with the %b option.
1.4 jmc 1540: .It \&%P Ns Ar X
1.1 millert 1541: Replaced by the percent into the current input file, based on line numbers.
1542: The line used is determined by the
1543: .Ar X ,
1544: as with the %b option.
1545: .It %s
1546: Same as %B.
1547: .It %t
1548: Causes any trailing spaces to be removed.
1549: Usually used at the end of the string, but may appear anywhere.
1550: .It %x
1551: Replaced by the name of the next input file in the list.
1552: .El
1553: .Pp
1554: If any item is unknown (for example, the file size if input is a pipe),
1555: a question mark is printed instead.
1556: .Pp
1557: The format of the prompt string can be changed depending on certain conditions.
1558: A question mark followed by a single character acts like an "IF":
1559: depending on the following character, a condition is evaluated.
1560: If the condition is true, any characters following the question mark
1561: and condition character, up to a period, are included in the prompt.
1562: If the condition is false, such characters are not included.
1563: A colon appearing between the question mark and the
1564: period can be used to establish an "ELSE": any characters between
1565: the colon and the period are included in the string, if and only if
1566: the IF condition is false.
1567: Condition characters (which follow a question mark) may be:
1568: .Bl -tag -width Ds
1569: .It ?a
1570: True if any characters have been included in the prompt so far.
1571: .It ?b Ns Ar X
1572: True if the byte offset of the specified line is known.
1573: .It ?B
1574: True if the size of the current input file is known.
1575: .It ?c
1576: True if the text is horizontally shifted (%c is not zero).
1577: .It ?d Ns Ar X
1578: True if the page number of the specified line is known.
1579: .It ?e
1580: True if at end-of-file.
1581: .It ?f
1582: True if there is an input filename
1583: (that is, if input is not a pipe).
1584: .It ?l Ns Ar X
1585: True if the line number of the specified line is known.
1586: .It ?L
1587: True if the line number of the last line in the file is known.
1588: .It ?m
1589: True if there is more than one input file.
1590: .It ?n
1591: True if this is the first prompt in a new input file.
1592: .It ?p Ns Ar X
1593: True if the percent into the current input file, based on byte offsets,
1594: of the specified line is known.
1595: .It ?P Ns Ar X
1596: True if the percent into the current input file, based on line numbers,
1597: of the specified line is known.
1598: .It ?s
1599: Same as "?B".
1600: .It ?x
1601: True if there is a next input file
1602: (that is, if the current input file is not the last one).
1603: .El
1604: .Pp
1605: Any characters other than the special ones
1606: (question mark, colon, period, percent, and backslash)
1607: become literally part of the prompt.
1608: Any of the special characters may be included in the prompt literally
1609: by preceding it with a backslash.
1610: .Pp
1611: Some examples:
1612: .Pp
1613: .Dl ?f%f:Standard input.
1614: .Pp
1615: This prompt prints the filename, if known;
1616: otherwise the string "Standard input".
1617: .Pp
1618: .Dl ?f%f .?ltLine %lt:?pt%pt\e%:?btByte %bt:-...
1619: .Pp
1620: This prompt would print the filename, if known.
1621: The filename is followed by the line number, if known,
1622: otherwise the percent if known, otherwise the byte offset if known.
1623: Otherwise, a dash is printed.
1624: Notice how each question mark has a matching period,
1625: and how the % after the %pt
1626: is included literally by escaping it with a backslash.
1627: .Pp
1628: .Dl ?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x..%t
1629: .Pp
1630: This prints the filename if this is the first prompt in a file,
1631: followed by the "file N of N" message if there is more
1632: than one input file.
1633: Then, if we are at end-of-file, the string "(END)" is printed
1634: followed by the name of the next file, if there is one.
1635: Finally, any trailing spaces are truncated.
1636: This is the default prompt.
1637: For reference, here are the defaults for
1.44 bentley 1638: the other two prompts
1639: .Po
1640: .Fl m
1641: and
1642: .Fl M
1643: respectively
1644: .Pc .
1.1 millert 1645: Each is broken into two lines here for readability only.
1646: .Bd -literal -offset indent
1.19 ray 1647: ?f%f\ .?m(file\ %i\ of\ %m)\ .?e(END)\ ?x-\ Next\e:\ %x.:
1.1 millert 1648: ?pB%pB\e%:byte\ %bB?s/%s...%t
1649:
1650: ?f%f\ .?n?m(file\ %i\ of\ %m)\ ..?ltlines\ %lt-%lb?L/%L.\ :
1651: byte\ %bB?s/%s.\ .?e(END)\ ?x-\ Next\e:\ %x.:?pB%pB\e%..%t
1652: .Ed
1653: .Pp
1654: And here is the default message produced by the = command:
1655: .Bd -literal -offset indent
1656: ?f%f\ .?m(file\ %i\ of\ %m)\ .?ltlines\ %lt-%lb?L/%L.\ .
1657: byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\e%..%t
1658: .Ed
1659: .Pp
1660: The prompt expansion features are also used for another purpose:
1661: if an environment variable
1662: .Ev LESSEDIT
1663: is defined, it is used as the command to be executed when the v command
1664: is invoked.
1665: The LESSEDIT string is expanded in the same way as the prompt strings.
1666: The default value for LESSEDIT is:
1667: .Pp
1668: .Dl %E\ ?lm+%lm.\ %f
1669: .Pp
1670: Note that this expands to the editor name, followed by a + and the
1671: line number, followed by the file name.
1672: If your editor does not accept the "+linenumber" syntax, or has other
1673: differences in invocation syntax, the
1674: .Ev LESSEDIT
1675: variable can be changed to modify this default.
1676: .Sh SECURITY
1677: When the environment variable
1678: .Ev LESSSECURE
1679: is set to 1,
1680: .Nm
1681: runs in a "secure" mode.
1682: This means these features are disabled:
1683: .Bl -tag -width Ds
1684: .It |
1685: The pipe command.
1686: .It :e
1687: The examine command.
1688: .It v
1689: The editing command.
1690: .It s -o
1691: Log files.
1.44 bentley 1692: .It Fl k
1.1 millert 1693: Use of lesskey files.
1.44 bentley 1694: .It Fl t
1.1 millert 1695: Use of tags files.
1696: .It " "
1697: Metacharacters in filenames, such as "*".
1698: .It " "
1699: Filename completion (TAB, ^L).
1700: .El
1.23 shadchin 1701: .Sh COMPATIBILITY WITH MORE
1702: If the environment variable
1703: .Ev LESS_IS_MORE
1704: is set to 1,
1705: or if the program is invoked via a file link named "more",
1706: .Nm
1707: behaves (mostly) in conformance with the POSIX "more" command specification.
1708: In this mode, less behaves differently in these ways:
1709: .Pp
1.43 jmc 1710: The sense of the
1711: .Fl c
1712: option is inverted:
1713: when
1714: .Xr more 1
1715: changes the display,
1716: the default is to scroll from the bottom of the screen,
1717: and the
1718: .Fl c
1719: option causes it to paint from the top line down.
1720: .Pp
1.37 jmc 1721: The
1722: .Fl e
1723: option works differently:
1724: it causes
1725: .Xr more 1
1726: to exit the first time it reaches EOF,
1727: not the second.
1.42 millert 1728: .Pp
1729: The
1730: .Fl i
1731: option acts like the
1732: .Fl I
1733: option.
1734: The normal behavior of the
1735: .Fl i
1736: option is unavailable in this mode.
1.23 shadchin 1737: .Pp
1.37 jmc 1738: The
1739: .Fl m
1740: option works differently:
1741: if it is not specified, the medium prompt is used;
1742: if it is specified, the short prompt is used.
1.23 shadchin 1743: .Pp
1.37 jmc 1744: The
1745: .Fl n
1746: option acts like the
1747: .Fl z
1748: option.
1749: The normal behavior of the
1750: .Fl n
1751: option is unavailable in this mode.
1752: .Pp
1753: The parameter to the
1754: .Fl p
1755: option is taken to be a
1.23 shadchin 1756: command rather than a search pattern.
1757: .Pp
1.43 jmc 1758: Options to suppress error messages when the terminal is dumb
1759: .Pq Fl d ,
1760: suppress highlighting of strings in search results
1761: .Pq Fl G ,
1762: and disable termcap initialization
1763: .Pq Fl X
1764: are on by default.
1765: .Pp
1.23 shadchin 1766: The
1767: .Ev LESS
1.39 jmc 1768: environment variables are ignored, and the
1.23 shadchin 1769: .Ev MORE
1770: environment variable is used in its place.
1.3 jmc 1771: .Sh ENVIRONMENT
1.1 millert 1772: Environment variables may be specified either in the system environment
1773: as usual, or in a
1774: .Xr lesskey 1
1775: file.
1776: If environment variables are defined in more than one place,
1777: variables defined in a local lesskey file take precedence over
1778: variables defined in the system environment, which take precedence
1779: over variables defined in the system-wide lesskey file.
1.38 jmc 1780: .Bl -tag -width LESSANSIENDCHARS
1.1 millert 1781: .It Ev COLUMNS
1782: Sets the number of columns on the screen.
1.41 jmc 1783: Takes precedence over the number of columns specified by the
1784: .Ev TERM
1785: variable,
1786: but may be overridden by window systems which support
1787: .Dv TIOCGWINSZ .
1.1 millert 1788: .It Ev EDITOR
1.41 jmc 1789: Specifies the default editor if
1790: .Ev VISUAL
1791: is not set.
1792: If neither are set,
1793: .Xr vi 1
1794: is used.
1.1 millert 1795: .It Ev HOME
1796: Name of the user's home directory
1797: (used to find a lesskey file).
1798: .It Ev LANG
1799: Language for determining the character set.
1800: .It Ev LC_CTYPE
1801: Language for determining the character set.
1802: .It Ev LESS
1803: Options which are passed to
1804: .Nm
1805: automatically.
1.38 jmc 1806: Command line options override the
1807: .Ev LESS
1808: environment variable.
1809: .Pp
1.44 bentley 1810: Some options like
1811: .Fl k
1812: require a string to follow the option letter.
1.38 jmc 1813: The string for that option is considered to end when a dollar sign ($) is found.
1814: For example, to separate a prompt value from any other options
1815: with dollar sign between them:
1816: .Pp
1817: .Dl LESS="-Ps--More--$-C -e"
1818: .Pp
1.44 bentley 1819: If the
1820: .Fl -use-backslash
1821: option appears earlier in the options, then
1.38 jmc 1822: a dollar sign or backslash may be included literally in an option string
1823: by preceding it with a backslash.
1.44 bentley 1824: If the
1825: .Fl -use-backslash
1826: option is not in effect, then backslashes are
1.38 jmc 1827: not treated specially, and there is no way to include a dollar sign
1828: in the option string.
1.1 millert 1829: .It Ev LESSANSIENDCHARS
1.23 shadchin 1830: Characters which may end an ANSI color escape sequence
1.1 millert 1831: (default "m").
1.23 shadchin 1832: .It Ev LESSANSIMIDCHARS
1833: Characters which may appear between the ESC character and the
1834: end character in an ANSI color escape sequence
1835: (default "0123456789;[?!"'#%()*+\ ").
1.1 millert 1836: .It Ev LESSBINFMT
1837: Format for displaying non-printable, non-control characters.
1838: .It Ev LESSCLOSE
1839: Command line to invoke the (optional) input-postprocessor.
1840: .It Ev LESSEDIT
1841: Editor prototype string (used for the v command).
1842: See discussion under
1843: .Sx PROMPTS .
1.23 shadchin 1844: .It Ev LESSHISTFILE
1845: Name of the history file used to remember search commands and
1846: shell commands between invocations of
1847: .Nm less .
1848: If set to "-" or "/dev/null", a history file is not used.
1.25 nicm 1849: The default is "-".
1.23 shadchin 1850: .It Ev LESSHISTSIZE
1851: The maximum number of commands to save in the history file.
1852: The default is 100.
1.1 millert 1853: .It Ev LESSKEY
1854: Name of the default lesskey(1) file.
1855: .It Ev LESSKEY_SYSTEM
1856: Name of the default system-wide lesskey(1) file.
1857: .It Ev LESSMETACHARS
1858: List of characters which are considered "metacharacters" by the shell.
1859: .It Ev LESSMETAESCAPE
1860: Prefix which
1861: .Nm
1862: will add before each metacharacter in a command sent to the shell.
1863: If LESSMETAESCAPE is an empty string, commands containing
1864: metacharacters will not be passed to the shell.
1865: .It Ev LESSOPEN
1866: Command line to invoke the (optional) input-preprocessor.
1867: .It Ev LESSSECURE
1868: Runs less in "secure" mode.
1869: See discussion under
1870: .Sx SECURITY .
1871: .It Ev LESSSEPARATOR
1872: String to be appended to a directory name in filename completion.
1.23 shadchin 1873: .It Ev LESSUTFBINFMT
1874: Format for displaying non-printable Unicode code points.
1875: .It Ev LESS_IS_MORE
1876: Emulate the
1877: .Xr more 1
1878: command.
1.1 millert 1879: .It Ev LINES
1880: Sets the number of lines on the screen.
1.41 jmc 1881: Takes precedence over the number of lines specified by the TERM variable,
1882: but may be overridden by window systems which support
1883: .Dv TIOCGWINSZ .
1.32 shadchin 1884: .It Ev MORE
1885: Options which are passed to
1886: .Nm
1.35 jmc 1887: automatically when running in
1.39 jmc 1888: .Xr more 1
1.32 shadchin 1889: compatible mode.
1.1 millert 1890: .It Ev SHELL
1.46 nicm 1891: The shell used to expand filenames.
1.1 millert 1892: .It Ev TERM
1.41 jmc 1893: Specifies the terminal type.
1894: Used by
1.1 millert 1895: .Nm
1.41 jmc 1896: to get the terminal characteristics necessary to manipulate the screen.
1.1 millert 1897: .It Ev VISUAL
1.41 jmc 1898: Specifies the default editor.
1899: If not set,
1.45 jmc 1900: .Ev EDITOR
1901: is used;
1.41 jmc 1902: if that is not set,
1903: .Xr vi 1
1904: is used.
1.1 millert 1905: .El
1906: .Sh SEE ALSO
1.37 jmc 1907: .Xr lesskey 1 ,
1908: .Xr more 1
1.7 jmc 1909: .Sh AUTHORS
1.38 jmc 1910: .An Mark Nudelman .
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