1 .\" (C) Copyright 1992-1999 Rickard E. Faith and David A. Wheeler
2 .\" (faith@cs.unc.edu and dwheeler@ida.org)
4 .\" %%%LICENSE_START(VERBATIM)
5 .\" Permission is granted to make and distribute verbatim copies of this
6 .\" manual provided the copyright notice and this permission notice are
7 .\" preserved on all copies.
9 .\" Permission is granted to copy and distribute modified versions of this
10 .\" manual under the conditions for verbatim copying, provided that the
11 .\" entire resulting derived work is distributed under the terms of a
12 .\" permission notice identical to this one.
14 .\" Since the Linux kernel and libraries are constantly changing, this
15 .\" manual page may be incorrect or out-of-date. The author(s) assume no
16 .\" responsibility for errors or omissions, or for damages resulting from
17 .\" the use of the information contained herein. The author(s) may not
18 .\" have taken the same level of care in the production of this manual,
19 .\" which is licensed free of charge, as they might when working
22 .\" Formatted or processed versions of this manual, if unaccompanied by
23 .\" the source, must acknowledge the copyright and authors of this work.
26 .\" Modified Sun Jul 25 11:06:05 1993 by Rik Faith (faith@cs.unc.edu)
27 .\" Modified Sat Jun 8 00:39:52 1996 by aeb
28 .\" Modified Wed Jun 16 23:00:00 1999 by David A. Wheeler (dwheeler@ida.org)
29 .\" Modified Thu Jul 15 12:43:28 1999 by aeb
30 .\" Modified Sun Jan 6 18:26:25 2002 by Martin Schulze <joey@infodrom.org>
31 .\" Modified Tue Jul 27 20:12:02 2004 by Colin Watson <cjwatson@debian.org>
32 .\" 2007-05-30, mtk: various rewrites and moved much text to new man-pages.7.
34 .TH MAN 7 2019-03-06 "Linux" "Linux Programmer's Manual"
36 man \- macros to format man pages
38 .B groff \-Tascii \-man
50 This manual page explains the
52 macro package (often called the
55 This macro package should be used by developers when
56 writing or porting man pages for Linux.
57 It is fairly compatible with other
58 versions of this macro package, so porting man pages should not be a major
59 problem (exceptions include the NET-2 BSD release, which uses a totally
60 different macro package called mdoc; see
63 Note that NET-2 BSD mdoc man pages can be used with
65 simply by specifying the
72 option is, however, recommended, since this will automatically detect which
73 macro package is in use.
75 For conventions that should be employed when writing man pages
76 for the Linux \fIman-pages\fP package, see
79 The first command in a man page (after comment lines,
80 that is, lines that start with \fB.\e"\fP) should be
84 .I "title section date source manual"
87 For details of the arguments that should be supplied to the
92 Note that BSD mdoc-formatted pages begin with the
98 Sections are started with
100 followed by the heading name.
101 .\" The following doesn't seem to be required (see Debian bug 411303),
102 .\" If the name contains spaces and appears
103 .\" on the same line as
105 .\" then place the heading in double quotes.
107 The only mandatory heading is NAME, which should be the first section and
108 be followed on the next line by a one-line description of the program:
116 It is extremely important that this format is followed, and that there is a
117 backslash before the single dash which follows the item name.
118 This syntax is used by the
120 program to create a database of short descriptions for the
127 for further details on the syntax of the NAME section.)
129 For a list of other sections that might appear in a manual page, see
132 The commands to select the type face are:
138 Bold alternating with italics
139 (especially useful for function specifications)
142 Bold alternating with Roman
143 (especially useful for referring to other
150 Italics alternating with bold
153 Italics alternating with Roman
156 Roman alternating with bold
159 Roman alternating with italics
162 Small alternating with bold
165 Small (useful for acronyms)
167 Traditionally, each command can have up to six arguments, but the GNU
168 implementation removes this limitation (you might still want to limit
169 yourself to 6 arguments for portability's sake).
170 Arguments are delimited by spaces.
171 Double quotes can be used to specify an argument which contains spaces.
172 All of the arguments will be printed next to each other without
173 intervening spaces, so that the
175 command can be used to specify a word in bold followed by a mark of
176 punctuation in Roman.
177 If no arguments are given, the command is applied to the following line
179 .SS Other macros and strings
181 Below are other relevant macros and predefined strings.
182 Unless noted otherwise, all macros
183 cause a break (end the current line of text).
184 Many of these macros set or use the "prevailing indent."
185 The "prevailing indent" value is set by any macro with the parameter
190 in which case the current prevailing indent will be used.
191 As a result, successive indented paragraphs can use the same indent without
192 respecifying the indent value.
193 A normal (nonindented) paragraph resets the prevailing indent value
194 to its default value (0.5 inches).
195 By default, a given indent is measured in ens;
196 try to use ens or ems as units for
197 indents, since these will automatically adjust to font size changes.
198 The other key macro definitions are:
199 .SS Normal paragraphs
204 (begin a new paragraph).
209 (begin a new paragraph).
212 Begin a new paragraph and reset prevailing indent.
213 .SS Relative margin indent
216 Start relative margin indent: moves the left margin
220 is omitted, the prevailing indent value is used).
221 A new prevailing indent is set to 0.5 inches.
222 As a result, all following paragraph(s) will be
223 indented until the corresponding
227 End relative margin indent and
228 restores the previous value of the prevailing indent.
229 .SS Indented paragraph macros
232 Begin paragraph with a hanging indent
233 (the first line of the paragraph is at the left margin of
234 normal paragraphs, and the rest of the paragraph's lines are indented).
237 Indented paragraph with optional hanging tag.
240 is omitted, the entire following paragraph is indented by
244 is provided, it is hung at the left margin
245 before the following indented paragraph
248 except the tag is included with the command instead of being on the
250 If the tag is too long, the text after the tag will be moved down to the
251 next line (text will not be lost or garbled).
252 For bulleted lists, use this macro with \e(bu (bullet) or \e(em (em dash)
253 as the tag, and for numbered lists, use the number or letter followed by
255 this simplifies translation to other formats.
258 Begin paragraph with hanging tag.
259 The tag is given on the next line, but
260 its results are like those of the
263 .SS Hypertext link macros
266 Insert a hypertext link to the URI (URL)
268 with all text up to the following
270 macro as the link text.
274 Terminate the link text of the preceding
276 macro, with the optional
278 (if present, usually a closing parenthesis and/or end-of-sentence
279 punctuation) immediately following.
280 For non-HTML output devices (e.g.,
282 the link text is followed by the URL in angle brackets; if there is no
283 link text, the URL is printed as its own link text, surrounded by angle
285 (Angle brackets may not be available on all output devices.)
286 For the HTML output device, the link text is hyperlinked to the URL; if
287 there is no link text, the URL is printed as its own link text.
289 These macros have been supported since GNU Troff 1.20 (2009-01-05) and
290 Heirloom Doctools Troff since 160217 (2016-02-17).
291 .SS Miscellaneous macros
294 Reset tabs to default tab values (every 0.5 inches);
295 does not cause a break.
298 Set inter-paragraph vertical distance to d
299 (if omitted, d=0.4v);
300 does not cause a break.
307 but used for a subsection inside a section).
308 .SS Predefined strings
311 package has the following predefined strings:
313 Registration Symbol: \*R
315 Change to default font size
317 Trademark Symbol: \*(Tm
319 Left angled double quote: \*(lq
321 Right angled double quote: \*(rq
325 is a troff macro package, in reality a large number of other tools
326 process man page files that don't implement all of troff's abilities.
327 Thus, it's best to avoid some of troff's more exotic abilities
328 where possible to permit these other tools to work correctly.
329 Avoid using the various troff preprocessors
330 (if you must, go ahead and use
336 commands instead for two-column tables).
337 Avoid using computations; most other tools can't process them.
338 Use simple commands that are easy to translate to other formats.
339 The following troff macros are believed to be safe (though in many cases
340 they will be ignored by translators):
367 You may also use many troff escape sequences (those sequences beginning
369 When you need to include the backslash character as normal text,
371 Other sequences you may use, where x or xx are any characters and N
372 is any digit, include:
388 Avoid using the escape sequences for drawing graphics.
390 Do not use the optional parameter for
393 Use only positive values for
398 with the same name as a macro in this or the
399 mdoc macro package with a different meaning; it's likely that
400 such redefinitions will be ignored.
401 Every positive indent
403 should be paired with a matching negative indent
404 (although you should be using the
411 should only have \(aqt\(aq or \(aqn\(aq as the condition.
414 that can be ignored should be used.
417 and the \fB\ef\fP escape sequence)
418 should only have the values 1, 2, 3, 4, R, I, B, P, or CW
419 (the ft command may also have no parameters).
421 If you use capabilities beyond these, check the
422 results carefully on several tools.
423 Once you've confirmed that the additional capability is safe,
424 let the maintainer of this
425 document know about the safe command or sequence
426 that should be added to this list.
428 .IR /usr/share/groff/ [*/] tmac/an.tmac
433 By all means include full URLs (or URIs) in the text itself;
436 can automatically turn them into hypertext links.
441 macros to identify links to related information.
442 If you include URLs, use the full URL
444 .UR http://www.kernel.org
446 to ensure that tools can automatically find the URLs.
448 Tools processing these files should open the file and examine the first
449 nonwhitespace character.
450 A period (.) or single quote (\(aq) at the beginning
451 of a line indicates a troff-based file (such as man or mdoc).
452 A left angle bracket (<) indicates an SGML/XML-based
453 file (such as HTML or Docbook).
454 Anything else suggests simple ASCII
455 text (e.g., a "catman" result).
457 Many man pages begin with \fB\(aq\e"\fP followed by a
458 space and a list of characters,
459 indicating how the page is to be preprocessed.
460 For portability's sake to non-troff translators we recommend
461 that you avoid using anything other than
463 and Linux can detect that automatically.
464 However, you might want to include this information so your man page
465 can be handled by other (less capable) systems.
466 Here are the definitions of the preprocessors invoked by these characters:
487 Most of the macros describe formatting (e.g., font type and spacing) instead
488 of marking semantic content (e.g., this text is a reference to another page),
489 compared to formats like mdoc and DocBook (even HTML has more semantic
491 This situation makes it harder to vary the
493 format for different media,
494 to make the formatting consistent for a given media, and to automatically
495 insert cross-references.
496 By sticking to the safe subset described above, it should be easier to
497 automate transitioning to a different reference page format in the future.
504 .\" James Clark (jjc@jclark.com) wrote the implementation of the macro package.
506 .\" Rickard E. Faith (faith@cs.unc.edu) wrote the initial version of
507 .\" this manual page.
509 .\" Jens Schweikhardt (schweikh@noc.fdn.de) wrote the Linux Man-Page Mini-HOWTO
510 .\" (which influenced this manual page).
512 .\" David A. Wheeler (dwheeler@ida.org) heavily modified this
513 .\" manual page, such as adding detailed information on sections and macros.
projects / thirdparty / man-pages.git / blob