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15 .\" manual page may be incorrect or out-of-date.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 2012-08-05 "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.\\"\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
264 (Feature supported with
267 In order to use hypertext link macros, it is necessary to load the
274 .BI \&.URL " url link trailer"
275 Inserts a hypertext link to the URI (URL)
279 as the text of the link.
282 will be printed immediately afterward.
283 When generating HTML this should translate into the HTML command
284 \fB<A HREF="\fP\fIurl\fP\fB">\fIlink\fP\fB</A>\fP\fItrailer\fP.
285 .\" The following is a kludge to get a paragraph into the listing.
288 This and other related macros are new, and
289 many tools won't do anything with them, but
290 since many tools (including troff) will simply ignore undefined macros
291 (or at worst insert their text) these are safe to insert.
292 .\" The following is a kludge to get a paragraph into the listing.
295 It can be useful to define your own
297 macro in manual pages for the benefit of those viewing it with a roff
300 That way, the URL, link text, and trailer text (if any) are still visible.
301 .\" The following is a kludge to get a paragraph into the listing.
308 \\\\$2 \\(laURL: \\\\$1 \\(ra\\\\$3
312 \&.if \\n[.g] .mso www.tmac
317 .I (later in the page)
319 This software comes from the
321 \&.URL "http://www.gnu.org/" "GNU Project" " of the"
323 \&.URL "http://www.fsf.org/" "Free Software Foundation" .
325 .\" The following is a kludge to get a paragraph into the listing.
332 macro package's definition of the URL macro will supersede the locally
335 A number of other link macros are available.
339 .SS Miscellaneous macros
342 Reset tabs to default tab values (every 0.5 inches);
343 does not cause a break.
346 Set inter-paragraph vertical distance to d
347 (if omitted, d=0.4v);
348 does not cause a break.
355 but used for a subsection inside a section).
356 .SS Predefined strings
359 package has the following predefined strings:
361 Registration Symbol: \*R
363 Change to default font size
365 Trademark Symbol: \*(Tm
367 Left angled double quote: \*(lq
369 Right angled double quote: \*(rq
373 is a troff macro package, in reality a large number of other tools
374 process man page files that don't implement all of troff's abilities.
375 Thus, it's best to avoid some of troff's more exotic abilities
376 where possible to permit these other tools to work correctly.
377 Avoid using the various troff preprocessors
378 (if you must, go ahead and use
384 commands instead for two-column tables).
385 Avoid using computations; most other tools can't process them.
386 Use simple commands that are easy to translate to other formats.
387 The following troff macros are believed to be safe (though in many cases
388 they will be ignored by translators):
415 You may also use many troff escape sequences (those sequences beginning
417 When you need to include the backslash character as normal text,
419 Other sequences you may use, where x or xx are any characters and N
420 is any digit, include:
436 Avoid using the escape sequences for drawing graphics.
438 Do not use the optional parameter for
441 Use only positive values for
446 with the same name as a macro in this or the
447 mdoc macro package with a different meaning; it's likely that
448 such redefinitions will be ignored.
449 Every positive indent
451 should be paired with a matching negative indent
452 (although you should be using the
459 should only have \(aqt\(aq or \(aqn\(aq as the condition.
462 that can be ignored should be used.
465 and the \fB\ef\fP escape sequence)
466 should only have the values 1, 2, 3, 4, R, I, B, P, or CW
467 (the ft command may also have no parameters).
469 If you use capabilities beyond these, check the
470 results carefully on several tools.
471 Once you've confirmed that the additional capability is safe,
472 let the maintainer of this
473 document know about the safe command or sequence
474 that should be added to this list.
476 .IR /usr/share/groff/ [*/] tmac/an.tmac
481 By all means include full URLs (or URIs) in the text itself;
484 can automatically turn them into hypertext links.
485 You can also use the new
487 macro to identify links to related information.
488 If you include URLs, use the full URL
490 .UR http://www.kernelnotes.org
492 to ensure that tools can automatically find the URLs.
494 Tools processing these files should open the file and examine the first
495 nonwhitespace character.
496 A period (.) or single quote (') at the beginning
497 of a line indicates a troff-based file (such as man or mdoc).
498 A left angle bracket (<) indicates an SGML/XML-based
499 file (such as HTML or Docbook).
500 Anything else suggests simple ASCII
501 text (e.g., a "catman" result).
503 Many man pages begin with \fB\'\e"\fP followed by a
504 space and a list of characters,
505 indicating how the page is to be preprocessed.
506 For portability's sake to non-troff translators we recommend
507 that you avoid using anything other than
509 and Linux can detect that automatically.
510 However, you might want to include this information so your man page
511 can be handled by other (less capable) systems.
512 Here are the definitions of the preprocessors invoked by these characters:
533 Most of the macros describe formatting (e.g., font type and spacing) instead
534 of marking semantic content (e.g., this text is a reference to another page),
535 compared to formats like mdoc and DocBook (even HTML has more semantic
537 This situation makes it harder to vary the
539 format for different media,
540 to make the formatting consistent for a given media, and to automatically
541 insert cross-references.
542 By sticking to the safe subset described above, it should be easier to
543 automate transitioning to a different reference page format in the future.
550 .\" James Clark (jjc@jclark.com) wrote the implementation of the macro package.
552 .\" Rickard E. Faith (faith@cs.unc.edu) wrote the initial version of
553 .\" this manual page.
555 .\" Jens Schweikhardt (schweikh@noc.fdn.de) wrote the Linux Man-Page Mini-HOWTO
556 .\" (which influenced this manual page).
558 .\" David A. Wheeler (dwheeler@ida.org) heavily modified this
559 .\" manual page, such as adding detailed information on sections and macros.
573 This page is part of release 3.68 of the Linux
576 A description of the project,
577 information about reporting bugs,
578 and the latest version of this page,
580 \%http://www.kernel.org/doc/man\-pages/.
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