1MAN(7) Linux Programmer's Manual MAN(7)
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6 man - macros to format man pages
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9 groff -Tascii -man file ...
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11 groff -Tps -man file ...
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13 man [section] title
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16 This manual page explains the groff an.tmac macro package (often called
17 the man macro package). This macro package should be used by develop‐
18 ers when writing or porting man pages for Linux. It is fairly compati‐
19 ble with other versions of this macro package, so porting man pages
20 should not be a major problem (exceptions include the NET-2 BSD
21 release, which uses a totally different macro package called mdoc; see
22 mdoc(7)).
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24 Note that NET-2 BSD mdoc man pages can be used with groff simply by
25 specifying the -mdoc option instead of the -man option. Using the
26 -mandoc option is, however, recommended, since this will automatically
27 detect which macro package is in use.
28
29 For conventions that should be employed when writing man pages for the
30 Linux man-pages package, see man-pages(7).
31
32 Title line
33 The first command in a man page (after comment lines, that is, lines
34 that start with .\") should be
35
36 .TH title section date source manual
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38 For details of the arguments that should be supplied to the TH command,
39 see man-pages(7).
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41 Note that BSD mdoc-formatted pages begin with the Dd command, not the
42 TH command.
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44 Sections
45 Sections are started with .SH followed by the heading name.
46
47 The only mandatory heading is NAME, which should be the first section
48 and be followed on the next line by a one line description of the pro‐
49 gram:
50
51 .SH NAME
52
53 It is extremely important that this format is followed, and that there
54 is a backslash before the single dash which follows the command name.
55 This syntax is used by the makewhatis(8) program to create a database
56 of short command descriptions for the whatis(1) and apropos(1) com‐
57 mands.
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59 For a list of other sections that might appear in a manual page, see
60 man-pages(7).
61
62 Fonts
63 The commands to select the type face are:
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65 .B Bold
66
67 .BI Bold alternating with italics (especially useful for function spec‐
68 ifications)
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70 .BR Bold alternating with Roman (especially useful for referring to
71 other manual pages)
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73 .I Italics
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75 .IB Italics alternating with bold
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77 .IR Italics alternating with Roman
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79 .RB Roman alternating with bold
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81 .RI Roman alternating with italics
82
83 .SB Small alternating with bold
84
85 .SM Small (useful for acronyms)
86
87 Traditionally, each command can have up to six arguments, but the GNU
88 implementation removes this limitation (you might still want to limit
89 yourself to 6 arguments for portability's sake). Arguments are delim‐
90 ited by spaces. Double quotes can be used to specify an argument which
91 contains spaces. All of the arguments will be printed next to each
92 other without intervening spaces, so that the .BR command can be used
93 to specify a word in bold followed by a mark of punctuation in Roman.
94 If no arguments are given, the command is applied to the following line
95 of text.
96
97 Other Macros and Strings
98 Below are other relevant macros and predefined strings. Unless noted
99 otherwise, all macros cause a break (end the current line of text).
100 Many of these macros set or use the "prevailing indent." The "prevail‐
101 ing indent" value is set by any macro with the parameter i below;
102 macros may omit i in which case the current prevailing indent will be
103 used. As a result, successive indented paragraphs can use the same
104 indent without re-specifying the indent value. A normal (non-indented)
105 paragraph resets the prevailing indent value to its default value (0.5
106 inches). By default a given indent is measured in ens; try to use ens
107 or ems as units for indents, since these will automatically adjust to
108 font size changes. The other key macro definitions are:
109
110 Normal Paragraphs
111 .LP Same as .PP (begin a new paragraph).
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113 .P Same as .PP (begin a new paragraph).
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115 .PP Begin a new paragraph and reset prevailing indent.
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117 Relative Margin Indent
118 .RS i Start relative margin indent: moves the left margin i to the
119 right (if i is omitted, the prevailing indent value is used).
120 A new prevailing indent is set to 0.5 inches. As a result,
121 all following paragraph(s) will be indented until the corre‐
122 sponding .RE.
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124 .RE End relative margin indent and restores the previous value of
125 the prevailing indent.
126
127 Indented Paragraph Macros
128 .HP i Begin paragraph with a hanging indent (the first line of the
129 paragraph is at the left margin of normal paragraphs, and the
130 rest of the paragraph's lines are indented).
131
132 .IP x i Indented paragraph with optional hanging tag. If the tag x is
133 omitted, the entire following paragraph is indented by i. If
134 the tag x is provided, it is hung at the left margin before
135 the following indented paragraph (this is just like .TP except
136 the tag is included with the command instead of being on the
137 following line). If the tag is too long, the text after the
138 tag will be moved down to the next line (text will not be lost
139 or garbled). For bulleted lists, use this macro with \(bu
140 (bullet) or \(em (em dash) as the tag, and for numbered lists,
141 use the number or letter followed by a period as the tag; this
142 simplifies translation to other formats.
143
144 .TP i Begin paragraph with hanging tag. The tag is given on the
145 next line, but its results are like those of the .IP command.
146
147 Hypertext Link Macros
148 (Feature supported with groff only.) In order to use hypertext link
149 macros, it is necessary to load the www.tmac macro package. Use the
150 request .mso www.tmac to do this.
151
152 .URL url link trailer
153 Inserts a hypertext link to the URI (URL) url, with link as
154 the text of the link. The trailer will be printed immediately
155 afterwards. When generating HTML this should translate into
156 the HTML command <A HREF="url">link</A>trailer.
157
158 This and other related macros are new, and many tools won't do
159 anything with them, but since many tools (including troff)
160 will simply ignore undefined macros (or at worst insert their
161 text) these are safe to insert.
162
163 It can be useful to define your own URL macro in manual pages
164 for the benefit of those viewing it with a roff viewer other
165 than groff. That way, the URL, link text, and trailer text
166 (if any) are still visible.
167
168 Here's an example:
169 .de URL
170 \\$2 \(laURL: \\$1 \(ra\\$3
171 ..
172 .if \n[.g] .mso www.tmac
173 .TH ...
174 (later in the page)
175 This software comes from the
176 .URL "http://www.gnu.org/" "GNU Project" " of the"
177 .URL "http://www.fsf.org/" "Free Software Foundation" .
178
179 In the above, if groff is being used, the www.tmac macro pack‐
180 age's definition of the URL macro will supersede the locally
181 defined one.
182
183 A number of other link macros are available. See groff_www(7) for more
184 details.
185
186 Miscellaneous Macros
187 .DT Reset tabs to default tab values (every 0.5 inches); does not
188 cause a break.
189
190 .PD d Set inter-paragraph vertical distance to d (if omitted,
191 d=0.4v); does not cause a break.
192
193 .SS t Subheading t (like .SH, but used for a subsection inside a
194 section).
195
196 Predefined Strings
197 The man package has the following predefined strings:
198
199 \*R Registration Symbol: ®
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201 \*S Change to default font size
202
203 \*(Tm Trademark Symbol: ™
204
205 \*(lq Left angled double quote: “
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207 \*(rq Right angled double quote: ”
208
209 Safe Subset
210 Although technically man is a troff macro package, in reality a large
211 number of other tools process man page files that don't implement all
212 of troff's abilities. Thus, it's best to avoid some of troff's more
213 exotic abilities where possible to permit these other tools to work
214 correctly. Avoid using the various troff preprocessors (if you must,
215 go ahead and use tbl(1), but try to use the IP and TP commands instead
216 for two-column tables). Avoid using computations; most other tools
217 can't process them. Use simple commands that are easy to translate to
218 other formats. The following troff macros are believed to be safe
219 (though in many cases they will be ignored by translators): \", ., ad,
220 bp, br, ce, de, ds, el, ie, if, fi, ft, hy, ig, in, na, ne, nf, nh, ps,
221 so, sp, ti, tr.
222
223 You may also use many troff escape sequences (those sequences beginning
224 with \). When you need to include the backslash character as normal
225 text, use \e. Other sequences you may use, where x or xx are any char‐
226 acters and N is any digit, include: \', \`, \-, \., \", \%, \*x, \*(xx,
227 \(xx, \$N, \nx, \n(xx, \fx, and \f(xx. Avoid using the escape
228 sequences for drawing graphics.
229
230 Do not use the optional parameter for bp (break page). Use only posi‐
231 tive values for sp (vertical space). Don't define a macro (de) with
232 the same name as a macro in this or the mdoc macro package with a dif‐
233 ferent meaning; it's likely that such redefinitions will be ignored.
234 Every positive indent (in) should be paired with a matching negative
235 indent (although you should be using the RS and RE macros instead).
236 The condition test (if,ie) should only have 't' or 'n' as the condi‐
237 tion. Only translations (tr) that can be ignored should be used. Font
238 changes (ft and the \f escape sequence) should only have the values 1,
239 2, 3, 4, R, I, B, P, or CW (the ft command may also have no parame‐
240 ters).
241
242 If you use capabilities beyond these, check the results carefully on
243 several tools. Once you've confirmed that the additional capability is
244 safe, let the maintainer of this document know about the safe command
245 or sequence that should be added to this list.
246
248 /usr/share/groff/[*/]tmac/an.tmac
249 /usr/man/whatis
250
252 By all means include full URLs (or URIs) in the text itself; some tools
253 such as man2html(1) can automatically turn them into hypertext links.
254 You can also use the new URL macro to identify links to related infor‐
255 mation. If you include URLs, use the full URL (e.g., <http://www.ker‐
256 nelnotes.org>) to ensure that tools can automatically find the URLs.
257
258 Tools processing these files should open the file and examine the first
259 non-whitespace character. A period (.) or single quote (') at the
260 beginning of a line indicates a troff-based file (such as man or mdoc).
261 A left angle bracket (<) indicates an SGML/XML-based file (such as HTML
262 or Docbook). Anything else suggests simple ASCII text (e.g., a "cat‐
263 man" result).
264
265 Many man pages begin with ´\" followed by a space and a list of charac‐
266 ters, indicating how the page is to be preprocessed. For portability's
267 sake to non-troff translators we recommend that you avoid using any‐
268 thing other than tbl(1), and Linux can detect that automatically. How‐
269 ever, you might want to include this information so your man page can
270 be handled by other (less capable) systems. Here are the definitions
271 of the preprocessors invoked by these characters:
272
273 e [22meqn(1)
274
275 g [22mgrap(1)
276
277 p [22mpic(1)
278
279 r [22mrefer(1)
280
281 t [22mtbl(1)
282
283 v [22mvgrind(1)
284
286 Most of the macros describe formatting (e.g., font type and spacing)
287 instead of marking semantic content (e.g., this text is a reference to
288 another page), compared to formats like mdoc and DocBook (even HTML has
289 more semantic markings). This situation makes it harder to vary the
290 man format for different media, to make the formatting consistent for a
291 given media, and to automatically insert cross-references. By sticking
292 to the safe subset described above, it should be easier to automate
293 transitioning to a different reference page format in the future.
294
295 The Sun macro TX is not implemented.
296
298 apropos(1), groff(1), man(1), man2html(1), whatis(1), groff_man(7),
299 groff_www(7), man-pages(7), mdoc(7), mdoc.samples(7)
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302 This page is part of release 3.22 of the Linux man-pages project. A
303 description of the project, and information about reporting bugs, can
304 be found at http://www.kernel.org/doc/man-pages/.
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308Linux 2007-05-30 MAN(7)