макросы для форматирования страниц руководства (macros to format man pages)
Описание (Description)
This manual page explains the groff an.tmac macro package (often
called the man macro package). This macro package should be used
by developers when writing or porting man pages for Linux. It is
fairly compatible with other versions of this macro package, so
porting man pages should not be a major problem (exceptions
include the NET-2 BSD release, which uses a totally different
macro package called mdoc; see mdoc(7)).
Note that NET-2 BSD mdoc man pages can be used with groff simply
by specifying the -mdoc option instead of the -man option. Using
the -mandoc option is, however, recommended, since this will
automatically detect which macro package is in use.
For conventions that should be employed when writing man pages
for the Linux man-pages package, see man-pages(7).
Title line
The first command in a man page (after comment lines, that is,
lines that start with .\") should be
.TH title section date source manual
For details of the arguments that should be supplied to the TH
command, see man-pages(7).
Note that BSD mdoc-formatted pages begin with the Dd command, not
the TH command.
Sections
Sections are started with .SH followed by the heading name.
The only mandatory heading is NAME, which should be the first
section and be followed on the next line by a one-line
description of the program:
.SH NAME
item \- description
It is extremely important that this format is followed, and that
there is a backslash before the single dash which follows the
item name. This syntax is used by the mandb(8) program to create
a database of short descriptions for the whatis(1) and apropos(1)
commands. (See lexgrog(1) for further details on the syntax of
the NAME section.)
For a list of other sections that might appear in a manual page,
see man-pages(7).
Fonts
The commands to select the type face are:
.B Bold
.BI Bold alternating with italics (especially useful for function
specifications)
.BR Bold alternating with Roman (especially useful for referring
to other manual pages)
.I Italics
.IB Italics alternating with bold
.IR Italics alternating with Roman
.RB Roman alternating with bold
.RI Roman alternating with italics
.SB Small alternating with bold
.SM Small (useful for acronyms)
Traditionally, each command can have up to six arguments, but the
GNU implementation removes this limitation (you might still want
to limit yourself to 6 arguments for portability's sake).
Arguments are delimited by spaces. Double quotes can be used to
specify an argument which contains spaces. For the macros that
produce alternating type faces, the arguments will be printed
next to each other without intervening spaces, so that the .BR
command can be used to specify a word in bold followed by a mark
of punctuation in Roman. If no arguments are given, the command
is applied to the following line of text.
Other macros and strings
Below are other relevant macros and predefined strings. Unless
noted otherwise, all macros cause a break (end the current line
of text). Many of these macros set or use the "prevailing
indent". The "prevailing indent" value is set by any macro with
the parameter i below; macros may omit i in which case the
current prevailing indent will be used. As a result, successive
indented paragraphs can use the same indent without respecifying
the indent value. A normal (nonindented) paragraph resets the
prevailing indent value to its default value (0.5 inches). By
default, a given indent is measured in ens; try to use ens or ems
as units for indents, since these will automatically adjust to
font size changes. The other key macro definitions are:
Normal paragraphs
.LP Same as .PP (begin a new paragraph).
.P Same as .PP (begin a new paragraph).
.PP Begin a new paragraph and reset prevailing indent.
Relative margin indent
.RS i Start relative margin indent: moves the left margin i to
the right (if i is omitted, the prevailing indent value
is used). A new prevailing indent is set to 0.5 inches.
As a result, all following paragraph(s) will be indented
until the corresponding .RE.
.RE End relative margin indent and restores the previous
value of the prevailing indent.
Indented paragraph macros
.HP i Begin paragraph with a hanging indent (the first line of
the paragraph is at the left margin of normal
paragraphs, and the rest of the paragraph's lines are
indented).
.IP x i Indented paragraph with optional hanging tag. If the
tag x is omitted, the entire following paragraph is
indented by i. If the tag x is provided, it is hung at
the left margin before the following indented paragraph
(this is just like .TP except the tag is included with
the command instead of being on the following line). If
the tag is too long, the text after the tag will be
moved down to the next line (text will not be lost or
garbled). For bulleted lists, use this macro with \(bu
(bullet) or \(em (em dash) as the tag, and for numbered
lists, use the number or letter followed by a period as
the tag; this simplifies translation to other formats.
.TP i Begin paragraph with hanging tag. The tag is given on
the next line, but its results are like those of the .IP
command.
Hypertext link macros
.UR url
Insert a hypertext link to the URI (URL) url, with all
text up to the following .UE macro as the link text.
.UE [trailer]
Terminate the link text of the preceding .UR macro, with
the optional trailer (if present, usually a closing
parenthesis and/or end-of-sentence punctuation)
immediately following. For non-HTML output devices (e.g.,
man -Tutf8), the link text is followed by the URL in angle
brackets; if there is no link text, the URL is printed as
its own link text, surrounded by angle brackets. (Angle
brackets may not be available on all output devices.) For
the HTML output device, the link text is hyperlinked to
the URL; if there is no link text, the URL is printed as
its own link text.
These macros have been supported since GNU Troff 1.20
(2009-01-05) and Heirloom Doctools Troff since 160217
(2016-02-17).
Miscellaneous macros
.DT Reset tabs to default tab values (every 0.5 inches);
does not cause a break.
.PD d Set inter-paragraph vertical distance to d (if omitted,
d=0.4v); does not cause a break.
.SS t Subheading t (like .SH, but used for a subsection inside
a section).
Predefined strings
The man package has the following predefined strings:
\*R Registration Symbol: ®
\*S Change to default font size
\*(Tm Trademark Symbol: ™
\*(lq Left angled double quote: '
\*(rq Right angled double quote: '
Safe subset
Although technically man is a troff macro package, in reality a
large number of other tools process man page files that don't
implement all of troff's abilities. Thus, it's best to avoid
some of troff's more exotic abilities where possible to permit
these other tools to work correctly. Avoid using the various
troff preprocessors (if you must, go ahead and use tbl(1), but
try to use the IP and TP commands instead for two-column tables).
Avoid using computations; most other tools can't process them.
Use simple commands that are easy to translate to other formats.
The following troff macros are believed to be safe (though in
many cases they will be ignored by translators): \", ., ad, bp,
br, ce, de, ds, el, ie, if, fi, ft, hy, ig, in, na, ne, nf, nh,
ps, so, sp, ti, tr.
You may also use many troff escape sequences (those sequences
beginning with \). When you need to include the backslash
character as normal text, use \e. Other sequences you may use,
where x or xx are any characters and N is any digit, include: \',
\`, \-, \., \", \%, \*x, \*(xx, \(xx, \$N, \nx, \n(xx, \fx, and
\f(xx. Avoid using the escape sequences for drawing graphics.
Do not use the optional parameter for bp (break page). Use only
positive values for sp (vertical space). Don't define a macro
(de) with the same name as a macro in this or the mdoc macro
package with a different meaning; it's likely that such
redefinitions will be ignored. Every positive indent (in) should
be paired with a matching negative indent (although you should be
using the RS and RE macros instead). The condition test (if,ie)
should only have 't' or 'n' as the condition. Only translations
(tr) that can be ignored should be used. Font changes (ft and
the \f escape sequence) should only have the values 1, 2, 3, 4,
R, I, B, P, or CW (the ft command may also have no parameters).
If you use capabilities beyond these, check the results carefully
on several tools. Once you've confirmed that the additional
capability is safe, let the maintainer of this document know
about the safe command or sequence that should be added to this
list.
