Manpage of MAN
MANSection: Linux Programmer's Manual (7)
NAMEman - macros to format man pages
SYNOPSISgroff -Tascii -manfile...
groff -Tps -manfile...
DESCRIPTIONThis manual page explains the groff an.tmacmacro package (often called the manmacro 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 groffsimply by specifying the -mdocoption instead of the -manoption. Using the -mandocoption 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 lineThe first command in a man page (after comment lines, that is, lines that start with .\") should be
.THtitle section date source manual
SectionsSections are started with .SHfollowed by the heading name.
The only mandatory heading is NAME, which should be the first section and be followed on theline by a one-line description of the program:
item \- description
For a list of other sections that might appear in a manual page, see man-pages(7).
FontsThe commands to select the type face are:
- Bold alternating with italics (especially useful for function specifications)
- Bold alternating with Roman (especially useful for referring to other manual pages)
- Italics alternating with bold
- Italics alternating with Roman
- Roman alternating with bold
- Roman alternating with italics
- Small alternating with bold
- 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. All of the arguments will be printedto each other without intervening spaces, so that the .BRcommand 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 ibelow; macros may omit iin 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:
- Same as .PP(begin a new paragraph).
- Same as .PP(begin a new paragraph).
- Begin a new paragraph and reset prevailing indent.
Relative margin indent
- .RS i
- Start relative margin indent: moves the left margin ito the right (if iis 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.
- End relative margin indent and restores the 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 xis omitted, the entire following paragraph is indented by i. If the tag xis provided, it is hung at the left margin before the following indented paragraph (this is just like .TPexcept 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 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 line, but its results are like those of the .IPcommand.
Hypertext link macros(Feature supported with groffonly.) In order to use hypertext link macros, it is necessary to load the www.tmacmacro package. Use the request .mso www.tmacto do this.
- .URL url link trailer
- Inserts a hypertext link to the URI (URL) url, with linkas the text of the link. The trailerwill be printed immediately afterward. When generating HTML this should translate into the HTML command <A HREF="url">link</A>trailer.
- This and other related macros are new, and many tools won't do anything with them, but since many tools (including troff) will simply ignore undefined macros (or at worst insert their text) these are safe to insert.
- It can be useful to define your own URLmacro in manual pages for the benefit of those viewing it with a roff viewer other than groff. That way, the URL, link text, and trailer text (if any) are still visible.
- Here's an example:
- In the above, if groffis being used, the www.tmacmacro package's definition of the URL macro will supersede the locally defined one.
A number of other link macros are available. See groff_www(7) for more details.
- 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 stringsThe manpackage has the following predefined strings:
- Registration Symbol: ®
- Change to default font size
- Trademark Symbol:
- Left angled double quote: ``
- Right angled double quote: ''
Safe subsetAlthough technically manis 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 IPand TPcommands 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 RSand REmacros instead). The condition test (if,ie) should only have aqtaq or aqnaq as the condition. Only translations (tr) that can be ignored should be used. Font changes (ftand 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.
By all means include full URLs (or URIs) in the text itself; some tools such as man2html(1) can automatically turn them into hypertext links. You can also use the new URLmacro to identify links to related information. If you include URLs, use the full URL (e.g., to ensure that tools can automatically find the URLs.
Tools processing these files should open the file and examine the first nonwhitespace character. A period (.) or single quote (') at the beginning of a line indicates a troff-based file (such as man or mdoc). A left angle bracket (<) indicates an SGML/XML-based file (such as HTML or Docbook). Anything else suggests simple ASCII text (e.g., a "catman" result).
Many man pages begin with '\" followed by a space and a list of characters, indicating how the page is to be preprocessed. For portability's sake to non-troff translators we recommend that you avoid using anything other than tbl(1), and Linux can detect that automatically. However, you might want to include this information so your man page can be handled by other (less capable) systems. Here are the definitions of the preprocessors invoked by these characters:
Most of the macros describe formatting (e.g., font type and spacing) instead of marking semantic content (e.g., this text is a reference to another page), compared to formats like mdoc and DocBook (even HTML has more semantic markings). This situation makes it harder to vary the manformat for different media, to make the formatting consistent for a given media, and to automatically insert cross-references. By sticking to the safe subset described above, it should be easier to automate transitioning to a different reference page format in the future.
SEE ALSOapropos(1), groff(1), lexgrog(1), man(1), man2html(1), whatis(1), groff_man(7), groff_www(7), man-pages(7), mdoc(7), mdoc.samples(7)
- SEE ALSO
This document was created by man2html, using the manual pages.
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