man — macros to format man pages
groff −Tascii −man ... groff −Tps −man ... man
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).
The first command in a man page (after comment lines,
        that is, lines that start with .\") should be
.THtitle 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 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
It is extremely important that this format is followed, and that there is a backslash before the single dash which follows the command name. This syntax is used by the makewhatis(8) program to create a database of short command descriptions for the whatis(1) and apropos(1) commands.
For a list of other sections that might appear in a manual page, see man-pages(7).
The commands to select the type face are:
Bold
Bold alternating with italics (especially useful for function specifications)
Bold alternating with Roman (especially useful for referring to other manual pages)
Italics
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 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.
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 re-specifying the indent value. A normal
        (non-indented) 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.
.RS iStart 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.
End relative margin indent and restores the previous value of the prevailing indent.
.HP iBegin 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 iIndented 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 iBegin paragraph with hanging tag. The tag is given
              on the next line, but its results are like those of
              the .IP
              command.
(Feature supported with groff only.) In order to
        use hypertext link macros, it is necessary to load the
        www.tmac macro
        package. Use the request .mso
        www.tmac to do this.
.URL url link trailerInserts a hypertext link to the URI (URL)
              url, with
              link as the
              text of the link. The trailer will be
              printed immediately afterwards. 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 URL macro 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:
.de URL
\\$2 \(laURL: \\$1 \(ra\\$3
..
.if \n[.g] .mso www.tmac
.TH
...(later in the page) This software comes from the .URL "http://www.gnu.org/" "GNU Project" " of the".URL "http://www.fsf.org/" "Free Software Foundation" .
In the above, if groff is being used,
              the www.tmac macro
              package's definition of the URL macro will supersede
              the locally defined one.
A number of other link macros are available. See groff_www(7) for more details.
Reset tabs to default tab values (every 0.5 inches); does not cause a break.
.PD dSet inter-paragraph vertical distance to d (if omitted, d=0.4v); does not cause a break.
.SS tSubheading t (like .SH, but used for a
              subsection inside a section).
The man
        package has the following predefined strings:
\*RRegistration Symbol: ®
\*SChange to default font size
\*(TmTrademark Symbol: ™
\*(lqLeft angled double quote: «
\*(rqRight angled double quote: »
Although technically man is a troff macro
        package, in reality a large number of other tools process
        man page files that don't implement all of troff's
        abilities. Thus, it's best to avoid some of troff's more
        exotic abilities where possible to permit these other tools
        to work correctly. Avoid using the various troff
        preprocessors (if you must, go ahead and use tbl(1), but try to use the
        IP and TP commands instead for two-column
        tables). Avoid using computations; most other tools can't
        process them. Use simple commands that are easy to
        translate to other formats. The following troff macros are
        believed to be safe (though in many cases they will be
        ignored by translators): \", ., ad, bp, br, ce, de, ds, el, ie, if, fi, ft, hy, ig, in, na, ne, nf, nh, ps, so, sp, ti, tr.
You may also use many troff escape sequences (those
        sequences beginning with \). 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.
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
      URL macro to identify links to
      related information. If you include URLs, use the full URL
      (e.g., <http://www.kernelnotes.org>) to ensure that
      tools can automatically find the URLs.
Tools processing these files should open the file and examine the first non-whitespace 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:
eqn(1)
grap(1)
pic(1)
refer(1)
tbl(1)
vgrind(1)
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 man format 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.
The Sun macro TX is not
      implemented.
apropos(1), groff(1), man(1), man2html(1), whatis(1), groff_man(7), groff_www(7), man-pages(7), mdoc(7), mdoc.samples(7)
This page is part of release 2.79 of the Linux man-pages project. A
      description of the project, and information about reporting
      bugs, can be found at
      http://www.kernel.org/doc/man-pages/.
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                 (C) Copyright 1992-1999 Rickard E. Faith and David A. Wheeler (faithcs.unc.edu and dwheelerida.org) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. Modified Sun Jul 25 11:06:05 1993 by Rik Faith (faithcs.unc.edu) Modified Sat Jun 8 00:39:52 1996 by aeb Modified Wed Jun 16 23:00:00 1999 by David A. Wheeler (dwheelerida.org) Modified Thu Jul 15 12:43:28 1999 by aeb Modified Sun Jan 6 18:26:25 2002 by Martin Schulze <joeyinfodrom.org> Modified Tue Jul 27 20:12:02 2004 by Colin Watson <cjwatsondebian.org> 2007-05-30, mtk: various rewrites and moved much text to new man-pages.7.  |