Provided by: manpages_2.77-1_all bug

NAME

       man - macros to format man pages

SYNOPSIS

       groff -Tascii -man file ...

       groff -Tps -man file ...

       man [section] title

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

       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).

   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.   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.

   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  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:

   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
       (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 trailer
                Inserts 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.

   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.

FILES

       /usr/share/groff/[*/]tmac/an.tmac
       /usr/man/whatis

NOTES

       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:

       e  eqn(1)

       g  grap(1)

       p  pic(1)

       r  refer(1)

       t  tbl(1)

       v  vgrind(1)

BUGS

       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.

SEE ALSO

       apropos(1), groff(1), man(1),  man2html(1),  groff_mdoc(7),  whatis(1),
       groff_man(7), groff_www(7), man-pages(7), mdoc(7)

COLOPHON

       This  page  is  part of release 2.77 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/.