Ubuntu Manpage: groff_tmac - macro files in the GNU roff typesetting system

Name

       groff_tmac - macro files in the GNU roff typesetting system

Description

       Definitions  of  macros, strings, and registers for use in a roff(7) document can be collected into macro
       files, roff input files designed to produce no output themselves but  instead  ease  the  preparation  of
       other  roff  documents.   There  is  no  syntactical  difference  between a macro file and any other roff
       document; only its purpose distinguishes it.  When a macro file is  installed  at  a  standard  location,
       named according to a certain convention, and suitable for use by a general audience, it is termed a macro
       package.  Macro packages can be loaded by supplying the -m option to troff(1) or a groff front end.

       Each macro package stores its macro, string, and register definitions in one or more  tmac  files.   This
       name originated in early Unix culture as an abbreviation of “troff macros”.

       A macro file must have a name in the form name.tmac (or tmac.name) and be placed in a “tmac directory” to
       be loadable with  the  -mname  option.   Section  “Environment”  of  troff(1)  lists  these  directories.
       Alternatively, a groff document requiring a macro file can load it with the mso (“macro source”) request.

       Like  any  other  roff  document,  a macro file can use the “so” request (“source”) to load further files
       relative to its own location.

       Macro files are named for their most noteworthy application, but a macro file need not define any macros.
       It  can  restrict itself to defining registers and strings or invoking other groff requests.  It can even
       be empty.

Macro packages

Macro packages come in two varieties; those which assume responsibility for page layout and other
critical functions (“major” or “full-service”) and those which do not (“supplemental” or “auxiliary”).
GNU roff provides most major macro packages found in AT&T and BSD Unix systems, an additional full-
service package, and many supplemental packages. Multiple full-service macro packages cannot be used by
the same document. Auxiliary packages can generally be freely combined, though attention to their use of
the groff language name spaces for identifiers (particularly registers, macros, strings, and diversions)
should be paid. Name space management was a significant challenge in AT&T troff; groff's support for
arbitrarily long identifiers affords few excuses for name collisions, apart from attempts at
compatibility with the demands of historical documents.

Man pages
an
man an is used to compose man pages in the format originating in Version 7 Unix (1979). It has a
small macro interface and is widely used; see groff_man(7).

doc
mdoc doc is used to compose man pages in the format originating in 4.3BSD-Reno (1990). It provides
many more features than an, but is also larger, more complex, and not as widely adopted; see
groff_mdoc(7).

Because readers of man pages often do not know in advance which macros are used to format a given
document, a wrapper is available.

andoc
mandoc This macro file, specific to groff, recognizes whether a document uses man or mdoc format and
loads the corresponding macro package. Multiple man pages, in either format, can be handled;
andoc reloads each macro package as necessary.

Full-service packages
The packages in this section provide a complete set of macros for writing documents of any kind, up to
whole books. They are similar in functionality; it is a matter of taste which one to use.

me The classical me macro package; see groff_me(7).

mm The semi-classical mm macro package; see groff_mm(7).

mom The mom macro package, only available in groff. As this was not based on other packages, it was
freely designed as quite a nice, modern macro package. See groff_mom(7).

ms The classical ms macro package; see groff_ms(7).

Localization packages
For Western languages, the localization file sets the hyphenation mode and loads hyphenation patterns and
exceptions. Localization files can also adjust the date format and provide translations of strings used
by some of the full-service macro packages; alter the input encoding (see the next section); and change
the amount of additional inter-sentence space. For Eastern languages, the localization file defines
character classes and sets flags on them. By default, troffrc loads the localization file for English.

trans loads localized strings used by various macro packages after their localized forms have been
prepared by a localization macro file.

groff provides the following localization files.

cs Czech; localizes man, me, mm, mom, and ms. Sets the input encoding to Latin-2 by loading
latin2.tmac.

de
den German; localizes man, me, mm, mom, and ms. Sets the input encoding to Latin-1 by loading
latin1.tmac.

de.tmac selects hyphenation patterns for traditional orthography, and den.tmac does the same for
the new orthography (“Rechtschreibreform”).

en English.

fr French; localizes man, me, mm, mom, and ms. Sets the input encoding to Latin-9 by loading
latin9.tmac.

it Italian; localizes man, me, mm, mom, and ms.

ja Japanese.

sv Swedish; localizes man, me, mm, mom, and ms. Sets the input encoding to Latin-1 by loading
latin1.tmac. Some of the localization of the mm package is handled separately; see groff_mmse(7)
(only in Swedish locales).

zh Chinese.

Input encodings
latin1
latin2
latin5
latin9 are various ISO 8859 input encodings supported by groff. On systems using ISO character
encodings, groff loads latin1.tmac automatically at startup. A document that uses Latin-2,
Latin-5, or Latin-9 can specify one of these alternative encodings.

cp1047 provides support for EBCDIC-based systems. On those platforms, groff loads cp1047.tmac
automatically at startup.

Because different input character codes constitute valid GNU troff input on ISO and EBCDIC systems, the
latin macro files cannot be used on EBCDIC systems, and cp1047 cannot be used on ISO systems.

Auxiliary packages
The macro packages in this section are not intended for stand-alone use, but can add functionality to any
other macro package or to plain (“raw”) groff documents.

62bit provides macros for addition, multiplication, and division of 62-bit integers (allowing safe
multiplication of signed 31-bit integers, for example).

hdtbl allows the generation of tables using a syntax similar to the HTML table model. This Heidelberger
table macro package is not a preprocessor, which can be useful if the contents of table entries
are determined by macro calls or string interpolations. Compare to tbl(1). It works only with
the ps and pdf output devices. See groff_hdtbl(7).

papersize
enables the paper format to be set on the command line by giving a “-d paper=format” option to
troff. Possible values for format are the ISO and DIN formats “A0–A6”, “B0–B6”, “C0–C6”, and
“D0–D6”; the U.S. formats “letter”, “legal”, “tabloid”, “ledger”, “statement”, and “executive”;
and the envelope formats “com10”, “monarch”, and “DL”. All formats, even those for envelopes, are
in portrait orientation: the length measurement is vertical. Appending “l” (ell) to any of these
denotes landscape orientation instead. This macro file assumes one-inch horizontal margins, and
sets registers recognized by the groff man, mdoc, mm, mom, and ms packages to configure them
accordingly. If you want different margins, you will need to use those packages' facilities, or
troff ll and/or po requests to adjust them. An output device typically requires command-line
options -p and -l to override the paper dimensions and orientation, respectively, defined in its
DESC file; see subsection “Paper format” of groff(1). This macro file is normally loaded at
startup by the troffrc file when formatting for a typesetting device (but not a terminal).

pdfpic provides a single macro, PDFPIC, to include a PDF graphic in a document using features of the pdf
output driver. For other output devices, PDFPIC calls PSPIC, with which it shares an interface
(see below). This macro file is normally loaded at startup by the troffrc file.

pic supplies definitions of the macros PS, PE, and PF, usable with the pic(1) preprocessor. They
center each picture. Use it if your document does not use a full-service macro package, or that
package does not supply working pic macro definitions. Except for man and mdoc, those provided
with groff already do so (exception: mm employs the name PF for a different purpose).

pspic provides a macro, PSPIC, that includes a PostScript graphic in a document. The ps, dvi, html, and
xhtml output devices support such inclusions; for all other drivers, the image is replaced with a
rectangular border of the same size. pspic.tmac is loaded at startup by the troffrc file.

Its syntax is as follows.

.PSPIC [-L|-R|-C|-I n] file [width [height]]

file is the name of the PostScript file; width and height give the desired width and height of the
image. If neither a width nor a height argument is specified, the image's natural width (as given
in the file's bounding box) or the current line length is used as the width, whatever is smaller.
The width and height arguments may have scaling units attached; the default scaling unit is i.
PSPIC scales the graphic uniformly in the horizontal and vertical directions so that it is no more
than width wide and height high. Option -C centers the graphic horizontally; this is the default.
-L and -R left- and right-align the graphic, respectively. -I indents the graphic by n (with a
default scaling unit of m).

To use PSPIC within a diversion, we recommend extending it with the following code, assuring that
the diversion's width completely covers the image's width.

.am PSPIC
. vpt 0
\h'(\\n[ps-offset]u + \\n[ps-deswid]u)'
. sp -1
. vpt 1
..

Failure to load PSPIC's image argument is not an error. (The psbb request does issue an error
diagnostic.) To make such a failure fatal, append to the pspic*error-hook macro.

.am pspic*error-hook
. ab
..

ptx provides a macro, xx, to format permuted index entries as produced by the GNU ptx(1) program. If
your formatting needs differ, copy the macro into your document and adapt it to your needs.

rfc1345
defines special character escape sequences named for the glyph mnemonics specified in RFC 1345 and
the digraph table of the Vim text editor. See groff_rfc1345(7).

sboxes offers an interface to the “pdf: background” device control command supported by gropdf(1). Using
this package, groff ms documents can draw colored rectangles beneath any output.

.BOXSTART SHADED color OUTLINED color INDENT size WEIGHT size
begins a box, where the argument after SHADED gives the fill color and that after OUTLINED
the border color. Omit the former to get a borderless filled box and the latter for a
border with no fill. The specified WEIGHT is used if the box is OUTLINED.

INDENT precedes a value which leaves a gap between the border and the contents inside the
box.

Each color must be a defined groff color name, and each size a valid groff numeric
expression. The keyword/value pairs can be specified in any order.

Boxes can be stacked, so you can start a box within another box; usually the later boxes would be
smaller than the containing box, but this is not enforced. When using BOXSTART, the left position
is the current indent minus the INDENT in the command, and the right position is the left position
(calculated above) plus the current line length and twice the indent.

.BOXSTOP
takes no parameters. It closes the most recently started box at the current vertical
position after adding its INDENT spacing.

Your groff documents can conditionally exercise the sboxes macros. The register GSBOX is defined
if the package is loaded, and interpolates a true value if the pdf output device is in use.

sboxes furthermore hooks into the groff_ms(7) package to receive notifications when footnotes are
growing, so that it can close boxes on a page before footnotes are printed. When that condition
obtains, sboxes will close open boxes two points above the footnote separator and re-open them on
the next page. (This amount probably will not match the box's INDENT.)

See “Using PDF boxes with groff and the ms macros” ⟨file:///usr/share/doc/groff-base/msboxes.pdf⟩
for a demonstration.

trace aids the debugging of groff documents by tracing macro calls. See groff_trace(7).

www defines macros corresponding to HTML elements. See groff_www(7).

Naming

AT&T nroff and troff were implemented before the conventions of the modern C getopt(3) call evolved, and
used a naming scheme for macro packages that looks odd to modern eyes. Macro packages were typically
loaded using the -m option to the formatter; when directly followed by its argument without an
intervening space, this looked like a long option preceded by a single minus—a sensation in the computer
stone age. Macro packages therefore came to be known by names that started with the letter “m”, which
was omitted from the name of the macro file as stored on disk. For example, the manuscript macro package
was stored as tmac.s and loaded with the option -ms.

groff commands permit space between an option and its argument. The syntax “groff -m s” makes the macro
file name more clear but may surprise users familiar with the original convention, unaware that the
package's “real” name was “s” all along. For such packages of long pedigree, groff accommodates
different users' expectations by supplying wrapper macro files that load the desired file with mso
requests. Thus, all of “groff -m s”, “groff -m ms”, “groff -ms”, and “groff -mms” serve to load the
manuscript macros.

Wrappers are not provided for packages of more recent vintage, like www.tmac.

As noted in passing above, AT&T troff named macro files in the form tmac.name. It has since become
conventional in operating systems to use a suffixed file name extension to suggest a file type or format.

Inclusion

       The traditional method of employing a macro package is to specify the -m package option to the formatter,
       which then reads package's macro file prior to any input files.  Historically, package was  sought  in  a
       file  named  tmac.package  (that  is, with a “tmac.” prefix).  GNU troff searches for package.tmac in the
       macro path; if not found, it looks for tmac.package instead, and vice versa.

       Alternatively, one could include a macro file by using the request “.so file-name” in the document; file-
       name is resolved relative to the location of the input document.  GNU troff offers an improved feature in
       the similar request “mso  package-file-name”,  which  searches  the  macro  path  for  package-file-name.
       Because  its  argument  is  a file name, its “.tmac” component must be included for the file to be found;
       however, as a convenience, if opening it fails, mso strips any such suffix and tries again with a “tmac.”
       prefix, and vice versa.

       If  a  sourced  file  requires preprocessing, for example if it includes tbl tables or eqn equations, the
       preprocessor soelim(1) must be used.  This can be achieved with a pipeline or, in  groff,  by  specifying
       the  -s  option  to  the  formatter  (or  front  end).   man(1)  librarian programs generally call soelim
       automatically.  (Macro packages themselves generally do not require preprocessing.)

Writing macros

A roff(7) document is a text file that is enriched by predefined formatting constructs, such as requests,
escape sequences, strings, numeric registers, and macros from a macro package. These elements are
described in roff(7).

To give a document a personal style, it is most useful to extend the existing elements by defining some
macros for repeating tasks; the best place for this is near the beginning of the document or in a
separate file.

Macros without arguments are just like strings. But the full power of macros occurs when arguments are
passed with a macro call. Within the macro definition, the arguments are available as the escape
sequences \$1, ..., \$9, \$[...], \$*, and \$@, the name under which the macro was called is in \$0, and
the number of arguments is in register \n[.$]; see groff(7).

Draft mode
Writing groff macros is easy when the escaping mechanism is temporarily disabled. In groff, this is done
by enclosing the macro definition(s) within a pair of .eo and .ec requests. Then the body in the macro
definition is just like a normal part of the document — text enhanced by calls of requests, macros,
strings, registers, etc. For example, the code above can be written in a simpler way by

.eo
.ds midpart was called with the following
.de print_args
\f[I]\$0\f[] \*[midpart] \n[.$] arguments:
\$*
..
.ec

Unfortunately, draft mode cannot be used universally. Although it is good enough for defining normal
macros, draft mode fails with advanced applications, such as indirectly defined strings, registers, etc.
An optimal way is to define and test all macros in draft mode and then do the backslash doubling as a
final step; do not forget to remove the .eo request.

Tips for macro definitions
• Start every line with a dot, for example, by using the groff request .nop for text lines, or write
your own macro that handles also text lines with a leading dot.

.de Text
. if (\\n[.$] == 0) \
. return
. nop \)\\$*\)
..

• Write a comment macro that works both for copy and draft modes; since the escape character is off
in draft mode, trouble might occur when comment escape sequences are used. For example, the
following macro just ignores its arguments, so it acts like a comment line:

.de c
..
.c This is like a comment line.

• In long macro definitions, make ample use of comment lines or almost-empty lines (this is, lines
which have a leading dot and nothing else) for a better structuring.

• To increase readability, use groff's indentation facility for requests and macro calls (arbitrary
whitespace after the leading dot).

Diversions
Diversions can be used to implement quite advanced programming constructs. They are comparable to
pointers to large data structures in the C programming language, but their usage is quite different.

In their simplest form, diversions are multi-line strings, but diversions get their power when used
dynamically within macros. The (formatted) information stored in a diversion can be retrieved by calling
the diversion just like a macro.

Most of the problems arising with diversions can be avoided if you remember that diversions always store
complete lines. Using diversions when the line buffer has not been flushed produces strange results; not
knowing this, many people get desperate about diversions. To ensure that a diversion works, add line
breaks at the right places. To be safe, enclose everything that has to do with diversions within a pair
of line breaks; for example, by explicitly using .br requests. This rule should be applied to diversion
definition, both inside and outside, and to all calls of diversions. This is a bit of overkill, but it
works nicely.

(If you really need diversions which should ignore the current partial line, use environments to save the
current partial line and/or use the .box request.)

The most powerful feature using diversions is to start a diversion within a macro definition and end it
within another macro. Then everything between each call of this macro pair is stored within the
diversion and can be manipulated from within the macros.

Authors

       This document was written by Bernd Warken ⟨groff-bernd.warken-72@web.de⟩,  Werner  Lemberg  ⟨wl@gnu.org⟩,
       and G. Branden Robinson ⟨g.branden.robinson@gmail.com⟩.