groff_tmac
GROFF_TMAC(5) GROFF_TMAC(5)
NAME
groff_tmac - macro files in the roff typesetting system
DESCRIPTION
The roff(7) type-setting system provides a set of macro packages suit-
able for special kinds of documents. Each macro package stores its
macros and definitions in a file called the package's tmac file. The
name is deduced from `TroffMACros'.
The tmac files are normal roff source documents, except that they usu-
ally contain only definitions and setup commands, but no text. All
tmac files are kept in a single or a small number of directories, the
tmac directories.
GROFF MACRO PACKAGES
groff provides all classical macro packages, some more full packages,
and some secondary packages for special purposes.
Man Pages
man This is the classical macro package for UNIX manual pages
(man pages); it is quite handy and easy to use; see
groff_man(7).
doc
mdoc An alternative macro package for man pages mainly used in BSD
systems; it provides many new features, but it is not the stan-
dard for man pages; see groff_mdoc(7).
Full Packages
The packages in this section provide a complete set of macros for writ-
ing 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 new mom macro package, only available in groff. As this is
not based on other packages, it can be freely designed. So it
is expected to become quite a nice, modern macro package. See
groff_mom(7).
ms The classical ms macro package; see groff_ms(7).
Special Packages
The macro packages in this section are not intended for stand-alone
usage, but can be used to add special functionality to any other macro
package or to plain groff.
tty-char
Overrides the definition of standard troff characters and some
groff characters for tty devices. The optical appearance is
intentionally inferior compared to that of normal tty formatting
to allow processing with critical equipment.
www Additions of elements known from the html format, as being used
in the internet (World Wide Web) pages; this includes URL links
and mail addresses; see groff_www(7).
NAMING
In classical roff systems, there was a funny naming scheme for macro
packages, due to a simplistic design in option parsing. Macro packages
were always included by option -m; when this option was directly fol-
lowed 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. To make this optically working for macro package names, all
classical macro packages choose a name that started with the letter
`m', which was omitted in the naming of the macro file.
For example, the macro package for the man pages was called man, while
its macro file tmac.an. So it could be activated by the argument an to
option -m, or -man for short.
For similar reasons, macro packages that did not start with an `m' had
a leading `m' added in the documentation and in talking; for example,
the package corresponding to tmac.doc was called mdoc in the documenta-
tion, although a more suitable name would be doc. For, when omitting
the space between the option and its argument, the command line option
for activating this package reads -mdoc.
To cope with all situations, actual versions of groff(1) are smart
about both naming schemes by providing two macro files for the
inflicted macro packages; one with a leading `m', the other one without
it. So in groff, the man macro package may be specified as on of the
following four methods:
sh# groff -m man
sh# groff -man
sh# groff -mman
sh# groff -m an
Recent packages that do not start with `m' do not use an additional `m'
in the documentation. For example, the www macro package may be speci-
fied only as one of the two methods:
sh# groff -m www
sh# groff -mwww
Obviously, variants like -mmwww would not make much sense.
A second strange feature of classical troff was to name macro files ac-
cording to tmac.name. In modern operating systems, the type of a file
is specified as postfix, the file name extension. Again, groff copes
with this situation by searching both anything.tmac and tmac.anything
if only anything is specified.
The easiest way to find out which macro packages are available on a
system is to check the man page groff(1), or the contents of the tmac
directories.
In groff, most macro packages are described in man pages called
groff_name(7), with a leading `m' for the classical packages.
INCLUSION
There are several ways to use a macro package in a document. The clas-
sical way is to specify the troff/groff option -m name at run-time;
this makes the contents of the macro package name available. In groff,
the file name.tmac is searched within the tmac path; if not found,
tmac.name will be searched for instead.
Alternatively, it is also possible to include a macro file by adding
the request .so filename into the document; the argument must be the
full file name of an existing file, possibly with the directory where
it is kept. In groff, this was improved by the similar request .mso
package, which added searching in the tmac path, just like option -m
does.
Note that in order to resolve the .so and .mso requests, the roff pre-
processor soelim(1) must be called if the files to be included need
preprocessing. This can be done either directly by a pipeline on the
command line or by using the troff/groff option -s. man calls soelim
automatically.
For example, suppose a macro file is stored as
/usr/share/groff/1.18.1/tmac/macros.tmac and is used in some document
called docu.roff.
At run-time, the formatter call for this is
sh# groff -m macrofile document.roff
To include the macro file directly in the document either
.mso macrofile.tmac
is used or
.so /usr/share/groff/1.18.1/tmac/macros.tmac
In both cases, the formatter is called with
sh# troff -s docu.roff
If you want to write your own groff macro file, call it whatever.tmac
and put it in some directory of the tmac path, see section FILES. Then
documents can include it with the .mso request or the option -m.
WRITING MACROS
A roff(7) document is a text file that is enriched by predefined for-
matting constructs, such as requests, escape sequences, strings, numer-
ic registers, and macros from a macro package. These elements are de-
scribed 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 reveals 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 0; see
groff(7).
Copy-in Mode
The phase when groff reads a macro is called copy-in mode in roff-talk.
This is comparable to the C preprocessing phase during the development
of a program written in the C language.
In this phase, groff interprets all backslashes; that means that all
escape sequences in the macro body are interpreted and replaced by
their value. For constant expression, this is wanted, but strings and
registers that might change between calls of the macro must be protect-
ed from being evaluated. This is most easily done by doubling the
backslash that introduces the escape sequence. This doubling is most
important for the positional parameters. For example, to print infor-
mation on the arguments that were passed to the macro to the terminal,
define a macro named `.print_args', say.
.ds midpart was called with
.de print_args
. tm \f[I]\\$0\f[] \\*[midpart] \\n[.$] arguments:
. tm \\$*
..
When calling this macro by
.print_args arg1 arg2
the following text is printed to the terminal:
print_args was called with the following 2 arguments:
arg1 arg2
Let's analyze each backslash in the macro definition. As the position-
al parameters and the number of arguments will change with each call of
the macro their leading backslash must be doubled, which results in
\\$* and \\[.$]. The same applies to the macro name because it could
be called with an alias name, so \\$0.
On the other hand, midpart is a constant string, it will not change, so
no doubling for \*[midpart]. The \f escape sequences are predefined
groff elements for setting the font within the text. Of course, this
behavior will not change, so no doubling with \f[I] and \f[].
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)
into a pair of .eo and .ec requests. Then the body in the macro defi-
nition 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
.de print_args
. tm \f[I]\$0\f[] \*[midpart] \n[.$] arguments:
. tm \$*
..
.ec
Unfortunately, draft mode cannot be used universally. Although it is
good enough for defining normal macros, draft mode will fail with ad-
vanced applications, such as indirectly defined strings, registers,
etc. An optimal way is to define and test all macros in draft mode and
then do the backslash doubling as a final step; do not forget to remove
the .eo request.
Tips for Macro Definitions
o Start every line with a dot, for example, by using the groff request
.nop for text lines, or write your own macro that handles also text
lines with a leading dot.
.de Text
. if (\\n[.$] == 0) \
. return
. nop \)\\$*[rs]
..
o Write a comment macro that works both for copy-in and draft mode; for
as escaping is off in draft mode, trouble might occur when normal
comments 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.
o In long macro definitions, make ample use of comment lines or empty
lines for a better structuring.
o To increase readability, use groff's indentation facility for re-
quests and macro calls (arbitrary whitespace after the leading dot).
Diversions
Diversions can be used to realize quite advanced programming con-
structs. 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 they get
their power when diversions are used dynamically within macros. The
information stored in a diversion can be retrieved by calling the di-
version just like a macro.
Most of the problems arising with diversions can be avoided if you are
conscious about the fact that diversions always deal with complete
lines. If diversions are used when the line buffer has not been
flashed, strange results are produced; not knowing this, many people
get desperate about diversions. To ensure that a diversion works, line
breaks should be added at the right places. To be on the secure side,
enclose everything that has to do with diversions into a pair of line
breaks; for example, by amply 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 every-
thing between each call of this macro pair is stored within the diver-
sion and can be manipulated from within the macros.
FILES
All macro names must be named name.tmac to fully use the tmac mecha-
nism. tmac.name as with classical packages is possible as well, but
deprecated.
The macro files are kept in the tmac directories; a colon separated
list of these constitutes the tmac path.
The search sequence for macro files is (in that order):
o the directories specified with troff/groff's -M command line option
o the directories given in the $GROFF_TMAC_PATH environment variable
o the current directory (only if in unsafe mode, which is enabled by
the -U command line switch)
o the home directory
o a platform-specific directory, being /usr/lib/groff/site-tmac in this
installation
o a site-specific (platform-independent) directory, being
/usr/share/groff/site-tmac in this installation
o the main tmac directory, being /usr/share/groff/1.18.1/tmac in this
installation
ENVIRONMENT
$GROFF_TMAC_PATH
A colon separated list of additional tmac directories in which
to search for macro files. See the previous section for a de-
tailed description.
AUTHOR
Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
This document is distributed under the terms of the FDL (GNU Free Docu-
mentation License) version 1.1 or later. You should have received a
copy of the FDL on your system, it is also available on-line at the GNU
copyleft site <http://www.gnu.org/copyleft/fdl.html>.
This document is part of groff, the GNU roff distribution. It was
written by Bernd Warken <bwarken@mayn.de>; it is maintained by Werner
Lemberg <wl@gnu.org>.
SEE ALSO
A complete reference for all parts of the groff system is found in the
groff info(1) file.
groff(1)
an overview of the groff system.
groff_man(7),
groff_mdoc(7),
groff_me(7),
groff_mm(7),
groff_mom(7),
groff_ms(7),
groff_www(7).
the groff tmac macro packages.
groff(7)
the groff language.
The Filesystem Hierarchy Standard is available at the FHS web site
<http://www.pathname.com/fhs/>.
Groff Version 1.18.1 21 August 2002 GROFF_TMAC(5)
