GROFF_TMAC(5) | File Formats Manual | GROFF_TMAC(5) |
groff_tmac - macro files in the roff typesetting system
The roff(7) type-setting system provides a set of macro packages suitable 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 usually 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 provides all classical macro packages, some more full packages, and some secondary packages for special purposes. Note that it is not possible to use multiple primary macro packages at the same time; saying e.g.
sh# groff -m man -m ms foo
or
sh# groff -m man foo -m ms bar
fails. Exception to this is the use of man pages written with either the mdoc or the man macro package. See below the description of the andoc.tmac file.
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.
sh# groff -ms -mfr foo.ms > foo.ps
Note that it can happen that some input encoding characters are not available for a particular output device. For example, saying
groff -Tlatin1 -mlatin9 ...
fails if you use the Euro character in the input. Usually, this limitation is present only for devices which have a limited set of output glyphs (-Tascii, -Tlatin1); for other devices it is usually sufficient to install proper fonts which contain the necessary glyphs.
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.
sh# groff -Tps -dpaper=a4l -P-pa4 -P-l -ms foo.ms > foo.ps
.am PSPIC . vpt 0 \h'(\\n[ps-offset]u + \\n[ps-deswid]u)' . sp -1 . vpt 1 ..
Classical roff systems were designed 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 always included with the option -m; when this option was 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. To make this invocation form work, classical troff macro packages used names 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 speech; for example, the package corresponding to tmac.doc was called mdoc in the documentation, 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 one 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 specified 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 in the form tmac.name. In modern operating systems, the type of a file is specified as a 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.
There are several ways to use a macro package in a document. The classical 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 is 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 preprocessor 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
and is used in some document called docu.roff.
At run-time, the formatter call for this is
sh# groff -m macros docu.roff
To include the macro file directly in the document either
.mso macros.tmac
is used or
.so /usr/share/groff/1.22.4/tmac/macros.tmac
In both cases, the formatter should be called with option -s to invoke soelim.
sh# groff -s docu.roff
If you want to write your own groff macro file, call it whatever.tmac and put it in a directory in the tmac path; see section “Files” below. Then documents can include it with the .mso request or the option -m.
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 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 \n[.$]; see groff(7).
The phase when groff reads a macro is called copy-in mode or copy 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 expressions, this is wanted, but strings and registers that might change between calls of the macro must be protected 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 information 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 positional parameters and the number of arguments 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 does 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 does not change, so no doubling with \f[I] and \f[].
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 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 .de print_args . tm \f[I]\$0\f[] \*[midpart] \n[.$] arguments: . tm \$* .. .ec
Unfortunately, draft mode cannot be used universally. Although it is good enough for defining normal macros, draft mode fails with advanced applications, such as indirectly defined strings, registers, etc. An optimal way is to define and test all macros in draft mode and then do the backslash doubling as a final step; do not forget to remove the .eo request.
.de Text . if (\\n[.$] == 0) \ . return . nop \)\\$*\) ..
.de c .. .c This is like a comment line.
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 they get their power when diversions are 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 remain aware of the fact that diversions always store complete lines. If diversions are used when the line buffer has not been flushed, 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 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.
All macro package files must be named name.tmac to fully use the tmac mechanism. 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):
This document was written by Bernd Warken and Werner Lemberg.
Groff: The GNU Implementation of troff, by Trent A. Fisher and Werner Lemberg, is the primary groff manual. You can browse it interactively with “info groff”.
The Filesystem Hierarchy Standard is available at the FHS web site.
7 March 2023 | groff 1.22.4 |