gtroff - the troff processor of the groff text formatting system
This manual page describes the GNU version of troff. It is part of the
groff document formatting system. It is functionally compatible with Unix
troff, but has many extensions, see groff_diff(7). Usually it should be
invoked using the groff(1) command which will also run preprocessors
and postprocessors in the appropriate order and with the appropriate options.
Whitespace is permitted between a command-line option and its argument.
cs] [-f fam]
[-F dir] [-I
dir] [-m name]
[-M dir] [-n
num] [-o list]
[-r cn] [-T
name] [-w name]
[-W name] [file ...]
- Generate an ASCII approximation of the typeset output.
- Print a backtrace with each warning or error message. This backtrace
should help track down the cause of the error. The line numbers given in
the backtrace may not always be correct, for gtroff's idea of line
numbers gets confused by as or am requests.
- Disable color output (always disabled in compatibility mode).
- Enable compatibility mode.
- Define c or name to be a string s; c must be a
one letter name.
- Inhibit all error messages of gtroff. Note that this doesn't affect
messages output to standard error by macro packages using the tm or
- Use fam as the default font family.
- Search in directory (or directory path) dir for subdirectories
devname (name is the name of the device) and there for the
DESC file and font files. dir is scanned before all other
- Read the standard input after all the named input files have been
- This option may be used to add a directory to the search path for files
(both those on the command line and those named in .psbb requests).
The search path is initialized with the current directory. This option may
be specified more than once; the directories are then searched in the
order specified (but before the current directory). If you want to make
the current directory be read before other directories, add -I. at
the appropriate place.
- No directory search is performed for files with an absolute file
The warnings that can be given by gtroff are divided into the following
categories. The name associated with each warning is used by the -w and
-W options; the number is used by the warn request, and by the
.warn register; it is always a power of 2 to allow bitwise composition.
- Read in the file name.tmac. If it isn't found, try tmac.name
instead. It will be first searched for in directories given with the
-M command-line option, then in directories given in the
GROFF_TMAC_PATH environment variable, then in the current directory
(only if in unsafe mode), the home directory,
- Search directory (or directory path) dir for macro files. This is
scanned before all other macro directories.
- Number the first page num.
- Output only pages in list, which is a comma-separated list of page
ranges; n means print page n, m-n means
print every page between m and n, -n means
print every page up to n, n- means print every page
from n. gtroff will exit after printing the last page in the
- Set number register c or name to n; c must be
a one character name; n can be any troff numeric expression.
- Don't load troffrc and troffrc-end.
- Prepare output for device name, rather than the default ps;
see groff(1) for a more detailed description.
- Unsafe mode. This will enable the following requests: open,
opena, pso, sy, and pi. For security reasons,
these potentially dangerous requests are disabled otherwise. It will also
add the current directory to the macro search path.
- Print the version number.
- Enable warning name. Available warnings are described in section
“Warnings” below. To enable most useful warnings use
-w all. To enable absolutely all warnings use -w w
instead. Multiple -w options are allowed.
- Inhibit warning name. Multiple -W options are allowed.
- Suppress formatted output.
- break 4
- In fill mode, lines which could not be broken so that their length was
less than the line length. This is enabled by default.
- char 1
- Non-existent characters. This is enabled by default.
- color 524288
- Color-related warnings.
- delim 8
- Missing or mismatched closing delimiters.
- di 256
- Use of di or da without an argument when there is no current
- el 16
- Use of the el request with no matching ie request.
- escape 32768
- Unrecognized escape sequences. When an unrecognized escape sequence is
encountered, the escape character is ignored.
- file 1048576
- Indicates a missing file for the mso request. Enabled by
- font 131072
- Non-existent fonts. This is enabled by default.
- ig 262144
- Invalid escapes in text ignored with the ig request. These are
conditions that are errors when they do not occur in ignored text.
- input 16384
- Invalid input characters.
- mac 512
- Use of undefined strings, macros and diversions. When an undefined string,
macro or diversion is used, that string is automatically defined as empty.
So, in most cases, at most one warning will be given for each name.
- missing 8192
- Requests that are missing non-optional arguments.
- number 2
- Invalid numeric expressions. This is enabled by default.
- range 64
- Out of range arguments.
- reg 1024
- Use of undefined number registers. When an undefined number register is
used, that register is automatically defined to have a value of 0.
So, in most cases, at most one warning will be given for use of a
- right-brace 4096
- Use of \} where a number was expected.
- scale 32
- Meaningless scaling indicators.
- space 65536
- Missing space between a request or macro and its argument. This warning
will be given when an undefined name longer than two characters is
encountered, and the first two characters of the name make a defined name.
The request or macro will not be invoked. When this warning is given, no
macro is automatically defined. This is enabled by default. This warning
will never occur in compatibility mode.
- syntax 128
- Dubious syntax in numeric expressions.
- tab 2048
- Inappropriate use of a tab character. Either use of a tab character where
a number was expected, or use of tab character in an unquoted macro
There are also names that can be used to refer to groups of
- All warnings except di, mac, and reg. It is intended
that this covers all warnings that are useful with traditional macro
- All warnings.
- A colon separated list of directories in which to search for macro files.
gtroff will scan directories given in the -M option before
these, and in standard directories (current directory if in unsafe mode,
home directory, /usr/lib/amd64/groff/site-tmac,
- Default device.
- A colon separated list of directories in which to search for the
devname directory. gtroff will scan directories given in the
-F option before these, and in standard directories
/usr/lib/font) after these.
- Initialization file (called before any other macro package).
- Initialization file (called after any other macro package).
- Macro files
- Device description file for device name.
- Font file for font F of device name.
Note that troffrc and troffrc-end are searched for
neither in the current nor the home directory by default for security
reasons (even if the -U option is given). Use the -M
command-line option or the GROFF_TMAC_PATH environment variable to
add these directories to the search path if necessary.
The GNU version of troff was originally written by James Clark; he also
wrote the original version of this document, which was modified by
Werner Lemberg and
- The main program of the groff system, a wrapper around
- A description of the groff language, including a short but complete
reference of all predefined requests, registers, and escapes of plain
groff. From the command line, this is called by
- The differences of the groff language and the classical
troff language. Currently, this is the most actual document of the
- An overview over groff and other roff systems, including
pointers to further related documentation.
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”.