Provided by: groff-base_1.22.4-8build1_amd64 
NAME
troff - the troff processor of the groff text formatting system
SYNOPSIS
troff [-abcivzCERU] [-d cs] [-f fam] [-F dir] [-I dir] [-m name] [-M dir] [-n num] [-o list] [-r cn]
[-T name] [-w name] [-W name] [file ...]
DESCRIPTION
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.
OPTIONS
Whitespace is permitted between a command-line option and its argument.
-a Generate an ASCII approximation of the typeset output.
-b 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
troff's idea of line numbers gets confused by as or am requests.
-c Disable color output (always disabled in compatibility mode).
-C Enable compatibility mode.
-dcs
-dname=s
Define c or name to be a string s; c must be a one letter name.
-E Inhibit all error messages of troff. Note that this doesn't affect messages output to standard
error by macro packages using the tm or tm1 requests.
-ffam Use fam as the default font family.
-Fdir 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 font
directories.
-i Read the standard input after all the named input files have been processed.
-Idir 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 name.
-mname 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, /usr/lib/groff/site-tmac, /usr/share/groff/site-tmac, and /usr/share/groff/1.22.4/
tmac.
-Mdir Search directory (or directory path) dir for macro files. This is scanned before all other macro
directories.
-nnum Number the first page num.
-olist 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. troff will exit after printing the last page in the list.
-rcn
-rname=n
Set number register c or name to n; c must be a one character name; n can be any troff numeric
expression.
-R Don't load troffrc and troffrc-end.
-Tname Prepare output for device name, rather than the default ps; see groff(1) for a more detailed
description.
-U 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.
-v Print the version number.
-wname 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.
-Wname Inhibit warning name. Multiple -W options are allowed.
-z Suppress formatted output.
WARNINGS
The warnings that can be given by troff 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.
┌─────────────────────┬─────────────────────────────┐
│Bit Code Warning │ Bit Code Warning │
├─────────────────────┼─────────────────────────────┤
│ 0 1 char │ 10 1024 reg │
│ 1 2 number │ 11 2048 tab │
│ 2 4 break │ 12 4096 right-brace │
│ 3 8 delim │ 13 8192 missing │
│ 4 16 el │ 14 16384 input │
│ 5 32 scale │ 15 32768 escape │
│ 6 64 range │ 16 65536 space │
│ 7 128 syntax │ 17 131072 font │
│ 8 256 di │ 18 262144 ig │
│ 9 512 mac │ 19 524288 color │
│ │ 20 1048576 file │
└─────────────────────┴─────────────────────────────┘
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 diversion.
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 default.
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 particular name.
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 argument.
There are also names that can be used to refer to groups of warnings:
all All warnings except di, mac, and reg. It is intended that this covers all warnings that are
useful with traditional macro packages.
w All warnings.
ENVIRONMENT
GROFF_TMAC_PATH
A colon separated list of directories in which to search for macro files. troff will scan
directories given in the -M option before these, and in standard directories (current directory if
in unsafe mode, home directory, /usr/lib/groff/site-tmac, /usr/share/groff/site-tmac, /usr/share/
groff/1.22.4/tmac) after these.
GROFF_TYPESETTER
Default device.
GROFF_FONT_PATH
A colon separated list of directories in which to search for the devname directory. troff will
scan directories given in the -F option before these, and in standard directories (/usr/share/
groff/site-font, /usr/share/groff/1.22.4/font, /usr/lib/font) after these.
FILES
/usr/share/groff/1.22.4/tmac/troffrc
Initialization file (called before any other macro package).
/usr/share/groff/1.22.4/tmac/troffrc-end
Initialization file (called after any other macro package).
/usr/share/groff/1.22.4/tmac/name.tmac
/usr/share/groff/1.22.4/tmac/tmac.name
Macro files
/usr/share/groff/1.22.4/font/devname/DESC
Device description file for device name.
/usr/share/groff/1.22.4/font/devname/F
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.
AUTHORS
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 ⟨wl@gnu.org⟩ and Bernd Warken ⟨groff-bernd.warken-72@
web.de⟩.
SEE ALSO
groff(1)
The main program of the groff system, a wrapper around troff.
groff(7)
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
man 7 groff
groff_diff(7)
The differences of the groff language and the classical troff language. Currently, this is the
most actual document of the groff system.
roff(7)
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”.