'\" t
.ig
troff.man

Last update : 12 Oct 2003

This file is part of groff, the GNU roff type-setting system.

Copyright (C) 1989, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.

written by James Clark

modified by Werner Lemberg <wl@gnu.org>
            Bernd Warken <bwarken@mayn.de>

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with the
Invariant Sections being this .ig-section and AUTHOR, with no
Front-Cover Texts, and with no Back-Cover Texts.

A copy of the Free Documentation License is included as a file called
FDL in the main directory of the groff source package.
..
.
.
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.\" --------------------------------------------------------------------
.\" Title
.\" --------------------------------------------------------------------
.
.TH @G@TROFF @MAN1EXT@ "@MDATE@" "Groff Version @VERSION@"
.SH NAME
@g@troff \- the troff processor of the groff text formatting system
.
.
.\" --------------------------------------------------------------------
.SH SYNOPSIS
.\" --------------------------------------------------------------------
.
.nr a \n(.j
.ad l
.nr i \n(.i
.in +\w'\fB@g@troff 'u
.ti \niu
.B @g@troff
.de OP
.ie \\n(.$-1 .RI "[\ \fB\\$1\fP" "\\$2" "\ ]"
.el .RB "[\ " "\\$1" "\ ]"
..
.OP \-abcivzCERU
.OP \-d cs
.OP \-f fam
.OP \-F dir
.OP \-I dir
.OP \-m name
.OP \-M dir
.OP \-n num
.OP \-o list
.OP \-r cn
.OP \-T name
.OP \-w name
.OP \-W name
.RI "[\ " files\|.\|.\|. "\ ]"
.br
.ad \na
.P
It is possible to have whitespace between a command line option and
its parameter.
.
.
.\" --------------------------------------------------------------------
.SH DESCRIPTION
.\" --------------------------------------------------------------------
.
This manual page describes the GNU version of
.BR troff .
It is part of the groff document formatting system.
.
It is functionally compatible with UNIX troff, but has many extensions,
see
.BR \%groff_diff (@MAN7EXT@).
Usually it should be invoked using the
.BR groff (@MAN1EXT@)
command which will also run preprocessors and postprocessors in the
appropriate order and with the appropriate options.
.
.
.\" --------------------------------------------------------------------
.SH OPTIONS
.\" --------------------------------------------------------------------
.
.TP \w'\-dname=s'u+2n
.B \-a
Generate an
.SM ASCII
approximation of the typeset output.
.
.TP
.B \-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
.BR @g@troff 's
idea of line numbers gets confused by
.B as
or 
.B am
requests.
.
.TP
.B \-c
Disable color output (always disabled in compatibility mode).
.
.TP
.B \-C
Enable compatibility mode.
.
.TP
.BI \-d cs
.TQ
.BI \-d name = s
Define
.I c
or
.I name
to be a string
.IR s ;
.I c
must be a one letter name.
.
.TP
.B \-E
Inhibit all error messages of
.BR @g@troff .
Note that this doesn't affect messages output to standard error by macro
packages using the
.B tm
or
.B tm1
requests.
.
.TP
.BI \-f fam
Use
.I fam
as the default font family.
.
.TP
.BI \-F dir
Search in directory (or directory path)
.I dir
for subdirectories
.BI dev name
.RI ( name
is the name of the device) and there for the
.B DESC
file and font files.
.I dir
is scanned before all other font directories.
.
.TP
.B \-i
Read the standard input after all the named input files have been
processed.
.
.TP
.BI \-I dir
This option may be used to specify a directory to search for
files (both those on the command line and those named in
.B \&.psbb
requests).
The current directory is always searched first.
This option may be specified more than once;
the directories will be searched in the order specified.
No directory search is performed for files specified using an absolute path.
.
.TP
.BI \-m name
Read in the file
.IB name .tmac\fR.
If it isn't found, try
.BI tmac. name
instead.
.
It will be first searched for in directories given with the
.B \-M
command line option, then in directories given in the
.B GROFF_TMAC_PATH
environment variable, then in the current directory (only if in unsafe
mode), the home directory, @SYSTEMMACRODIR@, @LOCALMACRODIR@, and
@MACRODIR@.
.
.TP
.BI \-M dir
Search directory (or directory path)
.I dir
for macro files.
.
This is scanned before all other macro directories.
.
.TP
.BI \-n num
Number the first page
.IR num .
.
.TP
.BI \-o list
Output only pages in
.IR list ,
which is a comma-separated list of page ranges;
.I n
means print page
.IR n ,
.IB m \- n
means print every page between
.I m
and
.IR n ,
.BI \- n
means print every page up to
.IR n ,
.IB n \-
means print every page from
.IR n .
.B @g@troff
will exit after printing the last page in the list.
.
.TP
.BI \-r cn
.TQ
.BI \-r name = n
Set number register
.I c
or
.I name
to
.IR n ;
.I c
must be a one character name;
.I n
can be any troff numeric expression.
.
.TP
.B \-R
Don't load
.B troffrc
and
.BR troffrc-end .
.
.TP
.BI \-T name
Prepare output for device
.IR name ,
rather than the default
.BR @DEVICE@ ;
see
.BR groff (@MAN1EXT@)
for a more detailed description.
.
.TP
.B \-U
Unsafe mode.
.
This will enable the following requests:
.BR open ,
.BR opena ,
.BR pso ,
.BR sy ,
and
.BR pi .
For security reasons, these potentially dangerous requests are disabled
otherwise.
.
It will also add the current directory to the macro search path.
.
.TP
.B \-v
Print the version number.
.
.TP
.BI \-w name
Enable warning
.IR  name .
Available warnings are described in the section
.I WARNINGS
below.
.
For example, to enable all warnings, use
.B \-w
.BR all .
Multiple
.B \-w
options are allowed.
.
.TP
.BI \-W name
Inhibit warning
.IR name .
Multiple
.B \-W
options are allowed.
.
.TP
.B \-z
Suppress formatted output.
.
.
.\" --------------------------------------------------------------------
.SH WARNINGS
.\" --------------------------------------------------------------------
.
The warnings that can be given by
.B @g@troff
are divided into the following categories.
.
The name associated with each warning is used by the
.B \-w
and
.B \-W
options; the number is used by the
.B warn
request, and by the
.B .warn
register; it is always a power of 2 to allow bitwise composition.
.
.P
.TS
tab(@), center, box;
c c c | c c c
r rI lB | r rI lB.
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
.TE
.
.P
.nr x \w'\fBright-brace'+1n+\w'00000'u
.ta \nxuR
.
.TP \nxu+3n
.BR break "\t4"
In fill mode, lines which could not be broken so that their length was
less than the line length.
.
This is enabled by default.
.
.TP
.BR char "\t1"
Non-existent characters.
.
This is enabled by default.
.
.TP
.BR color "\t524288"
Color related warnings.
.
.TP
.BR delim "\t8"
Missing or mismatched closing delimiters.
.
.TP
.BR di "\t256"
Use of
.B di
or
.B da
without an argument when there is no current diversion.
.
.TP
.BR el "\t16"
Use of the
.B el
request with no matching
.B ie
request.
.
.TP
.BR escape "\t32768"
Unrecognized escape sequences.
.
When an unrecognized escape sequence is encountered, the escape
character is ignored.
.
.TP
.BR font "\t131072"
Non-existent fonts.
.
This is enabled by default.
.
.TP
.BR ig "\t262144"
Invalid escapes in text ignored with the
.B ig
request.
.
These are conditions that are errors when they do not occur in ignored
text.
.
.TP
.BR input "\t16384"
Invalid input characters.
.
.TP
.BR mac "\t512"
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.
.
.TP
.BR missing "\t8192"
Requests that are missing non-optional arguments.
.
.TP
.BR number "\t2"
Invalid numeric expressions.
.
This is enabled by default.
.
.TP
.BR range "\t64"
Out of range arguments.
.
.TP
.BR reg "\t1024"
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.
.
.TP
.BR right-brace "\t4096"
Use of
.B \[rs]}
where a number was expected.
.
.TP
.BR scale "\t32"
Meaningless scaling indicators.
.
.TP
.BR space "\t65536"
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.
.
.TP
.BR syntax "\t128"
Dubious syntax in numeric expressions.
.
.TP
.BR tab "\t2048"
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.
.
.P
There are also names that can be used to refer to groups of warnings:
.
.TP
.B all
All warnings except
.BR di ,
.BR mac ,
and
.BR reg .
It is intended that this covers all warnings that are useful with
traditional macro packages.
.
.TP
.B w
All warnings.
.
.
.\" --------------------------------------------------------------------
.SH ENVIRONMENT
.\" --------------------------------------------------------------------
.
.TP
.SM
.B GROFF_TMAC_PATH
A colon separated list of directories in which to search for
macro files.
.B @g@troff
will scan directories given in the
.B \-M
option before these, and in standard directories (current directory if
in unsafe mode, home directory,
.BR @SYSTEMMACRODIR@ ,
.BR @LOCALMACRODIR@ ,
.BR @MACRODIR@ )
after these.
.
.TP
.SM
.B GROFF_TYPESETTER
Default device.
.
.TP
.SM
.B GROFF_FONT_PATH
A colon separated list of directories in which to search for the
.BI dev name
directory.
.B @g@troff
will scan directories given in the
.B \-F
option before these, and in standard directories
.RB ( @LOCALFONTDIR@ ,
.BR @FONTDIR@ ,
.BR @LEGACYFONTDIR@ )
after these.
.
.
.\" --------------------------------------------------------------------
.SH FILES
.\" --------------------------------------------------------------------
.
.Tp \w'@FONTDIR@/devname/DESC'u+3n
.B @MACRODIR@/troffrc
Initialization file (called before any other macro package).
.
.TP
.B @MACRODIR@/troffrc-end
Initialization file (called after any other macro package).
.
.TP
.BI @MACRODIR@/ name .tmac
.TQ
.BI @MACRODIR@/tmac. name
Macro files
.
.TP
.BI @FONTDIR@/dev name /DESC
Device description file for device
.IR name .
.
.TP
.BI @FONTDIR@/dev name / F
Font file for font
.I F
of device
.IR name .
.P
Note that
.B troffrc
and
.B troffrc-end
are neither searched in the current nor in the home directory by
default for security reasons (even if the
.B \-U
option is given).
.
Use the
.B \-M
command line option or the
.B GROFF_TMAC_PATH
environment variable to add these directories to the search path if
necessary.
.
.
.\" --------------------------------------------------------------------
.SH AUTHOR
.\" --------------------------------------------------------------------
.
Copyright (C) 1989, 2001, 2002, 2003 Free Software Foundation, Inc.
.
.P
This document is distributed under the terms of the FDL (GNU Free
Documentation 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
.URL http://www.gnu.org/copyleft/fdl.html "GNU copyleft site" .
This document was written by James Clark, with modifications from
.MTO wl@gnu.org "Werner Lemberg"
and
.MTO bwarken@mayn.de "Bernd Warken"
.
.P
This document is part of
.IR groff ,
the GNU roff distribution.
.
.
.\" --------------------------------------------------------------------
.SH "SEE ALSO"
.\" --------------------------------------------------------------------
.
.TP
.BR groff (@MAN1EXT@)
The main program of the
.I groff
system, a wrapper around
.IR @g@troff .
.
.TP
.BR groff (@MAN7EXT@)
A description of the
.I groff
language, including a short but complete reference of all predefined
requests, registers, and escapes of plain
.IR groff .
From the command line, this is called by
.RS
.IP
.B man 7 groff
.RE
.
.TP
.BR \%groff_diff (@MAN7EXT@)
The differences of the
.I groff
language and the
.I classical troff
language.
.
Currently, this is the most actual document of the
.I groff
system.
.
.TP
.BR roff (@MAN7EXT@)
An overview over
.I groff
and other
.I roff
systems, including pointers to further related documentation.
.
.P
The
.I groff info
.IR file ,
cf.\&
.BR info (@MAN1EXT@),
presents all groff documentation within a single document.
.
.cp \n[troff_C]
.
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