troff.man

早期freebsd实现

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.\" The BSD man macros can't handle " in arguments to font change macros,
.\" so use \(ts instead of ".
.tr \(ts"
.TH @G@TROFF 1 "@MDATE@" "Groff Version @VERSION@"
.SH NAME
@g@troff \- format documents
.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 \-abivzCER
.OP \-w name
.OP \-W name
.OP \-d cs
.OP \-f fam
.OP \-m name
.OP \-n num
.OP \-o list
.OP \-r cn
.OP \-T name
.OP \-F dir
.OP \-M dir
.RI "[\ " files\|.\|.\|. "\ ]"
.br
.ad \na
.SH DESCRIPTION
This manual page describes the GNU version of
.BR troff ,
which is part of the groff document formatting system.
It is highly compatible with Unix troff.
Usually it should be invoked using the groff 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: troff's idea of line numbers
gets confused by
.B as
or 
.B am
requests.
.TP
.B \-i
Read the standard input after all the named input files have been
processed.
.TP
.B \-v
Print the version number.
.TP
.BI \-w name
Enable warning
.IR  name .
Available warnings are described in
the Warnings subsection below.
Multiple
.B \-w
options are allowed.
.TP
.BI \-W name
Inhibit warning
.IR name .
Multiple
.B \-W
options are allowed.
.TP
.B \-E
Inhibit all error messages.
.TP
.B \-z
Suppress formatted output.
.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
.BI \-f fam
Use
.I fam
as the default font family.
.TP
.BI \-m name
Read in the file
.BI tmac. name\fR.
Normally this will be searched for in @MACRODIR@.
.TP
.B \-R
Don't load
.BR troffrc .
.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 .
.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
.BI \-T name
Prepare output for device
.IR name ,
rather than the default
.BR @DEVICE@ .
.TP
.BI \-F dir
Search
.I dir
for subdirectories
.BI dev name
.RI ( name
is the name of the device)
for the
.B DESC
file and font files before the normal
.BR @FONTDIR@ .
.TP
.BI \-M dir
Search directory
.I dir
for macro files before the normal
.BR @MACRODIR@ .
.SH USAGE
Only the features not in Unix troff are described here.
.SS Long names
The names of number registers, fonts, strings/macros/diversions,
special characters can be of any length. In escape sequences, where
you can use 
.BI ( xx
for a two character name, you can use
.BI [ xxx ]
for a name of arbitrary length:
.TP
.BI \e[ xxx ]
Print the special character called
.IR xxx .
.TP
.BI \ef[ xxx ]
Set font
.IR xxx .
.TP
.BI \e*[ xxx ]
Interpolate string
.IR xxx .
.TP
.BI \en[ xxx ]
Interpolate number register
.IR xxx .
.SS Fractional pointsizes
A
.I
scaled point
is equal to 1/sizescale
points, where
sizescale is specified in the
.B DESC
file (1 by default.)
There is a new scale indicator
.B z
which has the effect of multiplying by sizescale.
Requests and escape sequences in troff 
interpret arguments that represent a pointsize as being in units
of scaled points, but they evaluate each such argument
using a default scale indicator of
.BR z .
Arguments treated in this way are
the argument to the
.B ps
request,
the third argument to the
.B cs
request,
the second and fourth arguments to the
.B tkf
request,
the argument to the
.B \eH
escape sequence,
and those variants of the
.B \es
escape sequence that take a numeric expression as their argument.
.LP
For example, suppose sizescale is 1000;
then a scaled point will be equivalent to a millipoint;
the request
.B .ps 10.25
is equivalent to
.B .ps 10.25z
and so sets the pointsize to 10250 scaled points,
which is equal to 10.25 points.
.LP
The number register
.B \en(.s
returns the pointsize in points as a decimal fraction.
There is also a new number register
.B \en[.ps]
that returns the pointsize in scaled points.
.LP
It would make no sense to use the
.B z
scale indicator in a numeric expression
whose default scale indicator was neither
.B u
nor
.BR z ,
and so
.B troff
disallows this.
Similarily it would make no sense to use a scaling indicator
other than
.B z
or
.B u
in a numeric expression whose default scale indicator was
.BR z ,
and so
.B troff
disallows this as well.
.LP
There is also a new scale indicator
.B s
which multiplies by the number of units in a scaled point.
So, for example,
.B \en[.ps]s
is equal to
.BR 1m .
Be sure not to confuse the
.B s
and
.B z
scale indicators.
.SS Numeric expressions
.LP
Spaces are permitted in a number expression within parentheses.
.LP
.B M
indicates a scale of 100ths of an em.
.TP
.IB e1 >? e2
The maximum of
.I e1
and
.IR e2 .
.TP
.IB e1 <? e2
The minimum of
.I e1
and
.IR e2 .
.TP
.BI ( c ; e )
Evaluate
.I e
using
.I c
as the default scaling indicator.
If
.I c
is missing, ignore scaling indicators in the evaluation of
.IR e .
.SS New escape sequences
.TP
.BI \eA' anything '
This expands to
.B 1
or
.B 0
according as
.I anything
is or is not acceptable as the name of a string, macro, diversion,
number register, environment or font.
It will return
.B 0
if
.I anything
is empty.
This is useful if you want to lookup user input in some sort of
associative table.
.TP
.BI \eC' xxx '
Typeset character named
.IR xxx .
Normally it is more convenient to use
.BI \e[ xxx ]\fR.
But
.B \eC
has the advantage that it is compatible with recent versions of
.SM UNIX
and is available in compatibility mode.
.TP
.B \eE
This is equivalent to an escape character,
but it's not interpreted in copy-mode.
For example, strings to start and end superscripting could be defined
like this:
.RS
.IP
\&.ds { \ev'\-.3m'\es'\eEn[.s]*6u/10u'
.br
\&.ds } \es0\ev'.3m'
.LP
The use of
.B \eE
ensures that these definitions will work even if
.B \e*{
gets interpreted in copy-mode
(for example, by being used in a macro argument.)
.RE
.TP
.BI \eN' n '
Typeset the character with code
.I n
in the current font.
.I n
can be any integer.
Most devices only have characters with codes between 0 and 255.
If the current font does not contain a character with that code,
special fonts will
.I not
be searched.
The
.B \eN
escape sequence can be conveniently used on conjunction with the
.B char
request:
.RS
.IP
.B
\&.char \e[phone] \ef(ZD\eN'37'
.RE
.IP
The code of each character is given in the fourth column in the font
description file after the
.B charset
command.
It is possible to include unnamed characters in the font description
file by using a name of
.BR \-\-\- ;
the
.B \eN
escape sequence is the only way to use these.
.TP
.BI \eR' name\ \(+-n '
This has the same effect as
.RS
.IP
.BI .nr\  name\ \(+-n
.RE
.TP
.BI \es( nn
.TQ
.BI \es\(+-( nn
Set the point size to
.I nn
points;
.I nn
must be exactly two digits.
.TP
.BI \es[\(+- n ]
.TQ
.BI \es\(+-[ n ]
.TQ
.BI \es'\(+- n '
.TQ
.BI \es\(+-' n '
Set the point size to
.I n
scaled points;
.I n
is a numeric expression with a default scale indicator of
.BR z .
.TP
.BI \eV x
.TQ
.BI \eV( xx
.TQ
.BI \eV[ xxx ]
Interpolate the contents of the environment variable
.I xxx ,
as returned by
.BR getenv (3).
.B \eV
is interpreted in copy-mode.
.TP
.BI \eY x
.TQ
.BI \eY( xx
.TQ
.BI \eY[ xxx ]
This is approximately equivalent to
.BI \eX'\e*[ xxx ]'\fR.
However the contents of the string or macro
.I xxx
are not interpreted;
also it is permitted for
.I xxx
to have been defined as a macro and thus contain newlines
(it is not permitted for the argument to
.B \eX
to contain newlines).
The inclusion of newlines requires an extension to the Unix troff output
format, and will confuse drivers that do not know about this
extension.
.TP
.BI \eZ' anything '
Print anything and then restore the horizontal and vertical
position;
.I anything
may not contain tabs or leaders.
.TP
.B \e$0
The name by which the current macro was invoked.
The
.B als
request can make a macro have more than one name.
.TP
.B \e$*
In a macro, the concatenation of all the arguments separated by spaces.
.TP
.B \e$@
In a macro, the concatenation of all the arguments with each surrounded by
double quotes, and separated by spaces. 
.TP
.BI \e$( nn
.TQ
.BI \e$[ nnn ]
In a macro, this gives the
.IR nn -th
or
.IR nnn -th
argument.
Macros can have a unlimited number of arguments.
.TP
.BI \e? anything \e?
When used in a diversion, this will transparently embed
.I anything
in the diversion.
.I anything
is read in copy mode.
When the diversion is reread,
.I anything
will be interpreted.
.I anything
may not contain newlines; use
.B \e!
if you want to embed newlines in a diversion.
The escape sequence
.B \e?
is also recognised in copy mode and turned into a single internal
code; it is this code that terminates
.IR anything .
Thus
.RS
.RS
.ft B
.nf
.ne 15
\&.nr x 1
\&.nf
\&.di d
\e?\e\e?\e\e\e\e?\e\e\e\e\e\e\e\enx\e\e\e\e?\e\e?\e?
\&.di
\&.nr x 2
\&.di e
\&.d
\&.di
\&.nr x 3
\&.di f
\&.e
\&.di
\&.nr x 4
\&.f
.fi
.ft
.RE
.RE
.IP
will print
.BR 4 .
.TP
.B \e/
This increases the width of the preceding character so that
the spacing between that character and the following character
will be correct if the following character is a roman character.
For example, if an italic f is immediately followed by a roman
right parenthesis, then in many fonts the top right portion of the f
will overlap the top left of the right parenthesis producing \fIf\fR)\fR,
which is ugly.
Inserting
.B \e/
produces
.ie \n(.g \fIf\/\fR)\fR
.el \fIf\|\fR)\fR
and avoids this problem.
It is a good idea to use this escape sequence whenever an
italic character is immediately followed by a roman character without any
intervening space.
.TP
.B \e,
This modifies the spacing of the following character so that the spacing
between that character and the preceding character will correct if
the preceding character is a roman character.
For example, inserting
.B \e,
between the parenthesis and the f changes
\fR(\fIf\fR to
.ie \n(.g \fR(\,\fIf\fR.
.el \fR(\^\fIf\fR.
It is a good idea to use this escape sequence whenever a
roman character is immediately followed by an italic character without any
intervening space.
.TP
.B \e)
Like
.B \e&
except that it behaves like a character declared with the
.B cflags
request to be transparent for the purposes of end of sentence recognition.
.TP
.B \e~
This produces an unbreakable space that stretches like a normal inter-word
space when a line is adjusted.
.TP
.B \e#
Everything up to and including the next newline is ignored.
This is interpreted in copy mode.
This is like
.B \e%
except that
.B \e%
does not ignore the terminating newline.
.SS New requests
.TP
.BI .aln\  xx\ yy
Create an alias
.I xx
for number register object named
.IR yy .
The new name and the old name will be exactly equivalent.
If
.I yy
is undefined, a warning of type
.B reg
will be generated, and the request will be ignored.
.TP
.BI .als\  xx\ yy
Create an alias
.I xx
for request, string, macro, or diversion object named
.IR yy .
The new name and the old name will be exactly equivalent (it is similar to a
hard rather than a soft link).
If
.I yy
is undefined, a warning of type
.B mac
will be generated, and the request will be ignored.
The
.BR de ,
.BR am ,
.BR di ,
.BR da ,
.BR ds ,
and
.B as
requests only create a new object if the name of the macro, diversion
or string diversion is currently undefined or if it is defined to be a
request; normally they modify the value of an existing object.
.TP
.BI .asciify\  xx
This request only exists in order to make it possible
to make certain gross hacks work with GNU troff.
It `unformats' the diversion
.I xx
in such a way that
.SM ASCII
characters that were formatted and diverted into
.I xx
will be treated like ordinary input characters when
.I xx
is reread.
For example, this
.RS
.IP
.ne 7v+\n(.Vu
.ft B
.nf
.ss 24
\&.tr @.
\&.di x
\&@nr\e n\e 1
\&.br
\&.di
\&.tr @@
\&.asciify x
\&.x
.ss 12
.fi
.RE
.IP
will set register