3651 lines
71 KiB
Groff
3651 lines
71 KiB
Groff
'\" e
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.\" The above line should force the use of eqn as a preprocessor
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.ig
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groff_diff.man
|
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|
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Last update : 05 July 2002
|
|
|
|
This file is part of groff, the GNU roff type-setting system.
|
|
It is the source of the man-page groff_diff(7).
|
|
|
|
Copyright (C) 1989, 2001, 2002 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 AUTHORS, with no
|
|
Front-Cover Texts, and with no Back-Cover Texts.
|
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|
|
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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.
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.\" --------------------------------------------------------------------
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.\" Setup
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.\" --------------------------------------------------------------------
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.
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.mso www.tmac
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.
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.if n \{\
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. mso tty-char.tmac
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. ftr CR R
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. ftr CI I
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. ftr CB B
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.\}
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.
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.if '\*[.T]'dvi' \
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. ftr CB CW
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.
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.\" define a string tx for the TeX logo
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.ie t .ds tx T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X
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.el .ds tx TeX
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.
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.
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.\" --------------------------------------------------------------------
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.\" start of macro definitions
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.
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.eo
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.
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.de c
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..
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.
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.de TQ
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. br
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. ns
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. TP \$1
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..
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.de Text
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. RI "\$*"
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..
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.de Topic
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. TP 2m
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. Text \[bu]
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..
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.de squoted
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. ds @arg1 \$1
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. shift
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.\" Text \[oq]\f[CB]\*[@arg1]\f[]\[cq]\$*
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. Text \[oq]\f[B]\*[@arg1]\f[]\[cq]\$*
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. rm @arg1
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..
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.c A shell command line
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.de ShellCommand
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. br
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. IR "shell#" "\h'1m'\f[CB]\$*\f[]\/"
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..
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.c reference of a request or macro
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.de request
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. ds @arg1 \$1
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. shift 1
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.\" Text \f[CB]\*[@arg1]\f[]\$*
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. Text \f[B]\*[@arg1]\f[]\$*
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. rm @arg1
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|
..
|
|
.als option request
|
|
.
|
|
.c representation of an escape sequence
|
|
.de esc
|
|
. ds @arg1 \$1
|
|
. shift
|
|
.\" Text \f[CB]\[rs]\*[@arg1]\f[]\$*
|
|
. Text \f[B]\[rs]\*[@arg1]\&\f[]\$*
|
|
. rm @arg1
|
|
..
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.ec
|
|
.\" end of macro definitions
|
|
.
|
|
.\" from old groff_out.man
|
|
.ie \n(.g \
|
|
. ds ic \/
|
|
.el \
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. ds ic \^
|
|
.
|
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.
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.\" --------------------------------------------------------------------
|
|
.\" Title
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.TH GROFF_DIFF @MAN7EXT@ "@MDATE@" "Groff Version @VERSION@"
|
|
.SH NAME
|
|
groff_diff \- differences between GNU troff and classical troff
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH DESCRIPTION
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
This manual page describes the language differences between
|
|
.IR groff ,
|
|
the GNU
|
|
.I roff
|
|
text processing system and the classical
|
|
.I roff
|
|
formatter of the freely available Unix\~7 of the 1970s, documented in
|
|
the
|
|
.I Troff User's Manual
|
|
by
|
|
.I Osanna
|
|
and
|
|
.IR Kernighan .
|
|
This inludes the roff language as well as the intermediate output
|
|
format (troff output).
|
|
.
|
|
.P
|
|
The section
|
|
.I SEE ALSO
|
|
gives pointers to both the classical
|
|
.I roff
|
|
and the modern
|
|
.I groff
|
|
documentation.
|
|
.
|
|
.P
|
|
At the moment, this document is the place of the most actual
|
|
documentation within the
|
|
.I groff
|
|
system.
|
|
.
|
|
This might change in the future.
|
|
.
|
|
Actually, all novelties of the groff language are first described here
|
|
and will pervade into the other documents only at a later stage.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH "GROFF LANGUAGE"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
In this section, all additional features of
|
|
.I groff
|
|
compared to the classical Unix\~7
|
|
.I troff
|
|
are described in detail.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Long names"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The names of number registers, fonts, strings/\:macros/\:diversions,
|
|
special characters, and colors can be of any length.
|
|
.
|
|
In escape sequences, additionally to the classical
|
|
.BI ( xx
|
|
construction for a two character name, you can use
|
|
.BI [ xxx ]
|
|
for a name of arbitrary length, for example in
|
|
.
|
|
.TP \w'\[rs]f[xxx]'u+3n
|
|
.BI \[rs][ xxx ]
|
|
Print the special character called
|
|
.IR xxx .
|
|
.
|
|
.TP
|
|
.BI \[rs]f[ xxx ]
|
|
Set font
|
|
.IR xxx .
|
|
.
|
|
Additionally,
|
|
.B \[rs]f[]
|
|
is a new syntax equal to
|
|
.BR \[rs]fP ,
|
|
i.e., to return to the previous font.
|
|
.
|
|
.TP
|
|
.BI \[rs]*[ "xxx arg1 arg2 .\|.\|." ]
|
|
Interpolate string
|
|
.IR xxx ,
|
|
taking
|
|
.IR arg1 ,
|
|
.IR arg2 ,
|
|
.I .\|.\|.\&
|
|
as arguments.
|
|
.
|
|
.TP
|
|
.BI \[rs]n[ xxx ]
|
|
Interpolate number register
|
|
.IR xxx .
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Fractional pointsizes"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
A
|
|
.I scaled point
|
|
is equal to
|
|
.B 1/sizescale
|
|
points, where
|
|
.B sizescale
|
|
is specified in the
|
|
.B DESC
|
|
file (1 by default).
|
|
.
|
|
There is a new scale indicator
|
|
.B z
|
|
that 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 \[rs]H
|
|
escape sequence, and those variants of the
|
|
.B \[rs]s
|
|
escape sequence that take a numeric expression as their argument.
|
|
.
|
|
.P
|
|
For example, suppose sizescale is 1000; then a scaled point will be
|
|
equivalent to a millipoint; the call
|
|
.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.
|
|
.
|
|
.P
|
|
The number register
|
|
.B \[rs]n[.s]
|
|
returns the pointsize in points as decimal fraction.
|
|
.
|
|
There is also a new number register
|
|
.B \[rs]n[.ps]
|
|
that returns the pointsize in scaled points.
|
|
.
|
|
.P
|
|
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.
|
|
.
|
|
Similarly 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.
|
|
.
|
|
.P
|
|
There is also new scale indicator\~\c
|
|
.B s
|
|
which multiplies by the number of units in a scaled point.
|
|
.
|
|
So, for example,
|
|
.B \[rs]n[.ps]s
|
|
is equal to
|
|
.BR 1m .
|
|
Be sure not to confuse the
|
|
.B s
|
|
and
|
|
.B z
|
|
scale indicators.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Numeric expressions"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
Spaces are permitted in a number expression within parentheses.
|
|
.
|
|
.P
|
|
.B M
|
|
indicates a scale of 100ths of an em.
|
|
.B f
|
|
indicates a scale of 65536 units, providing fractions for color
|
|
definitions with the
|
|
.B defcolor
|
|
request.
|
|
.
|
|
For example, 0.5f = 32768u.
|
|
.
|
|
.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 \[rs]A' anything '
|
|
This expands to
|
|
.B 1
|
|
or
|
|
.B 0
|
|
resp., depending on whether
|
|
.I anything
|
|
is or is not acceptable as the name of a string, macro, diversion, number
|
|
register, environment, font, or color.
|
|
It will return\~\c
|
|
.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 \[rs]B' anything '
|
|
This expands to
|
|
.B 1
|
|
or
|
|
.B 0
|
|
resp., depending on whether
|
|
.I anything
|
|
is or is not a valid numeric expression.
|
|
.
|
|
It will return\~\c
|
|
.B 0
|
|
if
|
|
.I anything
|
|
is empty.
|
|
.
|
|
.TP
|
|
.BI \[rs]C' xxx '
|
|
Typeset character named
|
|
.IR xxx .
|
|
Normally it is more convenient to use
|
|
.BI \[rs][ xxx ]\f[R].
|
|
But
|
|
.B \[rs]C
|
|
has the advantage that it is compatible with recent versions of
|
|
.SM UNIX
|
|
and is available in compatibility mode.
|
|
.
|
|
.TP
|
|
.B \[rs]E
|
|
This is equivalent to an escape character, but it is not interpreted in
|
|
copy-mode.
|
|
.
|
|
For example, strings to start and end superscripting could be defined
|
|
like this
|
|
.
|
|
.RS
|
|
.IP
|
|
.ft CB
|
|
.Text .ds { \[rs]v'\-.3m'\[rs]s'\[rs]En[.s]*6u/10u'
|
|
.br
|
|
.Text .ds } \[rs]s0\[rs]v'.3m'
|
|
.ft
|
|
.
|
|
.P
|
|
The use of
|
|
.B \[rs]E
|
|
ensures that these definitions will work even if
|
|
.B \[rs]*{
|
|
gets interpreted in copy-mode (for example, by being used in a macro
|
|
argument).
|
|
.RE
|
|
.
|
|
.TP
|
|
.BI \[rs]F f
|
|
.TQ
|
|
.BI \[rs]F( fm
|
|
.TQ
|
|
.BI \[rs]F[ fam ]
|
|
Change font family.
|
|
.
|
|
This is the same as the
|
|
.B fam
|
|
request.
|
|
.
|
|
.B \[rs]F[]
|
|
switches back to the previous color (note that
|
|
.B \[rs]FP
|
|
won't work; it selects font family `P' instead).
|
|
.
|
|
.TP
|
|
.BI \[rs]m x
|
|
.TQ
|
|
.BI \[rs]m( xx
|
|
.TQ
|
|
.BI \[rs]m[ xxx ]
|
|
Set drawing color.
|
|
.B \[rs]m[]
|
|
switches back to the previous color.
|
|
.
|
|
.TP
|
|
.BI \[rs]M x
|
|
.TQ
|
|
.BI \[rs]M( xx
|
|
.TQ
|
|
.BI \[rs]M[ xxx ]
|
|
Set background color for filled objects drawn with the
|
|
.BI \[rs]D' .\|.\|. '
|
|
commands.
|
|
.B \[rs]M[]
|
|
switches back to the previous color.
|
|
.
|
|
.TP
|
|
.BI \[rs]N' 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 \[rs]N
|
|
escape sequence can be conveniently used in conjunction with the
|
|
.B char
|
|
request, for example
|
|
.
|
|
.RS
|
|
.ft CB
|
|
.IP
|
|
.Text .char \[rs][phone] \[rs]f(ZD\[rs]N'37'
|
|
.ft
|
|
.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 \[rs]N
|
|
escape sequence is the only way to use these.
|
|
.
|
|
.TP
|
|
.BI \[rs]O n
|
|
.TQ
|
|
.BI \[rs]O[ n ]
|
|
Suppressing troff output.
|
|
.
|
|
The escapes
|
|
.BR \[rs]02 ,
|
|
.BR \[rs]O3 ,
|
|
.BR \[rs]O4 ,
|
|
and
|
|
.B \[rs]O5
|
|
are intended for internal use by
|
|
.BR \%grohtml .
|
|
.
|
|
.RS
|
|
.TP
|
|
.B \[rs]O0
|
|
Disable any ditroff glyphs from being emitted to the device driver,
|
|
provided that the escape occurs at the outer level (see
|
|
.B \[rs]O3
|
|
and
|
|
.BR \[rs]O4 ).
|
|
.
|
|
.TP
|
|
.B \[rs]O1
|
|
Enable output of glyphs, provided that the escape occurs at the outer
|
|
level.
|
|
.IP
|
|
.B \[rs]O0
|
|
and
|
|
.B \[rs]O1
|
|
also reset the registers
|
|
.BR \[rs]n[opminx] ,
|
|
.BR \[rs]n[opminy] ,
|
|
.BR \[rs]n[opmaxx] ,
|
|
and
|
|
.B \[rs]n[opmaxy]
|
|
to\~-1.
|
|
.
|
|
These four registers mark the top left and bottom right hand corners
|
|
of a box which encompasses all written glyphs.
|
|
.
|
|
.TP
|
|
.B \[rs]O2
|
|
Provided that the escape occurs at the outer level, enable output of
|
|
glyphs and also write out to stderr the page number and four registers
|
|
encompassing the glyphs previously written since the last call to
|
|
.BR \[rs]O .
|
|
.
|
|
.TP
|
|
.B \[rs]O3
|
|
Begin a nesting level.
|
|
.
|
|
At start-up,
|
|
.B troff
|
|
is at outer level.
|
|
.
|
|
This is really an internal mechanism for
|
|
.B \%grohtml
|
|
while producing images.
|
|
.
|
|
They are generated by running the troff source through
|
|
.B troff
|
|
to the postscript device and
|
|
.B ghostscript
|
|
to produce images in PNG format.
|
|
.
|
|
The
|
|
.B \[rs]O3
|
|
escape will start a new page if the device is not html (to reduce the
|
|
possibility of images crossing a page boundary).
|
|
.
|
|
.TP
|
|
.B \[rs]O4
|
|
End a nesting level.
|
|
.
|
|
.TP
|
|
.BI \[rs]O5[ Pfilename ]
|
|
This escape is
|
|
.B \%grohtml
|
|
specific.
|
|
.
|
|
Provided that this escape occurs at the outer nesting level, write
|
|
.I filename
|
|
to stderr.
|
|
.
|
|
The position of the image,
|
|
.IR P ,
|
|
must be specified and must be one of l, r, c, or i (left, right,
|
|
centered, inline).
|
|
.
|
|
.I filename
|
|
will be associated with the production of the next inline image.
|
|
.RE
|
|
.
|
|
.TP
|
|
.BI \[rs]R' name\ \[+-]n '
|
|
This has the same effect as
|
|
.
|
|
.RS
|
|
.IP
|
|
.BI .nr\ name\ \[+-]n
|
|
.RE
|
|
.
|
|
.TP
|
|
.BI \[rs]s( nn
|
|
.TQ
|
|
.BI \[rs]s\[+-]( nn
|
|
Set the point size to
|
|
.I nn
|
|
points;
|
|
.I nn
|
|
must be exactly two digits.
|
|
.
|
|
.TP
|
|
.BI \[rs]s[\[+-] n ]
|
|
.TQ
|
|
.BI \[rs]s\[+-][ n ]
|
|
.TQ
|
|
.BI \[rs]s'\[+-] n '
|
|
.TQ
|
|
.BI \[rs]s\[+-]' n '
|
|
Set the point size to
|
|
.I n
|
|
scaled points;
|
|
.I n
|
|
is a numeric expression with a default scale indicator of\~\c
|
|
.BR z .
|
|
.
|
|
.TP
|
|
.BI \[rs]V x
|
|
.TQ
|
|
.BI \[rs]V( xx
|
|
.TQ
|
|
.BI \[rs]V[ xxx ]
|
|
Interpolate the contents of the environment variable
|
|
.IR xxx ,
|
|
as returned by
|
|
.BR getenv (3).
|
|
.B \[rs]V
|
|
is interpreted in copy-mode.
|
|
.
|
|
.TP
|
|
.BI \[rs]Y x
|
|
.TQ
|
|
.BI \[rs]Y( xx
|
|
.TQ
|
|
.BI \[rs]Y[ xxx ]
|
|
This is approximately equivalent to
|
|
.BI \[rs]X'\[rs]*[ xxx ]'\f[R].
|
|
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 \[rs]X
|
|
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 \[rs]Z' anything '
|
|
Print anything and then restore the horizontal and vertical position;
|
|
.I anything
|
|
may not contain tabs or leaders.
|
|
.
|
|
.TP
|
|
.B \[rs]$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 \[rs]$*
|
|
In a macro or string, the concatenation of all the arguments separated
|
|
by spaces.
|
|
.
|
|
.TP
|
|
.B \[rs]$@
|
|
In a macro or string, the concatenation of all the arguments with each
|
|
surrounded by double quotes, and separated by spaces.
|
|
.
|
|
.TP
|
|
.BI \[rs]$( nn
|
|
.TQ
|
|
.BI \[rs]$[ nnn ]
|
|
In a macro or string, this gives the
|
|
.IR nn -th
|
|
or
|
|
.IR nnn -th
|
|
argument.
|
|
.
|
|
Macros and strings can have an unlimited number of arguments.
|
|
.
|
|
.TP
|
|
.BI \[rs]? anything \[rs]?
|
|
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 \[rs]!\&
|
|
if you want to embed newlines in a diversion.
|
|
.
|
|
The escape sequence
|
|
.B \[rs]?\&
|
|
is also recognised in copy mode and turned into a single internal
|
|
code; it is this code that terminates
|
|
.IR anything .
|
|
Thus
|
|
.
|
|
.RS
|
|
.IP
|
|
.ne 14v+\n(.Vu
|
|
.ft CB
|
|
.nf
|
|
.Text .nr x 1
|
|
.Text .nf
|
|
.Text .di d
|
|
.Text \[rs]?\[rs]\[rs]?\[rs]\[rs]\[rs]\[rs]?\[rs]\[rs]\[rs]\[rs]\[rs]\[rs]\[rs]\c
|
|
.Text \[rs]nx\[rs]\[rs]\[rs]\[rs]?\[rs]\[rs]?\[rs]?
|
|
.Text .di
|
|
.Text .nr x 2
|
|
.Text .di e
|
|
.Text .d
|
|
.Text .di
|
|
.Text .nr x 3
|
|
.Text .di f
|
|
.Text .e
|
|
.Text .di
|
|
.Text .nr x 4
|
|
.Text .f
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
will print\~\c
|
|
.BR 4 .
|
|
.
|
|
.TP
|
|
.B \[rs]/
|
|
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.
|
|
.
|
|
.if t \{\
|
|
. nop For example, if an italic f is immediately followed by a roman
|
|
. nop right parenthesis, then in many fonts the top right portion of
|
|
. nop the f will overlap the top left of the right parenthesis
|
|
. nop producing \f[I]f\f[R])\f[R], which is ugly.
|
|
. nop Inserting
|
|
. B \[rs]/
|
|
. nop produces
|
|
. ie \n(.g \f[I]f\/\f[R])\f[R]
|
|
. el \f[I]f\|\f[R])\f[R]
|
|
. nop 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 \[rs],
|
|
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.
|
|
.
|
|
.if t \{\
|
|
. nop For example, inserting
|
|
. B \[rs],
|
|
. nop between the parenthesis and the f changes
|
|
. nop \f[R](\f[I]f\f[R] to
|
|
. ie \n(.g \f[R](\,\f[I]f\f[R].
|
|
. el \f[R](\^\f[I]f\f[R].
|
|
.\}
|
|
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 \[rs])
|
|
Like
|
|
.B \[rs]&
|
|
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 \[rs]~
|
|
This produces an unbreakable space that stretches like a normal
|
|
inter-word space when a line is adjusted.
|
|
.
|
|
.TP
|
|
.B \[rs]:
|
|
This causes the insertion of a zero-width break point.
|
|
.
|
|
It is equal to
|
|
.B \[rs]%
|
|
within a word but without insertion of a soft hyphen character.
|
|
.
|
|
.TP
|
|
.B \[rs]#
|
|
Everything up to and including the next newline is ignored.
|
|
.
|
|
This is interpreted in copy mode.
|
|
.
|
|
It is like
|
|
.B \[rs]"
|
|
except that
|
|
.B \[rs]"
|
|
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 .ami\ xx\ yy
|
|
Append to macro indirectly.
|
|
.
|
|
See the
|
|
.B dei
|
|
request below for more information.
|
|
.
|
|
.TP
|
|
.BI .am1\ xx\ yy
|
|
Similar to
|
|
.BR .am ,
|
|
but compatibility mode is switched off during execution.
|
|
.
|
|
To be more precise, a `compatibility save' token is inserted at the
|
|
beginning of the macro addition, and a `compatibility restore' token at
|
|
the end.
|
|
.
|
|
As a consequence, the requests
|
|
.BR am ,
|
|
.BR am1 ,
|
|
.BR de ,
|
|
and
|
|
.B de1
|
|
can be intermixed freely since the compatibility save/\:restore tokens
|
|
only affect the macro parts defined by
|
|
.B .am1
|
|
and
|
|
.BR .ds1 .
|
|
.
|
|
.TP
|
|
.BI .asciify\ xx
|
|
This request `unformats' the diversion
|
|
.I xx
|
|
in such a way that
|
|
.SM ASCII
|
|
and space characters (and some escape sequences) that were formatted
|
|
and diverted into
|
|
.I xx
|
|
will be treated like ordinary input characters when
|
|
.I xx
|
|
is reread.
|
|
Useful for diversions in conjunction with the
|
|
.B .writem
|
|
request.
|
|
.
|
|
It can be also used for gross hacks; for example, this
|
|
.
|
|
.RS
|
|
.IP
|
|
.ne 7v+\n(.Vu
|
|
.ft CB
|
|
.nf
|
|
.Text .tr @.
|
|
.Text .di x
|
|
.Text @nr n 1
|
|
.Text .br
|
|
.Text .di
|
|
.Text .tr @@
|
|
.Text .asciify x
|
|
.Text .x
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
will set register\~\c
|
|
.B n
|
|
to\~1.
|
|
.
|
|
Note that glyph information (font, font size, etc.) is not preserved;
|
|
use
|
|
.B .unformat
|
|
instead.
|
|
.
|
|
.TP
|
|
.BI .as1\ xx\ yy
|
|
Similar to
|
|
.BR .as ,
|
|
but compatibility mode is switched off during expansion.
|
|
.
|
|
To be more precise, a `compatibility save' token is inserted at the
|
|
beginning of the string, and a `compatibility restore' token at the end.
|
|
.
|
|
As a consequence, the requests
|
|
.BR as ,
|
|
.BR as1 ,
|
|
.BR ds ,
|
|
and
|
|
.B ds1
|
|
can be intermixed freely since the compatibility save/\:restore tokens
|
|
only affect the (sub)strings defined by
|
|
.B as1
|
|
and
|
|
.BR ds1 .
|
|
.
|
|
.TP
|
|
.B .backtrace
|
|
Print a backtrace of the input stack on stderr.
|
|
.
|
|
.TP
|
|
.BI .blm\ xx
|
|
Set the blank line macro to
|
|
.IR xx .
|
|
If there is a blank line macro, it will be invoked when a blank line
|
|
is encountered instead of the usual troff behaviour.
|
|
.
|
|
.TP
|
|
.BI .box\ xx
|
|
.TQ
|
|
.BI .boxa\ xx
|
|
These requests are similar to the
|
|
.B di
|
|
and
|
|
.B da
|
|
requests with the exception that a partially filled line will not
|
|
become part of the diversion (i.e., the diversion always starts with a
|
|
new line) but restored after ending the diversion, discarding the
|
|
partially filled line which possibly comes from the diversion.
|
|
.
|
|
.TP
|
|
.B .break
|
|
Break out of a while loop.
|
|
.
|
|
See also the
|
|
.B while
|
|
and
|
|
.B continue
|
|
requests.
|
|
.
|
|
Be sure not to confuse this with the
|
|
.B br
|
|
request.
|
|
.
|
|
.TP
|
|
.B .brp
|
|
This is the same as
|
|
.BR \[rs]p .
|
|
.
|
|
.TP
|
|
.BI .cflags\ n\ c1\ c2\|.\|.\|.\&
|
|
Characters
|
|
.IR c1 ,
|
|
.IR c2 ,\|.\|.\|.\&
|
|
have properties determined by
|
|
.IR n ,
|
|
which is ORed from the following:
|
|
.
|
|
.RS
|
|
.IP 1
|
|
The character ends sentences (initially characters
|
|
.B .?!\&
|
|
have this property).
|
|
.
|
|
.IP 2
|
|
Lines can be broken before the character (initially no characters have
|
|
this property); a line will not be broken at a character with this
|
|
property unless the characters on each side both have non-zero
|
|
hyphenation codes.
|
|
.
|
|
.IP 4
|
|
Lines can be broken after the character (initially characters
|
|
.B \-\[rs](hy\[rs](em
|
|
have this property); a line will not be broken at a character with
|
|
this property unless the characters on each side both have non-zero
|
|
hyphenation codes.
|
|
.
|
|
.IP 8
|
|
The character overlaps horizontally (initially characters
|
|
.B \[rs](ul\[rs](rn\[rs](ru
|
|
have this property).
|
|
.
|
|
.IP 16
|
|
The character overlaps vertically (initially character
|
|
.B \[rs](br
|
|
has this property).
|
|
.
|
|
.IP 32
|
|
An end-of-sentence character followed by any number of characters with
|
|
this property will be treated as the end of a sentence if followed by
|
|
a newline or two spaces; in other words the character is transparent
|
|
for the purposes of end-of-sentence recognition; this is the same as
|
|
having a zero space factor in \*[tx] (initially characters
|
|
.B \[dq]')]*\[rs](dg\[rs](rq
|
|
have this property).
|
|
.RE
|
|
.
|
|
.TP
|
|
.BI .char\ c\ string
|
|
Define character
|
|
.I c
|
|
to be
|
|
.IR string .
|
|
Every time character
|
|
.I c
|
|
needs to be printed,
|
|
.I string
|
|
will be processed in a temporary environment and the result will be
|
|
wrapped up into a single object.
|
|
.
|
|
Compatibility mode will be turned off and the escape character will be
|
|
set to
|
|
.B \[rs]
|
|
while
|
|
.I string
|
|
is being processed.
|
|
.
|
|
Any emboldening, constant spacing or track kerning will be applied to
|
|
this object rather than to individual characters in
|
|
.IR string .
|
|
.
|
|
.IP
|
|
A character defined by this request can be used just like a normal
|
|
character provided by the output device.
|
|
.
|
|
In particular other characters can be translated to it with the
|
|
.B tr
|
|
request; it can be made the leader character by the
|
|
.B lc
|
|
request; repeated patterns can be drawn with the character using the
|
|
.B \[rs]l
|
|
and
|
|
.B \[rs]L
|
|
escape sequences; words containing the character can be hyphenated
|
|
correctly, if the
|
|
.B hcode
|
|
request is used to give the character a hyphenation code.
|
|
.
|
|
.IP
|
|
There is a special anti-recursion feature: use of character within the
|
|
character's definition will be handled like normal characters not
|
|
defined with
|
|
.BR char .
|
|
.IP
|
|
A character definition can be removed with the
|
|
.B rchar
|
|
request.
|
|
.
|
|
.TP
|
|
.BI .chop\ xx
|
|
Chop the last character off macro, string, or diversion
|
|
.IR xx .
|
|
This is useful for removing the newline from the end of diversions
|
|
that are to be interpolated as strings.
|
|
.
|
|
.TP
|
|
.BI .close\ stream
|
|
Close the stream named
|
|
.IR stream ;
|
|
.I stream
|
|
will no longer be an acceptable argument to the
|
|
.B write
|
|
request.
|
|
.
|
|
See the
|
|
.B open
|
|
request.
|
|
.
|
|
.TP
|
|
.B .continue
|
|
Finish the current iteration of a while loop.
|
|
.
|
|
See also the
|
|
.B while
|
|
and
|
|
.B break
|
|
requests.
|
|
.
|
|
.TP
|
|
.BI .color\ n
|
|
If
|
|
.I n
|
|
is non-zero or missing, enable colors (this is the default), otherwise
|
|
disable them.
|
|
.
|
|
.TP
|
|
.BI .cp\ n
|
|
If
|
|
.I n
|
|
is non-zero or missing, enable compatibility mode, otherwise disable
|
|
it.
|
|
.
|
|
In compatibility mode, long names are not recognised, and the
|
|
incompatibilities caused by long names do not arise.
|
|
.
|
|
.TP
|
|
.BI .defcolor\ xxx\ scheme\ color_components
|
|
Define color.
|
|
.I scheme
|
|
can be one of the following values:
|
|
.B rgb
|
|
(three components),
|
|
.B cym
|
|
(three components),
|
|
.B cmyk
|
|
(four components), and
|
|
.B gray
|
|
or
|
|
.B grey
|
|
(one component).
|
|
.
|
|
Color components can be given either as a hexadecimal string or as
|
|
positive decimal integers in the range 0-65535.
|
|
.
|
|
A hexadecimal string contains all color components concatenated; it
|
|
must start with either
|
|
.B #
|
|
or
|
|
.BR ## .
|
|
The former specifies hex values in the range 0-255 (which are
|
|
internally multiplied by\~257), the latter in the range 0-65535.
|
|
.
|
|
Examples: #FFC0CB (pink), ##ffff0000ffff (magenta).
|
|
.
|
|
A new scaling indicator\~\c
|
|
.B f
|
|
has been introduced which multiplies its value by\~65536; this makes
|
|
it convenient to specify color components as fractions in the range 0
|
|
to\~1.
|
|
.
|
|
Example:
|
|
.
|
|
.RS
|
|
.IP
|
|
.ft CB
|
|
.Text .defcolor darkgreen rgb 0.1f 0.5f 0.2f
|
|
.br
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
Note that
|
|
.B f
|
|
is the default scaling indicator for the
|
|
.B defcolor
|
|
request, thus the above statement is equivalent to
|
|
.
|
|
.RS
|
|
.IP
|
|
.ft CB
|
|
.Text .defcolor darkgreen rgb 0.1 0.5 0.2
|
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.br
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.ft
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.RE
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.
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.IP
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|
The color named
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.B default
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|
(which is device-specific) can't be redefined.
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|
.
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|
It is possible that the default color for
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.esc M
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and
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.esc m
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|
is not the same.
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.
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.TP
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.BI .dei\ xx\ yy
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|
Define macro indirectly.
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.
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|
The following example
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.
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.RS
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.IP
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.ne 2v+\n(.Vu
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.ft CB
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.nf
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.Text .ds xx aa
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.Text .ds yy bb
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|
.Text .dei xx yy
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|
.fi
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|
.ft
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|
.RE
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|
.
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|
.IP
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|
is equivalent to
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|
.
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|
.RS
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|
.IP
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|
.ft CB
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|
.Text .de aa bb
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.br
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|
.ft
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|
.RE
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|
.
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|
.TP
|
|
.BI .de1\ xx\ yy
|
|
Similar to
|
|
.BR .de ,
|
|
but compatibility mode is switched off during execution.
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|
.
|
|
On entry, the current compatibility mode is saved and restored at exit.
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|
.
|
|
.TP
|
|
.BI .do\ xxx
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|
Interpret
|
|
.I .xxx
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|
with compatibility mode disabled.
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|
.
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|
For example,
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|
.
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|
.RS
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|
.
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|
.IP
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|
.ft CB
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|
.Text .do fam T
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|
.br
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|
.ft
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|
.
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|
.P
|
|
would have the same effect as
|
|
.
|
|
.IP
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|
.ft CB
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|
.Text .fam T
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|
.br
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|
.ft
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|
.
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|
.P
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|
except that it would work even if compatibility mode had been enabled.
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|
.
|
|
Note that the previous compatibility mode is restored before any files
|
|
sourced by
|
|
.I xxx
|
|
are interpreted.
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|
.
|
|
.RE
|
|
.
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|
.TP
|
|
.BI .ds1\ xx\ yy
|
|
Similar to
|
|
.BR .ds ,
|
|
but compatibility mode is switched off during expansion.
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|
.
|
|
To be more precise, a `compatibility save' token is inserted at the
|
|
beginning of the string, and a `compatibility restore' token at the end.
|
|
.
|
|
.TP
|
|
.B .ecs
|
|
Save current escape character.
|
|
.
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|
.TP
|
|
.B .ecr
|
|
Restore escape character saved with
|
|
.BR ecs .
|
|
Without a previous call to
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|
.BR ecs ,
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|
.RB ` \[rs] '
|
|
will be the new escape character.
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|
.
|
|
.TP
|
|
.BI .evc\ xx
|
|
Copy the contents of environment
|
|
.I xx
|
|
to the current environment.
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|
.
|
|
No pushing or popping of environments will be done.
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|
.
|
|
.TP
|
|
.BI .fam\ xx
|
|
Set the current font family to
|
|
.IR xx .
|
|
The current font family is part of the current environment.
|
|
If
|
|
.I xx
|
|
is missing, switch back to previous font family.
|
|
.
|
|
The value at start-up is `T'.
|
|
.
|
|
See the description of the
|
|
.B sty
|
|
request for more information on font families.
|
|
.
|
|
.TP
|
|
.BI .fchar\ c\ string
|
|
Define fallback character
|
|
.I c
|
|
to be
|
|
.IR string .
|
|
The syntax of this request is the same as the
|
|
.B char
|
|
request; the only difference is that a character defined with
|
|
.B char
|
|
hides the glyph with the same name in the current font, whereas a
|
|
character defined with
|
|
.B fchar
|
|
is checked only if the particular glyph isn't found in the current font.
|
|
.
|
|
This test happens before checking special fonts.
|
|
.
|
|
.TP
|
|
.BI .fspecial\ f\ s1\ s2\|.\|.\|.\&
|
|
When the current font is
|
|
.IR f ,
|
|
fonts
|
|
.IR s1 ,
|
|
.IR s2 ,\|.\|.\|.\&
|
|
will be special, that is, they will searched for characters not in
|
|
the current font.
|
|
.
|
|
Any fonts specified in the
|
|
.B special
|
|
request will be searched after fonts specified in the
|
|
.B fspecial
|
|
request.
|
|
.
|
|
.TP
|
|
.BI .ftr\ f\ g
|
|
Translate font
|
|
.I f
|
|
to
|
|
.IR g .
|
|
Whenever a font named
|
|
.I f
|
|
is referred to in an
|
|
.B \[rs]f
|
|
escape sequence, or in the
|
|
.BR ft ,
|
|
.BR ul ,
|
|
.BR bd ,
|
|
.BR cs ,
|
|
.BR tkf ,
|
|
.BR special ,
|
|
.BR fspecial ,
|
|
.BR fp ,
|
|
or
|
|
.BR sty
|
|
requests, font
|
|
.I g
|
|
will be used.
|
|
If
|
|
.I g
|
|
is missing, or equal to
|
|
.I f
|
|
then font
|
|
.I f
|
|
will not be translated.
|
|
.
|
|
.TP
|
|
.BI .hcode \ c1\ code1\ c2\ code2\|.\|.\|.\&
|
|
Set the hyphenation code of character
|
|
.I c1
|
|
to
|
|
.I code1
|
|
and that of
|
|
.I c2
|
|
to
|
|
.IR code2 .
|
|
A hyphenation code must be a single input character (not a special
|
|
character) other than a digit or a space.
|
|
.
|
|
Initially each lower-case letter \%a-z has a hyphenation code, which is
|
|
itself, and each upper-case letter \%A-Z has a hyphenation code which is
|
|
the lower-case version of itself.
|
|
.
|
|
See also the
|
|
.B hpf
|
|
request.
|
|
.
|
|
.TP
|
|
.BI .hla\ lang
|
|
Set the current hyphenation language to
|
|
.IR lang .
|
|
Hyphenation exceptions specified with the
|
|
.B hw
|
|
request and hyphenation patterns specified with the
|
|
.B hpf
|
|
request are both associated with the current hyphenation language.
|
|
.
|
|
The
|
|
.B hla
|
|
request is usually invoked by the
|
|
.B troffrc
|
|
file.
|
|
.
|
|
.TP
|
|
.BI .hlm\ n
|
|
Set the maximum number of consecutive hyphenated lines to\~\c
|
|
.IR n .
|
|
If
|
|
.I n
|
|
is negative, there is no maximum.
|
|
.
|
|
The default value is\~\-1.
|
|
.
|
|
This value is associated with the current environment.
|
|
.
|
|
Only lines output from an environment count towards the maximum
|
|
associated with that environment.
|
|
.
|
|
Hyphens resulting from
|
|
.B \[rs]%
|
|
are counted; explicit hyphens are not.
|
|
.
|
|
.TP
|
|
.BI .hpf\ file
|
|
Read hyphenation patterns from
|
|
.IR file ;
|
|
this will be searched for in the same way that
|
|
.IB name .tmac
|
|
is searched for when the
|
|
.BI \-m name
|
|
option is specified.
|
|
.
|
|
It should have the same format as (simple) \*[tx] patterns files.
|
|
.
|
|
More specifically, the following scanning rules are implemented.
|
|
.
|
|
.RS
|
|
.IP \[bu]
|
|
A percent sign starts a comment (up to the end of the line) even if
|
|
preceded by a backslash.
|
|
.
|
|
.IP \[bu]
|
|
No support for `digraphs' like
|
|
.BR \[rs]$ .
|
|
.
|
|
.IP \[bu]
|
|
.BI ^^ xx
|
|
.RI ( x
|
|
is 0-9 or a-f) and
|
|
.BI ^^ x
|
|
(character code of\~\c
|
|
.I x
|
|
in the range 0-127) are recognized; other use of
|
|
.B ^
|
|
causes an error.
|
|
.
|
|
.IP \[bu]
|
|
No macro expansion.
|
|
.
|
|
.IP \[bu]
|
|
.B hpf
|
|
checks for the expression
|
|
.B \[rs]patterns{.\|.\|.}
|
|
(possibly with whitespace before and after the braces).
|
|
.
|
|
Everything between the braces is taken as hyphenation patterns.
|
|
.
|
|
Consequently,
|
|
.B {
|
|
and
|
|
.B }
|
|
are not allowed in patterns.
|
|
.
|
|
.IP \[bu]
|
|
Similarly,
|
|
.B \[rs]hyphenation{.\|.\|.}
|
|
gives a list of hyphenation exceptions.
|
|
.
|
|
.IP \[bu]
|
|
.B \[rs]endinput
|
|
is recognized also.
|
|
.
|
|
.IP \[bu]
|
|
For backwards compatibility, if
|
|
.B \[rs]patterns
|
|
is missing, the whole file is treated as a list of hyphenation patterns
|
|
(only recognizing the
|
|
.BR % \~\c
|
|
character as the start of a comment).
|
|
.RE
|
|
.
|
|
.IP
|
|
Use the
|
|
.B hpfcode
|
|
request to map the encoding used in hyphenation patterns files to
|
|
.BR groff 's
|
|
input encoding.
|
|
.IP
|
|
The set of hyphenation patterns is associated with the current language
|
|
set by the
|
|
.B hla
|
|
request.
|
|
.
|
|
The
|
|
.B hpf
|
|
request is usually invoked by the
|
|
.B troffrc
|
|
file; a second call replaces the old patterns with the new ones.
|
|
.
|
|
.TP
|
|
.BI .hpfa\ file
|
|
The same as
|
|
.B hpf
|
|
except that the hyphenation patterns from
|
|
.I file
|
|
are appended to the patterns already loaded in the current language.
|
|
.
|
|
.TP
|
|
.BI .hpfcode\ a\ b\ c\ d\ .\|.\|.
|
|
After reading a hyphenation patterns file with the
|
|
.B hpf
|
|
or
|
|
.B hpfa
|
|
request, convert all characters with character code\~\c
|
|
.I a
|
|
in the recently read patterns to character code\~\c
|
|
.IR b ,
|
|
character code\~\c
|
|
.I c
|
|
to\~\c
|
|
.IR d ,
|
|
etc.
|
|
.
|
|
Initially, all character codes map to themselves.
|
|
.
|
|
The arguments of
|
|
.B hpfcode
|
|
must be integers in the range 0 to\~255.
|
|
.
|
|
Note that it is even possible to use character codes which are invalid in
|
|
.B groff
|
|
otherwise.
|
|
.
|
|
.TP
|
|
.BI .hym\ n
|
|
Set the
|
|
.I hyphenation margin
|
|
to\~\c
|
|
.IR n :
|
|
when the current adjustment mode is not\~\c
|
|
.BR b ,
|
|
the line will not be hyphenated if the line is no more than
|
|
.I n
|
|
short.
|
|
.
|
|
The default hyphenation margin is\~0.
|
|
.
|
|
The default scaling indicator for this request is\~\c
|
|
.IR m .
|
|
The hyphenation margin is associated with the current environment.
|
|
.
|
|
The current hyphenation margin is available in the
|
|
.B \[rs]n[.hym]
|
|
register.
|
|
.
|
|
.TP
|
|
.BI .hys\ n
|
|
Set the
|
|
.I hyphenation space
|
|
to\~\c
|
|
.IR n :
|
|
when the current adjustment mode is\~\c
|
|
.B b
|
|
don't hyphenate the line if the line can be justified by adding no
|
|
more than
|
|
.I n
|
|
extra space to each word space.
|
|
.
|
|
The default hyphenation space is\~0.
|
|
.
|
|
The default scaling indicator for this request is\~\c
|
|
.BR m .
|
|
The hyphenation space is associated with the current environment.
|
|
.
|
|
The current hyphenation space is available in the
|
|
.B \[rs]n[.hys]
|
|
register.
|
|
.
|
|
.TP
|
|
.BI .itc\ n\ macro
|
|
Variant of
|
|
.B .it
|
|
for which a line interrupted with
|
|
.B \[rs]c
|
|
counts as one input line.
|
|
.
|
|
.TP
|
|
.BI .kern\ n
|
|
If
|
|
.I n
|
|
is non-zero or missing, enable pairwise kerning, otherwise disable it.
|
|
.
|
|
.TP
|
|
.BI .length\ xx\ string
|
|
Compute the length of
|
|
.I string
|
|
and return it in the number register
|
|
.I xx
|
|
(which is not necessarily defined before).
|
|
.
|
|
.TP
|
|
.BI .linetabs\ n
|
|
If
|
|
.I n
|
|
is non-zero or missing, enable line-tabs mode, otherwise disable it
|
|
(which is the default).
|
|
.
|
|
In line-tabs mode, tab distances are computed relative to the
|
|
(current) output line.
|
|
.
|
|
Otherwise they are taken relative to the input line.
|
|
.
|
|
For example, the following
|
|
.
|
|
.RS
|
|
.IP
|
|
.ne 6v+\n(.Vu
|
|
.ft CB
|
|
.nf
|
|
.Text .ds x a\[rs]t\[rs]c
|
|
.Text .ds y b\[rs]t\[rs]c
|
|
.Text .ds z c
|
|
.Text .ta 1i 3i
|
|
.Text \[rs]*x
|
|
.Text \[rs]*y
|
|
.Text \[rs]*z
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
yields
|
|
.
|
|
.RS
|
|
.IP
|
|
a b c
|
|
.RE
|
|
.
|
|
.IP
|
|
In line-tabs mode, the same code gives
|
|
.
|
|
.RS
|
|
.IP
|
|
a b c
|
|
.RE
|
|
.
|
|
.IP
|
|
Line-tabs mode is associated with the current environment; the
|
|
read-only number register
|
|
.B \\[rs]n[.linetabs]
|
|
is set to\~1 if in line-tabs mode, and 0 otherwise.
|
|
.
|
|
.TP
|
|
.BI .mso\ file
|
|
The same as the
|
|
.B so
|
|
request except that
|
|
.I file
|
|
is searched for in the same directories as macro files for the the
|
|
.B \-m
|
|
command line option.
|
|
.
|
|
If the file name to be included has the form
|
|
.IB name .tmac
|
|
and it isn't found,
|
|
.B mso
|
|
tries to include
|
|
.BI tmac. name
|
|
instead and vice versa.
|
|
.
|
|
.TP
|
|
.BI .nop \ anything
|
|
Execute
|
|
.IR anything .
|
|
This is similar to `.if\ 1'.
|
|
.
|
|
.TP
|
|
.B .nroff
|
|
Make the
|
|
.B n
|
|
built-in condition true and the
|
|
.B t
|
|
built-in condition false.
|
|
.
|
|
This can be reversed using the
|
|
.B troff
|
|
request.
|
|
.
|
|
.TP
|
|
.BI .open\ stream\ filename
|
|
Open
|
|
.I filename
|
|
for writing and associate the stream named
|
|
.I stream
|
|
with it.
|
|
.
|
|
See also the
|
|
.B close
|
|
and
|
|
.B write
|
|
requests.
|
|
.
|
|
.TP
|
|
.BI .opena\ stream\ filename
|
|
Like
|
|
.BR open ,
|
|
but if
|
|
.I filename
|
|
exists, append to it instead of truncating it.
|
|
.
|
|
.TP
|
|
.BI .output\ string
|
|
Emit
|
|
.I string
|
|
directly to the intermediate output (subject to copy-mode interpretation);
|
|
this is similar to
|
|
.B \[rs]!
|
|
used at the top level.
|
|
.
|
|
An initial double quote in
|
|
.I string
|
|
is stripped off to allow initial blanks.
|
|
.
|
|
.TP
|
|
.B .pnr
|
|
Print the names and contents of all currently defined number registers
|
|
on stderr.
|
|
.
|
|
.TP
|
|
.BI .psbb \ filename
|
|
Get the bounding box of a PostScript image
|
|
.IR filename .
|
|
This file must conform to Adobe's Document Structuring Conventions;
|
|
the command looks for a
|
|
.B \%%%BoundingBox
|
|
comment to extract the bounding box values.
|
|
.
|
|
After a successful call, the coordinates (in PostScript units) of the
|
|
lower left and upper right corner can be found in the registers
|
|
.BR \[rs]n[llx] ,
|
|
.BR \[rs]n[lly] ,
|
|
.BR \[rs]n[urx] ,
|
|
and
|
|
.BR \[rs]n[ury] ,
|
|
respectively.
|
|
.
|
|
If some error has occurred, the four registers are set to zero.
|
|
.
|
|
.TP
|
|
.BI .pso \ command
|
|
This behaves like the
|
|
.B so
|
|
request except that input comes from the standard output of
|
|
.IR command .
|
|
.
|
|
.TP
|
|
.B .ptr
|
|
Print the names and positions of all traps (not including input line
|
|
traps and diversion traps) on stderr.
|
|
.
|
|
Empty slots in the page trap list are printed as well, because they
|
|
can affect the priority of subsequently planted traps.
|
|
.
|
|
.TP
|
|
.BI .pvs \ \[+-]n
|
|
Set the post-vertical line space to
|
|
.IR n ;
|
|
default scale indicator is\~\c
|
|
.BR p .
|
|
.
|
|
This value will be added to each line after it has been output.
|
|
.
|
|
With no argument, the post-vertical line space is set to its previous
|
|
value.
|
|
.
|
|
.IP
|
|
The total vertical line spacing consists of four components:
|
|
.B .vs
|
|
and
|
|
.B \[rs]x
|
|
with a negative value which are applied before the line is output, and
|
|
.B .pvs
|
|
and
|
|
.B \[rs]x
|
|
with a positive value which are applied after the line is output.
|
|
.
|
|
.TP
|
|
.BI .rchar\ c1\ c2\|.\|.\|.\&
|
|
Remove the definitions of characters
|
|
.IR c1 ,
|
|
.IR c2 ,\|.\|.\|.
|
|
This undoes the effect of a
|
|
.B char
|
|
request.
|
|
.
|
|
.TP
|
|
.B .return
|
|
Within a macro, return immediately.
|
|
.
|
|
No effect otherwise.
|
|
.
|
|
.TP
|
|
.B .rj
|
|
.TQ
|
|
.BI .rj \~n
|
|
Right justify the next
|
|
.IR n \~\c
|
|
input lines.
|
|
.
|
|
Without an argument right justify the next input line.
|
|
.
|
|
The number of lines to be right justified is available in the
|
|
.B \[rs]n[.rj]
|
|
register.
|
|
.
|
|
This implicitly does
|
|
.BR .ce \~0 .
|
|
The
|
|
.B ce
|
|
request implicitly does
|
|
.BR .rj \~0 .
|
|
.
|
|
.TP
|
|
.BI .rnn \ xx\ yy
|
|
Rename number register
|
|
.I xx
|
|
to
|
|
.IR yy .
|
|
.
|
|
.TP
|
|
.BI .shc\ c
|
|
Set the soft hyphen character to
|
|
.IR c .
|
|
If
|
|
.I c
|
|
is omitted, the soft hyphen character will be set to the default
|
|
.BR \[rs](hy .
|
|
The soft hyphen character is the character which will be inserted when
|
|
a word is hyphenated at a line break.
|
|
.
|
|
If the soft hyphen character does not exist in the font of the
|
|
character immediately preceding a potential break point, then the line
|
|
will not be broken at that point.
|
|
.
|
|
Neither definitions (specified with the
|
|
.B char
|
|
request) nor translations (specified with the
|
|
.B tr
|
|
request) are considered when finding the soft hyphen character.
|
|
.
|
|
.TP
|
|
.BI .shift\ n
|
|
In a macro, shift the arguments by
|
|
.I n
|
|
positions: argument\~\c
|
|
.I i
|
|
becomes argument
|
|
.IR i \- n ;
|
|
arguments 1 to\~\c
|
|
.I n
|
|
will no longer be available.
|
|
.
|
|
If
|
|
.I n
|
|
is missing, arguments will be shifted by\~1.
|
|
.
|
|
Shifting by negative amounts is currently undefined.
|
|
.
|
|
.TP
|
|
.BI .sizes\ s1\ s2\|.\|.\|.\|sn\ [0]
|
|
This command is similar to the
|
|
.B sizes
|
|
command of a
|
|
.B DESC
|
|
file.
|
|
.
|
|
It sets the available font sizes for the current font to
|
|
.IR s1 ,
|
|
.IR s2 ,\|.\|.\|.\|,\~ sn
|
|
scaled points.
|
|
.
|
|
The list of sizes can be terminated by an optional\~\c
|
|
.BR 0 .
|
|
.
|
|
Each
|
|
.I si
|
|
can also be a range of sizes
|
|
.IR m - n .
|
|
.
|
|
Contrary to the font file command, the list can't extend over more
|
|
than a single line.
|
|
.
|
|
.TP
|
|
.BI .special\ s1\ s2\|.\|.\|.\&
|
|
Fonts
|
|
.IR s1 ,
|
|
.IR s2 ,
|
|
are special and will be searched for characters not in the current
|
|
font.
|
|
.
|
|
.TP
|
|
.BI .spreadwarn\ limit
|
|
Make
|
|
.B troff
|
|
emit a warning if the additional space inserted for each space between
|
|
words in an output line is larger or equal to
|
|
.IR limit .
|
|
.
|
|
A negative value is changed to zero; no argument toggles the warning on
|
|
and off without changing
|
|
.IR limit .
|
|
.
|
|
The default scaling indicator is\~\c
|
|
.BR m .
|
|
.
|
|
At startup,
|
|
.B spreadwarn
|
|
is deactivated, and
|
|
.I limit
|
|
is set to 3m.
|
|
.
|
|
For example,
|
|
.B .spreadwarn\ 0.2m
|
|
will cause a warning if
|
|
.B troff
|
|
must add 0.2m or more for each interword space in a line.
|
|
.
|
|
This request is active only if text is justified to both margins (using
|
|
.BR .ad\ b ).
|
|
.
|
|
.TP
|
|
.BI .sty\ n\ f
|
|
Associate style\~\c
|
|
.I f
|
|
with font position\~\c
|
|
.IR n .
|
|
A font position can be associated either with a font or with a style.
|
|
.
|
|
The current font is the index of a font position and so is also either
|
|
a font or a style.
|
|
.
|
|
When it is a style, the font that is actually used is the font the
|
|
name of which is the concatenation of the name of the current family
|
|
and the name of the current style.
|
|
.
|
|
For example, if the current font is\~1 and font position\~1 is
|
|
associated with style\~\c
|
|
.B R
|
|
and the current font family is\~\c
|
|
.BR T ,
|
|
then font
|
|
.BR TR
|
|
will be used.
|
|
.
|
|
If the current font is not a style, then the current family is ignored.
|
|
.
|
|
When the requests
|
|
.BR cs ,
|
|
.BR bd ,
|
|
.BR tkf ,
|
|
.BR uf ,
|
|
or
|
|
.B fspecial
|
|
are applied to a style, then they will instead be applied to the
|
|
member of the current family corresponding to that style.
|
|
.
|
|
The default family can be set with the
|
|
.B \-f
|
|
option.
|
|
.
|
|
The
|
|
.B styles
|
|
command in the
|
|
.SM DESC
|
|
file controls which font positions (if any) are initially associated
|
|
with styles rather than fonts.
|
|
.
|
|
.TP
|
|
.BI .substring\ xx\ n1\ [ n2 ]
|
|
Replace the string named
|
|
.I xx
|
|
with the substring defined by the indices
|
|
.I n1
|
|
and
|
|
.IR n2 .
|
|
The first character in the string has index\~0.
|
|
.
|
|
If
|
|
.I n2
|
|
is omitted, it is taken to be equal to the string's length.
|
|
.
|
|
If the index value
|
|
.I n1
|
|
or
|
|
.I n2
|
|
is negative, it will be counted from the end of the string,
|
|
going backwards:
|
|
.
|
|
The last character has index\~-1, the character before the last
|
|
character has index\~-2, etc.
|
|
.
|
|
.TP
|
|
.BI .tkf\ f\ s1\ n1\ s2\ n2
|
|
Enable track kerning for font
|
|
.IR f .
|
|
When the current font is
|
|
.I f
|
|
the width of every character will be increased by an amount between
|
|
.I n1
|
|
and
|
|
.IR n2 ;
|
|
when the current point size is less than or equal to
|
|
.I s1
|
|
the width will be increased by
|
|
.IR n1 ;
|
|
when it is greater than or equal to
|
|
.I s2
|
|
the width will be increased by
|
|
.IR n2 ;
|
|
when the point size is greater than or equal to
|
|
.I s1
|
|
and less than or equal to
|
|
.I s2
|
|
the increase in width is a linear function of the point size.
|
|
.
|
|
.TP
|
|
.BI .tm1\ string
|
|
Similar to the
|
|
.B tm
|
|
request,
|
|
.I string
|
|
is read in copy mode and written on the standard error, but an initial
|
|
double quote in
|
|
.I string
|
|
is stripped off to allow initial blanks.
|
|
.
|
|
.TP
|
|
.BI .tmc\ string
|
|
Similar to
|
|
.B tm1
|
|
but without writing a final newline.
|
|
.
|
|
.TP
|
|
.BI .trf\ filename
|
|
Transparently output the contents of file
|
|
.IR filename .
|
|
Each line is output as if preceded by
|
|
.BR \[rs]! ;
|
|
however, the lines are not subject to copy-mode interpretation.
|
|
.
|
|
If the file does not end with a newline, then a newline will be added.
|
|
.
|
|
For example, you can define a macro\~\c
|
|
.I x
|
|
containing the contents of file\~\c
|
|
.IR f ,
|
|
using
|
|
.
|
|
.RS
|
|
.IP
|
|
.ne 2v+\n(.Vu
|
|
.ft CB
|
|
.nf
|
|
.Text .di x
|
|
.Text .trf f
|
|
.Text .di
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
Unlike with the
|
|
.B cf
|
|
request, the file cannot contain characters such as
|
|
.SM NUL
|
|
that are not legal troff input characters.
|
|
.
|
|
.TP
|
|
.BI .trin\ abcd
|
|
This is the same as the
|
|
.B tr
|
|
request except that the
|
|
.B asciify
|
|
request will use the character code (if any) before the character
|
|
translation.
|
|
.
|
|
Example:
|
|
.
|
|
.RS
|
|
.IP
|
|
.nf
|
|
.ft CB
|
|
.Text .trin ax
|
|
.Text .di xxx
|
|
.Text a
|
|
.Text .br
|
|
.Text .di
|
|
.Text .xxx
|
|
.Text .trin aa
|
|
.Text .asciify xxx
|
|
.Text .xxx
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
The result is
|
|
.BR x\ a .
|
|
.
|
|
Using
|
|
.BR tr ,
|
|
the result would be
|
|
.BR x\ x .
|
|
.
|
|
.TP
|
|
.BI .trnt\ abcd
|
|
This is the same as the
|
|
.B tr
|
|
request except that the translations do not apply to text that is
|
|
transparently throughput into a diversion with
|
|
.BR \[rs]! .
|
|
For example,
|
|
.
|
|
.RS
|
|
.IP
|
|
.nf
|
|
.ft CB
|
|
.Text .tr ab
|
|
.Text .di x
|
|
.Text \[rs]!.tm a
|
|
.Text .di
|
|
.Text .x
|
|
.fi
|
|
.ft
|
|
.RE
|
|
.
|
|
.IP
|
|
will print\~\c
|
|
.BR b ;
|
|
if
|
|
.B trnt
|
|
is used instead of
|
|
.B tr
|
|
it will print\~\c
|
|
.BR a .
|
|
.RE
|
|
.
|
|
.TP
|
|
.B .troff
|
|
Make the
|
|
.B n
|
|
built-in condition false, and the
|
|
.B t
|
|
built-in condition true.
|
|
.
|
|
This undoes the effect of the
|
|
.B nroff
|
|
request.
|
|
.
|
|
.TP
|
|
.BI .unformat\ xx
|
|
This request `unformats' the diversion
|
|
.IR xx .
|
|
Contrary to the
|
|
.B .asciify
|
|
request, which tries to convert formatted elements of the diversion
|
|
back to input tokens as much as possible,
|
|
.B .unformat
|
|
will only handle tabs and spaces between words (usually caused by
|
|
spaces or newlines in the input) specially.
|
|
.
|
|
The former are treated as if they were input tokens, and the latter
|
|
are stretchable again.
|
|
.
|
|
Note that the vertical size of lines is not preserved.
|
|
.
|
|
Glyph information (font, font size, space width, etc.) is retained.
|
|
.
|
|
Useful in conjunction with the
|
|
.B .box
|
|
and
|
|
.B .boxa
|
|
requests.
|
|
.
|
|
.TP
|
|
.BI .vpt\ n
|
|
Enable vertical position traps if
|
|
.I n
|
|
is non-zero, disable them otherwise.
|
|
.
|
|
Vertical position traps are traps set by the
|
|
.B wh
|
|
or
|
|
.B dt
|
|
requests.
|
|
.
|
|
Traps set by the
|
|
.B it
|
|
request are not vertical position traps.
|
|
.
|
|
The parameter that controls whether vertical position traps are
|
|
enabled is global.
|
|
.
|
|
Initially vertical position traps are enabled.
|
|
.
|
|
.TP
|
|
.BI .warn\ n
|
|
Control warnings.
|
|
.I n
|
|
is the sum of the numbers associated with each warning that is to be
|
|
enabled; all other warnings will be disabled.
|
|
.
|
|
The number associated with each warning is listed in
|
|
.BR @g@troff (@MAN1EXT@).
|
|
.
|
|
For example,
|
|
.B .warn\~0
|
|
will disable all warnings, and
|
|
.B .warn\~1
|
|
will disable all warnings except that about missing characters.
|
|
.
|
|
If
|
|
.I n
|
|
is not given, all warnings will be enabled.
|
|
.
|
|
.TP
|
|
.BI .warnscale\ si
|
|
Set the scaling indicator used in warnings to
|
|
.IR si .
|
|
.
|
|
Valid values for
|
|
.I si
|
|
are
|
|
.BR u ,
|
|
.BR i ,
|
|
.BR c ,
|
|
.BR p ,
|
|
and
|
|
.BR P .
|
|
.
|
|
At startup, it is set to\~\c
|
|
.BR i .
|
|
.
|
|
.TP
|
|
.BI .while \ c\ anything
|
|
While condition\~\c
|
|
.I c
|
|
is true, accept
|
|
.I anything
|
|
as input;
|
|
.IR c \~\c
|
|
can be any condition acceptable to an
|
|
.B if
|
|
request;
|
|
.I anything
|
|
can comprise multiple lines if the first line starts with
|
|
.B \[rs]{
|
|
and the last line ends with
|
|
.BR \[rs]} .
|
|
See also the
|
|
.B break
|
|
and
|
|
.B continue
|
|
requests.
|
|
.
|
|
.TP
|
|
.BI .write\ stream\ anything
|
|
Write
|
|
.I anything
|
|
to the stream named
|
|
.IR stream .
|
|
.I stream
|
|
must previously have been the subject of an
|
|
.B open
|
|
request.
|
|
.I anything
|
|
is read in copy mode;
|
|
a leading\~\c
|
|
.B \[dq]
|
|
will be stripped.
|
|
.
|
|
.TP
|
|
.BI .writec\ stream\ anything
|
|
Similar to
|
|
.B write
|
|
but without writing a final newline.
|
|
.
|
|
.TP
|
|
.BI .writem\ stream\ xx
|
|
Write the contents of the macro or string
|
|
.I xx
|
|
to the stream named
|
|
.IR stream .
|
|
.I stream
|
|
must previously have been the subject of an
|
|
.B open
|
|
request.
|
|
.I xx
|
|
is read in copy mode.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Extended requests"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.TP
|
|
.BI .cf\ filename
|
|
When used in a diversion, this will embed in the diversion an object
|
|
which, when reread, will cause the contents of
|
|
.I filename
|
|
to be transparently copied through to the output.
|
|
.
|
|
In UNIX troff, the contents of
|
|
.I filename
|
|
is immediately copied through to the output regardless of whether
|
|
there is a current diversion; this behaviour is so anomalous that it
|
|
must be considered a bug.
|
|
.
|
|
.TP
|
|
.BI .ev\ xx
|
|
If
|
|
.I xx
|
|
is not a number, this will switch to a named environment called
|
|
.IR xx .
|
|
The environment should be popped with a matching
|
|
.B ev
|
|
request without any arguments, just as for numbered environments.
|
|
.
|
|
There is no limit on the number of named environments; they will be
|
|
created the first time that they are referenced.
|
|
.
|
|
.TP
|
|
.BI .ss\ m\ n
|
|
When two arguments are given to the
|
|
.B ss
|
|
request, the second argument gives the
|
|
.IR "sentence space size" .
|
|
If the second argument is not given, the sentence space size
|
|
will be the same as the word space size.
|
|
.
|
|
Like the word space size, the sentence space is in units of
|
|
one twelfth of the spacewidth parameter for the current font.
|
|
.
|
|
Initially both the word space size and the sentence
|
|
space size are\~12.
|
|
.
|
|
Contrary to UNIX troff, GNU troff handles this request in nroff mode
|
|
also; a given value is then rounded down to the nearest multiple
|
|
of\~12.
|
|
.
|
|
The sentence space size is used in two circumstances.
|
|
.
|
|
If the end of a sentence occurs at the end of a line in fill mode,
|
|
then both an inter-word space and a sentence space will be added; if
|
|
two spaces follow the end of a sentence in the middle of a line, then
|
|
the second space will be a sentence space.
|
|
.
|
|
Note that the behaviour of UNIX troff will be exactly that exhibited
|
|
by GNU troff if a second argument is never given to the
|
|
.B ss
|
|
request.
|
|
.
|
|
In GNU troff, as in UNIX troff, you should always follow a sentence
|
|
with either a newline or two spaces.
|
|
.
|
|
.TP
|
|
.BI .ta\ n1\ n2\|.\|.\|.nn \ T\ r1\ r2\|.\|.\|.\|rn
|
|
Set tabs at positions
|
|
.IR n1 ,
|
|
.IR n2 ,\|.\|.\|.\|,
|
|
.I nn
|
|
and then set tabs at
|
|
.IR nn + r1 ,
|
|
.IR nn + r2 ,\|.\|.\|.\|,
|
|
.IR nn + rn
|
|
and then at
|
|
.IR nn + rn + r1 ,
|
|
.IR nn + rn + r2 ,\|.\|.\|.\|,
|
|
.IR nn + rn + rn ,
|
|
and so on.
|
|
For example,
|
|
.
|
|
.RS
|
|
.IP
|
|
.ft CB
|
|
.Text .ta T .5i
|
|
.br
|
|
.ft
|
|
.
|
|
.P
|
|
will set tabs every half an inch.
|
|
.RE
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "New number registers"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The following read-only registers are available:
|
|
.
|
|
.TP
|
|
.B \[rs]n[.C]
|
|
1\~if compatibility mode is in effect, 0\~otherwise.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.cdp]
|
|
The depth of the last character added to the current environment.
|
|
.
|
|
It is positive if the character extends below the baseline.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ce]
|
|
The number of lines remaining to be centered, as set by the
|
|
.B ce
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.cht]
|
|
The height of the last character added to the current environment.
|
|
.
|
|
It is positive if the character extends above the baseline.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.color]
|
|
1\~if colors are enabled, 0\~otherwise.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.csk]
|
|
The skew of the last character added to the current environment.
|
|
.
|
|
The
|
|
.I skew
|
|
of a character is how far to the right of the center of a character
|
|
the center of an accent over that character should be placed.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ev]
|
|
The name or number of the current environment.
|
|
.
|
|
This is a string-valued register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.fam]
|
|
The current font family.
|
|
.
|
|
This is a string-valued register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.fn]
|
|
The current (internal) real font name.
|
|
.
|
|
This is a string-valued register.
|
|
.
|
|
If the current font is a style, the value of
|
|
.B \[rs]n[.fn]
|
|
is the proper concatenation of family and style name.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.fp]
|
|
The number of the next free font position.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.g]
|
|
Always\~1.
|
|
.
|
|
Macros should use this to determine whether they are running under GNU
|
|
troff.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hla]
|
|
The current hyphenation language as set by the
|
|
.B hla
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hlc]
|
|
The number of immediately preceding consecutive hyphenated lines.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hlm]
|
|
The maximum allowed number of consecutive hyphenated lines, as set by
|
|
the
|
|
.B hlm
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hy]
|
|
The current hyphenation flags (as set by the
|
|
.B hy
|
|
request).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hym]
|
|
The current hyphenation margin (as set by the
|
|
.B hym
|
|
request).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.hys]
|
|
The current hyphenation space (as set by the
|
|
.B hys
|
|
request).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.in]
|
|
The indent that applies to the current output line.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.int]
|
|
Set to a positive value if last output line is interrupted (i.e., if
|
|
it contains
|
|
.IR \[rs]c ).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.kern]
|
|
1\~if pairwise kerning is enabled, 0\~otherwise.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.lg]
|
|
The current ligature mode (as set by the
|
|
.B lg
|
|
request).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.linetabs]
|
|
The current line-tabs mode (as set by the
|
|
.B linetabs
|
|
request).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ll]
|
|
The line length that applies to the current output line.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.lt]
|
|
The title length as set by the
|
|
.B lt
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ne]
|
|
The amount of space that was needed in the last
|
|
.B ne
|
|
request that caused a trap to be sprung.
|
|
.
|
|
Useful in conjunction with the
|
|
.B \[rs]n[.trunc]
|
|
register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ns]
|
|
1\~if no-space mode is active, 0\~otherwise.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.pn]
|
|
The number of the next page, either the value set by a
|
|
.B pn
|
|
request, or the number of the current page plus\~1.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ps]
|
|
The current pointsize in scaled points.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.psr]
|
|
The last-requested pointsize in scaled points.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.pvs]
|
|
The current post-vertical line space as set with the
|
|
.B pvs
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.rj]
|
|
The number of lines to be right-justified as set by the
|
|
.B rj
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.sr]
|
|
The last requested pointsize in points as a decimal fraction.
|
|
.
|
|
This is a string-valued register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.ss]
|
|
.TQ
|
|
.B \[rs]n[.sss]
|
|
These give the values of the parameters set by the first and second
|
|
arguments of the
|
|
.B ss
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.tabs]
|
|
A string representation of the current tab settings suitable for use
|
|
as an argument to the
|
|
.B ta
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.trunc]
|
|
The amount of vertical space truncated by the most recently sprung
|
|
vertical position trap, or, if the trap was sprung by a
|
|
.B ne
|
|
request, minus the amount of vertical motion produced by the
|
|
.B ne
|
|
request.
|
|
.
|
|
In other words, at the point a trap is sprung, it represents the
|
|
difference of what the vertical position would have been but for the
|
|
trap, and what the vertical position actually is.
|
|
.
|
|
Useful in conjunction with the
|
|
.B \[rs]n[.ne]
|
|
register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.vpt]
|
|
1\~if vertical position traps are enabled, 0\~otherwise.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.warn]
|
|
The sum of the numbers associated with each of the currently enabled
|
|
warnings.
|
|
.
|
|
The number associated with each warning is listed in
|
|
.BR @g@troff (@MAN1EXT@).
|
|
.
|
|
.TP
|
|
.B \[rs]n[.x]
|
|
The major version number.
|
|
.
|
|
For example, if the version number is 1.03, then
|
|
.B \[rs]n[.x]
|
|
will contain\~1.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.y]
|
|
The minor version number.
|
|
.
|
|
For example, if the version number is 1.03, then
|
|
.B \[rs]n[.y]
|
|
will contain\~03.
|
|
.
|
|
.TP
|
|
.B \[rs]n[.Y]
|
|
The revision number of groff.
|
|
.
|
|
.TP
|
|
.B \[rs]n[llx]
|
|
.TQ
|
|
.B \[rs]n[lly]
|
|
.TQ
|
|
.B \[rs]n[urx]
|
|
.TQ
|
|
.B \[rs]n[ury]
|
|
These four registers are set by the
|
|
.B .psbb
|
|
request and contain the bounding box values (in PostScript units) of a
|
|
given PostScript image.
|
|
.
|
|
.P
|
|
The following read/write registers are set by the
|
|
.B \[rs]w
|
|
escape sequence:
|
|
.
|
|
.TP
|
|
.B \[rs]n[rst]
|
|
.TQ
|
|
.B \[rs]n[rsb]
|
|
Like the
|
|
.B st
|
|
and
|
|
.B sb
|
|
registers, but take account of the heights and depths of characters.
|
|
.
|
|
.TP
|
|
.B \[rs]n[ssc]
|
|
The amount of horizontal space (possibly negative) that should be
|
|
added to the last character before a subscript.
|
|
.
|
|
.TP
|
|
.B \[rs]n[skw]
|
|
How far to right of the center of the last character in the
|
|
.B \[rs]w
|
|
argument, the center of an accent from a roman font should be placed
|
|
over that character.
|
|
.
|
|
.P
|
|
Other available read/write number registers are:
|
|
.
|
|
.TP
|
|
.B \[rs]n[c.]
|
|
The current input line number.
|
|
.B \[rs]n[.c]
|
|
is a read-only alias to this register.
|
|
.
|
|
.TP
|
|
.B \[rs]n[hours]
|
|
The number of hours past midnight.
|
|
.
|
|
Initialized at start-up.
|
|
.
|
|
.TP
|
|
.B \[rs]n[hp]
|
|
The current horizontal position at input line.
|
|
.
|
|
.TP
|
|
.B \[rs]n[minutes]
|
|
The number of minutes after the hour.
|
|
.
|
|
Initialized at start-up.
|
|
.
|
|
.TP
|
|
.B \[rs]n[seconds]
|
|
The number of seconds after the minute.
|
|
.
|
|
Initialized at start-up.
|
|
.
|
|
.TP
|
|
.B \[rs]n[systat]
|
|
The return value of the system() function executed by the last
|
|
.B sy
|
|
request.
|
|
.
|
|
.TP
|
|
.B \[rs]n[slimit]
|
|
If greater than\~0, the maximum number of objects on the input stack.
|
|
.
|
|
If less than or equal to\~0, there is no limit on the number of
|
|
objects on the input stack.
|
|
.
|
|
With no limit, recursion can continue until virtual memory is
|
|
exhausted.
|
|
.
|
|
.TP
|
|
.B \[rs]n[year]
|
|
The current year.
|
|
.
|
|
Note that the traditional
|
|
.B troff
|
|
number register
|
|
.B \[rs]n[yr]
|
|
is the current year minus 1900.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS Miscellaneous
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.B @g@troff
|
|
predefines a single (read/write) string-based register,
|
|
.BR \[rs]*(.T ,
|
|
which contains the argument given to the
|
|
.B -T
|
|
command line option, namely the current output device (for example,
|
|
.I latin1
|
|
or
|
|
.IR ascii ).
|
|
Note that this is not the same as the (read-only) number register
|
|
.B \[rs]n[.T]
|
|
which is defined to be\~1 if
|
|
.B troff
|
|
is called with the
|
|
.B -T
|
|
command line option, and zero otherwise.
|
|
.
|
|
This behaviour is different to UNIX troff.
|
|
.
|
|
.P
|
|
Fonts not listed in the
|
|
.SM DESC
|
|
file are automatically mounted on the next available font position
|
|
when they are referenced.
|
|
.
|
|
If a font is to be mounted explicitly with the
|
|
.B fp
|
|
request on an unused font position, it should be mounted on the first
|
|
unused font position, which can be found in the
|
|
.B \[rs]n[.fp]
|
|
register; although
|
|
.B troff
|
|
does not enforce this strictly, it will not allow a font to be mounted
|
|
at a position whose number is much greater than that of any currently
|
|
used position.
|
|
.
|
|
.P
|
|
Interpolating a string does not hide existing macro arguments.
|
|
.
|
|
Thus in a macro, a more efficient way of doing
|
|
.
|
|
.IP
|
|
.BI . xx\ \[rs]\[rs]$@
|
|
.P
|
|
is
|
|
.
|
|
.IP
|
|
.BI \[rs]\[rs]*[ xx ]\[rs]\[rs]
|
|
.
|
|
.P
|
|
If the font description file contains pairwise kerning information,
|
|
characters from that font will be kerned.
|
|
.
|
|
Kerning between two characters can be inhibited by placing a
|
|
.B \[rs]&
|
|
between them.
|
|
.
|
|
.P
|
|
In a string comparison in a condition, characters that appear at
|
|
different input levels to the first delimiter character will not be
|
|
recognised as the second or third delimiters.
|
|
.
|
|
This applies also to the
|
|
.B tl
|
|
request.
|
|
.
|
|
In a
|
|
.B \[rs]w
|
|
escape sequence, a character that appears at a different input level
|
|
to the starting delimiter character will not be recognised as the
|
|
closing delimiter character.
|
|
.
|
|
The same is true for
|
|
.BR \[rs]A ,
|
|
.BR \[rs]b ,
|
|
.BR \[rs]B ,
|
|
.BR \[rs]C ,
|
|
.BR \[rs]l ,
|
|
.BR \[rs]L ,
|
|
.BR \[rs]o ,
|
|
.BR \[rs]X ,
|
|
and
|
|
.BR \[rs]Z .
|
|
.
|
|
When decoding a macro or string argument that is delimited by double
|
|
quotes, a character that appears at a different input level to the starting
|
|
delimiter character will not be recognised as the closing delimiter
|
|
character.
|
|
.
|
|
The implementation of
|
|
.B \[rs]$@
|
|
ensures that the double quotes surrounding an argument will appear the
|
|
same input level, which will be different to the input level of the
|
|
argument itself.
|
|
.
|
|
In a long escape name
|
|
.B ]
|
|
will not be recognized as a closing delimiter except when it occurs at
|
|
the same input level as the opening
|
|
.BR ] .
|
|
.
|
|
In compatibility mode, no attention is paid to the input-level.
|
|
.
|
|
.P
|
|
There are some new types of condition:
|
|
.
|
|
.TP
|
|
.BI .if\ r xxx
|
|
True if there is a number register named
|
|
.IR xxx .
|
|
.
|
|
.TP
|
|
.BI .if\ d xxx
|
|
True if there is a string, macro, diversion, or request named
|
|
.IR xxx .
|
|
.
|
|
.TP
|
|
.BI .if\ m xxx
|
|
True if there is a color named
|
|
.IR xxx .
|
|
.
|
|
.TP
|
|
.BI .if\ c ch
|
|
True if there is a character
|
|
.IR ch
|
|
available;
|
|
.I ch
|
|
is either an
|
|
.SM ASCII
|
|
character or a special character
|
|
.BI \[rs]( xx
|
|
or
|
|
.BI \[rs][ xxx ]\f[R];
|
|
the condition will also be true if
|
|
.I ch
|
|
has been defined by the
|
|
.B char
|
|
request.
|
|
.
|
|
.P
|
|
The
|
|
.B tr
|
|
request can now map characters onto
|
|
.BR \[rs]~ .
|
|
.
|
|
.P
|
|
It is now possible to have whitespace between the first and second dot
|
|
(or the name of the ending macro) to end a macro definition.
|
|
.
|
|
Example:
|
|
.
|
|
.IP
|
|
.ne 6v+\n(.Vu
|
|
.ft CB
|
|
.nf
|
|
.Text .de foo
|
|
.Text . nop Hello, I'm `foo'.
|
|
.Text . nop I will now define `bar'.
|
|
.Text . de bar
|
|
.Text . nop Hello, I'm `bar'.
|
|
.Text . .
|
|
.Text . nop Done.
|
|
.Text ..
|
|
.Text .foo
|
|
.Text .bar
|
|
.fi
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH "INTERMEDIATE OUTPUT FORMAT"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
This section describes the format output by GNU troff.
|
|
.
|
|
The output format used by GNU troff is very similar to that used
|
|
by Unix device-independent troff.
|
|
.
|
|
Only the differences are documented here.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Units"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The argument to the
|
|
.B s
|
|
command is in scaled points (units of
|
|
.RI points/ n ,
|
|
where
|
|
.I n
|
|
is the argument to the
|
|
.B sizescale
|
|
command in the DESC file).
|
|
.
|
|
The argument to the
|
|
.B x\ Height
|
|
command is also in scaled points.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Text Commands"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.TP
|
|
.BI N n
|
|
Print character with index\~\c
|
|
.I n
|
|
(a non-negative integer) of the current font.
|
|
.
|
|
.P
|
|
If the
|
|
.B tcommand
|
|
line is present in the DESC file, troff will use the following two
|
|
commands.
|
|
.
|
|
.TP
|
|
.BI t xxx
|
|
.I xxx
|
|
is any sequence of characters terminated by a space or a newline; the
|
|
first character should be printed at the current position, the current
|
|
horizontal position should be increased by the width of the first
|
|
character, and so on for each character.
|
|
.
|
|
The width of the character is that given in the font file,
|
|
appropriately scaled for the current point size, and rounded so that
|
|
it is a multiple of the horizontal resolution.
|
|
.
|
|
Special characters cannot be printed using this command.
|
|
.
|
|
.TP
|
|
.BI u n\ xxx
|
|
This is same as the
|
|
.B t
|
|
command except that after printing each character, the current
|
|
horizontal position is increased by the sum of the width of that
|
|
character and
|
|
.IR n .
|
|
.
|
|
.P
|
|
Note that single characters can have the eighth bit set, as can the
|
|
names of fonts and special characters.
|
|
.
|
|
.P
|
|
The names of characters and fonts can be of arbitrary length; drivers
|
|
should not assume that they will be only two characters long.
|
|
.
|
|
.P
|
|
When a character is to be printed, that character will always be
|
|
in the current font.
|
|
.
|
|
Unlike device-independent troff, it is not necessary for drivers to
|
|
search special fonts to find a character.
|
|
.
|
|
.P
|
|
For color support, some new commands have been added:
|
|
.
|
|
.TP
|
|
.Text \f[B]mc \f[I]cyan magenta yellow\f[R]
|
|
.TQ
|
|
.Text \f[B]md\f[R]
|
|
.TQ
|
|
.Text \f[B]mg \f[I]gray\f[R]
|
|
.TQ
|
|
.Text \f[B]mk \f[I]cyan magenta yellow black\f[R]
|
|
.TQ
|
|
.Text \f[B]mr \f[I]red green blue\f[R]
|
|
Set the color components of the current drawing color, using various
|
|
color schemes.
|
|
.
|
|
.B md
|
|
resets the drawing color to the default value.
|
|
.
|
|
The arguments are integers in the range 0 to 65536.
|
|
.
|
|
.P
|
|
The
|
|
.B x
|
|
device control command has been extended.
|
|
.
|
|
.TP
|
|
.Text \f[B]x u \f[I]n\f[R]
|
|
If
|
|
.I n
|
|
is\~1, start underlining of spaces.
|
|
.
|
|
If
|
|
.I n
|
|
is\~0, stop underlining of spaces.
|
|
.
|
|
This is needed for the
|
|
.B cu
|
|
request in nroff mode and is ignored otherwise.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Drawing Commands"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The
|
|
.B D
|
|
drawing command has been extended.
|
|
.
|
|
These extensions will not be used by GNU pic if the
|
|
.B \-n
|
|
option is given.
|
|
.
|
|
.TP
|
|
.Text \f[B]Df \f[I]n\f[R]\*[ic]\[rs]n
|
|
Set the shade of gray to be used for filling solid objects to
|
|
.IR n ;
|
|
.I n
|
|
must be an integer between 0 and 1000, where 0 corresponds solid white
|
|
and 1000 to solid black, and values in between correspond to
|
|
intermediate shades of gray.
|
|
.
|
|
This applies only to solid circles, solid ellipses and solid
|
|
polygons.
|
|
.
|
|
By default, a level of 1000 will be used.
|
|
.
|
|
Whatever color a solid object has, it should completely obscure
|
|
everything beneath it.
|
|
.
|
|
A value greater than 1000 or less than 0 can also be used: this means
|
|
fill with the shade of gray that is currently being used for lines and
|
|
text.
|
|
.
|
|
Normally this will be black, but some drivers may provide a way of
|
|
changing this.
|
|
.
|
|
.TP
|
|
.Text \f[B]DC \f[I]d\f[R]\*[ic]\[rs]n
|
|
Draw a solid circle with a diameter of
|
|
.I d
|
|
with the leftmost point at the current position.
|
|
.
|
|
.TP
|
|
.Text \f[B]DE \f[I]dx dy\f[R]\*[ic]\[rs]n
|
|
Draw a solid ellipse with a horizontal diameter of
|
|
.I dx
|
|
and a vertical diameter of
|
|
.I dy
|
|
with the leftmost point at the current position.
|
|
.EQ
|
|
delim $$
|
|
.EN
|
|
.
|
|
.TP
|
|
.Text \f[B]Dp\f[R] $dx sub 1$ $dy sub 1$ $dx sub 2$ $dy sub 2$ $...$ $dx sub n$ $dy sub n$\[rs]n
|
|
Draw a polygon with, for $i = 1 ,..., n+1$, the
|
|
.IR i -th
|
|
vertex at the current position
|
|
.
|
|
$+ sum from j=1 to i-1 ( dx sub j , dy sub j )$.
|
|
.
|
|
At the moment, GNU pic only uses this command to generate triangles
|
|
and rectangles.
|
|
.
|
|
.TP
|
|
.Text \f[B]DP\f[R] $dx sub 1$ $dy sub 1$ $dx sub 2$ $dy sub 2$ $...$ $dx sub n$ $dy sub n$\[rs]n
|
|
.
|
|
Like
|
|
.B Dp
|
|
but draw a solid rather than outlined polygon.
|
|
.
|
|
.TP
|
|
.Text \f[B]Dt \f[I]n\f[R]\*[ic]\[rs]n
|
|
Set the current line thickness to
|
|
.I n
|
|
machine units.
|
|
.
|
|
Traditionally Unix troff drivers use a line thickness proportional to
|
|
the current point size; drivers should continue to do this if no
|
|
.B Dt
|
|
command has been given, or if a
|
|
.B Dt
|
|
command has been given with a negative value of
|
|
.IR n .
|
|
A zero value of
|
|
.I n
|
|
selects the smallest available line thickness.
|
|
.
|
|
.P
|
|
A difficulty arises in how the current position should be changed after
|
|
the execution of these commands.
|
|
.
|
|
This is not of great importance since the code generated by GNU pic
|
|
does not depend on this.
|
|
.
|
|
Given a drawing command of the form
|
|
.IP
|
|
\f[B]\[rs]D\[fm]\f[I]c\f[R] $x sub 1$ $y sub 1$ $x sub 2$ $y sub 2$ $...$ $x sub n$ $y sub n$\[fm]
|
|
.
|
|
.P
|
|
where
|
|
.I c
|
|
is not one of
|
|
.BR c ,
|
|
.BR e ,
|
|
.BR l ,
|
|
.BR a ,
|
|
or
|
|
.BR ~ ,
|
|
Unix troff will treat each of the $x sub i$ as a horizontal quantity,
|
|
and each of the $y sub i$ as a vertical quantity and will assume that
|
|
the width of the drawn object is $sum from i=1 to n x sub i$,
|
|
and that the height is $sum from i=1 to n y sub i$.
|
|
.
|
|
(The assumption about the height can be seen by examining the
|
|
.B st
|
|
and
|
|
.B sb
|
|
registers after using such a
|
|
.B D
|
|
command in a \[rs]w escape sequence).
|
|
.
|
|
This rule also holds for all the original drawing commands with the
|
|
exception of
|
|
.BR De .
|
|
For the sake of compatibility GNU troff also follows this rule, even
|
|
though it produces an ugly result in the case of the
|
|
.BR Dt ,
|
|
and, to a lesser extent,
|
|
.B DE
|
|
commands.
|
|
.
|
|
Thus after executing a
|
|
.B D
|
|
command of the form
|
|
.IP
|
|
\f[B]D\f[I]c\f[R] $x sub 1$ $y sub 1$ $x sub 2$ $y sub 2$ $...$ \c
|
|
$x sub n$ $y sub n$\[rs]n
|
|
.
|
|
.P
|
|
the current position should be increased by
|
|
.
|
|
$( sum from i=1 to n x sub i , sum from i=1 to n y sub i )$.
|
|
.
|
|
.P
|
|
Another set of extensions is
|
|
.
|
|
.TP
|
|
.Text \f[B]DFc \f[I]cyan magenta yellow\f[R]\*[ic]\[rs]n
|
|
.TQ
|
|
.Text \f[B]DFd\f[R]\*[ic]\[rs]n
|
|
.TQ
|
|
.Text \f[B]DFg \f[I]gray\f[R]\*[ic]\[rs]n
|
|
.TQ
|
|
.Text \f[B]DFk \f[I]cyan magenta yellow black\f[R]\*[ic]\[rs]n
|
|
.TQ
|
|
.Text \f[B]DFr \f[I]red green blue\f[R]\*[ic]\[rs]n
|
|
Set the color components of the filling color similar to the
|
|
.B m
|
|
commands above.
|
|
.
|
|
.P
|
|
Note that
|
|
.B Df
|
|
is now mapped onto
|
|
.BR DFg .
|
|
The current position isn't changed by those colour commands.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Device Control Commands"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
There is a continuation convention which permits the argument to the
|
|
.B x\ X
|
|
command to contain newlines: when outputting the argument to the
|
|
.B x\ X
|
|
command, GNU troff will follow each newline in the argument with a
|
|
.B +
|
|
character (as usual, it will terminate the entire argument with a
|
|
newline); thus if the line after the line containing the
|
|
.B x\ X
|
|
command starts with
|
|
.BR + ,
|
|
then the newline ending the line containing the
|
|
.B x\ X
|
|
command should be treated as part of the argument to the
|
|
.B x\ X
|
|
command, the
|
|
.B +
|
|
should be ignored, and the part of the line following the
|
|
.B +
|
|
should be treated like the part of the line following the
|
|
.B x\ X
|
|
command.
|
|
.
|
|
.P
|
|
The first three output commands are guaranteed to be:
|
|
.IP
|
|
.BI x\ T\ device
|
|
.br
|
|
.BI x\ res\ n\ h\ v
|
|
.br
|
|
.B x init
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH INCOMPATIBILITIES
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
In spite of the many extensions, groff has retained compatibility to
|
|
classical troff to a large degree.
|
|
.
|
|
For the cases where the extensions lead to collisions, a special
|
|
compatibility mode with the restricted, old functionality was created
|
|
for groff.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Groff Language"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.I groff
|
|
provides a
|
|
.B compatibility mode
|
|
that allows to process roff code written for classical
|
|
.troff
|
|
or for other implementations of roff in a consistent way.
|
|
.
|
|
.P
|
|
Compatibility mode can be turned on with the
|
|
.option \-C
|
|
command line option, and turned on or off with the
|
|
.request .cp
|
|
request.
|
|
.
|
|
The number register
|
|
.esc n(.C
|
|
is\~1 if compatibility mode is on, 0\~otherwise.
|
|
.
|
|
.P
|
|
This became necessary because the GNU concept for long names causes
|
|
some incompatibilities.
|
|
.I Classical troff
|
|
interprets
|
|
.IP
|
|
.request .dsabcd
|
|
.
|
|
.P
|
|
as defining a string
|
|
.B ab
|
|
with contents
|
|
.BR cd .
|
|
In
|
|
.IR groff
|
|
mode, this will be considered as a call of a macro named
|
|
.request dsabcd .
|
|
.
|
|
.P
|
|
Also
|
|
.I classical troff
|
|
interprets
|
|
.esc *[
|
|
or
|
|
.esc n[
|
|
as references to a string or number register called
|
|
.request [
|
|
while
|
|
.I groff
|
|
takes this as the start of a long name.
|
|
.
|
|
.P
|
|
In
|
|
.IR "compatibility mode" ,
|
|
groff interprets these things in the traditional way; so long
|
|
names are not recognized.
|
|
.
|
|
.P
|
|
On the other hand, groff in
|
|
.I GNU native mode
|
|
does not allow to use the single-character escapes
|
|
.esc \[rs]
|
|
(backslash),
|
|
.esc |
|
|
(vertical bar),
|
|
.esc ^
|
|
(caret),
|
|
.esc &
|
|
(ampersand),
|
|
.esc {
|
|
(opening brace),
|
|
.esc }
|
|
(closing brace),
|
|
.squoted "\[rs]\ "
|
|
(space),
|
|
.esc '
|
|
(single quote),
|
|
.esc `
|
|
(backquote),
|
|
.esc \-
|
|
(minus),
|
|
.esc _
|
|
(underline),
|
|
.esc !
|
|
(bang),
|
|
.esc %
|
|
(percent),
|
|
and
|
|
.esc c
|
|
(character c) in names of strings, macros, diversions, number
|
|
registers, fonts or environments, whereas
|
|
.I classical troff
|
|
does.
|
|
.
|
|
.P
|
|
The
|
|
.esc A
|
|
escape sequence can be helpful in avoiding these escape sequences in
|
|
names.
|
|
.
|
|
.P
|
|
Fractional pointsizes cause one noteworthy incompatibility.
|
|
.
|
|
In
|
|
.I classical
|
|
.IR troff ,
|
|
the
|
|
.request ps
|
|
request ignores scale indicators and so
|
|
.RS
|
|
.P
|
|
.B .ps\~10u
|
|
.RE
|
|
.
|
|
.P
|
|
will set the pointsize to 10\~points, whereas in groff native mode the
|
|
pointsize will be set to 10\~scaled points.
|
|
.
|
|
.P
|
|
In
|
|
.I groff
|
|
mode, there is a fundamental difference between unformatted input
|
|
characters, and formatted output characters.
|
|
.
|
|
Everything that affects how an output character will be output is
|
|
stored with the character; once an output character has been
|
|
constructed it is unaffected by any subsequent requests that are
|
|
executed, including the
|
|
.request bd ,
|
|
.request cs ,
|
|
.request tkf ,
|
|
.request tr ,
|
|
or
|
|
.request fp
|
|
requests.
|
|
.
|
|
.P
|
|
Normally output characters are constructed from input characters at
|
|
the moment immediately before the character is added to the current
|
|
output line.
|
|
.
|
|
Macros, diversions and strings are all, in fact, the same type of
|
|
object; they contain lists of input characters and output characters
|
|
in any combination.
|
|
.
|
|
.P
|
|
An output character does not behave like an input character for the
|
|
purposes of macro processing; it does not inherit any of the special
|
|
properties that the input character from which it was constructed
|
|
might have had.
|
|
.
|
|
The following example will make things clearer.
|
|
.
|
|
.P
|
|
.RS
|
|
.nf
|
|
.ft CB
|
|
.Text .di x
|
|
.Text \[rs]\[rs]\[rs]\[rs]
|
|
.Text .br
|
|
.Text .di
|
|
.Text .x
|
|
.ft
|
|
.fi
|
|
.RE
|
|
.
|
|
.P
|
|
In
|
|
.I GNU mode
|
|
this will be printed as
|
|
.esc \[rs] .
|
|
So each pair of input backslashes
|
|
.squoted \[rs]\[rs]
|
|
is turned into a single output backslash
|
|
.squoted \[rs]
|
|
and the resulting output backslashes are not interpreted as escape
|
|
characters when they are reread.
|
|
.
|
|
.P
|
|
.I Classical troff
|
|
would interpret them as escape characters when they were reread and
|
|
would end up printing a single backslash
|
|
.squoted \[rs] .
|
|
.
|
|
.P
|
|
In GNU, the correct way to get a printable version of the backslash
|
|
character
|
|
.squoted \[rs]
|
|
is the
|
|
.esc (rs
|
|
escape sequence, but classical troff does not provide a clean feature
|
|
for getting a non-syntactical backslash.
|
|
.
|
|
A close method is the printable version of the current escape
|
|
character using the
|
|
.esc e
|
|
escape sequence; this works if the current escape character is not
|
|
redefined.
|
|
.
|
|
It works in both GNU mode and compatibility mode, while dirty tricks
|
|
like specifying a sequence of multiple backslashes do not work
|
|
reliably; for the different handling in diversions, macro definitions,
|
|
or text mode quickly leads to a confusion about the necessary number of
|
|
backslashes.
|
|
.
|
|
.P
|
|
To store an escape sequence in a diversion that will be interpreted
|
|
when the diversion is reread, either the traditional
|
|
.esc !
|
|
transparent output facility or the
|
|
new
|
|
.esc ?
|
|
escape sequence can be used.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SS "Intermediate Output"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The groff intermediate output format is in a state of evolution.
|
|
.
|
|
So far it has some incompatibilities, but it is intended to establish
|
|
a full compatibility to the classical troff output format.
|
|
.
|
|
Actually the following incompatibilities exist:
|
|
.
|
|
.Topic
|
|
The positioning after the drawing of the polygons conflicts with the
|
|
classical definition.
|
|
.
|
|
.Topic
|
|
The intermediate output cannot be rescaled to other devices as
|
|
classical "device-independent" troff did.
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH AUTHORS
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
Copyright (C) 1989, 2001, 2002 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 by
|
|
.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.
|
|
.
|
|
Formerly, the contents of this document was kept in the manual
|
|
page
|
|
.BR @g@troff (@MAN1EXT@).
|
|
Only the parts dealing with the language aspects of the different
|
|
.I roff
|
|
systems were carried over into this document.
|
|
.
|
|
The
|
|
.I troff
|
|
command line options and warnings are still documented in
|
|
.BR @g@troff (@MAN1EXT@).
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.SH "SEE ALSO"
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
The
|
|
.I groff info
|
|
.IR file ,
|
|
cf.\&
|
|
.BR info (1)
|
|
presents all groff documentation within a single document.
|
|
.
|
|
.TP
|
|
.BR groff (@MAN1EXT@)
|
|
A list of all documentation around
|
|
.IR groff .
|
|
.
|
|
.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 using
|
|
.
|
|
.IP
|
|
.ShellCommand man\~7\~groff
|
|
.
|
|
.TP
|
|
.BR roff (@MAN7EXT@)
|
|
A survey of
|
|
.I roff
|
|
systems, including pointers to further historical documentation.
|
|
.
|
|
.TP
|
|
.RI [ CSTR\~#54\/ ]
|
|
The
|
|
.I Nroff/\:Troff User's Manual
|
|
by
|
|
.I J.\& F.\& Osanna
|
|
of 1976 in the revision of
|
|
.I Brian Kernighan
|
|
of 1992, being the
|
|
.URL http://\:cm.bell-labs.com/\:cm/\:cs/\:cstr/\:54.ps.gz \
|
|
"classical troff documentation" .
|
|
.
|
|
.
|
|
.\" --------------------------------------------------------------------
|
|
.\" Emacs variables
|
|
.\" --------------------------------------------------------------------
|
|
.
|
|
.\" Local Variables:
|
|
.\" mode: nroff
|
|
.\" End:
|