Note that no index is generated by the text backend.

[sgt/halibut] / doc / output.but

\C{output} Halibut output formats

This chapter describes each of Halibut's current \i{output formats}.
It gives some general information about the format, and also
describes all the \i{configuration directives} which are specific to
that format.

\H{output-text} Plain text

This output format generates the document as a single \i{plain text}
file. No index is generated.

The precise formatting of the text file can be controlled by a
variety of configuration directives. They are listed in the
following subsections.

\S{output-text-file} Output file name

\dt \I{\cw{\\cfg\{text-filename\}}}\cw{\\cfg\{text-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the text file.
This directive is implicitly generated if you provide a file name
parameter after the command-line option \i\c{--text} (see
\k{running-options}).

\S{output-text-dimensions} Indentation and line width

This section describes the configuration directives which control
the \i{horizontal dimensions} of the output text file: how much
paragraphs are indented by and how long the lines are.

\dt \I{\cw{\\cfg\{text-width\}}}\cw{\\cfg\{text-width\}\{}\e{width}\cw{\}}

\dd Sets the \I{text width}width of the main part of the document,
in characters. This width will be used for wrapping paragraphs and
for centring titles (if you have asked for titles to be centred -
see \k{output-text-headings}). This width does \e{not} include the
left indentation set by \cw{\\cfg\{text-indent\}}; if you specify an
indent of 8 and a width of 64, your maximum output line length will
be 72.

\dt \I{\cw{\\cfg\{text-indent\}}}\cw{\\cfg\{text-indent\}\{}\e{indent}\cw{\}}

\dd Sets the left \i{indentation} for the document. If you set this
to zero, your document will look like an ordinary text file as
someone with a text editor might have written it; if you set it
above zero, the text file will have a \i{margin} down the left in
the style of some printed manuals, and you can then configure the
section numbers to appear in this margin (see
\k{output-text-headings}).

\dt \I{\cw{\\cfg\{text-indent-code\}}}\cw{\\cfg\{text-indent-code\}\{}\e{indent}\cw{\}}

\dd Specifies how many extra characters of indentation (on top of
the normal left indent) should be given to \I{code paragraphs,
indentation} code paragraphs.

\dt \I{\cw{\\cfg\{text-list-indent\}}}\cw{\\cfg\{text-list-indent\}\{}\e{indent}\cw{\}}

\dd Specifies how many extra spaces should be used to indent the
bullet or number in a \I{bulletted list, indentation}bulletted or
\I{numbered list, indentation}numbered \I{list, indentation}list.
The actual body of the list item will be indented by this much
\e{plus} the value configured by \cw{\\cfg\{text-listitem-indent\}}.

\dt \I{\cw{\\cfg\{text-listitem-indent\}}}\cw{\\cfg\{text-listitem-indent\}\{}\e{indent}\cw{\}}

\dd Specifies how many extra spaces should be used to indent the
body of a list item, over and above the number configured in
\cw{\\cfg\{text-list-indent\}}.

\dt \I{\cw{\\cfg\{text-indent-preamble\}}}\cw{\\cfg\{text-indent-preamble\}\{}\e{boolean}\cw{\}}

\dd When this is set to \c{true}, the document \i{preamble} (i.e. any
paragraphs appearing before the first chapter heading) will be
indented to the level specified by \cw{\\cfg\{text-indent\}}. If
this setting is \c{false}, the document preamble will not be
indented at all from the left margin.

\S{output-text-headings} \ii{Configuring heading display}

The directives in this section allow you to configure the appearance
of the title, chapter and section headings in your text file.

Several of the directives listed below specify the \i{alignment} of
a heading. These alignment options have three possible values:

\dt \i\c{left}

\dd Align the heading to the very left of the text file (column zero).

\dt \i\c{leftplus}

\dd Align the section title to the left of the main display region
(in other words, indented to the level specified by
\cw{\\cfg\{text-indent\}}). The section \e{number} is placed to the
left of that (so that it goes in the margin if there is room).

\dt \i\c{centre}

\dd Centre the heading.

Also, several of the directives below specify how a title should be
\I{underlining}underlined. The parameter to one of these directives
should be either blank (\cw{\{\}}) or a piece of text which will be
repeated to produce the underline. So you might want to specify, for
example, \cw{\\text-title-underline\{=\}} but
\cw{\\text-chapter-underline\{\-\}}.

You can also specify more than one underline setting, and Halibut
will choose the first one that the output character set supports.
So, for example, you could write
\cw{\\text-chapter-underline\{\u203e\}\{\-\}}, and Halibut would use
the Unicode \q{OVERLINE} character where possible and fall back to
the ASCII minus sign otherwise.

\dt \I{\cw{\\cfg\{text-title-align\}}}\cw{\\cfg\{text-title-align\}\{}\e{alignment}\cw{\}}

\dd Specifies the alignment of the overall document title: \c{left},
\c{leftplus} or \c{centre}.

\dt \I{\cw{\\cfg\{text-title-underline\}}}\cw{\\cfg\{text-title-underline\}\{}\e{underline-character}\cw{\}}

\dd Specifies how the overall document title should be underlined.

\dt \I{\cw{\\cfg\{text-chapter-align\}}}\cw{\\cfg\{text-chapter-align\}\{}\e{alignment}\cw{\}}

\dd Specifies the alignment of chapter and appendix headings.

\dt \I{\cw{\\cfg\{text-chapter-underline\}}}\cw{\\cfg\{text-chapter-underline\}\{}\e{underline-character}\cw{\}}

\dd Specifies how chapter and appendix headings should be underlined.

\dt \I{\cw{\\cfg\{text-chapter-numeric\}}}\cw{\\cfg\{text-chapter-numeric\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, then chapter headings will not
contain the word \q{Chapter} (or whatever other word you have
defined in its place - see \k{input-sections} and \k{input-config});
they will just contain the chapter \e{number}, followed by the
chapter title. If you set this to \c{false}, chapter headings will
be prefixed by \q{Chapter} or equivalent.

\dt \I{\cw{\\cfg\{text-chapter-suffix\}}}\cw{\\cfg\{text-chapter-suffix\}\{}\e{text}\cw{\}}

\dd This specifies the suffix text to be appended to the chapter
number, before displaying the chapter title. For example, if you set
this to \q{\cw{:\_}}, then the chapter title might look something
like \q{Chapter 2: Doing Things}.

\dt \I{\cw{\\cfg\{text-section-align\}}}\cw{\\cfg\{text-section-align\}\{}\e{level}\cw{\}\{}\e{alignment}\cw{\}}

\dd Specifies the alignment of section headings at a particular
level. The \e{level} parameter specifies which level of section
headings you want to affect: 0 means first-level headings (\c{\\H}),
1 means second-level headings (\c{\\S}), 2 means the level below
that (\c{\\S2}), and so on. The \e{alignment} parameter is treated
just like the other alignment directives listed above.

\dt \I{\cw{\\cfg\{text-section-underline\}}}\cw{\\cfg\{text-section-underline\}\{}\e{level}\cw{\}\{}\e{underline-character}\cw{\}}

\dd Specifies how to underline section headings at a particular level.

\dt \I{\cw{\\cfg\{text-section-numeric\}}}\cw{\\cfg\{text-section-numeric\}\{}\e{level}\cw{\}\{}\e{boolean}\cw{\}}

\dd Specifies whether section headings at a particular level should
contain the word \q{Section} or equivalent (if \c{false}), or should
be numeric only (if \c{true}).

\dt \I{\cw{\\cfg\{text-section-suffix\}}}\cw{\\cfg\{text-section-suffix\}\{}\e{level}\cw{\}\{}\e{text}\cw{\}}

\dd Specifies the \I{suffix text, in section titles}suffix text to
be appended to section numbers at a particular level, before
displaying the section title.

\S{output-text-characters} Configuring the characters used

\dt \I{\cw{\\cfg\{text-bullet\}}}\cw{\\cfg\{text-bullet\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}...\cw{\}}]

\dd This specifies the text which should be used as the \i{bullet}
in bulletted lists. It can be one character
(\cw{\\cfg\{text-bullet\}\{-\}}), or more than one
(\cw{\\cfg\{text-bullet\}\{(*)\}}).

\lcont{

Like \cw{\\cfg\{quotes\}} (see \k{input-config}), you can specify multiple
possible options after this command, and Halibut will choose the first one
which the output character set supports. For example, you might write
\cw{\\cfg\{text-bullet\}\{\\u2022\}\{\\u00b7\}\{*\}}, in which case
Halibut would use the Unicode \q{BULLET} character where possible,
fall back to the ISO-8859-1 \q{MIDDLE DOT} if that wasn't available,
and resort to the ASCII asterisk if all else failed.

}

\dt \I{\cw{\\cfg\{text-rule\}}}\cw{\\cfg\{text-rule\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}...\cw{\}}]

\dd This specifies the text which should be used for drawing
\i{horizontal rules} (generated by \i\c{\\rule}; see
\k{input-rule}). It can be one character, or more than one. The
string you specify will be repeated to reach the required width, so
you can specify something like \q{\cw{-=}} to get a rule that looks
like \cw{-=-=-=}.

\lcont{

Like \cw{\\cfg\{text-bullet\}}, you can specify multiple fallback
options in this command.

}

\dt \I{\cw{\\cfg\{text-quotes\}}}\cw{\\cfg\{text-quotes\}\{}\e{open-quote}\cw{\}\{}\e{close-quote}\cw{\}}[\cw{\{}\e{open-quote}\cw{\}\{}\e{close-quote}...\cw{\}}]

\dd This specifies a set of quote characters for the text backend,
overriding any defined by \cw{\\cfg\{quotes\}}. It has the same syntax
(see \k{input-config}).

\lcont{

In this backend, these quotes will also be used to mark text enclosed
in the \c{\\c} command (see \k{input-code}).

}

\dt \I{\cw{\\cfg\{text-emphasis\}}}\cw{\\cfg\{text-emphasis\}\{}\e{start-emph}\cw{\}\{}\e{end-emph}\cw{\}}[\cw{\{}\e{start-emph}\cw{\}\{}\e{end-emph}...\cw{\}}]

\dd This specifies the characters which should be used to surround
emphasised text (written using the \c{\\e} command; see
\k{input-emph}).

\lcont{

You should separately specify the start-emphasis and end-emphasis
text, each of which can be more than one character if you want.
Also, like \cw{\\cfg\{text-quotes\}}, you can specify multiple pairs
of fallback options in this command, and Halibut will always use a
matching pair.

}

\S{output-text-misc} Miscellaneous configuration options

\dt \I\cw{\\cfg\{text-charset\}}\cw{\\cfg\{text-charset\}\{}\e{character set name}\cw{\}}

\dd This tells Halibut what \i{character set} the output should be
in. Any Unicode characters representable in this set will be output
verbatim; any other characters will not be output and their
\i{fallback text} (if any) will be used instead.

\lcont{

The character set names are the same as for
\cw{\\cfg\{input-charset\}} (see \k{input-config}). However, unlike
\cw{\\cfg\{input-charset\}}, this directive affects the \e{entire}
output; it's not possible to switch encodings halfway through.

}

\dt \I{\cw{\\cfg\{text-list-suffix\}}}\cw{\\cfg\{text-list-suffix\}\{}\e{text}\cw{\}}

\dd This text is appended to the number on a \i{numbered list} item
(see \k{input-list-number}). So if you want to label your lists as
\q{1)}, \q{2)} and so on, then you would write
\cw{\\cfg\{text-list-suffix\}\{)\}}.

\dt \I{\cw{\\cfg\{text-versionid\}}}\cw{\\cfg\{text-versionid\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, \i{version ID paragraphs} (defined
using the \i\c{\\versionid} command - see \k{input-blurb}) will be
included at the bottom of the text file. If it is set to \c{false},
they will be omitted completely.

\# FIXME: code indentation is configurable, therefore \quote
\# indentation probably ought to be as well.

\# FIXME: text-indent-* should be consistently named.

\S{output-text-defaults} Default settings

The \i{default settings} for Halibut's plain text output format are:

\c \cfg{text-filename}{output.txt}
\c
\c \cfg{text-width}{68}
\c \cfg{text-indent}{7}
\c \cfg{text-indent-code}{2}
\c \cfg{text-list-indent}{1}
\c \cfg{text-listitem-indent}{3}
\c \cfg{text-indent-preamble}{false}
\c
\c \cfg{text-title-align}{centre}
\c \cfg{text-title-underline}{\u2550}{=}
\c
\c \cfg{text-chapter-align}{left}
\c \cfg{text-chapter-underline}{\u203e}{-}
\c \cfg{text-chapter-numeric}{false}
\c \cfg{text-chapter-suffix}{: }
\c
\c \cfg{text-section-align}{0}{leftplus}
\c \cfg{text-section-underline}{0}{}
\c \cfg{text-section-numeric}{0}{true}
\c \cfg{text-section-suffix}{0}{ }
\c
\c \cfg{text-section-align}{1}{leftplus}
\c \cfg{text-section-underline}{1}{}
\c \cfg{text-section-numeric}{1}{true}
\c \cfg{text-section-suffix}{1}{ }
\c
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
\c
\c \cfg{text-bullet}{\u2022}{-}
\c \cfg{text-rule}{\u2500}{-}
\c \cfg{text-quotes}{\u2018}{\u2019}{`}{'}
\c \cfg{text-emphasis}{_}{_}
\c
\c \cfg{text-charset}{ASCII}
\c \cfg{text-list-suffix}{.}
\c \cfg{text-versionid}{true}

\H{output-html} HTML

This output format generates an \i{HTML} version of the document. By
default, this will be in multiple files, starting with
\c{Contents.html} and splitting the document into files by chapter
and/or subsection. You can configure precisely how the text is split
between HTML files using the configuration commands described in
this section. In particular, you can configure Halibut to output one
single HTML file instead of multiple ones.

Strictly speaking, the output format is \i{XHTML} 1.0 Transitional,
which is why all of the configuration directives start with the word
\c{xhtml} rather than \c{html}.

\S{output-html-file} Controlling the output file names

\dt \I{\cw{\\cfg\{xhtml-contents-filename\}}}\cw{\\cfg\{xhtml-contents-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the top-level
contents page. Since this is the first page a user ought to see when
beginning to read the document, a good choice in many cases might be
\c{index.html} (although this is not the default, for historical
reasons).

\dt \I{\cw{\\cfg\{xhtml-index-filename\}}}\cw{\\cfg\{xhtml-index-filename\}\{}\e{filename}\cw{\}}

\dd Sets the file name in which to store the document's index.

\dt \I{\cw{\\cfg\{xhtml-template-filename\}}}\cw{\\cfg\{xhtml-template-filename\}\{}\e{template}\cw{\}}

\dd Provides a \i{template} to be used when constructing the file
names of each chapter or section of the document. This template
should contain at least one \i\e{formatting command}, in the form of
a per cent sign followed by a letter. (If you need a literal per
cent sign, you can write \c{%%}.)

\lcont{

The formatting commands used in this template are:

\dt \I{%N-upper}\c{%N}

\dd Expands to the visible title of the section, with white space
removed. So in a chapter declared as \q{\cw{\\C\{fish\} Catching
Fish}}, this formatting command would expand to
\q{\cw{CatchingFish}}.

\dt \i\c{%n}

\dd Expands to the type and number of the section, without white
space. So in chapter 1 this would expand to \q{\cw{Chapter1}}; in
section A.4.3 it would expand to \q{\cw{SectionA.4.3}}, and so on.
If the section has no number (an unnumbered chapter created using
\c{\\U}), this directive falls back to doing the same thing as
\c{%N}.

\dt \i\c{%b}

\dd Expands to the bare number of the section. So in chapter 1 this
would expand to \q{\cw{1}}; in section A.4.3 it would expand to
\q{\cw{A.4.3}}, and so on. If the section has no number (an
unnumbered chapter created using \c{\\U}), this directive falls back
to doing the same thing as \c{%N}.

\dt \i\c{%k}

\dd Expands to the internal keyword specified in the section title.
So in a chapter declared as \q{\cw{\\C\{fish\} Catching Fish}}, this
formatting command would expand to \q{\cw{fish}}. If the section has
no keyword (an unnumbered chapter created using \c{\\U}), this
directive falls back to doing the same thing as \c{%N}.

These formatting directives can also be used in the
\cw{\\cfg\{xhtml-template-fragment\}} configuration directive (see
\k{output-html-misc}).

}

\dt \I{\cw{\\cfg\{xhtml-single-filename\}}}\cw{\\cfg\{xhtml-single-filename\}\{}\e{filename}\cw{\}}

\dd Sets the file name in which to store the entire document, if
Halibut is configured (using \c{\\cfg\{xhtml-leaf-level\}\{0\}} to
produce a single self-contained file. Both this directive \e{and}
\c{\\cfg\{xhtml-leaf-level\}\{0\}} are implicitly generated if you
provide a file name parameter after the command-line option
\i\c{--html} (see \k{running-options}).

\S{output-html-split} Controlling the splitting into HTML files

By default, the HTML output from Halibut is split into multiple
files. Each file typically contains a single chapter or section and
everything below it, unless subsections of that chapter are
themselves split off into further files.

Most files also contain a contents section, giving hyperlinks to the
sections in the file and/or the sections below it.

The configuration directives listed below allow you to configure the
splitting into files, and the details of the contents sections.

\dt \I{\cw{\\cfg\{xhtml-leaf-level\}}}\cw{\\cfg\{xhtml-leaf-level\}\{}\e{depth}\cw{\}}

\dd This setting indicates the depth of section which should be
given a \I{leaf file}\q{leaf} file (a file with no sub-files). So if
you set it to 1, for example, then every chapter will be given its
own HTML file, plus a top-level \i{contents file}. If you set this
to 2, then each chapter \e{and} each \c{\\H} section will have a
file, and the chapter files will mostly just contain links to their
\i{sub-file}s.

\lcont{

If you set this option to zero, then the whole document will appear
in a single file. If you do this, Halibut will call that file
\i\c{Manual.html} instead of \i\c{Contents.html}.

This option is automatically set to zero if you provide a file name
parameter after the command-line option \i\c{--html} (see
\k{running-options}), because you have specified a single file name
and so Halibut assumes you want the whole document to be placed in
that file.

}

\dt \I{\cw{\\cfg\{xhtml-contents-depth\}}}\cw{\\cfg\{xhtml-contents-depth-}\e{level}\cw{\}\{}\e{depth}\cw{\}}

\dd This directive allows you to specify how \I{depth of
contents}deep the contents section in a particular file should go.

\lcont{

The \e{level} parameter indicates which level of contents section
you are dealing with. 0 denotes the main contents section in the
topmost file \c{Contents.html}; 1 denotes a contents section in a
chapter file; 2 is a contents section in a file containing a \c{\\H}
heading, and so on. Currently you can't go below level 5 (which
corresponds to a \c{\\S3} heading).

The \e{depth} parameter indicates the maximum depth of heading which
will be shown in this contents section. Again, 1 denotes a chapter,
2 is a \c{\\H} heading, 3 is a \c{\\S} heading, and so on.

So, for example: \cw{\\cfg\{xhtml-contents-depth-1\}\{3\}} instructs
Halibut to put contents links in chapter files for all sections down
to \c{\\S} level, but not to go into any more detail than that.

}

\# FIXME: this is utterly ghastly. For a start, it should include
\# the level as a separate argument, like the text section config
\# directives. Secondly, it shouldn't be limited in depth!

\dt \I{\cw{\\cfg\{xhtml-leaf-contains-contents\}}}\cw{\\cfg\{xhtml-leaf-contains-contents\}\{}\e{boolean}\cw{\}}

\dd If you set this to \c{true}, then each leaf file will contain
its own contents section which summarises the text within it.

\dt \I{\cw{\\cfg\{xhtml-leaf-smallest-contents\}}}\cw{\\cfg\{xhtml-leaf-smallest-contents\}\{}\e{number}\cw{\}}

\dd Contents sections in leaf files are not output at all if they
contain very few entries (on the assumption that it just isn't worth
bothering). This directive configures the minimum number of entries
required in a leaf contents section to make Halibut bother
generating it at all.

\S{output-html-html} Including pieces of your own HTML

The directives in this section allow you to supply pieces of
\I{HTML}\i{verbatim HTML} code, which will be included in various
parts of the output files.

\dt \I{\cw{\\cfg\{xhtml-head-end\}}}\cw{\\cfg\{xhtml-head-end\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is placed at the end of
the \i\cw{<HEAD>} section of each output HTML file. So this is a
good place to put, for example, a link to a \i{CSS} \i{stylesheet}.

\dt \I{\cw{\\cfg\{xhtml-body-tag\}}}\cw{\\cfg\{xhtml-body-tag\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is used in place of the
\i\cw{<BODY>} tag in each output file. So if you wanted to define a
\i{background colour}, for example, you could write
\cw{\\cfg\{xhtml-body-tag\}\{<body bg="#123456">\}}.

\dt \I{\cw{\\cfg\{xhtml-body-start\}}}\cw{\\cfg\{xhtml-body-start\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is placed at the
beginning of the \i\cw{<BODY>} section of each output HTML file. So
if you intend your HTML files to be part of a web site with a
standard \i{house style}, and the style needs a \i{header} at the
top of every page, this is where you can add that header.

\dt \I{\cw{\\cfg\{xhtml-body-end\}}}\cw{\\cfg\{xhtml-body-end\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is placed at the end of
the \i\cw{<BODY>} section of each output HTML file. So if you intend
your HTML files to be part of a web site with a standard \i{house
style}, and the style needs a \i{footer} at the bottom of every
page, this is where you can add that footer.

\dt \I{\cw{\\cfg\{xhtml-address-start\}}}\cw{\\cfg\{xhtml-address-start\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is placed at the
beginning of the \i\cw{<ADDRESS>} section at the bottom of each
output HTML file. This might be a good place to put authors'
\i{contact details}, for example.

\dt \I{\cw{\\cfg\{xhtml-address-end\}}}\cw{\\cfg\{xhtml-address-end\}\{}\e{HTML text}\cw{\}}

\dd The text you provide in this directive is placed at the end of
the \i\cw{<ADDRESS>} section at the bottom of each output HTML file,
after the version IDs (if present).

\dt \I{\cw{\\cfg\{xhtml-navigation-attributes\}}}\cw{\\cfg\{xhtml-navigation-attributes\}\{}\e{HTML attributes}\cw{\}}

\dd The text you provide in this directive is included inside the
\cw{<P>} tag containing the \i{navigation links} at the top of each
page (\i{\q{Previous}} / \i{\q{Contents}} / \i{\q{Next}}). So if you
wanted the navigation links to have a particular CSS style, you
could write
\cw{\\cfg\{xhtml-navigation-attributes\}\{class="foo"\}}, and the
navigation-links paragraph would then begin with the tag \cw{<p
class="foo">}.

\S{output-html-headings} \ii{Configuring heading display}

\dt \I{\cw{\\cfg\{xhtml-chapter-numeric\}}}\cw{\\cfg\{xhtml-chapter-numeric\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, then chapter headings will not
contain the word \q{Chapter} (or whatever other word you have
defined in its place - see \k{input-sections} and \k{input-config});
they will just contain the chapter \e{number}, followed by the
chapter title. If you set this to \c{false}, chapter headings will
be prefixed by \q{Chapter} or equivalent.

\dt \I{\cw{\\cfg\{xhtml-chapter-suffix\}}}\cw{\\cfg\{xhtml-chapter-suffix\}\{}\e{text}\cw{\}}

\dd This specifies the suffix text to be appended to the chapter
number, before displaying the chapter title. For example, if you set
this to \q{\cw{:\_}}, then the chapter title might look something
like \q{Chapter 2: Doing Things}.

\dt \I{\cw{\\cfg\{xhtml-section-numeric\}}}\cw{\\cfg\{xhtml-section-numeric\}\{}\e{level}\cw{\}\{}\e{boolean}\cw{\}}

\dd Specifies whether section headings at a particular level should
contain the word \q{Section} or equivalent (if \c{false}), or should
be numeric only (if \c{true}). The \e{level} parameter specifies
which level of section headings you want to affect: 0 means
first-level headings (\c{\\H}), 1 means second-level headings
(\c{\\S}), 2 means the level below that (\c{\\S2}), and so on.

\dt \I{\cw{\\cfg\{xhtml-section-suffix\}}}\cw{\\cfg\{xhtml-section-suffix\}\{}\e{level}\cw{\}\{}\e{text}\cw{\}}

\dd Specifies the suffix text to be appended to section numbers at a
particular level, before displaying the section title.

\S{output-html-misc} Miscellaneous options

\dt \I{\cw{\\cfg\{xhtml-template-fragment\}}}\cw{\\cfg\{xhtml-template-fragment\}\{}\e{template}\cw{\}}

\dd This directive lets you specify a \i{template}, with exactly the
same syntax used in \cw{\\cfg\{xhtml-template-filename\}} (see
\k{output-html-file}), to be used for the anchor names (\i\cw{<A
NAME="...">}) used to allow URLs to refer to specific sections
within a particular HTML file. So if you set this to \q{\cw{%k}},
for example, then each individual section in your document will be
addressable by means of a URL ending in a \c{#} followed by your
internal section keyword.

\dt \I{\cw{\\cfg\{xhtml-versionid\}}}\cw{\\cfg\{xhtml-versionid\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, \i{version ID paragraphs} (defined using
the \i\c{\\versionid} command - see \k{input-blurb}) will be included
visibly in the \i\cw{<ADDRESS>} section at the bottom of each HTML
file. If it is set to \c{false}, they will be omitted completely.

\# FIXME: surely it would be better to include them in HTML
\# comments? The only question is whether they should be _visible_.

\dt \I{\cw{\\cfg\{xhtml-suppress-address\}}}\cw{\\cfg\{xhtml-suppress-address\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, the \i\cw{<ADDRESS>} section at the
bottom of each HTML file will be omitted completely. (This will
therefore also cause \i{version IDs} not to be included.)

\dt \I{\cw{\\cfg\{xhtml-author\}}}\cw{\\cfg\{xhtml-author\}\{}\e{text}\cw{\}}

\dd The text supplied here goes in a \I{\cw{<META>} tags}\cw{<META
name="author">} tag in the output HTML files, so that browsers which
support this can automatically identify the \i{author} of the document.

\dt \I{\cw{\\cfg\{xhtml-description\}}}\cw{\\cfg\{xhtml-description\}\{}\e{text}\cw{\}}

\dd The text supplied here goes in a \I{\cw{<META>} tags}\cw{<META
name="description">} tag in the output HTML files, so that browsers
which support this can easily pick out a brief \I{description, of
document}description of the document.

\S{output-html-defaults} Default settings

The \i{default settings} for Halibut's HTML output format are:

\c \cfg{xhtml-contents-filename}{Contents.html}
\c \cfg{xhtml-index-filename}{IndexPage.html}
\c \cfg{xhtml-template-filename}{%n.html}
\c \cfg{xhtml-single-filename}{Manual.html}
\c \cfg{xhtml-template-fragment}{%b}
\c
\c \cfg{xhtml-leaf-level}{2}
\c \cfg{xhtml-leaf-contains-contents}{false}
\c \cfg{xhtml-leaf-smallest-contents}{4}
\c \cfg{xhtml-contents-depth-0}{2}
\c \cfg{xhtml-contents-depth-1}{3}
\c \cfg{xhtml-contents-depth-2}{4}
\c \cfg{xhtml-contents-depth-3}{5}
\c \cfg{xhtml-contents-depth-4}{6}
\c \cfg{xhtml-contents-depth-5}{7}
\c
\c \cfg{xhtml-head-end}{}
\c \cfg{xhtml-body-tag}{<body>}
\c \cfg{xhtml-body-start}{}
\c \cfg{xhtml-body-end}{}
\c \cfg{xhtml-address-start}{}
\c \cfg{xhtml-address-end}{}
\c \cfg{xhtml-navigation-attributes}{}
\c
\c \cfg{xhtml-versionid}{true}
\c \cfg{xhtml-suppress-address}{false}
\c \cfg{xhtml-author}{}
\c \cfg{xhtml-description}{}
\c
\c \cfg{xhtml-chapter-numeric}{false}
\c \cfg{xhtml-chapter-suffix}{: }
\c
\c \cfg{xhtml-section-numeric}{0}{true}
\c \cfg{xhtml-section-suffix}{0}{ }
\c
\c \cfg{xhtml-section-numeric}{1}{true}
\c \cfg{xhtml-section-suffix}{1}{ }
\c
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

\H{output-whlp} Windows Help

This output format generates data that can be used by the \i{Windows
Help} program \cw{WINHELP.EXE}. There are two actual files
generated, one ending in \c{.hlp} and the other ending in \c{.cnt}.

The output is in the \q{\i{Win1252}} character set.

The Windows Help output format supports the following configuration
directives:

\dt \I{\cw{\\cfg\{winhelp-filename\}}}\cw{\\cfg\{winhelp-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the man page.
This directive is implicitly generated if you provide a file name
parameter after the command-line option \i\c{--winhelp} (see
\k{running-options}).

\lcont{

Your output file name should end with \c{.hlp}; if it doesn't,
Halibut will append it. Halibut will also generate a contents file
(ending in \c{.cnt}) alongside the file name you specify.

}

\dt \I{\cw{\\cfg\{winhelp-contents-titlepage\}}}\cw{\\cfg\{winhelp-contents-titlepage\}\{}\e{title}\cw{\}}

\dd Sets the text used to describe the help page containing the blurb
(see \k{input-blurb}) and table of contents.

\dt
\I{\cw{\\cfg\{winhelp-section-suffix\}}}\cw{\\cfg\{winhelp-section-suffix\}\{}\e{text}\cw{\}}

\dd Specifies the \I{suffix text, in section titles}suffix text to
be appended to section numbers, before displaying the section title.
(Applies to all levels.)

\dt \I{\cw{\\cfg\{winhelp-list-suffix\}}}\cw{\\cfg\{winhelp-list-suffix\}\{}\e{text}\cw{\}}

\dd This text is appended to the number on a \i{numbered list} item,
in exactly the same way as \cw{\\cfg\{text-list-suffix\}} (see
\k{output-text-misc}).

\dt \I{\cw{\\cfg\{winhelp-bullet\}}}\cw{\\cfg\{winhelp-bullet\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

\dd Specifies the text to use as the \i{bullet} in bulletted lists.
You can specify multiple fallback options. Works exactly like the
\cw{\\cfg\{text-bullet\}} directive (see
\k{output-text-characters}).

\dt \I{\cw{\\cfg\{winhelp-quotes\}}}\cw{\\cfg\{winhelp-quotes\}\{}\e{open-quote}\cw{\}\{}\e{close-quote}\cw{\}}[\cw{\{}\e{open-quote}\cw{\}\{}\e{close-quote}...\cw{\}}]

\dd Specifies the quotation marks to use, overriding any
\cw{\\cfg\{quotes\}} directive. You can specify multiple
fallback options. Works exactly like the \cw{\\cfg\{text-quotes\}}
directive (see \k{output-text-characters}).

\dt \I{\cw{\\cfg\{winhelp-topic\}}}\cw{\\cfg\{winhelp-topic\}\{}\e{topic-name}\cw{\}}

\dd This directive defines a Windows \i{Help topic} name in the current
section. Topic names can be used by the program invoking
\cw{WINHELP.EXE} to jump straight to a particular section. So you
can use this for \i{context-sensitive help}.

\lcont{

For example, if you used this directive in a particular section:

\c \cfg{winhelp-topic}{savingfiles}

then a Windows application could invoke Windows Help to jump to that
particular section in the help file like this:

\c WinHelp(hwnd, "mydoc.hlp", HELP_COMMAND,
\c         (DWORD)"JI(`',`savingfiles')");

You can use this configuration directive many times, in many
different subsections of your document, in order to define a lot of
different help contexts which you can use in this way.

}

The \i{default settings} for the Windows Help output format are:

\c \cfg{winhelp-filename}{output.hlp}
\c \cfg{winhelp-contents-titlepage}{Title page}
\c \cfg{winhelp-section-suffix}{: }
\c \cfg{winhelp-list-suffix}{.}
\c \cfg{winhelp-bullet}{\u2022}{-}
\c \cfg{winhelp-quotes}{\u2018}{\u2019}{"}{"}

and no \c{\\cfg\{winhelp-topic\}} directives anywhere.

\H{output-man} Unix \cw{man} pages

This output format generates a Unix \i{\cw{man} page}. That is to say,
it generates \i\c{nroff} input designed to work with the \c{-mandoc}
macro package.

The available configuration options for this format are as follows:

\dt \I{\cw{\\cfg\{man-filename\}}}\cw{\\cfg\{man-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the man page.
This directive is implicitly generated if you provide a file name
parameter after the command-line option \i\c{--man} (see
\k{running-options}).

\dt \I{\cw{\\cfg\{man-identity\}}}\cw{\\cfg\{man-identity\}\{}\e{text}\cw{\}\{}\e{text...}\cw{\}}

\dd This directive is used to generate the initial \i{\c{.TH}
directive} that appears at the top of a \cw{man} page. It expects to
be followed by some number of brace pairs containing text, which will
be used in the \i{headers} and \i{footers} of the formatted output.

\lcont{

A traditional order for the arguments appears to be:

\n The name of the program.

\n The (numeric) manual section.

\n The date that the \cw{man} page was written.

\n The name of any containing suite of which the program is a part.

\n The name of the \i{author} of the \cw{man} page.

For example, a typical \cw{man} page might contain

\c \cfg{man-identity}{make-foo}{1}{June 2003}{foo-utils}{Fred
\c Bloggs}

}

\dt \I{\cw{\\cfg\{man-headnumbers\}}}\cw{\\cfg\{man-headnumbers\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, then \i{section headings} in the
\cw{man} page will have their \i{section numbers} displayed as usual. If
set to \c{false}, the section numbers will be omitted. (\cw{man}
pages traditionally have section names such as \q{SYNOPSIS},
\q{OPTIONS} and \q{BUGS}, and do not typically number them, so
\c{false} is the setting which conforms most closely to normal
\cw{man} style.)

\dt \I{\cw{\\cfg\{man-mindepth\}}}\cw{\\cfg\{man-mindepth\}\{}\e{depth}\cw{\}}

\dd If this is set to a number greater than 0, then section headings
\e{higher} than the given depth will not be displayed. If it is set
to zero, all section headings will be displayed as normal.

\lcont{

The point of this is so that you can use the same Halibut input file
to generate a quick-reference \cw{man} page for a program, \e{and} to
include that \cw{man} page as an appendix in your program's full manual.
If you are to include the \cw{man} page as an appendix, then the internal
headings within the page will probably need to be at \c{\\H} or
\c{\\S} level; therefore, when you format that input file on its own
to create the \cw{man} page itself, you will need to have defined a
\c{\\C} and possibly a \c{\\H} heading beforehand, which you don't
want to see displayed.

Here's an example. You might have a file \c{appendix.but}, which
simply says

\c \A{manpages} \cw{man} pages for the Foo tool suite
\c
\c \cfg{man-mindepth}{2}

Then you have a file \c{make-foo.but}, and probably others like it
as well, each of which looks something like this:

\c \cfg{man-identity}{make-foo}{1}{June 2003}{foo-utils}{Fred
\c Bloggs}
\c
\c \H{man-foo} \cw{man} page for \c{make-foo}
\c 
\c \S{man-foo-name} NAME
\c
\c \c{make-foo} - create Foo files for the Foo tool suite
\c
\c \S{man-foo-synopsis} SYNOPSIS
\c
\c ... and so on ...
\e iiiiiiiiiiiiiiiii

So when you're generating your main manual, you can include
\c{appendix.but} followed by \c{make-foo.but} and any other \cw{man}
pages you have, and your \cw{man} pages will be formatted neatly as
part of an appendix. Then, in a separate run of Halibut, you can
just do

\c halibut appendix.but make-foo.but

and this will generate a \cw{man} page \c{output.1}, in which the
headings \q{\cw{man} pages for the Foo tool suite} and \q{\cw{man}
page for \c{make-foo}} will not be displayed because of the
\c{man-mindepth} directive. So the first visible heading in the
output \cw{man} page will be \q{NAME}, exactly as a user would
expect.

}

\dt \I{\cw{\\cfg\{man-charset\}}}\cw{\\cfg\{man-charset\}\{}\e{character set}\cw{\}}

\dd Specifies what character set the output should be in, similarly to
\cw{\\cfg\{text-charset\}} (see \k{output-text-misc}).

\# FIXME: you're probably on your own in making sure that it's
sensible to output man pages in that charset.

\dt \I{\cw{\\cfg\{man-bullet\}}}\cw{\\cfg\{man-bullet\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

\dd Specifies the text to use as the \i{bullet} in bulletted lists.
You can specify multiple fallback options. Works exactly like the
\cw{\\cfg\{text-bullet\}} directive (see \k{output-text-characters}).

\dt \I{\cw{\\cfg\{man-quotes\}}}\cw{\\cfg\{man-quotes\}\{}\e{open-quote}\cw{\}\{}\e{close-quote}\cw{\}}[\cw{\{}\e{open-quote}\cw{\}\{}\e{close-quote}...\cw{\}}]

\dd Specifies the quotation marks to use, overriding any
\cw{\\cfg\{quotes\}} directive. You can specify multiple
fallback options. Works exactly like the \cw{\\cfg\{text-quotes\}}
directive (see \k{output-text-characters}).

The \i{default settings} for the \cw{man} page output format are:

\c \cfg{man-filename}{output.1}
\c \cfg{man-identity}{}
\c \cfg{man-headnumbers}{false}
\c \cfg{man-mindepth}{0}
\c \cfg{man-charset}{ASCII}
\c \cfg{man-bullet}{\u2022}{o}
\c \cfg{man-quotes}{\u2018}{\u2019}{"}{"}

\H{output-info} GNU \c{info}

This output format generates files which can be used with the \i{GNU
\c{info}} program.

There are typically multiple output files: a primary file whose name
usually ends in \c{.info}, and one or more subsidiary files whose
names have numbers on the end, so that they end in \c{.info-1},
\c{.info-2} and so on. Alternatively, this output format can be
configured to output a single large file containing the whole
document.

The \c{info} output format supports the following configuration
directives:

\dt \I{\cw{\\cfg\{info-filename\}}}\cw{\\cfg\{info-filename\}\{}\e{filename}\cw{\}}

\dd Sets the output file name in which to store the \c{info} file.
This directive is implicitly generated if you provide a file name
parameter after the command-line option \i\c{--info} (see
\k{running-options}).

\lcont{

The suffixes \c{-1}, \c{-2}, \c{-3} and so on will be appended to
your output file name to produce any subsidiary files required.

Note that \c{info} files refer to their own names internally, so
these files cannot be \I{renaming \c{info} files}renamed after
creation and remain useful.

}

\dt \I{\cw{\\cfg\{info-width\}}}\cw{\\cfg\{info-width\}\{}\e{width}\cw{\}}

\dd Sets the \I{text width}width of the main part of the document,
in characters. Works exactly like the \cw{\\cfg\{text-width\}}
directive (see \k{output-text-dimensions}).

\dt \I{\cw{\\cfg\{info-indent-code\}}}\cw{\\cfg\{info-indent-code\}\{}\e{indent}\cw{\}}

\dd Specifies the extra indentation for \I{code paragraphs,
indentation} code paragraphs. Works exactly like the
\cw{\\cfg\{text-indent-code\}} directive (see
\k{output-text-dimensions}).

\dt \I{\cw{\\cfg\{info-index-width\}}}\cw{\\cfg\{info-index-width\}\{}\e{width}\cw{\}}

\dd Specifies how much horizontal space to leave in the index node
for the text of \i{index terms}, before displaying the sections the
terms occur in.

\dt \I{\cw{\\cfg\{info-list-indent\}}}\cw{\\cfg\{info-list-indent\}\{}\e{indent}\cw{\}}

\dd Specifies the extra indentation before the bullet or number in a
\I{bulletted list, indentation}\I{numbered list, indentation}list
item. Works exactly like the \cw{\\cfg\{text-list-indent\}}
directive (see \k{output-text-dimensions}).

\dt \I{\cw{\\cfg\{info-listitem-indent\}}}\cw{\\cfg\{info-listitem-indent\}\{}\e{indent}\cw{\}}

\dd Specifies the additional indentation before the body of a list
item. Works exactly like the \cw{\\cfg\{text-listitem-indent\}}
directive (see \k{output-text-dimensions}).

\dt \I{\cw{\\cfg\{info-charset\}}}\cw{\\cfg\{info-charset\}\{}\e{character set}\cw{\}}

\dd Specifies what character set the output should be in, similarly to
\cw{\\cfg\{text-charset\}} (see \k{output-text-misc}).

\# FIXME: if you try sufficiently hard, you can probably find an
output encoding that will break the info format by trampling on its
special characters. So either don't do that, or tell us what we should
do about it.

\dt \I{\cw{\\cfg\{info-section-suffix\}}}\cw{\\cfg\{info-section-suffix\}\{}\e{text}\cw{\}}

\dd Specifies the suffix text to be appended to each section number
before displaying the section title. For example, if you set this to
\q{\cw{:\_}}, then a typical section title might look something like
\q{Section 3.1: Something Like This}.

\dt \I{\cw{\\cfg\{info-underline\}}}\cw{\\cfg\{info-underline\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

\dd Specifies the text to be used to underline section titles. Works
very much like the \cw{\\cfg\{text-chapter-underline\}} directive
(see \k{output-text-headings}). You can specify more than one
option, and Halibut will choose the first one supported by the
character set.

\dt \I{\cw{\\cfg\{info-bullet\}}}\cw{\\cfg\{info-bullet\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

\dd Specifies the text to use as the \i{bullet} in bulletted lists.
You can specify multiple fallback options. Works exactly like the
\cw{\\cfg\{text-bullet\}} directive (see
\k{output-text-characters}).

\dt \I{\cw{\\cfg\{info-rule\}}}\cw{\\cfg\{info-rule\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

\dd Specifies the text used to draw \i{horizontal rules}. You can
specify multiple fallback options. Works exactly like the
\cw{\\cfg\{text-rule\}} directive (see \k{output-text-characters}).

\dt \I{\cw{\\cfg\{info-quotes\}}}\cw{\\cfg\{info-quotes\}\{}\e{open-quote}\cw{\}\{}\e{close-quote}\cw{\}}[\cw{\{}\e{open-quote}\cw{\}\{}\e{close-quote}...\cw{\}}]

\dd Specifies the quotation marks to use, overriding any
\cw{\\cfg\{quotes\}} directive. You can specify multiple
fallback options. Works exactly like the \cw{\\cfg\{text-quotes\}}
directive (see \k{output-text-characters}).

\dt \I{\cw{\\cfg\{info-emphasis\}}}\cw{\\cfg\{info-emphasis\}\{}\e{start-emph}\cw{\}\{}\e{end-emph}\cw{\}}[\cw{\{}\e{start-emph}\cw{\}\{}\e{end-emph}...\cw{\}}]

\dd Specifies how to display emphasised text. You can specify
multiple fallback options. Works exactly like the
\cw{\\cfg\{text-emphasis\}} directive (see
\k{output-text-characters}).

\dt \I{\cw{\\cfg\{info-list-suffix\}}}\cw{\\cfg\{info-list-suffix\}\{}\e{text}\cw{\}}

\dd Specifies the text to append to the item numbers in a
\i{numbered list}. Works exactly like the
\cw{\\cfg\{text-list-suffix\}} directive (see
\k{output-text-misc}).

\dt \I{\cw{\\cfg\{info-max-file-size\}}}\cw{\\cfg\{info-max-file-size\}\{}\e{bytes}\cw{\}}

\dd Sets the preferred \i{maximum file size} for each subsidiary
file. As a special case, if you set this to zero, there will be no
subsidiary files and the whole document will be placed in a single
self-contained output file. (However, note that this file can still
not be renamed usefully.)

\lcont{

The preferred maximum file size is only a guideline. Halibut may be
forced to exceed it if a single section of the document is larger
than the maximum size (since individual \c{info} nodes may not be
split between files).

}

\dt \I{\cw{\\cfg\{info-dir-entry\}}}\cw{\\cfg\{info-dir-entry\}\{}\e{section}\cw{\}\{}\e{short
name}\cw{\}\{}\e{long name}\cw{\}}[\cw{\{}\e{keyword}\cw{\}}]

\dd Constructs an \i\cw{INFO-DIR-ENTRY} section and places it in the
header of the Info file. This mechanism is used to automatically
generate the \i{\c{dir} file} at the root of a Unix system's
\c{info} collection.

\lcont{

The parameters to this directive are:

\dt \e{section}

\dd Specifies the section of the \c{dir} file in which you want your
document referenced. For example, \q{Development}, or \q{Games}, or
\q{Miscellaneous}.

\dt \e{short name}

\dd Specifies a short name for the directory entry, which will
appear at the start of the menu line.

\dt \e{long name}

\dd Specifies a long name for the directory entry, which will appear
at the end of the menu line.

\dt \e{keyword}

\dd This parameter is optional. If it is present, then the directory
entry will cause a jump to a particular subsection of your document,
rather than starting at the top. The subsection will be the one
referred to by the given keyword (see \k{input-sections} for details
about assigning keywords to document sections).

For example, in a document describing many game programs, the
configuration directive

\c \cfg{info-dir-entry}{Games}{Chess}{Electronic chess
\c game}{chess}

might produce text in the \c{dir} file looking something like this:

\c Games
\c * Chess: (mygames)Chapter 3.   Electronic chess game

if the output file were called \c{mygames.info} and the keyword
\c{chess} had been used to define Chapter 3 of the document.

}

The \i{default settings} for the \c{info} output format are:

\c \cfg{info-filename}{output.info}
\c
\c \cfg{info-width}{70}
\c \cfg{info-indent-code}{2}
\c \cfg{info-index-width}{40}
\c \cfg{info-list-indent}{1}
\c \cfg{info-listitem-indent}{3}
\c
\c \cfg{info-charset}{ASCII}
\c
\c \cfg{info-section-suffix}{: }
\c
\c \cfg{info-underline}{\u203e}{-}
\c \cfg{info-bullet}{\u2022}{-}
\c \cfg{info-rule}{\u2500}{-}
\c \cfg{info-quotes}{\u2018}{\u2019}{`}{'}
\c \cfg{info-emphasis}{_}{_}
\c
\c \cfg{info-list-suffix}{.}
\c \cfg{info-max-file-size}{65536}

and no \cw{\\cfg\{info-dir-entry\}} directives.

\H{output-ps} \i{PostScript}

This output format generates a printable manual in PostScript format.

This format is currently very new and is not yet configurable. There
is only one available configuration option:

\dt \I{\cw{\\cfg\{ps-filename\}}}\cw{\\cfg\{ps-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the PostScript
file. This directive is implicitly generated if you provide a file
name parameter after the command-line option \i\c{--ps} (see
\k{running-options}).

The \i{default settings} for the PostScript output format are:

\c \cfg{ps-filename}{output.ps}

\H{output-pdf} \i{PDF}

This output format generates a printable manual in PDF format. This
should look exactly identical to the PostScript output (see
\k{output-ps}), but also uses some PDF interactive features to
provide an outline of all the document's sections and clickable
cross-references between sections.

This format is currently very new and is not yet configurable. There
is only one available configuration option:

\dt \I{\cw{\\cfg\{pdf-filename\}}}\cw{\\cfg\{pdf-filename\}\{}\e{filename}\cw{\}}

\dd Sets the \i{output file name} in which to store the PDF file.
This directive is implicitly generated if you provide a file name
parameter after the command-line option \i\c{--pdf} (see
\k{running-options}).

The \i{default settings} for the PDF output format are:

\c \cfg{pdf-filename}{output.pdf}