\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 table of contents or 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-text}\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-text}\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-shownumber\}}}\cw{\\cfg\{text-chapter-shownumber\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{false}, then chapter headings will \e{only}
contain the chapter title: they will not contain the word
\q{Chapter} (or whatever other word you have defined in its place),
and neither will they contain the chapter number. If set to
\c{false}, this overrides \cw{\\cfg\{text-chapter-numeric\}}.

\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 \cq{:\_}, 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-text}\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-shownumber\}}}\cw{\\cfg\{text-section-shownumber\}\{}\e{level}\cw{\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{false}, then section headings at the
specified level will \e{only} contain the section title: they will
not contain the word \q{Section} (or whatever other word you have
defined in its place), and neither will they contain the section
number. If set to \c{false}, this overrides
\cw{\\cfg\{text-section-numeric\}}.

\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-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-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 \cq{-=} 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}).

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

\dd This specifies the characters which should be used to surround
strong text (written using the \c{\\s} 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-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-shownumber}{true}
\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-shownumber}{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-shownumber}{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-charset}{ASCII}
\c \cfg{text-bullet}{\u2022}{-}
\c \cfg{text-rule}{\u2500}{-}
\c \cfg{text-quotes}{\u2018}{\u2019}{`}{'}
\c \cfg{text-emphasis}{_}{_}
\c
\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.

\I{\cw{\\cfg\{xhtml-anything\}}}Configuration directives with an
\c{xhtml-} prefix are synonyms for those with an \c{html-} prefix.

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

\dt \I{\cw{\\cfg\{html-contents-filename\}}}\cw{\\cfg\{html-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\{html-index-filename\}}}\cw{\\cfg\{html-index-filename\}\{}\e{filename}\cw{\}}

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

\dt \I{\cw{\\cfg\{html-template-filename\}}}\cw{\\cfg\{html-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 \cq{\\C\{fish\} Catching
Fish}, this formatting command would expand to
\cq{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 \cq{Chapter1}; in
section A.4.3 it would expand to \cq{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 number of the section, in a format suitable for an
HTML fragment name. The first character of the section type is
prepended to the section number. So in chapter 1 this would expand to
\cq{C1}; in section A.4.3 it would expand to \cq{SA.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 \cq{\\C\{fish\} Catching Fish}, this
formatting command would expand to \cq{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\{html-template-fragment\}} configuration directive (see
\k{output-html-misc}).

}

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

\dd Sets the file name in which to store the entire document, if
Halibut is configured (using \c{\\cfg\{html-leaf-level\}\{0\}}) to
produce a single self-contained file. Both this directive \e{and}
\c{\\cfg\{html-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\{html-leaf-level\}}}\cw{\\cfg\{html-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} by default.

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.

You can also specify the special name \c{infinity} (or \c{infinite}
or \c{inf}) if you want to ensure that \e{every} section and
subsection ends up in a separate file no matter how deep you go.

}

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

\dd This directive allows you to specify how \I{depth of
contents}deep any contents section in a particular level of 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.

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\{html-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.

For backwards compatibility, the alternative syntax
\cw{\\cfg\{html-contents-depth-}\e{level}\cw{\}\{}\e{depth}\cw{\}}
is also supported.

}

\dt \I{\cw{\\cfg\{html-leaf-contains-contents\}}}\cw{\\cfg\{html-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\{html-leaf-smallest-contents\}}}\cw{\\cfg\{html-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.

Note that none of Halibut's usual character set translation is applied
to this code; it is assumed to already be in a suitable encoding for
the target HTML files.

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

\dd This configuration directive is local: you specify it within a
document section, and it acts on that section only.

\lcont{

The text you provide in this directive is placed at the end of the
\i\cw{<HEAD>} section of whichever output HTML file contains the
section in which the directive was placed. You can specify this
directive multiple times in multiple sections if you like.

This directive is particularly useful for constructing \i{MacOS
on-line help}, which is mostly normal HTML but which requires a
special \i\cw{<META NAME="AppleTitle">} tag in the topmost source
file. You can arrange this by placing this configuration directive
in the preamble or the introduction section, something like this:

\c \cfg{html-local-head}{<meta name="AppleTitle"
\c content="MyApp Help">}

}

\dt \I{\cw{\\cfg\{html-body-tag\}}}\cw{\\cfg\{html-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\{html-body-tag\}\{<body bg="#123456">\}}.

\dt \I{\cw{\\cfg\{html-body-start\}}}\cw{\\cfg\{html-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\{html-body-end\}}}\cw{\\cfg\{html-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, before any address
section. 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\{html-address-start\}}}\cw{\\cfg\{html-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\{html-address-end\}}}\cw{\\cfg\{html-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\{html-navigation-attributes\}}}\cw{\\cfg\{html-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\{html-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\{html-chapter-numeric\}}}\cw{\\cfg\{html-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\{html-chapter-shownumber\}}}\cw{\\cfg\{html-chapter-shownumber\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{false}, then chapter headings will \e{only}
contain the chapter title: they will not contain the word
\q{Chapter} (or whatever other word you have defined in its place),
and neither will they contain the chapter number. If set to
\c{false}, this overrides \cw{\\cfg\{html-chapter-numeric\}}.

\dt \I{\cw{\\cfg\{html-chapter-suffix\}}}\cw{\\cfg\{html-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 \cq{:\_}, then the chapter title might look something
like \q{Chapter 2: Doing Things}.

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

\# {level} can be omitted (defaults to 0). Is this intentional?

\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\{html-section-shownumber\}}}\cw{\\cfg\{html-section-shownumber\}\{}\e{level}\cw{\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{false}, then section headings at the
specified level will \e{only} contain the section title: they will
not contain the word \q{Section} (or whatever other word you have
defined in its place), and neither will they contain the section
number. If set to \c{false}, this overrides
\cw{\\cfg\{html-section-numeric\}}.

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

\# {level} can be omitted (defaults to 0). Is this intentional?

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

\S{output-html-names} Configuring standard text

These directives let you fine-tune the names Halibut uses in places
such as the navigation bar to refer to various parts of the document,
and other standard pieces of text, for instance to change them to a
different language.

\dt \I{\cw{\\cfg\{html-preamble-text\}}}\cw{\\cfg\{html-preamble-text\}\{}\e{text}\cw{\}}

\dt \I{\cw{\\cfg\{html-contents-text\}}}\cw{\\cfg\{html-contents-text\}\{}\e{text}\cw{\}}

\dt \I{\cw{\\cfg\{html-index-text\}}}\cw{\\cfg\{html-index-text\}\{}\e{text}\cw{\}}

\dd Text used to refer to the preamble (i.e., any paragraphs before
the first chapter heading), contents, and index respectively, in the
navigation bar, contents, and index.

\lcont{

(\c{html-contents-text} and \c{html-index-text} override the
cross-format configuration keywords \c{contents} and \c{index} (see
\k{input-config}, if both appear. They are legacy keywords preserved
for backwards compatibility; you should generally use \c{contents}
and \c{index}.)

}

\dt \I{\cw{\\cfg\{html-title-separator\}}}\cw{\\cfg\{html-title-separator\}\{}\e{text}\cw{\}}

\dd If multiple headings are used in a file's \cw{<TITLE>} tag, this
text is used to separate them.

\# Under what circumstances can this occur?

\dt \I{\cw{\\cfg\{html-index-main-separator\}}}\cw{\\cfg\{html-index-main-separator\}\{}\e{text}\cw{\}}

\dd Separator between index term and references in the index.

\dt \I{\cw{\\cfg\{html-index-multiple-separator\}}}\cw{\\cfg\{html-index-multiple-separator\}\{}\e{text}\cw{\}}

\dd Separator between multiple references for a single index term in
the index.

\dt \I{\cw{\\cfg\{html-pre-versionid\}}}\cw{\\cfg\{html-pre-versionid\}\{}\e{text}\cw{\}}

\dt \I{\cw{\\cfg\{html-post-versionid\}}}\cw{\\cfg\{html-post-versionid\}\{}\e{text}\cw{\}}

\dd Text surrounding each output \i{version ID paragraph}.

\dt \I{\cw{\\cfg\{html-nav-prev-text\}}}\cw{\\cfg\{html-nav-prev-text\}\{}\e{text}\cw{\}}

\dt \I{\cw{\\cfg\{html-nav-next-text\}}}\cw{\\cfg\{html-nav-next-text\}\{}\e{text}\cw{\}}

\dt \I{\cw{\\cfg\{html-nav-up-text\}}}\cw{\\cfg\{html-nav-up-text\}\{}\e{text}\cw{\}}

\dd The text used for the \q{previous page}, \q{next page}, and \q{up}
links on the navigation bar.

\dt \I{\cw{\\cfg\{html-nav-separator\}}}\cw{\\cfg\{html-nav-separator\}\{}\e{text}\cw{\}}

\dd Separator between links in the navigation bar.

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

Unlike the other backends, HTML does not have a single
\i\cw{\\cfg\{html-charset\}} directive, as there are several levels of
character encoding to consider.

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

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

\dd The character encoding of the HTML file to be output. Unicode
characters in this encoding's repertoire are included literally rather
than as \i{HTML entities}.

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

\dd Only Unicode characters representable in this character set will be
output; any others will be omitted and use their fallback text, if
any. Characters not in \q{html-output-charset} will be represented as
HTML numeric entities.

\dt \I{\cw{\\cfg\{html-quotes\}}}\cw{\\cfg\{html-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}).

\S{output-html-misc} Miscellaneous options

\dt \I\cw{\\cfg\{html-version\}}\cw{\\cfg\{html-version\}\{}\e{version}\cw{\}}

\dd Identifies the precise version of HTML that is output. This
affects the declaration within the HTML, and also has minor effects on
the body of the HTML so that it is valid for the declared version. The
available variants are:

\lcont{

\dt \cw{html3.2}

\dd W3C HTML 3.2

\dt \cw{html4}

\dd W3C HTML 4.01 Strict

\dt \cw{iso-html}

\dd ISO/IEC 15445:2000

\dt \cw{xhtml1.0transitional}

\dd W3C XHTML 1.0 Transitional

\dt \cw{xhtml1.0strict}

\dd W3C XHTML 1.0 Strict

}

\dt \I{\cw{\\cfg\{html-template-fragment\}}}\cw{\\cfg\{html-template-fragment\}\{}\e{template}\cw{\}}[\cw{\{}\e{template}\cw{\}\{}...\cw{\}}]

\dd This directive lets you specify a \i{template}, with exactly the
same syntax used in \cw{\\cfg\{html-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 \cq{%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.

\lcont{

If more than one template is specified, anchors are generated in all
the specified formats; Halibut's own cross-references are generated
with the first template.

Characters that are not permitted in anchor names are stripped. If
there are no valid characters left, or a fragment is non-unique,
Halibut starts inventing fragment names and suffixes as appropriate.

Note that there are potentially fragment names that are not controlled
by this mechanism, such as index references.

}

\dt \I{\cw{\\cfg\{html-versionid\}}}\cw{\\cfg\{html-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 only be included as HTML
comments.

\dt \I{\cw{\\cfg\{html-rellinks\}}}\cw{\\cfg\{html-rellinks\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, machine-readable relational links will
be emitted in each HTML file (\I{\cw{<LINK>} tags}\cw{<LINK
REL="next">} and so on within the \i\cw{<HEAD>} section)
providing links to related files. The same set of links are provided
as in the navigation bar (with which this should not be confused).

\lcont{

Some browsers make use of this semantic information, for instance to
allow easy navigation through related pages, and to prefetch the next
page. (Search engines can also make use of it.) However, many browsers
ignore this markup, so it would be unwise to rely on it for
navigation.

The use and rendering of this information is entirely up to the
browser; none of the other Halibut options for the navigation bar will
have any effect.

}

\dt \I{\cw{\\cfg\{html-suppress-navlinks\}}}\cw{\\cfg\{html-suppress-navlinks\}\{}\e{boolean}\cw{\}}

\dd If this is set to \c{true}, the usual \i{navigation links} within
the \e{body} of each HTML file (near the top of the rendered page) will
be suppressed.

\dt \I{\cw{\\cfg\{html-suppress-address\}}}\cw{\\cfg\{html-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 visibly.)

\dt \I{\cw{\\cfg\{html-author\}}}\cw{\\cfg\{html-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\{html-description\}}}\cw{\\cfg\{html-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{html-contents-filename}{Contents.html}
\c \cfg{html-index-filename}{IndexPage.html}
\c \cfg{html-template-filename}{%n.html}
\c \cfg{html-single-filename}{Manual.html}
\c
\c \cfg{html-leaf-level}{2}
\c \cfg{html-leaf-contains-contents}{false}
\c \cfg{html-leaf-smallest-contents}{4}
\c \cfg{html-contents-depth}{0}{2}
\c \cfg{html-contents-depth}{1}{3}
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
\c
\c \cfg{html-head-end}{}
\c \cfg{html-body-tag}{<body>}
\c \cfg{html-body-start}{}
\c \cfg{html-body-end}{}
\c \cfg{html-address-start}{}
\c \cfg{html-address-end}{}
\c \cfg{html-navigation-attributes}{}
\c
\c \cfg{html-chapter-numeric}{false}
\c \cfg{html-chapter-shownumber}{true}
\c \cfg{html-chapter-suffix}{: }
\c
\c \cfg{html-section-numeric}{0}{true}
\c \cfg{html-section-shownumber}{0}{true}
\c \cfg{html-section-suffix}{0}{ }
\c
\c \cfg{html-section-numeric}{1}{true}
\c \cfg{html-section-shownumber}{1}{true}
\c \cfg{html-section-suffix}{1}{ }
\c
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
\c
\c \cfg{html-preamble-text}{Preamble}
\c \cfg{html-contents-text}{Contents}
\c \cfg{html-index-text}{Index}
\c \cfg{html-title-separator}{ - }
\c \cfg{html-index-main-separator}{: }
\c \cfg{html-index-multiple-separator}{, }
\c \cfg{html-pre-versionid}{[}
\c \cfg{html-post-versionid}{]}
\c \cfg{html-nav-prev-text}{Previous}
\c \cfg{html-nav-next-text}{Next}
\c \cfg{html-nav-up-text}{Up}
\c \cfg{html-nav-separator}{ | }
\c
\c \cfg{html-output-charset}{ASCII}
\c \cfg{html-restrict-charset}{UTF-8}
\c \cfg{html-quotes}{\u2018}{\u2019}{"}{"}
\c
\c \cfg{html-version}{html4}
\c \cfg{html-template-fragment}{%b}
\c \cfg{html-versionid}{true}
\c \cfg{html-rellinks}{true}
\c \cfg{html-suppress-navlinks{false}
\c \cfg{html-suppress-address}{false}
\c \cfg{html-author}{}
\c \cfg{html-description}{}

\H{output-chm} Windows \i{HTML Help}

This output format generates a \c{.chm} file suitable for use with the
Windows HTML Help system.

Older versions of Halibut could only generate HTML Help by writing out
a set of source files acceptable to the MS help compiler. Nowadays
Halibut can generate CHM directly, so that's no longer necessary.
However, the legacy method is still available if you need it; see
\k{output-html-mshtmlhelp} for details.

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

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

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

\S{output-chm-mostconfig} Configuration shared with the HTML back end

As the name suggests, an HTML Help file is mostly a compressed
container for HTML files. So the CHM back end shares a great deal of
its code with the HTML back end, and as a result, it supports the same
range of format configuration options.

(One exception to this general rule is that the configuration options
relating to generating \e{HTML Help compiler input} are not supported
in CHM mode, because they wouldn't make any sense! The
\cw{html-mshtmlhelp-*} options described in \k{output-html-mshtmlhelp}
have no analogue starting \cw{chm-}.)

However, because HTML and CHM are used in different ways, you may need
to configure the two back ends differently. So in CHM mode, Halibut
supports all the same configuration directives described in
\k{output-html}, but with their names changed so that they begin with
\cq{chm-} in place of \cq{html-}. This lets you maintain two sets of
configuration independently; for example, you could specify
\c{\\cfg\{html-chapter-numeric\}\{true\}} and
\c{\\cfg\{chm-chapter-numeric\}\{false\}} in the same source file, and
then when you ran Halibut with both the \c{--html} and \c{--chm}
options, it would produce purely numeric chapter titles in the HTML
output but not in the CHM file.

If you do decide to apply a piece of configuration across both these
back ends, you can prefix it with \cq{htmlall-} instead of \cq{html-}
or \cq{chm-}. For example,
\c{\\cfg\{htmlall-chapter-numeric\}\{true\}} will enable purely
numeric chapter titles in \e{both} the HTML and CHM output.

\S{output-chm-extra} Including extra files in the CHM

CHM files are mostly a container for HTML, and the HTML files inside
them are allowed to cross-refer to all the usual other kinds of file
that HTML might refer to, such as images, stylesheets and even
Javascript. If you want to make use of this capability, you need to
tell Halibut what extra files it needs to incorporate into the CHM
container.

\dt \I{\cw{\\cfg\{chm-extra-file\}}}\cw{\\cfg\{chm-extra-file\}\{}\e{filename}\cw{\}}

\dt \I{\cw{\\cfg\{chm-extra-file\}}}\cw{\\cfg\{chm-extra-file\}\{}\e{filename}\cw{\}\{}\e{name inside CHM}\cw{\}}

\dd Tells Halibut to read an additional input file from \e{filename}
and incorporate it into the CHM.

\lcont{

In the first form of the directive, the file will be given the same
name within the CHM's internal namespace (i.e. for the purposes of
linking to it from HTML files) as Halibut used to load it from disk.
If you need to include the file with a different internal name, you
can use the second form of the directive, which separately specifies
the name under which Halibut should look for the input file and the
name it should give it inside the CHM.

You can specify this directive multiple times, to include more than
one file.

}

\S{output-chm-internalnames} Renaming the CHM internal support files

As well as ordinary HTML, there are also two special files inside a
CHM, containing the table of contents and the index. Halibut generates
these automatically, and you normally don't have to worry about them.
However, it is \e{just} possible (though very unlikely!) that you
might find they conflict with the name of some file you wanted to
include in the CHM yourself, and hence, Halibut provides configuration
options to change them if you need to.

\dt \I{\cw{\\cfg\{chm-contents-name\}}}\cw{\\cfg\{chm-contents-name\}\{}\e{filename}\cw{\}}

\dd Controls the name of the internal contents file in the CHM.

\dt \I{\cw{\\cfg\{chm-index-name\}}}\cw{\\cfg\{chm-index-name\}\{}\e{filename}\cw{\}}

\dd Controls the name of the internal index file in the CHM.

\S{output-chm-defaults} Default settings

The \i{default settings} for Halibut's CHM output format are mostly
the same as for the standard HTML output. However, a few defaults are
changed to be more in line with the way CHM wants to do things.

\c \cfg{chm-filename}{output.chm}
\c \cfg{chm-contents-name}{contents.hhc}
\c \cfg{chm-index-name}{index.hhk}
\c \cfg{chm-leaf-level}{infinite}
\c \cfg{chm-suppress-navlinks{true}
\c \cfg{chm-suppress-address}{true}

\S{output-html-mshtmlhelp} Generating input to the MS Windows \i{HTML
Help compiler}

Before Halibut gained the ability to write out CHM files directly, it
used a more cumbersome system in which you could run it in HTML mode
and enable some extra options that would write out supporting files
needed by the official Windows HTML Help compiler, so that you could
still generate a CHM file from your Halibut source in multiple build
steps.

This legacy system for HTML Help generation is still supported, partly
to avoid backwards-compatibility breakage for anyone already using it,
and also because it permits more flexibility in the resulting CHM
files: Halibut's own CHM file generation makes some fixed decisions
about window layout and styling, whereas if you use the official help
compiler you can start from Halibut's default project file and make
whatever manual changes you like to that sort of thing.

To enable the generation of MS HTML Help auxiliary files, use the
following configuration directives:

\dt \I\cw{\\cfg\{html-mshtmlhelp-project\}}\cw{\\cfg\{html-mshtmlhelp-project\}\{}\e{filename}\cw{\}}

\dd Instructs Halibut to output an HTML Help project file with the
specified name. You will almost certainly want the filename to end
in the extension \c{.hhp} (although Halibut will not enforce this).
If you use this option, you must also use the
\cw{html-mshtmlhelp-chm} option to specify the desired name of the
compiled help file.

\dt \I\cw{\\cfg\{html-mshtmlhelp-chm\}}\cw{\\cfg\{html-mshtmlhelp-chm\}\{}\e{filename}\cw{\}}

\dd Specifies the desired name of the compiled HTML Help file. You
will almost certainly want this to have the extension \c{.chm}
(although Halibut will not enforce this). The name you specify here
will be written into the help project file. If you specify this
option, you must also use the \cw{html-mshtmlhelp-project} option to
request a help project file in the first place.

\dt \I\cw{\\cfg\{html-mshtmlhelp-contents\}}\cw{\\cfg\{html-mshtmlhelp-contents\}\{}\e{filename}\cw{\}}

\dd Instructs Halibut to output an HTML Help contents file with the
specified name, and refer to it in the help project file. You will
almost certainly want the filename to end in the extension \c{.hhc}
(although Halibut will not enforce this). This option will be
ignored if you have not also specified a help project file.

\lcont{

Creating a contents file like this causes the HTML Help viewer to
display a contents tree in the pane to the left of the main text
window. You can choose to generate an HTML Help project without this
feature, in which case the user will still be able to navigate
around the document by using the ordinary internal links in the HTML
files themselves just as if it were a web page. However, using a
contents file is recommended.

}

\dt \I\cw{\\cfg\{html-mshtmlhelp-index\}}\cw{\\cfg\{html-mshtmlhelp-index\}\{}\e{filename}\cw{\}}

\dd Instructs Halibut to output an HTML Help index file with the
specified name, and refer to it in the help project file. You will
almost certainly want the filename to end in the extension \c{.hhk}
(although Halibut will not enforce this). This option will be
ignored if you have not also specified a help project file.

\lcont{

Specifying this option suppresses the generation of an HTML-based
index file (see \cw{\\cfg\{html-index-filename\}} in
\k{output-html-file}).

Creating an index file like this causes the HTML Help viewer to
provide a list of index terms in a pane to the left of the main text
window. You can choose to generate an HTML Help project without this
feature, in which case a conventional HTML index will be generated
instead (assuming you have any index terms at all defined) and the
user will still be able to use that. However, using an index file is
recommended.

Halibut will not output an index file at all, or link to one from
the help project file, if your document contains no index entries.

}

If you use the above options, Halibut will output a help project
file which you should be able to feed straight to the command-line
MS HTML Help compiler (\cw{HHC.EXE}), or load into the MS HTML Help
Workshop (\cw{HHW.EXE}).

You may also wish to alter other HTML configuration options to make
the resulting help file look more like a help file and less like a web
page. If you use Halibut's direct CHM output, this is done for you
automatically (see \k{output-chm-defaults}); but if you're using the
HTML output mode then I recommend the following changes.

\b \cw{\\cfg\{html-leaf-level\}\{infinite\}}, because HTML Help
works best with lots of small files (\q{topics}) rather than a few
large ones. In particular, the contents and index mechanisms can
only reference files, not subsections within files.

\b \cw{\\cfg\{html-suppress-navlinks\}\{true\}}, because HTML Help
has its own navigation facilities and it looks a bit strange to
duplicate them.

\b \cw{\\cfg\{html-suppress-address\}\{true\}}, because the
\cw{<ADDRESS>} section makes less sense in a help file than it does
on a web page.

\H{output-whlp} Legacy Windows Help

This output format generates data that can be used by the legacy
\i{Windows Help} program \cw{WINHLP32.EXE}. There are two actual files
generated, one ending in \c{.hlp} and the other ending in \c{.cnt}.

This legacy Windows Help format was discontinued in 2006 in favour of
HTML Help, which Halibut can also generate. You probably want to use
that instead for any new project. See \k{output-chm} for more
information on this.

Currently, the Windows Help output is hardcoded to be in the
\q{\i{Win1252}} character set. (If anyone knows how character sets
are encoded in Windows Help files, we'd appreciate help.)

The Windows Help output format supports the following configuration
directives:

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

\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 help file.
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.

}

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

\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}).

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

\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-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.

}

\S{output-whlp-defaults} Default settings

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

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

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:

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

\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}).

\S{output-man-identity} Configuring headers and footers

\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}

}

\S{output-man-headings} Configuring heading display

\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.

}

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

\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-characters}).

\# 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-rule\}}}\cw{\\cfg\{man-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}) when the manual page is rendered into text.
It should only be one character long, but otherwise
it works like the \cw{\\cfg\{text-rule\}} 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}).

\S{output-man-defaults} Default settings

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

\c \cfg{man-filename}{output.1}
\c
\c \cfg{man-identity}{}
\c
\c \cfg{man-headnumbers}{false}
\c \cfg{man-mindepth}{0}
\c
\c \cfg{man-charset}{ASCII}
\c \cfg{man-bullet}{\u2022}{o}
\c \cfg{man-rule}{\u2500}{-}
\c \cfg{man-quotes}{\u2018}{\u2019}{"}{"}

\H{output-info} GNU Info

This output format generates files which can be used with the \i{GNU
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 Info output format supports the following configuration
directives:

\S{output-info-file} Controlling the output filenames

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

\dd Sets the output file name in which to store the 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 Info files refer to their own names internally, so
these files cannot be \I{renaming Info files}renamed after
creation and remain useful.

}

\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 Info nodes may not be
split between files).

}

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

\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}).

\S{output-info-headings} Configuring heading display

\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
\cq{:\_}, then a typical section title might look something like
\q{Section 3.1: Something Like This}.

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

\dd Specifies the text to be used to \I{underlining}underline 
the overall document title. Works
very much like the \cw{\\cfg\{text-title-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-chapter-underline\}}}\cw{\\cfg\{info-chapter-underline\}\{}\e{text}\cw{\}}[\cw{\{}\e{text}\cw{\}}...]

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

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

\dd Specifies how to underline 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.

\S{output-info-characters} Controlling the characters used

\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-characters}).

\# 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-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-strong\}}}\cw{\\cfg\{info-strong\}\{}\e{start-strong}\cw{\}\{}\e{end-strong}\cw{\}}[\cw{\{}\e{start-strong}\cw{\}\{}\e{end-strong}...\cw{\}}]

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

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

\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-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
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.

}

\S{output-info-defaults} Default settings

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

\c \cfg{info-filename}{output.info}
\c \cfg{info-max-file-size}{65536}
\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-section-suffix}{: }
\c \cfg{info-title-underline}{*}
\c \cfg{info-chapter-underline}{=}
\c \cfg{info-section-underline}{0}{-}
\c \cfg{info-section-underline}{1}{.}
\c \cfg{info-section-underline}{2}{.}
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
\c
\c \cfg{info-charset}{ASCII}
\c \cfg{info-bullet}{\u2022}{-}
\c \cfg{info-rule}{\u2500}{-}
\c \cfg{info-quotes}{\u2018}{\u2019}{`}{'}
\c \cfg{info-emphasis}{_}{_}
\c \cfg{info-strong}{*}{*}
\c
\c \cfg{info-list-suffix}{.}

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

\H{output-paper} Paper formats

These output formats (currently PDF and PostScript) generate printable
manuals. As such, they share a number of configuration directives.

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

This output format generates a printable manual in PDF format. In
addition, it uses some PDF interactive features to
provide an outline of all the document's sections and clickable
cross-references between sections.

There is one configuration option specific to PDF:

\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}

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

This output format generates a printable manual in PostScript format.
This should look exactly identical to the PDF output (see
\k{output-ps}), and uses \i\c{pdfmark} to arrange that if converted
to PDF it will contain the same interactive features.

There is one configuration option specific to PostScript:

\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}

\S{output-paper-dimensions} Configuring layout and \i{measurements}

All measurements are in PostScript \i{points} (72 points to the inch).

\S2{output-paper-pagesize} Page properties

\dt \I{\cw{\\cfg\{paper-page-width\}}}\cw{\\cfg\{paper-page-width\}\{}\e{points}\cw{\}}

\dt \I{\cw{\\cfg\{paper-page-height\}}}\cw{\\cfg\{paper-page-height\}\{}\e{points}\cw{\}}

\dd Specify the absolute limits of the paper.

\dt \I{\cw{\\cfg\{paper-left-margin\}}}\cw{\\cfg\{paper-left-margin\}\{}\e{points}\cw{\}}

\dt \I{\cw{\\cfg\{paper-top-margin\}}}\cw{\\cfg\{paper-top-margin\}\{}\e{points}\cw{\}}

\dt \I{\cw{\\cfg\{paper-right-margin\}}}\cw{\\cfg\{paper-right-margin\}\{}\e{points}\cw{\}}

\dt \I{\cw{\\cfg\{paper-bottom-margin\}}}\cw{\\cfg\{paper-bottom-margin\}\{}\e{points}\cw{\}}

\dd Specify the margins. Most text appears within these margins,
except:

\lcont{

\b Section numbers, which appear in the left margin.

\b The footer (containing page numbers), which appears in the bottom
margin.

}

\S2{output-paper-line} Vertical spacing

\dt \I{\cw{\\cfg\{paper-base-leading\}}}\cw{\\cfg\{paper-base-leading\}\{}\e{points}\cw{\}}

\dd Specifies the amount of space between lines of text within a
paragraph. (So, if the font size is 12pt and there is 2pt of leading,
there will be 14pt between successive baselines.)

\dt \I{\cw{\\cfg\{paper-base-para-spacing\}}}\cw{\\cfg\{paper-base-para-spacing\}\{}\e{points}\cw{\}}

\dd Specifies the amount of vertical space between paragraphs. (The
vertical space between paragraphs does \e{not} include
\c{paper-base-leading}.)

\S2{output-paper-indentation} Indentation

\dt \I{\cw{\\cfg\{paper-list-indent\}}}\cw{\\cfg\{paper-list-indent\}\{}\e{points}\cw{\}}

\dd Specifies the indentation of the bullet or number in a
\I{bulletted list, indentation}bulletted or \I{numbered list,
indentation}numbered \I{list, indentation}list, similarly to
\cw{\\cfg\{text-list-indent\}} (see \k{output-text-dimensions}).

\dt \I{\cw{\\cfg\{paper-listitem-indent\}}}\cw{\\cfg\{paper-listitem-indent\}\{}\e{points}\cw{\}}

\dd Specifies the \e{extra} indentation for the body of a list item,
over and above the amount configured in \cw{\\cfg\{paper-list-indent\}}.

\# FIXME: doesn't actually work, AFAICT.

\dt \I{\cw{\\cfg\{paper-quote-indent\}}}\cw{\\cfg\{paper-quote-indent\}\{}\e{points}\cw{\}}

\dd Specifies the amount of indentation for a level of quoting. Used
for \cw{\\quote} (see \k{input-quote}) and code quotes with \cw{\\c}
(see \k{input-code}).

\S2{output-paper-headings} Headings

\dt \I{\cw{\\cfg\{paper-chapter-top-space\}}}\cw{\\cfg\{paper-chapter-top-space\}\{}\e{points}\cw{\}}

\dd Specifies the space between the top margin and the top of the
chapter heading. (Each chapter begins on a new page.)

\dt \I{\cw{\\cfg\{paper-chapter-underline-thickness\}}}\cw{\\cfg\{paper-chapter-underline-thickness\}\{}\e{points}\cw{\}}

\dd Specifies the vertical thickness of the black rule under chapter
headings.

\dt \I{\cw{\\cfg\{paper-chapter-underline-depth\}}}\cw{\\cfg\{paper-chapter-underline-depth\}\{}\e{points}\cw{\}}

\dd Specifies the distance between the base of the chapter heading and
the \e{base} of the underlying rule.

\dt \I{\cw{\\cfg\{paper-sect-num-left-space\}}}\cw{\\cfg\{paper-sect-num-left-space\}\{}\e{points}\cw{\}}

\dd Specifies the distance between the left margin and the \e{right}
of section numbers (which are in the left margin).

\S2{output-paper-index} Contents and index

\dt \I{\cw{\\cfg\{paper-contents-indent-step\}}}\cw{\\cfg\{paper-contents-indent-step\}\{}\e{points}\cw{\}}

\dd Specifies by how much to indent each entry in the table of
contents per level of subdivision in the document. (In other words,
chapter titles appear at the left of the table of contents, headings
within the chapter are indented by the amount configured here,
subheadings by twice that, and so on.)

\dt \I{\cw{\\cfg\{paper-contents-margin\}}}\cw{\\cfg\{paper-contents-margin\}\{}\e{points}\cw{\}}

\dd Specifies the amount of space on the right of the table of
contents which should be reserved for page numbers only. Headings in
the table of contents which extend into this space will be wrapped.

\dt \I{\cw{\\cfg\{paper-leader-separation\}}}\cw{\\cfg\{paper-leader-separation\}\{}\e{points}\cw{\}}

\dd Specifies the horizontal spacing between dots in \i\e{leaders}
(the dotted lines that appear between section headings and page
numbers in the table of contents).

\dt \I{\cw{\\cfg\{paper-footer-distance\}}}\cw{\\cfg\{paper-footer-distance\}\{}\e{points}\cw{\}}

\dd Specifies the distance between the bottom margin and the \e{base}
of the footer (which contains page numbers).

\dt \I{\cw{\\cfg\{paper-index-columns\}}}\cw{\\cfg\{paper-index-columns\}\{}\e{columns}\cw{\}}

\dd Specifies the number of columns the index should be divided into.

\# FIXME: with this set to 1, the right-alignment of some index entry
page numbers in the Halibut manual is decidedly wonky.

\dt \I{\cw{\\cfg\{paper-index-gutter\}}}\cw{\\cfg\{paper-index-gutter\}\{}\e{points}\cw{\}}

\dd Specifies the amount of \I{gutter} horizontal space between index
columns.

\dt \I{\cw{\\cfg\{paper-index-minsep\}}}\cw{\\cfg\{paper-index-minsep\}\{}\e{points}\cw{\}}

\dd Specifies the minimum allowable horizontal space between an index
entry and its page number. If the gap is smaller, the page number is
moved to the next line.

\S2{output-paper-fonts} \ii{Fonts}

The directives in this section control which fonts Halibut uses for
various kinds of text.  Directives for setting the font normally take
three font names, the first of which is used for normal text, the
second for emphasised text, and the third for code.  Any fonts which
aren't specified are left unchanged.

Halibut intrinsically knows about some fonts, and these fonts are also
built into all PDF and most PostScript implementations.
These fonts can be used without further formality.  Halibut can also use
other fonts, and can \I{embedding fonts}embed them it its PDF and
PostScript output.  These other fonts are supplied to Halibut by
simply adding them to the list of input files on its command line.

To use a \i{Type 1 font} Halibut needs both the font file itself,
in either hexadecimal (\I{PFA files}PFA) or IBM PC (\I{PFB files}PFB)
format, and an \i{Adobe Font Metrics} (\I{AFM files}AFM) file.  The AFM
file must be specified first on the command line.  If Halibut gets an
AFM file without a corresponding Type 1 font file, the PostScript and
PDF output files will still use that font, but they won't contain it.

Using a \i{TrueType font} is rather simpler, and simply requires you to
pass the font file to Halibut.  Halibut does place a few restrictions on
TrueType fonts, notably that they must include a \i{Unicode} mapping
table and a PostScript name.

Fonts are specified using their PostScript names.  Running Halibut with
the \i\cw{\-\-list-fonts} option causes it to display the PostScript
names of all the fonts it intrinsically knows about, along with any
fonts the were supplied as input files.

\ii{Font sizes} are specified in PostScript \i{points} (72 to the inch).

\dt \I{\cw{\\cfg\{paper-title-fonts\}}}\cw{\\cfg\{paper-title-fonts\}\{}\e{normal-font}\cw{\}}[\cw{\{}\e{emph-font}\cw{\}}[\cw{\{}\e{code-font}\cw{\}}]]

\dd Specifies the fonts to use for text in the document title.

\dt \I{\cw{\\cfg\{paper-title-font-size\}}}\cw{\\cfg\{paper-title-font-size\}\{}\e{points}\cw{\}}

\dd Specifies the \i{font size} of the document title.

\dt \I{\cw{\\cfg\{paper-chapter-fonts\}}}\cw{\\cfg\{paper-chapter-fonts\}\{}\e{normal-font}\cw{\}}[\cw{\{}\e{emph-font}\cw{\}}[\cw{\{}\e{code-font}\cw{\}}]]

\dd Specifies the fonts to use for text in chapter titles.

\dt \I{\cw{\\cfg\{paper-chapter-font-size\}}}\cw{\\cfg\{paper-chapter-font-size\}\{}\e{points}\cw{\}}

\dd Specifies the \i{font size} of chapter titles.

\dt \I{\cw{\\cfg\{paper-section-fonts\}}}\cw{\\cfg\{paper-section-fonts\}\{}\e{level}\cw{\}\{}\e{normal-font}\cw{\}}[\cw{\{}\e{emph-font}\cw{\}}[\cw{\{}\e{code-font}\cw{\}}]]

\dd Specifies the fonts to use for text in section headings at the \e{level}
specified.

\dt \I{\cw{\\cfg\{paper-section-font-size\}}}\cw{\\cfg\{paper-section-font-size\}\{}\e{level}\cw{\}\{}\e{points}\cw{\}}

\dd Specifies the \i{font size} of section headings at the \e{level}
specified.

\dt \I{\cw{\\cfg\{paper-base-fonts\}}}\cw{\\cfg\{paper-base-fonts\}\{}\e{normal-font}\cw{\}}[\cw{\{}\e{emph-font}\cw{\}}[\cw{\{}\e{code-font}\cw{\}}]]

\dd Specifies the fonts to use for text in the body text.

\dt \I{\cw{\\cfg\{paper-base-font-size\}}}\cw{\\cfg\{paper-base-font-size\}\{}\e{points}\cw{\}}

\dd Specifies the \i{font size} of body text.

\dt \I{\cw{\\cfg\{paper-code-fonts\}}}\cw{\\cfg\{paper-code-fonts\}\{}\e{bold-font}\cw{\}}[\cw{\{}\e{italic-font}\cw{\}}[\cw{\{}\e{normal-font}\cw{\}}]]

\dd Specifies the fonts to use for text in code paragraphs.  The
\e{bold-font} is used for bold text, the \e{italic-font} for
emphasised text, and the \e{normal-font} for normal code.

\dt \I{\cw{\\cfg\{paper-code-font-size\}}}\cw{\\cfg\{paper-code-font-size\}\{}\e{points}\cw{\}}

\dd Specifies the \i{font size} of text in code paragraphs.

\dt \I{\cw{\\cfg\{paper-pagenum-font-size\}}}\cw{\\cfg\{paper-pagenum-font-size\}\{}\e{points}\cw{\}}

\dd Specifies the font size to use for \i{page numbers}.

\S2{output-paper-misc} Miscellaneous

\dt \I{\cw{\\cfg\{paper-rule-thickness\}}}\cw{\\cfg\{paper-rule-thickness\}\{}\e{points}\cw{\}}

\dd Specifies the vertical thickness of the rule produced by the
\cw{\\rule} command (see \k{input-rule}). (Note that no extra space is
reserved for thicker rules.)

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

\dt \I{\cw{\\cfg\{paper-bullet\}}}\cw{\\cfg\{paper-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\{paper-quotes\}}}\cw{\\cfg\{paper-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}).

\S{output-paper-defaults} Default settings for paper formats

The default page size corresponds to 210\_\u00D7{x}\_297\_mm, i.e.,
\i{A4 paper}.

\c \cfg{paper-page-width}{595} 
\c \cfg{paper-page-height}{842} 
\c
\c \cfg{paper-left-margin}{72} 
\c \cfg{paper-top-margin}{72} 
\c \cfg{paper-right-margin}{72} 
\c \cfg{paper-bottom-margin}{108} 
\c
\c \cfg{paper-base-leading}{1} 
\c \cfg{paper-base-para-spacing}{10} 
\c
\c \cfg{paper-list-indent}{6} 
\c \cfg{paper-listitem-indent}{18} 
\c \cfg{paper-quote-indent}{18} 
\c
\c \cfg{paper-chapter-top-space}{72} 
\c \cfg{paper-chapter-underline-thickness}{3} 
\c \cfg{paper-chapter-underline-depth}{14} 
\c \cfg{paper-sect-num-left-space}{12} 
\c
\c \cfg{paper-contents-indent-step}{24} 
\c \cfg{paper-contents-margin}{84} 
\c \cfg{paper-leader-separation}{12} 
\c \cfg{paper-footer-distance}{32} 
\c \cfg{paper-index-columns}{2} 
\c \cfg{paper-index-gutter}{36} 
\c \cfg{paper-index-minsep}{18} 
\c
\c \cfg{paper-base-fonts}{Times-Roman}{Times-Italic}{Courier}
\c \cfg{paper-base-font-size}{12} 
\c \cfg{paper-code-fonts}{Courier-Bold}{Courier-Oblique}{Courier}
\c \cfg{paper-code-font-size}{12}
\c \cfg{paper-title-fonts}{Helvetica-Bold}
\c     {Helvetica-BoldOblique}{Courier-Bold}
\c \cfg{paper-title-font-size}{24}
\c \cfg{paper-chapter-fonts}{Helvetica-Bold}
\c     {Helvetica-BoldOblique}{Courier-Bold}
\c \cfg{paper-chapter-font-size}{20}
\c \cfg{paper-section-fonts}{0}{Helvetica-Bold}
\c     {Helvetica-BoldOblique}{Courier-Bold}
\c \cfg{paper-section-font-size}{0}{16}
\c \cfg{paper-section-fonts}{1}{Helvetica-Bold}
\c     {Helvetica-BoldOblique}{Courier-Bold}
\c \cfg{paper-section-font-size}{1}{14}
\c \cfg{paper-section-fonts}{2}{Helvetica-Bold}
\c     {Helvetica-BoldOblique}{Courier-Bold}
\c \cfg{paper-section-font-size}{2}{13}
\c ... and so on for all section levels below this ...
\e iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
\c
\c \cfg{paper-pagenum-font-size}{12} 
\c
\c \cfg{paper-rule-thickness}{1} 
\c
\c \cfg{paper-bullet}{\u2022}{-}
\c \cfg{paper-quotes}{\u2018}{\u2019}{'}{'}
