Documenting WineHow to help out with the Wine documentation effort...Writing Wine API Documentation
Written by &name-douglas-ridgway; &email-douglas-ridgway;
(Extracted from wine/documentation/README.documentation)
To improve the documentation of the Wine API, just add
comments to the existing source. For example,
/******************************************************************
* CopyMetaFileA (GDI32.23)
*
* Copies the metafile corresponding to hSrcMetaFile to either
* a disk file, if a filename is given, or to a new memory based
* metafile, if lpFileName is NULL.
*
* RETURNS
*
* Handle to metafile copy on success, NULL on failure.
*
* BUGS
*
* Copying to disk returns NULL even if successful.
*/
HMETAFILE WINAPI CopyMetaFileA(
HMETAFILE hSrcMetaFile, /* handle of metafile to copy */
LPCSTR lpFilename /* filename if copying to a file */
) { ... }
becomes, after processing with c2man and
nroff -man,
CopyMetaFileA(3w) CopyMetaFileA(3w)
NAME
CopyMetaFileA (GDI32.23)
SYNOPSIS
HMETAFILE CopyMetaFileA
(
HMETAFILE hSrcMetaFile,
LPCSTR lpFilename
);
PARAMETERS
HMETAFILE hSrcMetaFile
Handle of metafile to copy.
LPCSTR lpFilename
Filename if copying to a file.
DESCRIPTION
Copies the metafile corresponding to hSrcMetaFile to
either a disk file, if a filename is given, or to a new
memory based metafile, if lpFileName is NULL.
RETURNS
Handle to metafile copy on success, NULL on failure.
BUGS
Copying to disk returns NULL even if successful.
SEE ALSO
GetMetaFileA(3w), GetMetaFileW(3w), CopyMetaFileW(3w),
PlayMetaFile(3w), SetMetaFileBitsEx(3w), GetMetaFileBit-
sEx(3w)
The Wine DocBook System
Written by &name-john-sheets; &email-john-sheets;Writing Documentation with DocBook
DocBook is a flavor of SGML
(Standard Generalized Markup
Language), a syntax for marking up the contents
of documents. HTML is another very common flavor of SGML;
DocBook markup looks very similar to HTML markup, although
the names of the markup tags differ.
Terminology
SGML markup contains a number of syntactical elements that
serve different purposes in the markup. We'll run through
the basics here to make sure we're on the same page when
we refer to SGML semantics.
The basic currency of SGML is the
tag. A simple tag consists of a
pair of angle brackets and the name of the tag. For
example, the para tag would appear in
an SGML document as para. This start tag indicates
that the immediately following text should be classified
according to the tag. In regular SGML, each opening tag
must have a matching end tag to show where the start tag's
contents end. End tags begin with
</ markup, e.g.,
para.
The combination of a start tag, contents, and an end tag
is called an element. SGML
elements can be nested inside of each other, or contain
only text, or may be a combination of both text and other
elements, although in most cases it is better to limit
your elements to one or the other.
The XML (eXtensible Markup
Language) specification, a modern subset of
the SGML specification, adds a so-called empty
tag, for elements that contain no text
content. The entire element is a single tag, ending with
/>, e.g.,
<xref/>. However, use of this
tag style restricts you to XML DocBook processing, and
your document may no longer compile with SGML-only
processing systems.
Often a processing system will need more information about
an element than you can provide with just tags. SGML
allows you to add extra hints in the form
of SGML attributes to pass along
this information. The most common use of attributes in
DocBook is giving specific elements a name, or an ID, so
you can refer to it from elsewhere. This ID can be used
for many things, including file-naming for HTML output,
hyper-linking to specific parts of the document, and even
pulling text from that element (see the xref tag).
An SGML attribute appears inside the start tag, between
the < and > brackets. For example, if you wanted to
set the id attribute
of the book element to
mybook, you would create a start tag like
this: <book id="mybook">
Notice that the contents of the attribute are enclosed in
quote marks. These quotes are optional in SGML, but
mandatory in XML. It's a good habit to use quotes, as it
will make it much easier to migrate your documents to an
XML processing system later on.
You can also specify more than one attribute in a single
tag: <book id="mybook" status="draft">
Another commonly used type of SGML markup is the
entity. An entity lets you
associate a block of text with a name. You declare the
entity once, at the beginning of your document, and can
invoke it as many times as you like throughout the
document. You can use entities as shorthand, or to make
it easier to maintain certain phrases in a central
location, or even to insert the contents of an entire file
into your document.
An entity in your document is always surrounded by the
& and ; characters. One
entity you'll need sooner or later is the one for the
< character. Since SGML expects all
tags to begin with a <, the
< is a reserved character. To use it in
your document (as I am doing here), you must insert it
with the < entity. Each time
the SGML processor encounters <,
it will place a literal < in the output
document.
The final term you'll need to know when writing simple
DocBook documents is the DTD
(Document Type Declaration). The
DTD defines the flavor of SGML a given document is written
in. It lists all the legal tag names, like book, para, and so on, and declares
how those tags are allowed to be used together. For
example, it doesn't make sense to put a book element inside a para paragraph element -- only
the reverse.
The DTD thus defines the legal structure of the document.
It also declares which attributes can be used with which
tags. The SGML processing system can use the DTD to make
sure the document is laid out properly before attempting
to process it. SGML-aware text editors like Emacs can also use the DTD to
guide you while you write, offering you choices about
which tags you can add in different places in the
document, and beeping at you when you try to add a tag
where it doesn't belong.
Generally, you will declare which DTD you want to use as
the first line of your SGML document. In the case of
DocBook, you will use something like this:
<!doctype book PUBLIC "-//OASIS//DTD
DocBook V3.1//EN" []> <book> ...
</book>
Note that you must specify your toplevel element inside
the doctype declaration. If you were writing an article
rather than a book, you might use this declaration instead:
<!doctype article PUBLIC "-//OASIS//DTD DocBook V3.1//EN" []>
<article>
...
</article>The Document
Once you're comfortable with SGML, creating a DocBook
document is quite simple and straightforward. Even
though DocBook contains over 300 different tags, you can
usually get by with only a small subset of those tags.
Most of them are for inline formatting, rather than for
document structuring. Furthermore, the common tags have
short, intuitive names.
Below is a (completely nonsensical) example to illustrate
how a simple document might be laid out. Notice that all
chapter and sect1 elements have id attributes. This is not
mandatory, but is a good habit to get into, as DocBook is
commonly converted into HTML, with a separate generated
file for each book,
chapter, and/or sect1 element. If the given
element has an id
attribute, the processor will typically name the file
accordingly. Thus, the below document might result in
index.html,
chapter-one.html,
blobs.html, and so on.
Also notice the text marked off with <!--
and --> characters. These
denote SGML comments. SGML processors will completely
ignore anything between these markers, similar to
/* and */ comments in C
source code.
A Poet's Guide to NonsenseBlobs and GribblesThe Story Behind Blobs
Blobs are often mistaken for ice cubes and rain
puddles...
Your Friend the Gribble
A Gribble is a cute, unassuming little fellow...
Gribble Temperament
When left without food for several days...
Gribble Appearance
Most Gribbles have a shock of white fur running from...
PhantasmagoriaDretch Pools
When most poets think of Dretch Pools, they tend to...
]]>
Common Elements
Once you get used to the syntax of SGML, the next hurdle
in writing DocBook documentation is to learn the many
DocBook-specific tag names, and when to use them. DocBook
was created for technical documentation, and as such, the
tag names and document structure are slanted towards the
needs of such documentation.
To cover its target audience, DocBook declares a wide
variety of specialized tags, including tags for formatting
source code (with somewhat of a C/C++ bias), computer
prompts, GUI application features, keystrokes, and so on.
DocBook also includes tags for universal formatting needs,
like headers, footnotes, tables, and graphics.
We won't cover all of these elements here (over 300
DocBook tags exist!), but we will cover the basics. To
learn more about the other tags, check out the official
DocBook guide, at http://docbook.org. To
see how they are used in practice, download the SGML
source for this manual (the Wine Developer Guide) and
browse through it, comparing it to the generated HTML (or
PostScript or PDF).
There are often many correct ways to mark up a given piece
of text, and you may have to make guesses about which tag
to use. Sometimes you'll have to make compromises.
However, remember that it is possible to further customize the output of
the SGML processors. If you don't like the way a certain
tag looks in HTML, that doesn't mean you should choose a
different tag based on its output formatting. The
processing stylesheets can be altered to fix the
formatting of that same tag everywhere in the document
(not just in the place you're working on). For example,
if you're frustrated that the systemitem tag doesn't produce
any formatting by default, you should fix the stylesheets,
not change the valid systemitem tag to, for example,
an emphasis tag.
Here are the common SGML elements:
Structural Elementsbook
The book is the most common toplevel element, and is
probably the one you should use for your document.
set
If you want to group more than one book into a
single unit, you can place them all inside a set.
This is useful when you want to bundle up
documentation in alternate ways. We do this with
the Wine documentation, using a set to put everything
into a single directory (see
documentation/wine-doc.sgml),
and a book to
put each Wine guide into a separate directory (see
documentation/wine-devel.sgml,
etc.).
chapter
A chapter
element includes a single entire chapter of the
book.
part
If the chapters in your book fall into major
categories or groupings (as in the Wine Developer
Guide), you can place each collection of chapters
into a part
element.
sect?
DocBook has many section elements to divide the
contents of a chapter into smaller chunks. The
encouraged approach is to use the numbered section
tags, sect1,
sect2, sect3, sect4, and sect5 (if necessary).
These tags must be nested in order: you can't place
a sect3 directly
inside a sect1.
You have to nest the sect3 inside a sect2, and so forth.
Documents with these explicit section groupings are
easier for SGML processors to deal with, and lead to
better organized documents. DocBook also supplies a
section element
which you can nest inside itself, but its use is
discouraged in favor of the numbered section tags.
title
The title of a book, chapter, part, section, etc.
In most of the major structural elements, like
chapter,
part, and the
various section tags, title is mandatory. In
other elements like book and note, it's optional.
para
The basic unit of text is the paragraph, represented
by the para tag.
This is probably the tag you'll use most often. In
fact, in a simple document, you can probably get
away with using only book, chapter, title, and para.
article
For shorter, more targeted documents, like topic
pieces and whitepapers, you can use article as your toplevel
element.
Inline Formatting Elementsfilename
The name of a file. You can optionally set the
class attribute
to Directory,
HeaderFile, and
SymLink to further classify the
filename.
userinput
Literal text entered by the user.
computeroutput
Literal text output by the computer.
literal
A catch-all element for literal computer data. Its
use is somewhat vague; try to use a more specific
tag if possible, like userinput or computeroutput.
quote
An inline quotation. This tag typically inserts
quotation marks for you, so you would write quoteThis is a
quotequote rather
than "This is a quote". This usage may be a little
bulkier, but it does allow for automated formatting
of all quoted material in the document. Thus, if
you wanted all quotations to appear in italic, you
could make the change once in your stylesheet,
rather than doing a search and replace throughout
the document. For larger chunks of quoted text, you
can use blockquote.
note
Insert a side note for the reader. By default, the
SGML processor usually prefixes the content with
"Note:". You can change this text by adding a
title element.
Thus, to add a visible FIXME comment to the
documentation, you might write:
FIXMEThis section needs more info about...
]]>
The results will look something like this:
FIXMEThis section needs more info about...sgmltag
Used for inserting SGML tags, etc., into a SGML
document without resorting to a lot of entity
quoting, e.g., <. You can change the
appearance of the text with the class attribute. Some
common values of this are
starttag,
endtag,
attribute,
attvalue, and even
sgmlcomment. See this SGML file,
documentation/documentation.sgml,
for examples.
prompt
The text used for a computer prompt, for example a
shell prompt, or command-line application prompt.
replaceable
Meta-text that should be replaced by the user, not
typed in literally, e.g., in command descriptions
and --help outputs.
constant
A programming constant, e.g.,
MAX_PATH.
symbol
A symbolic value replaced, for example, by a
pre-processor. This applies primarily to C macros,
but may have other uses. Use the constant tag instead of
symbol where
appropriate.
function
A programming function name.
parameter
Programming language parameters you pass with a
function.
option
Parameters you pass to a command-line executable.
varname
Variable name, typically in a programming language.
type
Programming language types, e.g., from a typedef
definition. May have other uses, too.
structname
The name of a C-language struct
declaration, e.g., sockaddr.
structfield
A field inside a C struct.
command
An executable binary, e.g., wine
or ls.
envar
An environment variable, e.g, $PATH.
systemitem
A generic catch-all for system-related things, like
OS names, computer names, system resources, etc.
email
An email address. The SGML processor will typically
add extra formatting characters, and even a
mailto: link for HTML pages.
Usage: emailuser@host.comemailfirstterm
Special emphasis for introducing a new term. Can
also be linked to a glossary entry, if
desired.
Item Listing Elementsitemizedlist
For bulleted lists, no numbering. You can tweak the
layout with SGML attributes.
orderedlist
A numbered list; the SGML processor will insert the
numbers for you. You can suggest numbering styles
with the numeration attribute.
simplelist
A very simple list of items, often inlined. Control
the layout with the type attribute.
variablelist
A list of terms with definitions or descriptions,
like this very list!
Block Text Quoting Elementsprogramlisting
Quote a block of source code. Typically highlighted
in the output and set off from normal text.
screen
Quote a block of visible computer output, like the
output of a command or chunks of debug logs.
Hyperlink Elementslink
Generic hypertext link, used for pointing to other
sections within the current document. You supply
the visible text for the link, plus the name of the id attribute of the
element that you want to link to. For example:
<link linkend="configuring-wine">the section on configuring wine</link>
...
<sect2 id="configuring-wine">
...xref
In-document hyperlink that can generate its own
text. Similar to the link tag, you use the
linkend
attribute to specify which target element you want
to jump to:
<xref linkend="configuring-wine">
...
<sect2 id="configuring-wine">
...
By default, most SGML processors will autogenerate
some generic text for the xref link, like
Section 2.3.1. You can use the
endterm
attribute to grab the visible text content of the
hyperlink from another element:
<xref linkend="configuring-wine" endterm="config-title">
...
<sect2 id="configuring-wine">
<title id="config-title">Configuring Wine</title>
...
This would create a link to the
configuring-wine element,
displaying the text of the
config-title element for the
hyperlink. Most often, you'll add an id attribute to the
title of the
section you're linking to, as above, in which case
the SGML processor will use the target's title text
for the link text.
Alternatively, you can use an xreflabel attribute in
the target element tag to specify the link text:
<sect1 id="configuring-wine" xreflabel="Configuring Wine">xref is an
empty element. You don't need a closing tag for
it (this is defined in the DTD). In SGML
documents, you should use the form xref, while in XML
documents you should use
<xref/>.
anchor
An invisible tag, used for inserting id attributes into a
document to link to arbitrary places (i.e., when
it's not close enough to link to the top of an
element).
ulink
Hyperlink in URL form, e.g., http://www.winehq.com.
olink
Indirect hyperlink; can be used for linking to
external documents. Not often used in practice.
Multiple SGML files
How to split an SGML document into multiple files...
The SGML Environment
You can write SGML/DocBook documents in any text editor you
might find (although as we'll find in , some editors are more friendly for
this task than others). However, if you want to convert
those documents into a more friendly form for reading, such
as HTML, PostScript, or PDF, you will need a working SGML
environment. This section attempts to lay out the various
SGML rendering systems, and how they are set up on the
popular Linux distributions.
DSSSL Environment
Explain tools and methodologies..
XSLT Environment
Explain tools and methodologies...
SGML on Redhat
Most Linux distributions have everything you need already
bundled up in package form. Unfortunately, each
distribution seems to handle its SGML environment
differently, installing it into different paths, and
naming its packages according to its own whims.
SGML on Debian
List package names and install locations...
SGML on Other Distributions
List package names and install locations...
PSGML Mode in Emacs
Although you can write SGML documentation in any simple text
editor, some editors provide extra support for entering SGML
tags, and for verifying that the SGML you create is valid.
SGML has been around for a long time, and many commercial
editors exist for it; however, until recently open source
SGML editors have been scarce.
FIXME
List the available commercial and open source SGML
editors.
The most commonly used open source SGML editor is Emacs,
with the PSGML mode, or extension.
Emacs does not supply a GUI or WYSIWYG (What You See Is What
You Get) interface, but it does provide many helpful
shortcuts for creating SGML, as well as automatic
formatting, validity checking, and the ability to create
your own macros to simplify complex, repetitive actions.
We'll touch briefly on each of these points.
The first thing you need is a working installation of Emacs
(or XEmacs), with the PSGML package. Most Linux
distributions provide both as easy-to-install packages.
Next, you'll need a working SGML environment. See for more info on setting that
up.
The DocBook Build SystemBasic Infrastructure
How the build/make system works (makefiles, db2html,
db2html-winehq, jade, stylesheets).
Tweaking the DSSSL stylesheets
Things you can tweak, and how to do it (examples from
default.dsl and winehq.dsl).
Generating docs for Wine web sites
Explain make_winehq, rsync, etc.