<!doctype debiandoc system>

<!--
 Debian doc-base Manual
 Copyright (C)1998 Christian Schwarz;
 released under the terms of the GNU
 General Public License, version 2 or (at your option) any later.
 -->

<book>

<title>Debian doc-base Manual
<author>Christian Schwarz <email/schwarz@debian.org/
<author>Adam P. Harris <email/aph@debian.org/
<version>version $Revision: $ <date>

<abstract>
This manual describes what doc-base is and how it can be used to
manage online manuals on Debian systems.
</abstract>

<copyright>Copyright &copy;1998 Christian Schwarz.
<p>

This manual is free software; you may redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
<p>

This is distributed in the hope that it will be useful, but
<em>without any warranty</em>; without even the implied warranty of
merchantability or fitness for a particular purpose.  See the GNU
General Public License for more details.
<p>

A copy of the GNU General Public License is available as
<tt>/usr/doc/copyright/GPL</tt> in the Debian GNU/Linux distribution
or on the World Wide Web at
<tt>http://www.gnu.org/copyleft/gpl.html</tt>. You can also obtain it
by writing to the Free Software Foundation, Inc., 59 Temple Place,
Suite 330, Boston, MA 02111-1307 USA
<p>

<toc sect>

<chapt>About doc-base
<p>

Some time ago, there was a big discussion on the Debian mailing lists
about the preferred documentation format in Debian because the current
section in the policy manual about documentation contradicts itself
(cf. bug #7890). The discussion showed clearly that people have very
different opinions on that topic and thus, we'll have to implement a
flexible solution so that everyone is pleased.

<p>

The doc-base package tries to implement such a flexible solution:
Every Debian package that provides online documentation (other than
manual pages) will register these documents to doc-base via the
<prgn/install-docs/ script (see below) at installation time and
de-register the manuals again once the package is removed.

<p>

With this registration process, doc-base will be provided with details
about the installed manuals, file names, documentation formats,
etc. Based on the doc-base configuration which can easily adjusted by
the local system administrator, doc-base will eventually convert
between different documentation formats (where available, for example,
texinfo source to GNU info or PostScript), optionally compress or
remove HTML manuals which are also available in GNU info format,
etc. etc.

<p>

Since all manuals will eventually by registered, doc-base can also be
used to solve another outstanding problem: Debian currently has two
different online documentation systems, dwww and dhelp. Since both
systems have their advantages and disadvantages, it has been decided
to support both packages and let the system administrator choose which
implementation he/she prefers.

<p>

However, this requires all packages to support both online
documentation systems. This can be done easily via doc-base (see
below).

<p>

In summary, doc-base' main functionality is:

<p>

<list compact>
<item>convert online manuals between different documentation formats
     (depending on its configuration), and
<p>
<item>register online manuals to Debian's online help systems dwww and
     dhelp.
<p>
</list>
<p>

Until now, only the second part has been implemented.
<p>

<chapt>The packages interface
<p>

<sect>Introduction
<p>

Each Debian package that installs online manuals (any format) should
register its manuals to doc-base. This is done by installing a
doc-base <em/control file/ and calling <prgn/install-docs/ from the
<prgn/postinst/ script.
<p>

<sect>Document ids
<p>

Each piece of online documentation that is registered to doc-base must
have an unique <em/document id/.
<p>

The document id is usually taken from the document's title or from the
package name. Here are a few examples:
<p>

<example>
DOCID                  Title
---------------------- ----------------------------
debian-policy          Debian Policy Manual
developers-reference   Debian Developers Reference
doc-base               Debian doc-base Manual
emacs-manual           GNU Emacs Manual
</example>
<p>

Just as package names, the document id may only consist lower case
letters (a-z), digits (0-9), plus (+) or minus (-) signs, and dots
(.).
<p>

<sect>Control files
<p>

For each piece online documentation, doc-base needs a <em/control
file/ that describes the documentation and the documentation file
formats that are provided initially.
<p>

Here is an example of a control file:
<p>

<example>
Document: doc-base
Title: Debian doc-base Manual
Author: Christian Schwarz
Abstract: This manual describes what doc-base is
 and how it can be used to
 manage online manuals on Debian systems.
Section: Apps/Programming

Format: debiandoc-sgml
Files: /usr/doc/doc-base/doc-base.sgml.gz

Format: text
Files: /usr/doc/doc-base/doc-base.text.gz

Format: HTML
Index: /usr/doc/doc-base/doc-base.html/index.html
Files: /usr/doc/doc-base/doc-base.html/*.html
</example>
<p>

As you can see from this example, the the syntax--just as the whole
design of doc-base--is heavily influenced by dpkg. This is important
since every maintainer will have to work with doc-base and thus, it
should be simply to remember the basic ideas.

<p>

The syntax of the control file is simple: Empty lines seperate
sections (see below). The other line use a field-value syntax.  Field
values may be wrapped over several lines if the first character of
subsequent lines is a space; if the value should contain an empty line
a single dot (.) has to be placed in the second column. The field
names are case-insensitive.

<p>

The first section of the control file describes the document, starting
with the document id (the `Document:' field), the title, etc. This
information will be used when the manual is registered to the online
menu systems (dhelp, dwww, etc.).

<p>

The following sections describe the different formats which are
provided by the package. This information will be needed when the
format-conversion feature is implemented. (Note, that these fields are
likely to be changed as soon as I start with the implementation.)

<p>

For now, only the format `HTML' is recognized. The `Index:' field has
to contain the absolute file name of the title page of the
document. (This file will be specified as front page link when the
document is registered to dwww or dhelp.)

<p>

<sect>Registering documents using install-docs
<p>

In order to register a piece of online documentation to doc-base, the
package has to install the control file (see above) as file
<tt>/usr/share/doc-base/<var/document-id/</tt>.
<p>

Then, it should call <prgn/install-docs/ from its <tt/postinst/ script
like this

<example>
    if command -v install-docs >/dev/null 2>&1; then
      install-docs -i /usr/share/doc-base/&lt;document-id&gt;
    fi
</example>

and from the <tt/prerm/ script like this

<example>
    if command -v install-docs >/dev/null 2>&1; then
      install-docs -r &lt;document-id&gt;
    fi
</example>
<p>

With that, doc-base will automatically register the online manuals to
dwww and dhelp when the package is installed, and de-register the
manuals when the package is remove.
<p>

<chapt>Getting information about installed documents
<p>

If you want to get information about the status of an installed
manual, you can use the `<tt/-s/' or `<tt/--status/' option of
<prgn/install-docs/ followed by the document id:

<example>
$ install-docs -s foo
---document-information---
Document: foo
Abstract: This manual is about foos, bars, and Debian.
Author: Wile E. Coyote
Section: debian
Title: Debian Foo's Manual

---format-description---
Format: debiandoc-sgml
Files: /usr/doc/foo/sgml/foo.sgml.gz

---format-description---
Format: html
Files: /usr/doc/foo/html-sgml/*.html
Index: /usr/doc/foo/html-sgml/index.html

---status-information---
Control-File: ../foo-0.0/foo.desc
Registered-to-dhelp: 1
Registered-to-dwww: 1
</example>
<p>

In some cases, doc-base creates files when installing a document. For
example, when a document is registered to dhelp a file `<tt/.dhelp/'
is generated. You can check out which files have been created by
doc-base with the `<tt/-L/' or `<tt/--listfiles/' options followed by
the document id. Here is an example:

<example>
$ install-docs -L foo
/usr/doc/foo/html-sgml/.dhelp
/usr/lib/menu/doc-base-foo
</example>
<p>

<chapt>TODO List

<p> The following items are listed, in approximate priority, as to-do
items.  Our first priority is to define the core issues of the Slink
(Debian 2.1) Debian Documentation System, which will have status a
Sub-Policy.

<list>
  <item> Policy: document the doc-base document registration file
  format separately (or SUBDOC it) as a proposed Debian documentation
  system policy.  Discussion is underway at
  <email>debian-doc@lists.debian.org</email>; Adam P. Harris is in
  charge of this.

  <item> Policy: define a first-cut standard as the document
  heirarchy. Discussion is underway at
  <email>debian-doc@lists.debian.org</email>; Marcus Brinkmann is in
  charge of this.

  <item> Documentation update: show clean and minimal use of
  'install-docs' from maintainer script.

  <item> It is <em>extremely</em> difficult to deal coherently with a
  misnamed control file, or a mismatch between a control file and the
  document field.  This hit me in the transition between doc-base 0.4
  to 0.5 (in 0.4 I had added, in a file install-docs-man, a document
  id named install-doc-man).  Something needs to be done about that.

  <item> Determine a cleaner way to manage the various little files
  such as .dhelp and doc-base status files.  This also involves
  behavior on remove or purge of the doc-base packges.  I believe
  derived files such as .dhelp will eventually go away in Slink
  anyhow, since packages should understand the doc-base document
  registration control file format directly.

  <item> Internationalization.
  
  <item> Automated format conversion, including user preferences.

</list>

</book>