DocBook

From ArchWiki

From Wikipedia:

DocBook is a semantic markup language for technical documentation. It was originally intended for writing technical documents related to computer hardware and software, but it can be used for any other sort of documentation.
As a semantic language, DocBook enables its users to create document content in a presentation-neutral form that captures the logical structure of the content; that content can then be published in a variety of formats, including HTML, XHTML, EPUB, PDF, man pages, Web help and HTML Help, without requiring users to make any changes to the source. In other words, when a document is written in DocBook format it becomes easily portable into other formats, rather than needing to be rewritten.

Installation

Install docbook-xml and docbook-xsl.

Validating XML file

To validate the XML file use: 

$ xmllint --valid --noout /path/to/file.xml

This will generate no output if the file is proper XML.

Converting into XHTML

Single file

To convert into a XHTML file (single file) use: 

$ xsltproc /usr/share/xml/docbook/$(pacman -Q docbook-xsl | cut -d ' ' -f 2 | cut -d '-' -f 1)/xhtml/docbook.xsl /path/to/file.xml > output.html

Segmented

To convert into a segmented XHTML file (each section in its own file) use: 

$ xsltproc /usr/share/xml/docbook/$(pacman -Q docbook-xsl | cut -d ' ' -f 2 | cut -d '-' -f 1)/xhtml/chunk.xsl /path/to/file.xml

Automating

You can add these to ~/.bashrc (or similar shell startup file): 

alias doc2html1="xsltproc /usr/share/xml/docbook/xhtml/docbook.xsl"
alias doc2multihtml="xsltproc /usr/share/xml/docbook/xhtml/chunk.xsl"
alias docvalidate="xmllint --valid --noout"

Troubleshooting

Compilation errors

If you have already installed the packages above, but begin to see compilation errors such as: 

GEN    appdata-validate.1
I/O error : Attempt to load network entity http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl
warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"
cannot parse http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl

Then reinstall docbook-xml and docbook-xsl. If something has corrupted the catalog file, this will run xmlcatalog and rebuild /etc/xml/catalog, which may resolve these compile errors.

Tips and tricks

Comments

Comments are somewhat problematic within an XML file. One possibility is to use a non-existing processing-instruction, e.g.: 

<?ignore
comment line 1: can be a valid xml line
comment line 2: can be a valid xml line
?>

More details at https://stackoverflow.com/a/14650451.

See also