Open Catalog files include:
the individual catalogs provided with the DTDs, sylesheets or entities.
the centralized catalogs used as central source of information that is specific to docbook, tei, or any other DTD
the super catalog that references indirectly all the available catalog files
The centralized catalog file names must end in .cat and reside in /etc/sgml. They contain only comments and CATALOG directives pointing to the "real" catalogs, like:
-- sample contents of /etc/sgml/foo-1.05.cat -- CATALOG /usr/share/sgml/foo/xml-dtd-1.05/catalog CATALOG /usr/share/sgml/foo/xsl-stylesheets-0.1/catalogOne can use DELEGATE instead of CATALOG if this directive is known to be supported.
The centralized catalogs are DTD-specific and can be version-numbered.
Here are examples of such centralized catalogs:
/etc/sgml/catalog is the "super catalog". It contains CATALOG pointers to all the centralized catalogs:
-- sample contents of /etc/sgml/catalog -- CATALOG /etc/sgml/sgml-docbook.cat CATALOG /etc/sgml/xhtml.cat CATALOG /etc/sgml/mathml.catOne can use DELEGATE instead of CATALOG if this directive is known to be supported.
It should not point to centralized catalogs that are merely symbolic links and therefore are already mentioned.
Users should be able to define their own centralized catalogs and their own super catalog in their home directories:
The SGML/XML computer programs are not supposed to use centralized catalogs, although their use is strongly encouraged: if other mechanisms allow one to locate the real catalogs, they can be used as well. However distribution packagers should always take care of feeding the right entries into the super catalog and the centralized catalogs. The interface for a script named install-catalog that does these maintenance tasks is described here:
install-catalog [--add | --remove] [centralized_catalog] [ordinary_catalog]Example:
bash# install-catalog --add \ /etc/sgml/sgml-docbook-3.1 \ /usr/share/sgml/docbook/dsssl-stylesheets-1.54/catalog