PSGML is the most common and most
powerful mode for editing SGML documents.
When properly configured, it will allow you to use
Emacs to insert tags and check markup
consistency. You could use it for HTML as
well. Check the PSGML
web site for downloads, installation instructions, and
detailed documentation.
There is one important thing to note with
PSGML: its author assumed that your
main SGML DTD directory
would be /usr/local/lib/sgml. If, as in the
examples in this chapter, you use
/usr/local/share/sgml, you have to
compensate for this, either by setting
SGML_CATALOG_FILES environment variable, or you
can customize your PSGML installation
(its manual tells you how).
Put the following in your ~/.emacs
environment file (adjusting the path names to be appropriate for
your system):
; ********** for SGML mode (psgml)
(setq sgml-omittag t)
(setq sgml-shorttag t)
(setq sgml-minimize-attributes nil)
(setq sgml-always-quote-attributes t)
(setq sgml-indent-step 1)
(setq sgml-indent-data t)
(setq sgml-parent-document nil)
(setq sgml-default-dtd-file "./reference.ced")
(setq sgml-exposed-tags nil)
(setq sgml-catalog-files '("/usr/local/share/sgml/catalog"))
(setq sgml-ecat-files nil)
(autoload 'sgml-mode "psgml" "Major mode to edit SGML files." t )
and in the same file add an entry for SGML
into the (existing) definition for
auto-mode-alist:
(setq
auto-mode-alist
'(("\\.sgml$" . sgml-mode)
))
Currently, each SGML source file has the
following block at the end of the file:
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"./reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:("/usr/lib/sgml/catalog")
sgml-local-ecat-files:nil
End:
-->
This will set up a number of editing mode parameters even if you
do not set up your ~/.emacs file, but it is
a bit unfortunate, since if you followed the installation
instructions above, then the catalog path will not match your
location. Hence you might need to turn off local variables:
(setq inhibit-local-variables t)
The PostgreSQL distribution includes a
parsed DTD definitions file reference.ced.
You may find that when using PSGML, a comfortable way of working
with these separate files of book parts is to insert a proper
DOCTYPE declaration while you're editing them.
If you are working on this source, for instance, it is an
appendix chapter, so you would specify the document as an
"appendix" instance of a DocBook document by making
the first line look like this:
<!doctype appendix PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
This means that anything and everything that reads
SGML will get it right, and I can verify the
document with nsgmls -s docguide.sgml. (But
you need to take out that line before building the entire
documentation set.)
