4.2. Nsgmls

The Bochs documentation is written in SGML docbook style, so any tool which can check SGML syntax can be used to check the docbook. The DTD (data type description) for docbook tells exactly which elements can be used and where. It says which attributes are required and which are optional, and how elements should be nested. The term "validate" has a specific meaning in SGML. When you validate a SGML document, it means that you read the DTD and then check that the document conforms to all the rules of the DTD.

A program called nsgmls, written by James Clark , can validate an SGML document such as our docbook. Although nsgmls can do many other things, this command will validate the docbook against the DTD which defines the syntax:

nsgmls -s filename

Nsgmls is part of SP, a "free object-oriented toolkit for SGML parsing and entity management" by James Clark . SP can be found at http://www.jclark.com/sp. There is a complete man page for nsgmls here.