frontend-spec - interface between jw and its frontends
jw(1) calls frontends like frontends/docbook to get
the informations specific to a given input format. The frontend knows which
information to return from the first command line parameter. It gets all
necessary data via environment variables ready to use.
This document describes that command line parameter and those
environment variables.
The frontend should return 0 if there weren't any problem, and
return a positive value otherwise.
- $1
- The command line parameter, specifying which information to return. It can
take the following values:
- centralized-catalog
- The frontend must return the DTD-specific centralized catalog name.
Centralized catalogs normally reside in /etc/sgml and provide the
location of all the catalog files useful for handling this input type (the
catalog for the DTD, the catalog for the stylesheets, the catalog for the
entities, ...)
- style-sheet
- The frontend must return the filename of the style sheet to be used for
this document type and with the chosen backend.
-
SGML_CATALOGS_DIR
- The directory where the centralized catalogs reside. It is normally
/etc/sgml.
(This variable is valid only while determining the centralized
catalog to use.)
-
SGML_BASE_DIR
- The base directory of the SGML system. It is normally
/usr/share/sgml.
(This variable is valid only while determining the style sheet
to use.)
- SGML_FILE
- The name of the file to convert.
(This variable is valid only while determining the centralized
catalog to use.)
- SGML_TYPE
- The type of the backend to use, whether it produces output files to be
displayed online or to be printed out. It can take the value html or
print.
(This variable is valid only while determining the style sheet
to use).
-
SGML_STYLESHEETS
- The desired custom stylesheet type, either none or default. If none, the
frontend must return the file name of the style sheet provided by the
system beneath the docbook-utils. If default, the frontend must return the
custom stylesheet provided by the docbook-utils.
(This variable is valid only while determining the style sheet
to use).
- SGML_XML
- The metalanguage of the file to convert, either sgml or xml.
(This variable is valid only while determining the centralized
catalog to use).
Jochem Huhmann <joh@revier.com>