Copyright © 2004 Panagiotis Louridas
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Table of Contents
The Extensible Stylesheet Language Transformations (XSLT) specification defines an XML template language for transforming XML documents. An XSLT engine reads an XSLT file and an XML document and transforms the document accordingly.
We want to perform a series of XSLT transformations to a series of documents. An obvious solution is to use the operating system's pipe mechanism and start a series of transformation processes, each one taking as input the output of the previous transformation. It would be interesting, though, and perhaps more efficient if we could do our job within a single process.
libxslt is a library for doing XSLT transformations. It is built on libxml, which is a library for handling XML documents. libxml and libxslt are used by the GNOME project. Although developed in the *NIX world, both libxml and libxslt have been ported to the MS-Windows platform. In principle an application using libxslt should be easily portable between the two systems. In practice, however, there arise various wrinkles. These do not have anything to do with libxml or libxslt per se, but rather with the different compilation and linking procedures of each system.
The presented solution is an extension of John Fleck's libxslt tutorial, but the present tutorial tries to be self-contained. It develops a minimal libxslt application (libxslt_pipes) that can perform a series of transformations to a series of files in a pipe-like manner. An invocation might be:
libxslt_pipes --out results.xml foo.xsl bar.xsl doc1.xml doc2.xml
The foo.xsl stylesheet will be applied to doc1.xml and the bar.xsl stylesheet will be applied to the resulting document; then the two stylesheets will be applied in the same sequence to bar.xsl. The results are sent to results.xml (if no output is specified they are sent to standard output).
The application is compiled in both *NIX systems and MS-Windows, where by *NIX systems we mean Linux, BSD, and other members of the family. The gcc suite is used in the *NIX platform and the Microsoft compiler and linker are used in the MS-Windows platform.
We need to include the necessary libraries:
#include <stdio.h> #include <string.h> #include <stdlib.h> #include <libxslt/transform.h> #include <libxslt/xsltutils.h>
The first group of include directives includes general C libraries. The libraries we need to make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file declares the API for some generic utilitith make libxslt work are in the second group. The transform.h header file declares the API that does the bulk of the actual processing. The xsltutils.h header file decla