#include <libxml/parser.h>
#include <libxml/xpath.h>

xmlDocPtr
getdoc (char *docname) {
	xmlDocPtr doc;
	doc = xmlParseFile(docname);
	
	if (doc == NULL ) {
		fprintf(stderr,"Document not parsed successfully. \n");
		return NULL;
	}

	return doc;
}

xmlXPathObjectPtr
getnodeset (xmlDocPtr doc, xmlChar *xpath){
	
	xmlXPathContextPtr context;
	xmlXPathObjectPtr result;

	context = xmlXPathNewContext(doc);
	if (context == NULL) {
		printf("Error in xmlXPathNewContext\n");
		return NULL;
	}
	result = xmlXPathEvalExpression(xpath, context);
	xmlXPathFreeContext(context);
	if (result == NULL) {
		printf("Error in xmlXPathEvalExpression\n");
		return NULL;
	}
	if(xmlXPathNodeSetIsEmpty(result->nodesetval)){
		xmlXPathFreeObject(result);
                printf("No result\n");
		return NULL;
	}
	return result;
}
int
main(int argc, char **argv) {

	char *docname;
	xmlDocPtr doc;
	xmlChar *xpath = (xmlChar*) "//keyword";
	xmlNodeSetPtr nodeset;
	xmlXPathObjectPtr result;
	int i;
	xmlChar *keyword;
		
	if (argc <= 1) {
		printf("Usage: %s docname\n", argv[0]);
		return(0);
	}

	docname = argv[1];
	doc = getdoc(docname);
	result = getnodeset (doc, xpath);
	if (result) {
		nodeset = result->nodesetval;
		for (i=0; i < nodeset->nodeNr; i++) {
			keyword = xmlNodeListGetString(doc, nodeset->nodeTab[i]->xmlChildrenNode, 1);
		printf("keyword: %s\n", keyword);
		xmlFree(keyword);
		}
		xmlXPathFreeObject (result);
	}
	xmlFreeDoc(doc);
	xmlCleanupParser();
	return (1);
}