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121 lines
2.9 KiB
C
121 lines
2.9 KiB
C
/**
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* section: xmlReader
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* synopsis: Show how to extract subdocuments with xmlReader
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* purpose: Demonstrate the use of xmlTextReaderPreservePattern()
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* to parse an XML file with the xmlReader while collecting
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* only some subparts of the document.
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* (Note that the XMLReader functions require libxml2 version later
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* than 2.6.)
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* usage: reader3
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* test: reader3 > reader3.tmp && diff reader3.tmp $(srcdir)/reader3.res
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* author: Daniel Veillard
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* copy: see Copyright for the status of this software.
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*/
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#include <stdio.h>
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#include <libxml/xmlreader.h>
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#if defined(LIBXML_READER_ENABLED) && defined(LIBXML_PATTERN_ENABLED) && defined(LIBXML_OUTPUT_ENABLED)
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/**
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* streamFile:
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* @filename: the file name to parse
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*
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* Parse and print information about an XML file.
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*
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* Returns the resulting doc with just the elements preserved.
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*/
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static xmlDocPtr
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extractFile(const char *filename, const xmlChar *pattern) {
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xmlDocPtr doc;
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xmlTextReaderPtr reader;
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int ret;
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/*
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* build an xmlReader for that file
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*/
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reader = xmlReaderForFile(filename, NULL, 0);
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if (reader != NULL) {
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/*
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* add the pattern to preserve
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*/
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if (xmlTextReaderPreservePattern(reader, pattern, NULL) < 0) {
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fprintf(stderr, "%s : failed add preserve pattern %s\n",
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filename, (const char *) pattern);
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}
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/*
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* Parse and traverse the tree, collecting the nodes in the process
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*/
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ret = xmlTextReaderRead(reader);
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while (ret == 1) {
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ret = xmlTextReaderRead(reader);
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}
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if (ret != 0) {
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fprintf(stderr, "%s : failed to parse\n", filename);
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xmlFreeTextReader(reader);
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return(NULL);
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}
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/*
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* get the resulting nodes
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*/
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doc = xmlTextReaderCurrentDoc(reader);
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/*
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* Free up the reader
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*/
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xmlFreeTextReader(reader);
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} else {
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fprintf(stderr, "Unable to open %s\n", filename);
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return(NULL);
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}
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return(doc);
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}
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int main(int argc, char **argv) {
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const char *filename = "test3.xml";
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const char *pattern = "preserved";
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xmlDocPtr doc;
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if (argc == 3) {
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filename = argv[1];
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pattern = argv[2];
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}
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/*
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* this initialize the library and check potential ABI mismatches
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* between the version it was compiled for and the actual shared
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* library used.
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*/
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LIBXML_TEST_VERSION
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doc = extractFile(filename, (const xmlChar *) pattern);
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if (doc != NULL) {
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/*
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* output the result.
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*/
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xmlDocDump(stdout, doc);
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/*
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* don't forget to free up the doc
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*/
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xmlFreeDoc(doc);
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}
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/*
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* Cleanup function for the XML library.
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*/
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xmlCleanupParser();
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/*
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* this is to debug memory for regression tests
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*/
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xmlMemoryDump();
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return(0);
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}
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#else
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int main(void) {
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fprintf(stderr, "Reader, Pattern or output support not compiled in\n");
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exit(1);
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}
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#endif
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