3 * synopsis: Show how to extract subdocuments with xmlReader
4 * purpose: Demonstrate the use of xmlTextReaderPreservePattern()
5 * to parse an XML file with the xmlReader while collecting
6 * only some subparts of the document.
7 * (Note that the XMLReader functions require libxml2 version later
10 * test: reader3 > reader3.tmp ; diff reader3.tmp reader3.res ; rm reader3.tmp
11 * author: Daniel Veillard
12 * copy: see Copyright for the status of this software.
16 #include <libxml/xmlreader.h>
18 #if defined(LIBXML_READER_ENABLED) && defined(LIBXML_PATTERN_ENABLED) && defined(LIBXML_OUTPUT_ENABLED)
23 * @filename: the file name to parse
25 * Parse and print information about an XML file.
27 * Returns the resulting doc with just the elements preserved.
30 extractFile(const char *filename, const xmlChar *pattern) {
32 xmlTextReaderPtr reader;
36 * build an xmlReader for that file
38 reader = xmlReaderForFile(filename, NULL, 0);
41 * add the pattern to preserve
43 if (xmlTextReaderPreservePattern(reader, pattern, NULL) < 0) {
44 fprintf(stderr, "%s : failed add preserve pattern %s\n",
45 filename, (const char *) pattern);
48 * Parse and traverse the tree, collecting the nodes in the process
50 ret = xmlTextReaderRead(reader);
52 ret = xmlTextReaderRead(reader);
55 fprintf(stderr, "%s : failed to parse\n", filename);
56 xmlFreeTextReader(reader);
60 * get the resulting nodes
62 doc = xmlTextReaderCurrentDoc(reader);
66 xmlFreeTextReader(reader);
68 fprintf(stderr, "Unable to open %s\n", filename);
74 int main(int argc, char **argv) {
75 const char *filename = "test3.xml";
76 const char *pattern = "preserved";
85 * this initialize the library and check potential ABI mismatches
86 * between the version it was compiled for and the actual shared
91 doc = extractFile(filename, (const xmlChar *) pattern);
96 xmlDocDump(stdout, doc);
98 * don't forget to free up the doc
105 * Cleanup function for the XML library.
109 * this is to debug memory for regression tests
117 fprintf(stderr, "Reader, Pattern or output support not compiled in\n");