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      1 /**
      2  * section: xmlReader
      3  * synopsis: Parse multiple XML files reusing an xmlReader
      4  * purpose: Demonstrate the use of xmlReaderForFile() and
      5  * xmlReaderNewFile to parse XML files while reusing the reader object
      6  * and parser context.  (Note that the XMLReader functions require
      7  * libxml2 version later than 2.6.)
      8  * usage: reader4 <filename> [ filename ... ]
      9  * test: reader4 test1.xml test2.xml test3.xml > reader4.tmp && diff reader4.tmp $(srcdir)/reader4.res
     10  * author: Graham Bennett
     11  * copy: see Copyright for the status of this software.
     12  */
     13 
     14 #include <stdio.h>
     15 #include <libxml/xmlreader.h>
     16 
     17 #ifdef LIBXML_READER_ENABLED
     18 
     19 static void processDoc(xmlTextReaderPtr readerPtr) {
     20     int ret;
     21     xmlDocPtr docPtr;
     22     const xmlChar *URL;
     23 
     24     ret = xmlTextReaderRead(readerPtr);
     25     while (ret == 1) {
     26       ret = xmlTextReaderRead(readerPtr);
     27     }
     28 
     29     /*
     30      * One can obtain the document pointer to get insteresting
     31      * information about the document like the URL, but one must also
     32      * be sure to clean it up at the end (see below).
     33      */
     34     docPtr = xmlTextReaderCurrentDoc(readerPtr);
     35     if (NULL == docPtr) {
     36       fprintf(stderr, "failed to obtain document\n");
     37       return;
     38     }
     39 
     40     URL = docPtr->URL;
     41     if (NULL == URL) {
     42       fprintf(stderr, "Failed to obtain URL\n");
     43     }
     44 
     45     if (ret != 0) {
     46       fprintf(stderr, "%s: Failed to parse\n", URL);
     47       return;
     48     }
     49 
     50     printf("%s: Processed ok\n", (const char *)URL);
     51 }
     52 
     53 int main(int argc, char **argv) {
     54     xmlTextReaderPtr readerPtr;
     55     int i;
     56     xmlDocPtr docPtr;
     57 
     58     if (argc < 2)
     59         return(1);
     60 
     61     /*
     62      * this initialises the library and check potential ABI mismatches
     63      * between the version it was compiled for and the actual shared
     64      * library used.
     65      */
     66     LIBXML_TEST_VERSION
     67 
     68     /*
     69      * Create a new reader for the first file and process the
     70      * document.
     71      */
     72     readerPtr = xmlReaderForFile(argv[1], NULL, 0);
     73     if (NULL == readerPtr) {
     74       fprintf(stderr, "%s: failed to create reader\n", argv[1]);
     75       return(1);
     76     }
     77     processDoc(readerPtr);
     78 
     79     /*
     80      * The reader can be reused for subsequent files.
     81      */
     82     for (i=2; i < argc; ++i) {
     83       	xmlReaderNewFile(readerPtr, argv[i], NULL, 0);
     84 	if (NULL == readerPtr) {
     85 	  fprintf(stderr, "%s: failed to create reader\n", argv[i]);
     86 	  return(1);
     87 	}
     88         processDoc(readerPtr);
     89     }
     90 
     91     /*
     92      * Since we've called xmlTextReaderCurrentDoc, we now have to
     93      * clean up after ourselves.  We only have to do this the last
     94      * time, because xmlReaderNewFile calls xmlCtxtReset which takes
     95      * care of it.
     96      */
     97     docPtr = xmlTextReaderCurrentDoc(readerPtr);
     98     if (docPtr != NULL)
     99       xmlFreeDoc(docPtr);
    100 
    101     /*
    102      * Clean up the reader.
    103      */
    104     xmlFreeTextReader(readerPtr);
    105 
    106     /*
    107      * Cleanup function for the XML library.
    108      */
    109     xmlCleanupParser();
    110     /*
    111      * this is to debug memory for regression tests
    112      */
    113     xmlMemoryDump();
    114     return(0);
    115 }
    116 
    117 #else
    118 int main(void) {
    119     fprintf(stderr, "xmlReader support not compiled in\n");
    120     exit(1);
    121 }
    122 #endif
    123