Daniel Veillard | 1e90661 | 2003-12-05 14:57:46 +0000 | [diff] [blame^] | 1 | /** |
| 2 | * section: xmlReader |
| 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 | * usage: reader3 |
| 8 | * test: reader3 > reader3.tmp ; diff reader3.tmp reader3.out ; rm reader3.tmp |
| 9 | * author: Daniel Veillard |
| 10 | * copy: see Copyright for the status of this software. |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <libxml/xmlreader.h> |
| 15 | |
| 16 | /** |
| 17 | * streamFile: |
| 18 | * @filename: the file name to parse |
| 19 | * |
| 20 | * Parse and print information about an XML file. |
| 21 | * |
| 22 | * Returns the resulting doc with just the elements preserved. |
| 23 | */ |
| 24 | static xmlDocPtr |
| 25 | extractFile(const char *filename, const xmlChar *pattern) { |
| 26 | xmlDocPtr doc; |
| 27 | xmlTextReaderPtr reader; |
| 28 | int ret; |
| 29 | |
| 30 | /* |
| 31 | * build an xmlReader for that file |
| 32 | */ |
| 33 | reader = xmlReaderForFile(filename, NULL, 0); |
| 34 | if (reader != NULL) { |
| 35 | /* |
| 36 | * add the pattern to preserve |
| 37 | */ |
| 38 | if (xmlTextReaderPreservePattern(reader, pattern) < 0) { |
| 39 | fprintf(stderr, "%s : failed add preserve pattern %s\n", |
| 40 | filename, (const char *) pattern); |
| 41 | } |
| 42 | /* |
| 43 | * Parse and traverse the tree, collecting the nodes in the process |
| 44 | */ |
| 45 | ret = xmlTextReaderRead(reader); |
| 46 | while (ret == 1) { |
| 47 | ret = xmlTextReaderRead(reader); |
| 48 | } |
| 49 | if (ret != 0) { |
| 50 | fprintf(stderr, "%s : failed to parse\n", filename); |
| 51 | xmlFreeTextReader(reader); |
| 52 | return(NULL); |
| 53 | } |
| 54 | /* |
| 55 | * get the resulting nodes |
| 56 | */ |
| 57 | doc = xmlTextReaderCurrentDoc(reader); |
| 58 | /* |
| 59 | * Free up the reader |
| 60 | */ |
| 61 | xmlFreeTextReader(reader); |
| 62 | } else { |
| 63 | fprintf(stderr, "Unable to open %s\n", filename); |
| 64 | return(NULL); |
| 65 | } |
| 66 | return(doc); |
| 67 | } |
| 68 | |
| 69 | int main(int argc, char **argv) { |
| 70 | const char *filename = "test3.xml"; |
| 71 | const char *pattern = "preserved"; |
| 72 | xmlDocPtr doc; |
| 73 | |
| 74 | if (argc == 3) { |
| 75 | filename = argv[1]; |
| 76 | pattern = argv[2]; |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * this initialize the library and check potential ABI mismatches |
| 81 | * between the version it was compiled for and the actual shared |
| 82 | * library used. |
| 83 | */ |
| 84 | LIBXML_TEST_VERSION |
| 85 | |
| 86 | doc = extractFile(filename, (const xmlChar *) pattern); |
| 87 | if (doc != NULL) { |
| 88 | /* |
| 89 | * ouptut the result. |
| 90 | */ |
| 91 | xmlDocDump(stdout, doc); |
| 92 | /* |
| 93 | * don't forget to free up the doc |
| 94 | */ |
| 95 | xmlFreeDoc(doc); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | /* |
| 100 | * Cleanup function for the XML library. |
| 101 | */ |
| 102 | xmlCleanupParser(); |
| 103 | return(0); |
| 104 | } |