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author | Daniel Veillard <veillard@src.gnome.org> | 2004-03-25 10:43:16 +0000 |
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committer | Daniel Veillard <veillard@src.gnome.org> | 2004-03-25 10:43:16 +0000 |
commit | 88155d85e5474f25214bf7d23f38180b649c7ae6 (patch) | |
tree | 36a7511fe539e186cb015b2b1bd4b69858783c2c /doc/examples/parse4.c | |
parent | ebe25d492075cb8fa141027e7627dfdfdd0262b8 (diff) | |
download | libxml2-88155d85e5474f25214bf7d23f38180b649c7ae6.tar.gz |
Added a couple of parsing examples, Daniel
Diffstat (limited to 'doc/examples/parse4.c')
-rw-r--r-- | doc/examples/parse4.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/doc/examples/parse4.c b/doc/examples/parse4.c new file mode 100644 index 00000000..97825f0f --- /dev/null +++ b/doc/examples/parse4.c @@ -0,0 +1,137 @@ +/** + * section: Parsing + * synopsis: Parse an XML document chunk by chunk to a tree and free it + * purpose: Demonstrate the use of xmlCreatePushParserCtxt() and + * xmlParseChunk() to read an XML file progressively + * into a tree and and xmlFreeDoc() to free the resulting tree + * usage: parse4 test3.xml + * test: parse4 test3.xml + * author: Daniel Veillard + * copy: see Copyright for the status of this software. + */ + +#include <stdio.h> +#include <libxml/parser.h> +#include <libxml/tree.h> + +static FILE *desc; + +/** + * readPacket: + * @mem: array to store the packet + * @size: the packet size + * + * read at most @size bytes from the document and store it in @mem + * + * Returns the number of bytes read + */ +static int +readPacket(char *mem, int size) { + int res; + + res = fread(mem, 1, size, desc); + return(res); +} + +/** + * example4Func: + * @filename: a filename or an URL + * + * Parse the resource and free the resulting tree + */ +static void +example4Func(const char *filename) { + xmlParserCtxtPtr ctxt; + char chars[4]; + int size = 4; + xmlDocPtr doc; /* the resulting document tree */ + int res; + + /* + * Read a few first byte to check the input used for the + * encoding detection at the parser level. + */ + res = readPacket(chars, 4); + if (res <= 0) { + fprintf(stderr, "Failed to parse %s\n", filename); + return; + } + + /* + * Create a progressive parsing context, the 2 first arguments + * are not used since we want to build a tree and not use a SAX + * parsing interface. We also pass the first bytes of the document + * to allow encoding detection when creating the parser but this + * is optional. + */ + ctxt = xmlCreatePushParserCtxt(NULL, NULL, + chars, res, filename); + if (ctxt == NULL) { + fprintf(stderr, "Failed to create parser context !\n"); + return; + } + + /* + * loop on the input getting the document data, of course 4 bytes + * at a time is not realistic but allows to verify testing on small + * documents. + */ + while ((res = readPacket(chars, 4)) > 0) { + xmlParseChunk(ctxt, chars, res, 0); + } + + /* + * there is no more input, indicate the parsing is finished. + */ + xmlParseChunk(ctxt, chars, 0, 1); + + /* + * collect the document back and if it was wellformed + * and destroy the parser context. + */ + doc = ctxt->myDoc; + res = ctxt->wellFormed; + xmlFreeParserCtxt(ctxt); + + if (!res) { + fprintf(stderr, "Failed to parse %s\n", filename); + } + + /* + * since we don't use the document, destroy it now. + */ + xmlFreeDoc(doc); +} + +int main(int argc, char **argv) { + if (argc != 2) + return(1); + + /* + * this initialize the library and check potential ABI mismatches + * between the version it was compiled for and the actual shared + * library used. + */ + LIBXML_TEST_VERSION + + /* + * simulate a progressive parsing using the input file. + */ + desc = fopen(argv[1], "rb"); + if (desc != NULL) { + example4Func(argv[1]); + fclose(desc); + } else { + fprintf(stderr, "Failed to parse %s\n", argv[1]); + } + + /* + * Cleanup function for the XML library. + */ + xmlCleanupParser(); + /* + * this is to debug memory for regression tests + */ + xmlMemoryDump(); + return(0); +} |