Linux环境下C使用的XML解析库:libxml2

D. XPath例程代码
#include
#include
xmlDocPtr
getdoc (char *docname) {
xmlDocPtr doc;
doc = xmlParseFile(docname);
if (doc == NULL ) {
fprintf(stderr,"Document not parsed successfully. \n");
return NULL;
}
return doc;
}
xmlXPathObjectPtr
getnodeset (xmlDocPtr doc, xmlChar *xpath){
xmlXPathContextPtr context;
xmlXPathObjectPtr result;
context = xmlXPathNewContext(doc);
result = xmlXPathEval;
if(xmlXPathNodeSetIsEmpty(result->nodesetval)){
printf("No result\n");
return NULL;
}
xmlXPathFreeContext(context);
return result;
}
int
main(int argc, char **argv) {
char *docname;
xmlDocPtr doc;
xmlChar *xpath = ("//keyword");
xmlNodeSetPtr nodeset;
xmlXPathObjectPtr result;
int i;
xmlChar *keyword;
if (argc <= 1) {
printf("Usage: %s docname\n", argv[0]);
return(0);
}
docname = argv[1];
doc = getdoc(docname);
result = getnodeset (doc, xpath);
if (result) {
nodeset = result->nodesetval;
for (i=0; i < nodeset->nodeNr; i++) {
keyword = xmlNodeListGetString(doc, nodeset->nodeTab[i]->printf
("keyword: %s\n", keyword);
xmlFree(keyword);
}
xmlXPathFreeObject (result);
}
xmlFreeDoc(doc);
xmlCleanupParser();
return (1);
}
E. 添加keyword例程代码
#include
#include
#include
#include
#include
void
parseStory (xmlDocPtr doc, xmlNodePtr cur, char *keyword) {
xmlNewTextChild (cur, NULL, "keyword", keyword);
return;
}
xmlDocPtr
parseDoc(char *docname, char *keyword) {
xmlDocPtr doc;
xmlNodePtr cur;
doc = xmlParseFile(docname);
if (doc == NULL ) {
fprintf(stderr,"Document not parsed successfully. \n");
return (NULL);
}
cur = xmlDocGetRootElement(doc);
if (cur == NULL) {
fprintf(stderr,"empty document\n");
xmlFreeDoc(doc);
return (NULL);
}
if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
fprintf(stderr,"document of the wrong type, root node != story");
xmlFreeDoc(doc);
return (NULL);
}
cur = cur->xmlChildrenNode;
while (cur != NULL) {
if ((!xmlStrcmp(cur->name, (const xmlChar *)"storyinfo"))){
parseStory (doc, cur, keyword);
}
cur = cur->next;
}
return(doc);
}
int
main(int argc, char **argv) {
char *docname;
char *keyword;
xmlDocPtr doc;
if (argc <= 2) {
printf("Usage: %s docname, keyword\n", argv[0]);
return(0);
}
docname = argv[1];
keyword = argv[2];
doc = parseDoc (docname, keyword);
if (doc != NULL) {
xmlSaveFormatFile (docname, doc, 0);
xmlFreeDoc(doc);
}
return (1);
}
F. 添加属性例程代码
#include
#include
#include
#include
#include
xmlDocPtr
parseDoc(char *docname, char *uri) {
xmlDocPtr doc;
xmlNodePtr cur;
xmlNodePtr newnode;
xmlAttrPtr newattr;
doc = xmlParseFile(docname);
if (doc == NULL ) {
fprintf(stderr,"Document not parsed successfully. \n");
return (NULL);
}
cur = xmlDocGetRootElement(doc);
if (cur == NULL) {
fprintf(stderr,"empty document\n");
xmlFreeDoc(doc);
return (NULL);
}
if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
fprintf(stderr,"document of the wrong type, root node != story");
xmlFreeDoc(doc);
return (NULL);
}
newnode = xmlNewTextChild (cur, NULL, "reference", NULL);
newattr = xmlNewProp (newnode, "uri", uri);
return(doc);
}
int
main(int argc, char **argv) {
char *docname;
char *uri;
xmlDocPtr doc;
if (argc <= 2) {
printf("Usage: %s docname, uri\n", argv[0]);
return(0);
}
docname = argv[1];
uri = argv[2];
doc = parseDoc (docname, uri);
if (doc != NULL) {
xmlSaveFormatFile (docname, doc, 1);
xmlFreeDoc(doc);
}
return (1);
}
G. 取得属性值例程代码
#include
#include
#include
#include
#include
void
getReference (xmlDocPtr doc, xmlNodePtr cur) {
xmlChar *uri;
cur = cur->xmlChildrenNode;
while (cur != NULL) {
if ((!xmlStrcmp(cur->name, (const xmlChar *)"reference"))) {
uri = xmlGetProp(cur, "uri");
printf("uri: %s\n", uri);
xmlFree(uri);
}
cur = cur->next;
}
return;
}
void
parseDoc(char *docname) {
xmlDocPtr doc;
xmlNodePtr cur;
doc = xmlParseFile(docname);
if (doc == NULL ) {
fprintf(stderr,"Document not parsed successfully. \n");
return;
}
cur = xmlDocGetRootElement(doc);
if (cur == NULL) {
fprintf(stderr,"empty document\n");
xmlFreeDoc(doc);
return;
}
if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
fprintf(stderr,"document of the wrong type, root node != story");
xmlFreeDoc(doc);
return;
}
getReference (doc, cur);
xmlFreeDoc(doc);
return;
}
int
main(int argc, char **argv) {
char *docname;
if (argc <= 1) {
printf("Usage: %s docname\n", argv[0]);
return(0);
}
docname = argv[1];
parseDoc (docname);
return (1);
}
H. 编码转换例程代码
#include
#include
unsigned char*
convert (unsigned char *in, char *encoding)
{
unsigned char *out;
int ret,size,out_size,temp;
xmlCharEncodingHandlerPtr handler;
size = (int)strlen(in)+1;
out_size = size*2-1;
out = malloc((size_t)out_size);
if (out) {
handler = xmlFindCharEncodingHandler(encoding);
if (!handler) {
free(out);
out = NULL;
}
}
if (out) {
temp=size-1;
ret = handler->input(out, &out_size, in, &temp);
if (ret || temp-size+1) {
if (ret) {
printf("conversion wasn't successful.\n");
} else {
printf("conversion wasn't successful. converted: }
free(out);
out = NULL;
} else {
out = realloc(out,out_size+1);
out[out_size]=0; /*null terminating out*/
}
} else {
printf("no mem\n");
}
return (out);
}
int
main(int argc, char **argv) {
unsigned char *content, *out;
xmlDocPtr doc;
xmlNodePtr rootnode;
char *encoding = "ISO-8859-1";
if (argc <= 1) {
printf("Usage: %s content\n", argv[0]);
return(0);
}
content = argv[1];
out = convert(content, encoding);
doc = xmlNewDoc ("1.0");
rootnode = xmlNewDocNode(doc, NULL, (const xmlChar*)"root", out);
xmlDocSetRootElement(doc, rootnode);
xmlSaveFormatFileEnc("-", doc, encoding, 1);
return (1);
}
…………………………………………………………………………………………
char *convert(char *instr,char *encoding)
{
xmlCharEncodingHandlerPtr handler;
xmlBufferPtr in,out;
handler = xmlFindCharEncodingHandler(encoding);
if(NULL != handler)
{
in = xmlBufferCreate();
xmlBufferWriteChar(in,instr);
out = xmlBufferCreate();
if(xmlCharEncInFunc(handler, out, in)
{
xmlBufferFree(in);
xmlBufferFree(out);
return NULL;
}
else
{
xmlBufferFree(in);
return (char *)out-〉content;
}
}
}