libxml2读写

#include<libxml/parser.h>
#include<libxml/tree.h>

void writeXML(char* fileName)
{
    xmlDocPtr doc;
    xmlNodePtr rootNode;
    
    xmlNodePtr basicNode;
    xmlNodePtr nodeContents;
    
    xmlNodePtr sonNode;
    xmlNodePtr grandsonNode;
    
    //create document
    doc = xmlNewDoc(BAD_CAST XML_DEFAULT_VERSION);
    rootNode = xmlNewNode(NULL,BAD_CAST "rootNode");
    
    //set root node
    xmlDocSetRootElement(doc,rootNode);

    //add nodes
    xmlNewTextChild(rootNode, NULL, BAD_CAST "nodes", BAD_CAST "nodes1");
    xmlNewTextChild(rootNode, NULL, BAD_CAST "nodes", BAD_CAST "nodes2");
    xmlNewTextChild(rootNode, NULL, BAD_CAST "nodes", BAD_CAST "nodes3");
    
    //add a basic node which has attribute and contents
    basicNode = xmlNewNode(NULL,BAD_CAST "basicNode");
    nodeContents = xmlNewText(BAD_CAST "contents");
    xmlNewProp(basicNode,BAD_CAST "size",BAD_CAST "123");//add a attribute
    xmlAddChild(basicNode,nodeContents);//add contents to node
    xmlAddChild(rootNode,basicNode);//add node to root
    
    //nesting
    sonNode = xmlNewNode(NULL,BAD_CAST "son");
    grandsonNode = xmlNewNode(NULL,BAD_CAST "grandson");
    xmlAddChild(grandsonNode,xmlNewText(BAD_CAST "nesting node"));
    xmlAddChild(sonNode,grandsonNode);
    xmlAddChild(rootNode,sonNode);

	  //save file
    int save = xmlSaveFile(fileName,doc);
    if(save!=-1){
	    printf("write %d bytes\n",save);
    }
    
    //free memory
    xmlFreeDoc(doc);
    xmlCleanupParser();
}

void readXML(char* fileName)
{
		xmlDocPtr doc;
		xmlNodePtr node;
		xmlChar *key;
		doc = xmlReadFile(fileName,"UTF-8",XML_PARSE_RECOVER);
		if(doc == NULL){
			return;
		}
		node = xmlDocGetRootElement(doc);
		if(node == NULL){
			return;
		}
		if(!xmlStrcmp(node->name,BAD_CAST "root")){
			xmlFreeDoc(doc);
			return;
		}
		
		node = node->xmlChildrenNode;
		xmlNodePtr attrNode = node;
		printf("start reading...\n");
		while(node!=NULL){
			if(!xmlStrcmp(node->name,(const xmlChar*)"basicNode")){
				key = xmlNodeGetContent(node);//get the contents of the node
				printf("basicNode:%s\n",key);
				xmlFree(key);
			}
			if(xmlHasProp(node,BAD_CAST "size")){
				attrNode = node;//save node which has attribute-"size"
			}
			node = node->next;
		}
		// get attribute
		xmlAttrPtr attrPtr = attrNode->properties;
		while(attrPtr!=NULL){
			 if (!xmlStrcmp(attrPtr->name, BAD_CAST "size")){
	         xmlChar* attr = xmlGetProp(attrNode,BAD_CAST "size");
	         printf("sizeAttr=%s\n",attr);
	         xmlFree(attr);
	     }
	     attrPtr = attrPtr->next;
		}
		xmlFree(doc);
}

int main(){
    char *fileName = "Demo.xml";
    writeXML(fileName);
    readXML(fileName);
}

write 193 bytes
start reading...
basicNode:contents
sizeAttr=123