doc = xmlParseFile(pXMLFileName);
       if (doc == NULL ) 
       {
             fprintf(stderr,"XMLParser:Document not parsed successfully. \n");
             retval = -1;
             goto ERROR_RET;
       }
       cur = xmlDocGetRootElement(doc);         // 会得到NodeRoot 节点.
       if (cur == NULL) 
       {
             fprintf(stderr,"XMLParser:Empty document.\n");
             retval = -2;
             goto ERROR_RET;
       }

       //     ...  do something
       parsexml(doc,cur);         // 定义见下面.

    ERROR_RET:
       if(doc != NULL)
           xmlFreeDoc(doc);
       return retval;
    }
   其中,:
   结构xmlNodePtr 定义如下(libxml/tree.h):
    typedef struct _xmlNode xmlNode;
    typedef xmlNode *xmlNodePtr;
    struct _xmlNode {
    void           *_private; /* application data */
    xmlElementType   type; /* type number, must be second ! */
    const xmlChar   *name;      /* the name of the node, or the entity */ 
    struct _xmlNode *children; /* parent->childs link */
    struct _xmlNode *last; /* last child link */
    struct _xmlNode *parent; /* child->parent link */
    struct _xmlNode *next; /* next sibling link  */
    struct _xmlNode *prev; /* previous sibling link  */
    struct _xmlDoc  *doc; /* the containing document */

    /* End of common part */
    xmlNs           *ns;        /* pointer to the associated namespace */
    xmlChar         *content;   /* the content */
    struct _xmlAttr *properties;/* properties list */
    xmlNs           *nsDef;     /* namespace definitions on this node */
    void            *psvi; /* for type/PSVI informations */
    unsigned short   line; /* line number */
    unsigned short   extra; /* extra data for XPath/XSLT */
    };
    我们可以使用节点结构中的指针成员来遍历xml树中的各个节点.
    我一般使用递归的方式遍历xml树:
   int parsexml(xmlDocPtr doc, xmlNodePtr cur)
   {
       while (cur != NULL)
       {
          // do something about every node
           printf("name: %s\n",cur->name);
          {
                //  for example,we get the "ver" attribute of every node
                xmlChar *uri = NULL; 
                uri = xmlGetProp(cur,(const xmlChar *) "ver"); 
                if(uri != NULL)
                {
                  printf("ver: %s\n", uri);
                   xmlFree(uri);
                }
                ;   // ... others

             }
    
             parsexml(doc,cur->xmlChildrenNode);
             cur = cur->next;
          }
          return 0;
      }
     对于我们已经获取的结点,我们可以使用以下函数获取其各项属性各项属性:
      XMLPUBFUN xmlChar * XMLCALL xmlGetProp  (xmlNodePtr node,const xmlChar *name); (libxml/tree.h)
      获得该节点的某项属性,其中,属性名称使用 第二个参数name指定,第一个参数需要传入结点指针.
      属性的值通过函数返回传出,返回类型是 xmlChar,这里注意,返回的地址是指向堆的,这意味着你需要
      在使用完毕后,手动释放这块内存.这里使用xmlfree函数,并将指针传入即可.
      
      
      更多函数参见 libxml/tree.h

      最后,你需要调用xmlFreeDoc函数进行必要的释放工作.
      
      完整代码:
      http://www.blogjava.net/Files/lixf/testlibxml.rar