Some uses of LIBXML2

0. LIBXML2 is a cross-platform C library for manipulating XML files. API Reference.

1. Structure:

1     /*Document Structure Body*/2typedef xmldoc *xmldocptr;3 4     /*node Structure Body*/5typedefstruct_xmlnode XmlNode;6typedef XmlNode *xmlnodeptr;7     struct_xmlnode {8         void*_private;/*Application Data*/9Xmlelementtype type;/*type number, must be second!*/Ten         ConstXmlchar *name;/*the name of the node, or the entity*/ One         struct_xmlnode *children;/*parent->childs Link*/ A         struct_xmlnode *last;/*Last Child link*/ -         struct_xmlnode *parent;/*child->parent Link*/ -         struct_xmlnode *next;/*Next Sibling link*/ the         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*/ AXmlNs *nsdef;/*namespace definitions on this node*/ at         void*PSVI;/*For TYPE/PSVI informations*/ -Unsigned ShortLine/* Line number*/ -Unsigned ShortExtra/*extra data for xpath/xslt*/ -     }; -  - Other APIs: inXmlchildelementcount/*gets the number of child nodes of a node*/ -     /*transcoding API*/ to#include"iconv.h" +     intIConvert (Const Char*from_code,Const Char*to_code,Const Char*from_str, size_t F_len,Char*to_str, size_t T_len) -     { the iconv_t cd; * size_t ret; $cd =Iconv_open (To_code, from_code);Panax Notoginseng         if(cd = = (iconv_t)-1 ) { -Perror ("Iconv Open error\n"); the             return-1; +         } ARET = Iconv (CD, &from_str, &f_len, &to_str, &T_len); the         if(ret = = (size_t)-1 ) +         { -Perror ("iconv error\n"); $ iconv_close (CD); $             return-1; -         } - iconv_close (CD); the         returnret; -}

2. READ:

1     Xmldocptr doc = xmlreadfile ("file.xml"0)2/     * or */ 3     Xmldocptr doc = xmlparsefile ("file.xml");

3. Traversal:

1     /*The order of preservation of the sibling nodes and the order of the files are not guaranteed to be consistent*/2     /*the internal byte encoding of the libxml is utf-8, so if the node content is GBK Chinese, it needs to be transcoded with Iconv .*/3     /*Root*/4Xmlnodeptr cur =Xmldocgetrootelement (DOC);5     /*Children & Sibling*/6Cur = cur->children;7      while(cur) {8         if(XMLSTRCMP (Cur->name, Bad_cast ("nodename")) ==0 ) {9             /*Read Property*/Ten             Char* P_value = Xmlgetprop (cur, bad_cast ("Propername")); One             /*Read Content*/ A             Char* N_value =xmlnodegetcontent (cur); -             /*convert encode if needed*/ -ret = IConvert ("Utf-8","GBK", N_value, Xmlstrlen (N_value), Outbuffer, Outlen); the             ... -             /*Free is needed*/ - Xmlfree (p_value); - Xmlfree (n_value); +         } -Cur = cur->Next; +     } AXmlfree (DOC);

4. Find:

1. If only one of the result items is found, the node can be found by self-traversal;
2. There are multiple nodes matching, can find the node set by xmlxpatheval*;

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Some uses of LIBXML2