release/src/router/libxml2/doc/tutorial/apd.html

   1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>D. Code for XPath Example</title><meta name="generator" content="DocBook XSL Stylesheets V1.61.2"><link rel="home" href="index.html" title="Libxml Tutorial"><link rel="up" href="index.html" title="Libxml Tutorial"><link rel="previous" href="apc.html" title="C. Code for Keyword Example"><link rel="next" href="ape.html" title="E. Code for Add Keyword Example"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">D. Code for XPath Example</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apc.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ape.html">Next</a></td></tr></table><hr></div><div class="appendix" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="xpathappendix"></a>D. Code for XPath Example</h2></div></div><div></div></div><p>
   2       </p><pre class="programlisting">
   3 #include &lt;libxml/parser.h&gt;
   4 #include &lt;libxml/xpath.h&gt;
   5
   6 xmlDocPtr
   7 getdoc (char *docname) {
   8         xmlDocPtr doc;
   9         doc = xmlParseFile(docname);
  10
  11         if (doc == NULL ) {
  12                 fprintf(stderr,"Document not parsed successfully. \n");
  13                 return NULL;
  14         }
  15
  16         return doc;
  17 }
  18
  19 xmlXPathObjectPtr
  20 getnodeset (xmlDocPtr doc, xmlChar *xpath){
  21
  22         xmlXPathContextPtr context;
  23         xmlXPathObjectPtr result;
  24
  25         context = xmlXPathNewContext(doc);
  26         if (context == NULL) {
  27                 printf("Error in xmlXPathNewContext\n");
  28                 return NULL;
  29         }
  30         result = xmlXPathEvalExpression(xpath, context);
  31         xmlXPathFreeContext(context);
  32         if (result == NULL) {
  33                 printf("Error in xmlXPathEvalExpression\n");
  34                 return NULL;
  35         }
  36         if(xmlXPathNodeSetIsEmpty(result-&gt;nodesetval)){
  37                 xmlXPathFreeObject(result);
  38                 printf("No result\n");
  39                 return NULL;
  40         }
  41         return result;
  42 }
  43 int
  44 main(int argc, char **argv) {
  45
  46         char *docname;
  47         xmlDocPtr doc;
  48         xmlChar *xpath = (xmlChar*) "//keyword";
  49         xmlNodeSetPtr nodeset;
  50         xmlXPathObjectPtr result;
  51         int i;
  52         xmlChar *keyword;
  53
  54         if (argc &lt;= 1) {
  55                 printf("Usage: %s docname\n", argv[0]);
  56                 return(0);
  57         }
  58
  59         docname = argv[1];
  60         doc = getdoc(docname);
  61         result = getnodeset (doc, xpath);
  62         if (result) {
  63                 nodeset = result-&gt;nodesetval;
  64                 for (i=0; i &lt; nodeset-&gt;nodeNr; i++) {
  65                         keyword = xmlNodeListGetString(doc, nodeset-&gt;nodeTab[i]-&gt;xmlChildrenNode, 1);
  66                 printf("keyword: %s\n", keyword);
  67                 xmlFree(keyword);
  68                 }
  69                 xmlXPathFreeObject (result);
  70         }
  71         xmlFreeDoc(doc);
  72         xmlCleanupParser();
  73         return (1);
  74 }
  75 </pre><p>
  76     </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apc.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ape.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">C. Code for Keyword Example </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> E. Code for Add Keyword Example</td></tr></table></div></body></html>