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 <libxml/parser.h> 4 #include <libxml/xpath.h> 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->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 <= 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->nodesetval; 64 for (i=0; i < nodeset->nodeNr; i++) { 65 keyword = xmlNodeListGetString(doc, nodeset->nodeTab[i]->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> 77