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POlibxml2 error with namespaces and xpath
 

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  1. POlibxml2 error with namespaces and xpath
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    <p>I am pasting some code here that compiles with no warning using gcc file.c -lxml2, assuming that libxml2 is installed in your system. </p> <pre><code>#include &lt;libxml/parser.h&gt; #include &lt;libxml/xpath.h&gt; #include &lt;assert.h&gt; #include &lt;libxml/tree.h&gt; #include &lt;libxml/xpathInternals.h&gt; xmlDocPtr getdoc (char *docname) { xmlDocPtr doc; doc = xmlParseFile(docname); if (doc == NULL ) { fprintf(stderr,"Document not parsed successfully. \n"); return NULL; } return doc; } xmlXPathObjectPtr getnodeset (xmlDocPtr doc, xmlChar *xpath){ xmlXPathContextPtr context; xmlXPathObjectPtr result; context = xmlXPathNewContext(doc); if (context == NULL) { printf("Error in xmlXPathNewContext\n"); return NULL; } if(xmlXPathRegisterNs(context, BAD_CAST "new", BAD_CAST "http://www.example.com/new") != 0) { fprintf(stderr,"Error: unable to register NS with prefix"); return NULL; } result = xmlXPathEvalExpression(xpath, context); xmlXPathFreeContext(context); if (result == NULL) { printf("Error in xmlXPathEvalExpression\n"); return NULL; } if(xmlXPathNodeSetIsEmpty(result-&gt;nodesetval)){ xmlXPathFreeObject(result); printf("No result\n"); return NULL; } return result; } int main(int argc, char **argv) { char *docname; xmlDocPtr doc; xmlChar *xpath = (xmlChar*) "/new:book/section1"; xmlNodeSetPtr nodeset; xmlXPathObjectPtr result; int i; xmlChar *keyword; if (argc &lt;= 1) { printf("Usage: %s docname\n", argv[0]); return(0); } docname = argv[1]; doc = getdoc(docname); result = getnodeset (doc, xpath); if (result) { nodeset = result-&gt;nodesetval; for (i=0; i &lt; nodeset-&gt;nodeNr; i++) { keyword = xmlNodeListGetString(doc, nodeset-&gt;nodeTab[i]-&gt;xmlChildrenNode, 1); printf("keyword: %s\n", keyword); xmlFree(keyword); } xmlXPathFreeObject (result); } xmlFreeDoc(doc); xmlCleanupParser(); return (1); } </code></pre> <p>My problem is that I want to parse the following xml</p> <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt; &lt;book xmlns="http://www.example.com/new"&gt; &lt;section1&gt;Sec_1&lt;/section1&gt; &lt;section2&gt;Sec_2&lt;/section2&gt; &lt;/book&gt; </code></pre> <p>the book element defines a namespace inside that element. I want to print the value in the xpath /book/section1 and it returns NULL. When I am trying to return the element under a namespace I also get errors, ie /new:book/section1</p> <p>I assume that my code fails because I am not using correctly the namespace prefixes. I run out of time. Could you please help?</p>
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