| 1 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Parsing the file</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="ar01s02.html" title="Data Types"><link rel="next" href="ar01s04.html" title="Retrieving Element Content"></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">Parsing the file</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ar01s02.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="ar01s04.html">Next</a></td></tr></table><hr></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="xmltutorialparsing"></a>Parsing the file</h2></div></div><div></div></div><p><a class="indexterm" name="fileparsing"></a>
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| 2 | Parsing the file requires only the name of the file and a single
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| 3 | function call, plus error checking. Full code: <a href="apc.html" title="C. Code for Keyword Example">Appendix C, <i>Code for Keyword Example</i></a></p><p>
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| 4 | </p><pre class="programlisting">
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| 5 | <a name="declaredoc"></a><img src="images/callouts/1.png" alt="1" border="0"> xmlDocPtr doc;
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| 6 | <a name="declarenode"></a><img src="images/callouts/2.png" alt="2" border="0"> xmlNodePtr cur;
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| 7 |
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| 8 | <a name="parsefile"></a><img src="images/callouts/3.png" alt="3" border="0"> doc = xmlParseFile(docname);
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| 9 |
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| 10 | <a name="checkparseerror"></a><img src="images/callouts/4.png" alt="4" border="0"> if (doc == NULL ) {
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| 11 | fprintf(stderr,"Document not parsed successfully. \n");
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| 12 | return;
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| 13 | }
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| 14 |
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| 15 | <a name="getrootelement"></a><img src="images/callouts/5.png" alt="5" border="0"> cur = xmlDocGetRootElement(doc);
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| 16 |
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| 17 | <a name="checkemptyerror"></a><img src="images/callouts/6.png" alt="6" border="0"> if (cur == NULL) {
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| 18 | fprintf(stderr,"empty document\n");
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| 19 | xmlFreeDoc(doc);
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| 20 | return;
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| 21 | }
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| 22 |
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| 23 | <a name="checkroottype"></a><img src="images/callouts/7.png" alt="7" border="0"> if (xmlStrcmp(cur->name, (const xmlChar *) "story")) {
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| 24 | fprintf(stderr,"document of the wrong type, root node != story");
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| 25 | xmlFreeDoc(doc);
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| 26 | return;
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| 27 | }
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| 28 |
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| 29 | </pre><p>
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| 30 | </p><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><a href="#declaredoc"><img src="images/callouts/1.png" alt="1" border="0"></a> </td><td valign="top" align="left"><p>Declare the pointer that will point to your parsed document.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#declarenode"><img src="images/callouts/2.png" alt="2" border="0"></a> </td><td valign="top" align="left"><p>Declare a node pointer (you'll need this in order to
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| 31 | interact with individual nodes).</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkparseerror"><img src="images/callouts/4.png" alt="4" border="0"></a> </td><td valign="top" align="left"><p>Check to see that the document was successfully parsed. If it
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| 32 | was not, <span class="application">libxml</span> will at this point
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| 33 | register an error and stop.
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| 34 | </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left">Note</th></tr><tr><td colspan="2" align="left" valign="top"><p><a class="indexterm" name="id2525337"></a>
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| 35 | One common example of an error at this point is improper
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| 36 | handling of encoding. The <span class="acronym">XML</span> standard requires
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| 37 | documents stored with an encoding other than UTF-8 or UTF-16 to
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| 38 | contain an explicit declaration of their encoding. If the
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| 39 | declaration is there, <span class="application">libxml</span> will
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| 40 | automatically perform the necessary conversion to UTF-8 for
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| 41 | you. More information on <span class="acronym">XML's</span> encoding
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| 42 | requirements is contained in the <a href="http://www.w3.org/TR/REC-xml#charencoding" target="_top">standard</a>.</p></td></tr></table></div><p>
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| 43 | </p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#getrootelement"><img src="images/callouts/5.png" alt="5" border="0"></a> </td><td valign="top" align="left"><p>Retrieve the document's root element.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkemptyerror"><img src="images/callouts/6.png" alt="6" border="0"></a> </td><td valign="top" align="left"><p>Check to make sure the document actually contains something.</p></td></tr><tr><td width="5%" valign="top" align="left"><a href="#checkroottype"><img src="images/callouts/7.png" alt="7" border="0"></a> </td><td valign="top" align="left"><p>In our case, we need to make sure the document is the right
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| 44 | type. "story" is the root type of the documents used in this
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| 45 | tutorial.</p></td></tr></table></div><p>
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| 46 | <a class="indexterm" name="id2525415"></a>
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| 47 | </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s02.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="ar01s04.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Data Types </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Retrieving Element Content</td></tr></table></div></body></html>
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