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 <h1>The XML C library for Gnome</h1>
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 <p>Table of Contents:</p>
 <ul>
 <li><a href="FAQ.html#License">License(s)</a></li>
   <li><a href="FAQ.html#Installati">Installation</a></li>
   <li><a href="FAQ.html#Compilatio">Compilation</a></li>
   <li><a href="FAQ.html#Developer">Developer corner</a></li>
 </ul>
 <h3>
 <a name="License">License</a>(s)</h3>
 <ol>
 <li>
 <em>Licensing Terms for libxml</em>
     <p>libxml is released under the <a href="http://www.opensource.org/licenses/mit-license.html">MIT
     License</a>; see the file Copyright in the distribution for the precise
     wording</p>
   </li>
   <li>
 <em>Can I embed libxml in a proprietary application ?</em>
     <p>Yes. The MIT License allows you to keep proprietary the changes you
     made to libxml, but it would be graceful to send-back bug fixes and
     improvements as patches for possible incorporation in the main
     development tree.</p>
   </li>
 </ol>
 <h3><a name="Installati">Installation</a></h3>
 <ol>
 <li>Unless you are forced to because your application links with a Gnome
     library requiring it,  <strong><span style="background-color: #FF0000">Do
     Not Use libxml1</span></strong>, use libxml2</li>
   <li>
 <em>Where can I get libxml</em> ?
     <p>The original distribution comes from <a href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">gnome.org</a>
 </p>
     <p>Most Linux and BSD distributions include libxml, this is probably the
     safer way for end-users to use libxml.</p>
     <p>David Doolin provides precompiled Windows versions at <a href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/%20%20%20%20%20%20%20%20%20">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a>
 </p>
   </li>
   <li>
 <em>I see libxml and libxml2 releases, which one should I install ?</em>
     <ul>
 <li>If you are not constrained by backward compatibility issues with
         existing applications, install libxml2 only</li>
       <li>If you are not doing development, you can safely install both.
         Usually the packages <a href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
         compatible (this is not the case for development packages).</li>
       <li>If you are a developer and your system provides separate packaging
         for shared libraries and the development components, it is possible
         to install libxml and libxml2, and also <a href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
         and <a href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
         too for libxml2 &gt;= 2.3.0</li>
       <li>If you are developing a new application, please develop against
         libxml2(-devel)</li>
     </ul>
 </li>
   <li>
 <em>I can't install the libxml package, it conflicts with libxml0</em>
     <p>You probably have an old libxml0 package used to provide the shared
     library for libxml.so.0, you can probably safely remove it. The libxml
     packages provided on <a href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
     libxml.so.0</p>
   </li>
   <li>
 <em>I can't install the libxml(2) RPM package due to failed
     dependencies</em>
     <p>The most generic solution is to re-fetch the latest src.rpm , and
     rebuild it locally with</p>
     <p>
 <code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
     <p>If everything goes well it will generate two binary rpm packages (one
     providing the shared libs and xmllint, and the other one, the -devel
     package, providing includes, static libraries and scripts needed to build
     applications with libxml(2)) that you can install locally.</p>
   </li>
 </ol>
 <h3><a name="Compilatio">Compilation</a></h3>
 <ol>
 <li>
 <em>What is the process to compile libxml ?</em>
     <p>As most UNIX libraries libxml follows the &quot;standard&quot;:</p>
     <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
     <p><code>cd libxml-xxxx</code></p>
     <p><code>./configure --help</code></p>
     <p>to see the options, then the compilation/installation proper</p>
     <p><code>./configure [possible options]</code></p>
     <p><code>make</code></p>
     <p><code>make install</code></p>
     <p>At that point you may have to rerun ldconfig or a similar utility to
     update your list of installed shared libs.</p>
   </li>
   <li>
 <em>What other libraries are needed to compile/install libxml ?</em>
     <p>Libxml does not require any other library, the normal C ANSI API
     should be sufficient (please report any violation to this rule you may
     find).</p>
     <p>However if found at configuration time libxml will detect and use the
     following libs:</p>
     <ul>
 <li>
 <a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
         highly portable and available widely compression library.</li>
       <li>iconv: a powerful character encoding conversion library. It is
         included by default in recent glibc libraries, so it doesn't need to
         be installed specifically on Linux. It now seems a <a href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
         of the official UNIX</a> specification. Here is one <a href="http://www.gnu.org/software/libiconv/">implementation of the
         library</a> which source can be found <a href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
     </ul>
 </li>
   <li>
 <em>Make check fails on some platforms</em>
     <p>Sometimes the regression tests' results don't completely match the
     value produced by the parser, and the makefile uses diff to print the
     delta. On some platforms the diff return breaks the compilation process;
     if the diff is small this is probably not a serious problem.</p>
     <p>Sometimes (especially on Solaris) make checks fail due to limitations
     in make. Try using GNU-make instead.</p>
   </li>
   <li>
 <em>I use the CVS version and there is no configure script</em>
     <p>The configure script (and other Makefiles) are generated. Use the
     autogen.sh script to regenerate the configure script and Makefiles,
     like:</p>
     <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
   </li>
   <li>
 <em>I have troubles when running make tests with gcc-3.0</em>
     <p>It seems the initial release of gcc-3.0 has a problem with the
     optimizer which miscompiles the URI module. Please use another
     compiler.</p>
   </li>
 </ol>
 <h3>
 <a name="Developer">Developer</a> corner</h3>
 <ol>
 <li>
 <em>xmlDocDump() generates output on one line.</em>
     <p>Libxml will not <strong>invent</strong> spaces in the content of a
     document since <strong>all spaces in the content of a document are
     significant</strong>. If you build a tree from the API and want
     indentation:</p>
     <ol>
 <li>the correct way is to generate those yourself too.</li>
       <li>the dangerous way is to ask libxml to add those blanks to your
         content <strong>modifying the content of your document in the
         process</strong>. The result may not be what you expect. There is
         <strong>NO</strong> way to guarantee that such a modification won't
         affect other parts of the content of your document. See <a href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
         ()</a> and <a href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
         ()</a>
 </li>
     </ol>
 </li>
   <li>Extra nodes in the document:
     <p><em>For a XML file as below:</em></p>
     <pre>&lt;?xml version=&quot;1.0&quot;?&gt;
 &lt;PLAN xmlns=&quot;http://www.argus.ca/autotest/1.0/&quot;&gt;
 &lt;NODE CommFlag=&quot;0&quot;/&gt;
 &lt;NODE CommFlag=&quot;1&quot;/&gt;
 &lt;/PLAN&gt;</pre>
     <p><em>after parsing it with the function
     pxmlDoc=xmlParseFile(...);</em></p>
     <p><em>I want to the get the content of the first node (node with the
     CommFlag=&quot;0&quot;)</em></p>
     <p><em>so I did it as following;</em></p>
     <pre>xmlNodePtr pnode;
 pnode=pxmlDoc-&gt;children-&gt;children;</pre>
     <p><em>but it does not work. If I change it to</em></p>
     <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
     <p><em>then it works.  Can someone explain it to me.</em></p>
     <p></p>
     <p>In XML all characters in the content of the document are significant
     <strong>including blanks and formatting line breaks</strong>.</p>
     <p>The extra nodes you are wondering about are just that, text nodes with
     the formatting spaces which are part of the document but that people tend
     to forget. There is a function <a href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
     ()</a>  to remove those at parse time, but that's an heuristic, and its
     use should be limited to cases where you are certain there is no
     mixed-content in the document.</p>
   </li>
   <li>
 <em>I get compilation errors of existing code like when accessing
     <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
     <p>You are compiling code developed for libxml version 1 and using a
     libxml2 development environment. Either switch back to libxml v1 devel or
     even better fix the code to compile with libxml2 (or both) by <a href="upgrade.html">following the instructions</a>.</p>
   </li>
   <li>
 <em>I get compilation errors about non existing
     <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
     fields.</em>
     <p>The source code you are using has been <a href="upgrade.html">upgraded</a> to be able to compile with both libxml
     and libxml2, but you need to install a more recent version:
     libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
   </li>
   <li>
 <em>XPath implementation looks seriously broken</em>
     <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
     a recent version, there are no known bugs in the current version.</p>
   </li>
   <li>
 <em>The example provided in the web page does not compile.</em>
     <p>It's hard to maintain the documentation in sync with the code
     &lt;grin/&gt; ...</p>
     <p>Check the previous points 1/ and 2/ raised before, and please send
     patches.</p>
   </li>
   <li>
 <em>Where can I get more examples and information than privoded on the
     web page?</em>
     <p>Ideally a libxml book would be nice. I have no such plan ... But you
     can:</p>
     <ul>
 <li>check more deeply the <a href="html/libxml-lib.html">existing
         generated doc</a>
 </li>
       <li>look for examples of use for libxml function using the Gnome code.
         For example the following will query the full Gnome CVS base for the
         use of the <strong>xmlAddChild()</strong> function:
         <p><a href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
         <p>This may be slow, a large hardware donation to the gnome project
         could cure this :-)</p>
       </li>
       <li>
 <a href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&amp;dir=gnome-xml">Browse
         the libxml source</a> , I try to write code as clean and documented
         as possible, so looking at it may be helpful. In particular the code
         of xmllint.c and of the various testXXX.c test programs should
         provide good examples of how to do things with the library.</li>
     </ul>
 </li>
   <li>What about C++ ?
     <p>libxml is written in pure C in order to allow easy reuse on a number
     of platforms, including embedded systems. I don't intend to convert to
     C++.</p>
     <p>There are however a few C++ wrappers which may fulfill your needs:</p>
     <ul>
 <li>by Ari Johnson &lt;ari@btigate.com&gt;:
         <p>Website: <a href="http://lusis.org/~ari/xml%2B%2B/">http://lusis.org/~ari/xml++/</a>
 </p>
         <p>Download: <a href="http://lusis.org/~ari/xml%2B%2B/libxml%2B%2B.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a>
 </p>
       </li>
       <li>by Peter Jones &lt;pjones@pmade.org&gt;
         <p>Website: <a href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a>
 </p>
       </li>
     </ul>
 </li>
   <li>How to validate a document a posteriori ?
     <p>It is possible to validate documents which had not been validated at
     initial parsing time or documents which have been built from scratch
     using the API. Use the <a href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
     function. It is also possible to simply add a DTD to an existing
     document:</p>
     <pre>xmlDocPtr doc; /* your existing document */
 xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */

         dtd-&gt;name = xmlStrDup((xmlChar*)&quot;root_name&quot;); /* use the given root */

         doc-&gt;intSubset = dtd;
         if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
         else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
           </pre>
   </li>
   <li>So what is this funky &quot;xmlChar&quot; used all the time?
     <p>It is a null terminated sequence of utf-8 characters. And only utf-8!
     You need to convert strings encoded in different ways to utf-8 before
     passing them to the API.  This can be accomplished with the iconv library
     for instance.</p>
   </li>
   <li>etc ...</li>
 </ol>
 <p></p>
 <p><a href="bugs.html">Daniel Veillard</a></p>
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	<li><a href="entities.html">Entities or no entities</a></li>
	<li><a href="namespaces.html">Namespaces</a></li>
	<li><a href="upgrade.html">Upgrading 1.x code</a></li>
	<li><a href="threads.html">Thread safety</a></li>
	<li><a href="DOM.html">DOM Principles</a></li>
	<li><a href="example.html">A real example</a></li>
	<li><a href="contribs.html">Contributions</a></li>
	<li><a href="xmlreader.html">The Reader Interface</a></li>
	<li><a href="tutorial/index.html">Tutorial</a></li>
	<li><a href="guidelines.html">XML Guidelines</a></li>
	<li>
	<a href="xml.html">flat page</a>, <a href="site.xsl">stylesheet</a>
	</li>
	</ul>
	</td></tr>
	</table>
	<table width="100%" border="0" cellspacing="1" cellpadding="3">
	<tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Related links</b></center></td></tr>
	<tr><td bgcolor="#fffacd"><ul>
	<li><a href="http://mail.gnome.org/archives/xml/">Mail archive</a></li>
	<li><a href="http://xmlsoft.org/XSLT/">XSLT libxslt</a></li>
	<li><a href="http://phd.cs.unibo.it/gdome2/">DOM gdome2</a></li>
	<li><a href="http://www.aleksey.com/xmlsec/">XML-DSig xmlsec</a></li>
	<li><a href="ftp://xmlsoft.org/">FTP</a></li>
	<li><a href="http://www.zlatkovic.com/projects/libxml/">Windows binaries</a></li>
	<li><a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
	<li><a href="http://www.zveno.com/open_source/libxml2xslt.html">MacOsX binaries</a></li>
	<li><a href="http://sourceforge.net/projects/libxml2-pas/">Pascal bindings</a></li>
	<li><a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml&product=libxml2">Bug Tracker</a></li>
	</ul></td></tr>
	</table>
	<table width="100%" border="0" cellspacing="1" cellpadding="3">
	<tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>API Indexes</b></center></td></tr>
	<tr><td bgcolor="#fffacd"><ul>
	<li><a href="APIchunk0.html">Alphabetic</a></li>
	<li><a href="APIconstructors.html">Constructors</a></li>
	<li><a href="APIfunctions.html">Functions/Types</a></li>
	<li><a href="APIfiles.html">Modules</a></li>
	<li><a href="APIsymbols.html">Symbols</a></li>
	</ul></td></tr>
	</table>
	</td></tr></table></td>
	<td valign="top" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%"><tr><td><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table border="0" cellpadding="3" cellspacing="1" width="100%"><tr><td bgcolor="#fffacd">
	<p>Table of Contents:</p>
	<ul>
	<li><a href="FAQ.html#License">License(s)</a></li>
	<li><a href="FAQ.html#Installati">Installation</a></li>
	<li><a href="FAQ.html#Compilatio">Compilation</a></li>
	<li><a href="FAQ.html#Developer">Developer corner</a></li>
	</ul>
	<h3>
	<a name="License">License</a>(s)</h3>
	<ol>
	<li>
	<em>Licensing Terms for libxml</em>
	<p>libxml is released under the <a href="http://www.opensource.org/licenses/mit-license.html">MIT
	License</a>; see the file Copyright in the distribution for the precise
	wording</p>
	</li>
	<li>
	<em>Can I embed libxml in a proprietary application ?</em>
	<p>Yes. The MIT License allows you to keep proprietary the changes you
	made to libxml, but it would be graceful to send-back bug fixes and
	improvements as patches for possible incorporation in the main
	development tree.</p>
	</li>
	</ol>
	<h3><a name="Installati">Installation</a></h3>
	<ol>
	<li>Unless you are forced to because your application links with a Gnome
	library requiring it, <strong><span style="background-color: #FF0000">Do
	Not Use libxml1</span></strong>, use libxml2</li>
	<li>
	<em>Where can I get libxml</em> ?
	<p>The original distribution comes from <a href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.5/">gnome.org</a>
	</p>
	<p>Most Linux and BSD distributions include libxml, this is probably the
	safer way for end-users to use libxml.</p>
	<p>David Doolin provides precompiled Windows versions at <a href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/%20%20%20%20%20%20%20%20%20">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a>
	</p>
	</li>
	<li>
	<em>I see libxml and libxml2 releases, which one should I install ?</em>
	<ul>
	<li>If you are not constrained by backward compatibility issues with
	existing applications, install libxml2 only</li>
	<li>If you are not doing development, you can safely install both.
	Usually the packages <a href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
	compatible (this is not the case for development packages).</li>
	<li>If you are a developer and your system provides separate packaging
	for shared libraries and the development components, it is possible
	to install libxml and libxml2, and also <a href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
	and <a href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
	too for libxml2 >= 2.3.0</li>
	<li>If you are developing a new application, please develop against
	libxml2(-devel)</li>
	</ul>
	</li>
	<li>
	<em>I can't install the libxml package, it conflicts with libxml0</em>
	<p>You probably have an old libxml0 package used to provide the shared
	library for libxml.so.0, you can probably safely remove it. The libxml
	packages provided on <a href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide
	libxml.so.0</p>
	</li>
	<li>
	<em>I can't install the libxml(2) RPM package due to failed
	dependencies</em>
	<p>The most generic solution is to re-fetch the latest src.rpm , and
	rebuild it locally with</p>
	<p>
	<code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
	<p>If everything goes well it will generate two binary rpm packages (one
	providing the shared libs and xmllint, and the other one, the -devel
	package, providing includes, static libraries and scripts needed to build
	applications with libxml(2)) that you can install locally.</p>
	</li>
	</ol>
	<h3><a name="Compilatio">Compilation</a></h3>
	<ol>
	<li>
	<em>What is the process to compile libxml ?</em>
	<p>As most UNIX libraries libxml follows the "standard":</p>
	<p><code>gunzip -c xxx.tar.gz \| tar xvf -</code></p>
	<p><code>cd libxml-xxxx</code></p>
	<p><code>./configure --help</code></p>
	<p>to see the options, then the compilation/installation proper</p>
	<p><code>./configure [possible options]</code></p>
	<p><code>make</code></p>
	<p><code>make install</code></p>
	<p>At that point you may have to rerun ldconfig or a similar utility to
	update your list of installed shared libs.</p>
	</li>
	<li>
	<em>What other libraries are needed to compile/install libxml ?</em>
	<p>Libxml does not require any other library, the normal C ANSI API
	should be sufficient (please report any violation to this rule you may
	find).</p>
	<p>However if found at configuration time libxml will detect and use the
	following libs:</p>
	<ul>
	<li>
	<a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
	highly portable and available widely compression library.</li>
	<li>iconv: a powerful character encoding conversion library. It is
	included by default in recent glibc libraries, so it doesn't need to
	be installed specifically on Linux. It now seems a <a href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
	of the official UNIX</a> specification. Here is one <a href="http://www.gnu.org/software/libiconv/">implementation of the
	library</a> which source can be found <a href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
	</ul>
	</li>
	<li>
	<em>Make check fails on some platforms</em>
	<p>Sometimes the regression tests' results don't completely match the
	value produced by the parser, and the makefile uses diff to print the
	delta. On some platforms the diff return breaks the compilation process;
	if the diff is small this is probably not a serious problem.</p>
	<p>Sometimes (especially on Solaris) make checks fail due to limitations
	in make. Try using GNU-make instead.</p>
	</li>
	<li>
	<em>I use the CVS version and there is no configure script</em>
	<p>The configure script (and other Makefiles) are generated. Use the
	autogen.sh script to regenerate the configure script and Makefiles,
	like:</p>
	<p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
	</li>
	<li>
	<em>I have troubles when running make tests with gcc-3.0</em>
	<p>It seems the initial release of gcc-3.0 has a problem with the
	optimizer which miscompiles the URI module. Please use another
	compiler.</p>
	</li>
	</ol>
	<h3>
	<a name="Developer">Developer</a> corner</h3>
	<ol>
	<li>
	<em>xmlDocDump() generates output on one line.</em>
	<p>Libxml will not <strong>invent</strong> spaces in the content of a
	document since <strong>all spaces in the content of a document are
	significant</strong>. If you build a tree from the API and want
	indentation:</p>
	<ol>
	<li>the correct way is to generate those yourself too.</li>
	<li>the dangerous way is to ask libxml to add those blanks to your
	content <strong>modifying the content of your document in the
	process</strong>. The result may not be what you expect. There is
	<strong>NO</strong> way to guarantee that such a modification won't
	affect other parts of the content of your document. See <a href="http://xmlsoft.org/html/libxml-parser.html#XMLKEEPBLANKSDEFAULT">xmlKeepBlanksDefault
	()</a> and <a href="http://xmlsoft.org/html/libxml-tree.html#XMLSAVEFORMATFILE">xmlSaveFormatFile
	()</a>
	</li>
	</ol>
	</li>
	<li>Extra nodes in the document:
	<p><em>For a XML file as below:</em></p>
	<pre><?xml version="1.0"?>
	<PLAN xmlns="http://www.argus.ca/autotest/1.0/">
	<NODE CommFlag="0"/>
	<NODE CommFlag="1"/>
	</PLAN></pre>
	<p><em>after parsing it with the function
	pxmlDoc=xmlParseFile(...);</em></p>
	<p><em>I want to the get the content of the first node (node with the
	CommFlag="0")</em></p>
	<p><em>so I did it as following;</em></p>
	<pre>xmlNodePtr pnode;
	pnode=pxmlDoc->children->children;</pre>
	<p><em>but it does not work. If I change it to</em></p>
	<pre>pnode=pxmlDoc->children->children->next;</pre>
	<p><em>then it works. Can someone explain it to me.</em></p>
	<p></p>
	<p>In XML all characters in the content of the document are significant
	<strong>including blanks and formatting line breaks</strong>.</p>
	<p>The extra nodes you are wondering about are just that, text nodes with
	the formatting spaces which are part of the document but that people tend
	to forget. There is a function <a href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
	()</a> to remove those at parse time, but that's an heuristic, and its
	use should be limited to cases where you are certain there is no
	mixed-content in the document.</p>
	</li>
	<li>
	<em>I get compilation errors of existing code like when accessing
	<strong>root</strong> or <strong>child fields</strong> of nodes.</em>
	<p>You are compiling code developed for libxml version 1 and using a
	libxml2 development environment. Either switch back to libxml v1 devel or
	even better fix the code to compile with libxml2 (or both) by <a href="upgrade.html">following the instructions</a>.</p>
	</li>
	<li>
	<em>I get compilation errors about non existing
	<strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
	fields.</em>
	<p>The source code you are using has been <a href="upgrade.html">upgraded</a> to be able to compile with both libxml
	and libxml2, but you need to install a more recent version:
	libxml(-devel) >= 1.8.8 or libxml2(-devel) >= 2.1.0</p>
	</li>
	<li>
	<em>XPath implementation looks seriously broken</em>
	<p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to
	a recent version, there are no known bugs in the current version.</p>
	</li>
	<li>
	<em>The example provided in the web page does not compile.</em>
	<p>It's hard to maintain the documentation in sync with the code
	<grin/> ...</p>
	<p>Check the previous points 1/ and 2/ raised before, and please send
	patches.</p>
	</li>
	<li>
	<em>Where can I get more examples and information than privoded on the
	web page?</em>
	<p>Ideally a libxml book would be nice. I have no such plan ... But you
	can:</p>
	<ul>
	<li>check more deeply the <a href="html/libxml-lib.html">existing
	generated doc</a>
	</li>
	<li>look for examples of use for libxml function using the Gnome code.
	For example the following will query the full Gnome CVS base for the
	use of the <strong>xmlAddChild()</strong> function:
	<p><a href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p>
	<p>This may be slow, a large hardware donation to the gnome project
	could cure this :-)</p>
	</li>
	<li>
	<a href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Browse
	the libxml source</a> , I try to write code as clean and documented
	as possible, so looking at it may be helpful. In particular the code
	of xmllint.c and of the various testXXX.c test programs should
	provide good examples of how to do things with the library.</li>
	</ul>
	</li>
	<li>What about C++ ?
	<p>libxml is written in pure C in order to allow easy reuse on a number
	of platforms, including embedded systems. I don't intend to convert to
	C++.</p>
	<p>There are however a few C++ wrappers which may fulfill your needs:</p>
	<ul>
	<li>by Ari Johnson <ari@btigate.com>:
	<p>Website: <a href="http://lusis.org/~ari/xml%2B%2B/">http://lusis.org/~ari/xml++/</a>
	</p>
	<p>Download: <a href="http://lusis.org/~ari/xml%2B%2B/libxml%2B%2B.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a>
	</p>
	</li>
	<li>by Peter Jones <pjones@pmade.org>
	<p>Website: <a href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a>
	</p>
	</li>
	</ul>
	</li>
	<li>How to validate a document a posteriori ?
	<p>It is possible to validate documents which had not been validated at
	initial parsing time or documents which have been built from scratch
	using the API. Use the <a href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a>
	function. It is also possible to simply add a DTD to an existing
	document:</p>
	<pre>xmlDocPtr doc; /* your existing document */
	xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */

	dtd->name = xmlStrDup((xmlChar)"root_name"); / use the given root */

	doc->intSubset = dtd;
	if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
	else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd);
	</pre>
	</li>
	<li>So what is this funky "xmlChar" used all the time?
	<p>It is a null terminated sequence of utf-8 characters. And only utf-8!
	You need to convert strings encoded in different ways to utf-8 before
	passing them to the API. This can be accomplished with the iconv library
	for instance.</p>
	</li>
	<li>etc ...</li>
	</ol>
	<p></p>
	<p><a href="bugs.html">Daniel Veillard</a></p>
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