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diff --git a/doc/FAQ.html b/doc/FAQ.html new file mode 100644 index 0000000..472863f --- /dev/null +++ b/doc/FAQ.html @@ -0,0 +1,244 @@ +<?xml version="1.0" encoding="ISO-8859-1"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /><link rel="SHORTCUT ICON" href="/favicon.ico" /><style type="text/css"> +TD {font-family: Verdana,Arial,Helvetica} +BODY {font-family: Verdana,Arial,Helvetica; margin-top: 2em; margin-left: 0em; margin-right: 0em} +H1 {font-family: Verdana,Arial,Helvetica} +H2 {font-family: Verdana,Arial,Helvetica} +H3 {font-family: Verdana,Arial,Helvetica} +A:link, A:visited, A:active { text-decoration: underline } +</style><title>FAQ</title></head><body bgcolor="#8b7765" text="#000000" link="#000000" vlink="#000000"><table border="0" width="100%" cellpadding="5" cellspacing="0" align="center"><tr><td width="120"><a href="http://swpat.ffii.org/"><img src="epatents.png" alt="Action against software patents" /></a></td><td width="180"><a href="http://www.gnome.org/"><img src="gnome2.png" alt="Gnome2 Logo" /></a><a href="http://www.w3.org/Status"><img src="w3c.png" alt="W3C Logo" /></a><a href="http://www.redhat.com/"><img src="redhat.gif" alt="Red Hat Logo" /></a><div align="left"><a href="http://xmlsoft.org/"><img src="Libxml2-Logo-180x168.gif" alt="Made with Libxml2 Logo" /></a></div></td><td><table border="0" width="90%" cellpadding="2" cellspacing="0" align="center" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3" bgcolor="#fffacd"><tr><td align="center"><h1>The XML C parser and toolkit of Gnome</h1><h2>FAQ</h2></td></tr></table></td></tr></table></td></tr></table><table border="0" cellpadding="4" cellspacing="0" width="100%" align="center"><tr><td bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td valign="top" width="200" bgcolor="#8b7765"><table border="0" cellspacing="0" cellpadding="1" width="100%" bgcolor="#000000"><tr><td><table width="100%" border="0" cellspacing="1" cellpadding="3"><tr><td colspan="1" bgcolor="#eecfa1" align="center"><center><b>Main Menu</b></center></td></tr><tr><td bgcolor="#fffacd"><form action="search.php" enctype="application/x-www-form-urlencoded" method="get"><input name="query" type="text" size="20" value="" /><input name="submit" type="submit" value="Search ..." /></form><ul><li><a href="index.html">Home</a></li><li><a href="intro.html">Introduction</a></li><li><a href="FAQ.html">FAQ</a></li><li><a href="docs.html" style="font-weight:bold">Developer Menu</a></li><li><a href="bugs.html">Reporting bugs and getting help</a></li><li><a href="help.html">How to help</a></li><li><a href="downloads.html">Downloads</a></li><li><a href="news.html">News</a></li><li><a href="XMLinfo.html">XML</a></li><li><a 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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=libxml2">Bug Tracker</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" id="License">License</a>(s)</h3><ol><li><em>Licensing Terms for libxml</em> + <p>libxml2 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 libxml2 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" id="Installati">Installation</a></h3><ol><li><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/libxml2/2.6/">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/ ">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" id="Compilatio">Compilation</a></h3><ol><li><em>What is the process to compile libxml2 ?</em> + <p>As most UNIX libraries libxml2 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 libxml2 ?</em> + <p>Libxml2 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 libxml2 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" id="Developer">Developer</a> corner</h3><ol><li><em>Troubles compiling or linking programs using libxml2</em> + <p>Usually the problem comes from the fact that the compiler doesn't get + the right compilation or linking flags. There is a small shell script + <code>xml2-config</code> which is installed as part of libxml2 usual + install process which provides those flags. Use</p> + <p><code>xml2-config --cflags</code></p> + <p>to get the compilation flags and</p> + <p><code>xml2-config --libs</code></p> + <p>to get the linker flags. Usually this is done directly from the + Makefile as:</p> + <p><code>CFLAGS=`xml2-config --cflags`</code></p> + <p><code>LIBS=`xml2-config --libs`</code></p> + </li> + <li><em>xmlDocDump() generates output on one line.</em> + <p>Libxml2 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 libxml2 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 provided on the + web page?</em> + <p>Ideally a libxml2 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>have a look at <a href="examples/index.html">the set of + examples</a>.</li> + <li>look for examples of use for libxml2 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 libxml2 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>libxml2 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 is however a C++ wrapper which may fulfill your needs:</p> + <ul><li>by Ari Johnson <ari@btigate.com>: + <p>Website: <a href="http://libxmlplusplus.sourceforge.net/">http://libxmlplusplus.sourceforge.net/</a></p> + <p>Download: <a href="http://sourceforge.net/project/showfiles.php?group_id=12999">http://sourceforge.net/project/showfiles.php?group_id=12999</a></p> + </li> + <!-- Website is currently unavailable as of 2003-08-02 + <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></td></tr></table></td></tr></table></td></tr></table></td></tr></table></td></tr></table></body></html> |