Daniel Veillard | c654d60 | 2001-05-01 12:42:26 +0000 | [diff] [blame] | 1 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" |
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Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 5 | <title>Libxml Frequently Asked Questions</title> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 6 | <meta name="GENERATOR" content="amaya V4.1"> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 7 | <meta http-equiv="Content-Type" content="text/html"> |
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Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 11 | <h1 align="center">Libxml Frequently Asked Questions</h1> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 12 | |
| 13 | <p>Location: <a |
| 14 | href="http://xmlsoft.org/FAQ.html">http://xmlsoft.org/FAQ.html</a></p> |
| 15 | |
| 16 | <p>Libxml home page: <a href="http://xmlsoft.org/">http://xmlsoft.org/</a></p> |
| 17 | |
| 18 | <p>Mailing-list archive: <a |
| 19 | href="http://xmlsoft.org/messages/">http://xmlsoft.org/messages/</a></p> |
| 20 | |
Daniel Veillard | be40c8b | 2000-07-14 12:10:59 +0000 | [diff] [blame] | 21 | <p>Version: $Revision$</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 22 | |
| 23 | <p>Table of Content:</p> |
| 24 | <ul> |
| 25 | <li><a href="#Licence">Licence(s)</a></li> |
| 26 | <li><a href="#Installati">Installation</a></li> |
| 27 | <li><a href="#Compilatio">Compilation</a></li> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 28 | <li><a href="#Developer">Developer corner</a></li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 29 | </ul> |
| 30 | |
| 31 | <h2><a name="Licence">Licence</a>(s)</h2> |
| 32 | <ol> |
| 33 | <li><em>Licensing Terms for libxml</em> |
| 34 | <p>libxml is released under 2 (compatible) licences:</p> |
| 35 | <ul> |
| 36 | <li>the <a href="http://www.gnu.org/copyleft/lgpl.html">LGPL</a>: GNU |
| 37 | Library General Public License</li> |
| 38 | <li>the <a |
| 39 | href="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C |
| 40 | IPR</a>: very similar to the XWindow licence</li> |
| 41 | </ul> |
| 42 | </li> |
| 43 | <li><em>Can I embed libxml in a proprietary application ?</em> |
| 44 | <p>Yes. The W3C IPR allows you to also keep proprietary the changes you |
| 45 | made to libxml, but it would be graceful to provide back bugfixes and |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 46 | improvements as patches for possible incorporation in the main development |
| 47 | tree</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 48 | </li> |
| 49 | </ol> |
| 50 | |
| 51 | <h2><a name="Installati">Installation</a></h2> |
| 52 | <ol> |
Daniel Veillard | e0c1d72 | 2001-03-21 10:28:36 +0000 | [diff] [blame] | 53 | <li>Unless you are forced to because your application links with a Gnome |
| 54 | library requiring it, <strong><span style="background-color: #FF0000">Do |
| 55 | Not Use libxml1</span></strong>, use libxml2</li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 56 | <li><em>Where can I get libxml</em> ? |
| 57 | <p>The original distribution comes from <a |
| 58 | href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a |
| 59 | href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p> |
| 60 | <p>Most linux and Bsd distribution includes libxml, this is probably the |
| 61 | safer way for end-users</p> |
| 62 | <p>David Doolin provides precompiled Windows versions at <a |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 63 | href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 64 | </li> |
| 65 | <li><em>I see libxml and libxml2 releases, which one should I install ?</em> |
| 66 | <ul> |
| 67 | <li>If you are not concerned by any existing backward compatibility with |
| 68 | existing application, install libxml2 only</li> |
| 69 | <li>If you are not doing development, you can safely install both. |
| 70 | usually the packages <a |
| 71 | href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a |
| 72 | href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are |
| 73 | compatible (this is not the case for development packages)</li> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 74 | <li>If you are a developer and your system provides separate packaging |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 75 | for shared libraries and the development components, it is possible to |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 76 | install libxml and libxml2, and also <a |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 77 | href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a> |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 78 | and <a |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 79 | href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a> |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 80 | too for libxml2 >= 2.3.0</li> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 81 | <li>If you are developing a new application, please develop against |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 82 | libxml2(-devel)</li> |
| 83 | </ul> |
| 84 | </li> |
| 85 | <li><em>I can't install the libxml package it conflicts with libxml0</em> |
| 86 | <p>You probably have an old libxml0 package used to provide the shared |
| 87 | library for libxml.so.0, you can probably safely remove it. Anyway the |
| 88 | libxml packages provided on <a |
| 89 | href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides |
| 90 | libxml.so.0</p> |
| 91 | </li> |
Daniel Veillard | c654d60 | 2001-05-01 12:42:26 +0000 | [diff] [blame] | 92 | <li><em>I can't install the libxml(2) RPM package due to failed |
| 93 | dependancies</em> |
| 94 | <p>The most generic solution is to refetch the latest src.rpm , and |
| 95 | rebuild it locally with</p> |
| 96 | <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code></p> |
| 97 | <p>if everything goes well it will generate two binary rpm (one providing |
| 98 | the shared libs and xmllint, and the other one, the -devel package |
| 99 | providing includes, static libraries and scripts needed to build |
| 100 | applications with libxml(2)) that you can install locally.</p> |
| 101 | </li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 102 | </ol> |
| 103 | |
| 104 | <h2><a name="Compilatio">Compilation</a></h2> |
| 105 | <ol> |
| 106 | <li><em>What is the process to compile libxml ?</em> |
| 107 | <p>As most UNIX libraries libxml follows the "standard":</p> |
| 108 | <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p> |
| 109 | <p><code>cd libxml-xxxx</code></p> |
| 110 | <p><code>./configure --help</code></p> |
| 111 | <p>to see the options, then the compilation/installation proper</p> |
| 112 | <p><code>./configure [possible options]</code></p> |
| 113 | <p><code>make</code></p> |
| 114 | <p><code>make install</code></p> |
| 115 | <p>At that point you may have to rerun ldconfig or similar utility to |
| 116 | update your list of installed shared libs.</p> |
| 117 | </li> |
| 118 | <li><em>What other libraries are needed to compile/install libxml ?</em> |
| 119 | <p>Libxml does not requires any other library, the normal C ANSI API |
| 120 | should be sufficient (please report any violation to this rule you may |
| 121 | find).</p> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 122 | <p>However if found at configuration time libxml will detect and use the |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 123 | following libs:</p> |
| 124 | <ul> |
| 125 | <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a>: a |
| 126 | highly portable and available widely compression library</li> |
| 127 | <li>iconv: a powerful character encoding conversion library. It's |
| 128 | included by default on recent glibc libraries, so it doesn't need to |
| 129 | be installed specifically on linux. It seems it's now <a |
| 130 | href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part of |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 131 | the official UNIX</a> specification. Here is one <a |
| 132 | href="http://clisp.cons.org/~haible/packages-libiconv.html">implementation |
| 133 | of the library</a> which source can be found <a |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 134 | href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 135 | </ul> |
| 136 | </li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 137 | <li><em>libxml does not compile with HP-UX's optional ANSI-C compiler</em> |
| 138 | <p>this is due to macro limitations. Try to add " -Wp,-H16800 -Ae" to the |
| 139 | CFLAGS</p> |
| 140 | <p>you can also install and use gcc instead or use a precompiled version |
| 141 | of libxml, both available from the <a |
| 142 | href="http://hpux.cae.wisc.edu/hppd/auto/summary_all.html">HP-UX Porting |
| 143 | and Archive Centre</a></p> |
| 144 | </li> |
| 145 | <li><em>make check fails on some platforms</em> |
| 146 | <p>Sometime the regression tests results don't completely match the value |
| 147 | produced by the parser, and the makefile uses diff to print the delta. On |
| 148 | some platforms the diff return breaks the compilation process, if the diff |
| 149 | is small this is probably not a serious problem</p> |
| 150 | </li> |
Daniel Veillard | 6761eee | 2001-06-11 10:29:38 +0000 | [diff] [blame] | 151 | <li><em>I use the CVS version and there is no configure script</em> |
| 152 | <p>The configure (and other Makefiles) are generated. Use the autogen.sh |
| 153 | script to regenerate the configure and Makefiles, like:</p> |
| 154 | <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p> |
| 155 | </li> |
Daniel Veillard | 7b06bcb | 2001-06-22 16:03:51 +0000 | [diff] [blame] | 156 | <li><em>I have troubles when running make tests with gcc-3.0</em> |
| 157 | <p>It seems the initial release of gcc-3.0 has a problem with the |
| 158 | optimizer which miscompiles the URI module. Please use another |
| 159 | compiler</p> |
| 160 | </li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 161 | </ol> |
| 162 | |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 163 | <h2><a name="Developer">Developer</a> corner</h2> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 164 | <ol> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 165 | <li>Extra nodes in the document: |
Daniel Veillard | 62bccd5 | 2001-02-10 09:40:10 +0000 | [diff] [blame] | 166 | <p><em>For a XML file as below:</em></p> |
| 167 | <pre><?xml version="1.0"?> |
Daniel Veillard | a666359 | 2001-02-10 09:41:12 +0000 | [diff] [blame] | 168 | <PLAN xmlns="http://www.argus.ca/autotest/1.0/"> |
Daniel Veillard | 62bccd5 | 2001-02-10 09:40:10 +0000 | [diff] [blame] | 169 | <NODE CommFlag="0"/> |
| 170 | <NODE CommFlag="1"/> |
| 171 | </PLAN></pre> |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 172 | <p><em>after parsing it with the function |
| 173 | pxmlDoc=xmlParseFile(...);</em></p> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 174 | <p><em>I want to the get the content of the first node (node with the |
| 175 | CommFlag="0")</em></p> |
| 176 | <p><em>so I did it as following;</em></p> |
Daniel Veillard | 62bccd5 | 2001-02-10 09:40:10 +0000 | [diff] [blame] | 177 | <pre>xmlNodePtr pode; |
| 178 | pnode=pxmlDoc->children->children;</pre> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 179 | <p><em>but it does not work. If I change it to</em></p> |
Daniel Veillard | 62bccd5 | 2001-02-10 09:40:10 +0000 | [diff] [blame] | 180 | <pre>pnode=pxmlDoc->children->children->next;</pre> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 181 | <p><em>then it works. Can someone explain it to me.</em></p> |
| 182 | <p></p> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 183 | <p>In XML all characters in the content of the document are significant |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 184 | <strong>including blanks and formatting line breaks</strong>.</p> |
| 185 | <p>The extra nodes you are wondering about are just that, text nodes with |
| 186 | the formatting spaces wich are part of the document but that people tend |
| 187 | to forget. There is a function <a |
| 188 | href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault |
| 189 | ()</a> to remove those at parse time, but that's an heuristic, and its |
| 190 | use should be limited to case where you are sure there is no mixed-content |
| 191 | in the document.</p> |
| 192 | </li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 193 | <li><em>I get compilation errors of existing code like when accessing |
| 194 | <strong>root</strong> or <strong>childs fields</strong> of nodes</em> |
Daniel Veillard | 3f3b4f3 | 2001-03-13 15:12:39 +0000 | [diff] [blame] | 195 | <p>You are compiling code developed for libxml version 1 and using a |
| 196 | libxml2 development environment. Either switch back to libxml v1 devel or |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 197 | even better fix the code to compile with libxml2 (or both) by <a |
| 198 | href="upgrade.html">following the instructions</a>.</p> |
| 199 | </li> |
| 200 | <li><em>I get compilation errors about non existing |
| 201 | <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong> |
| 202 | fields</em> |
| 203 | <p>The source code you are using has been <a |
| 204 | href="upgrade.html">upgraded</a> to be able to compile with both libxml |
| 205 | and libxml2, but you need to install a more recent version: libxml(-devel) |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 206 | >= 1.8.8 or libxml2(-devel) >= 2.1.0</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 207 | </li> |
| 208 | <li><em>XPath implementation looks seriously broken</em> |
Daniel Veillard | 7f41b3e | 2001-02-10 09:35:37 +0000 | [diff] [blame] | 209 | <p>XPath implementation prior to 2.3.0 was really incomplete, upgrade to a |
| 210 | recent version, the implementation and debug of libxslt generated fixes |
Daniel Veillard | 480363b | 2001-03-16 22:04:15 +0000 | [diff] [blame] | 211 | for most obvious problems.</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 212 | </li> |
| 213 | <li><em>The example provided in the web page does not compile</em> |
| 214 | <p>It's hard to maintain the documentation in sync with the code |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 215 | <grin/> ...</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 216 | <p>Check the previous points 1/ and 2/ raised before, and send |
| 217 | patches.</p> |
| 218 | </li> |
| 219 | <li><em>Where can I get more examples and informations than in the web |
| 220 | page</em> |
| 221 | <p>Ideally a libxml book would be nice. I have no such plan ... But you |
| 222 | can:</p> |
| 223 | <ul> |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 224 | <li>check more deeply the <a href="html/libxml-lib.html">existing |
| 225 | generated doc</a></li> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 226 | <li>looks for examples of use for libxml function using the Gnome code |
| 227 | for example the following will query the full Gnome CVs base for the |
| 228 | use of the <strong>xmlAddChild()</strong> function: |
| 229 | <p><a |
| 230 | href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p> |
| 231 | <p>This may be slow, a large hardware donation to the gnome project |
| 232 | could cure this :-)</p> |
| 233 | </li> |
| 234 | <li><a |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 235 | href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Browse |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 236 | the libxml source</a>, I try to write code as clean and documented as |
| 237 | possible, so looking at it may be helpful</li> |
| 238 | </ul> |
| 239 | </li> |
| 240 | <li>What about C++ ? |
| 241 | <p>libxml is written in pure C in order to allow easy reuse on a number of |
| 242 | platforms, including embedded systems. I don't intend to convert to |
| 243 | C++.</p> |
| 244 | <p>There is however a C++ wrapper provided by Ari Johnson |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 245 | <ari@btigate.com> which may fullfill your needs:</p> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 246 | <p>Website: <a |
| 247 | href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p> |
| 248 | <p>Download: <a |
| 249 | href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p> |
| 250 | </li> |
| 251 | <li>How to validate a document a posteriori ? |
| 252 | <p>It is possible to validate documents which had not been validated at |
| 253 | initial parsing time or documents who have been built from scratch using |
| 254 | the API. Use the <a |
Daniel Veillard | 9cb5ff4 | 2001-01-29 08:22:21 +0000 | [diff] [blame] | 255 | href="http://xmlsoft.org/html/libxml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 256 | function. It is also possible to simply add a Dtd to an existing |
| 257 | document:</p> |
| 258 | <pre>xmlDocPtr doc; /* your existing document */ |
| 259 | xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */ |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 260 | dtd->name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */ |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 261 | |
Daniel Veillard | e9202a0 | 2000-10-16 16:58:19 +0000 | [diff] [blame] | 262 | doc->intSubset = dtd; |
| 263 | if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd); |
| 264 | else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd); |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 265 | </pre> |
| 266 | </li> |
| 267 | <li>etc ...</li> |
| 268 | </ol> |
| 269 | |
| 270 | <p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p> |
| 271 | |
| 272 | <p>$Id$</p> |
| 273 | </body> |
| 274 | </html> |