Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" |
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| 5 | <title>Libxml Frequently asqued Questions</title> |
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| 11 | <h1 align="center">Libxml Frequently Asqued Questions</h1> |
| 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> |
| 28 | <li><a href="#Developper">Developper corner</a></li> |
| 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 |
| 46 | improvements as patches for possible incorporation in the main |
| 47 | developement tree</p> |
| 48 | </li> |
| 49 | </ol> |
| 50 | |
| 51 | <h2><a name="Installati">Installation</a></h2> |
| 52 | <ol> |
| 53 | <li><em>Where can I get libxml</em> ? |
| 54 | <p>The original distribution comes from <a |
| 55 | href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a |
| 56 | href="ftp://ftp.gnome.org/pub/GNOME/stable/sources/libxml/">gnome.org</a></p> |
| 57 | <p>Most linux and Bsd distribution includes libxml, this is probably the |
| 58 | safer way for end-users</p> |
| 59 | <p>David Doolin provides precompiled Windows versions at <a |
| 60 | href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ |
| 61 | ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p> |
| 62 | </li> |
| 63 | <li><em>I see libxml and libxml2 releases, which one should I install ?</em> |
| 64 | <ul> |
| 65 | <li>If you are not concerned by any existing backward compatibility with |
| 66 | existing application, install libxml2 only</li> |
| 67 | <li>If you are not doing development, you can safely install both. |
| 68 | usually the packages <a |
| 69 | href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a |
| 70 | href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are |
| 71 | compatible (this is not the case for development packages)</li> |
| 72 | <li>If you are a developper and your system provides separate packaging |
| 73 | for shared libraries and the development components, it is possible to |
| 74 | install libxml and libxml2, and depending on your development needs |
| 75 | have either <a |
| 76 | href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a> |
| 77 | or <a |
| 78 | href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a> |
| 79 | too</li> |
| 80 | <li>If you are developping a new application, please develop against |
| 81 | libxml2(-devel)</li> |
| 82 | </ul> |
| 83 | </li> |
| 84 | <li><em>I can't install the libxml package it conflicts with libxml0</em> |
| 85 | <p>You probably have an old libxml0 package used to provide the shared |
| 86 | library for libxml.so.0, you can probably safely remove it. Anyway the |
| 87 | libxml packages provided on <a |
| 88 | href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provides |
| 89 | libxml.so.0</p> |
| 90 | </li> |
| 91 | </ol> |
| 92 | |
| 93 | <h2><a name="Compilatio">Compilation</a></h2> |
| 94 | <ol> |
| 95 | <li><em>What is the process to compile libxml ?</em> |
| 96 | <p>As most UNIX libraries libxml follows the "standard":</p> |
| 97 | <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p> |
| 98 | <p><code>cd libxml-xxxx</code></p> |
| 99 | <p><code>./configure --help</code></p> |
| 100 | <p>to see the options, then the compilation/installation proper</p> |
| 101 | <p><code>./configure [possible options]</code></p> |
| 102 | <p><code>make</code></p> |
| 103 | <p><code>make install</code></p> |
| 104 | <p>At that point you may have to rerun ldconfig or similar utility to |
| 105 | update your list of installed shared libs.</p> |
| 106 | </li> |
| 107 | <li><em>What other libraries are needed to compile/install libxml ?</em> |
| 108 | <p>Libxml does not requires any other library, the normal C ANSI API |
| 109 | should be sufficient (please report any violation to this rule you may |
| 110 | find).</p> |
| 111 | <p>However if found at configuration time libxml will deect and use the |
| 112 | following libs:</p> |
| 113 | <ul> |
| 114 | <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a>: a |
| 115 | highly portable and available widely compression library</li> |
| 116 | <li>iconv: a powerful character encoding conversion library. It's |
| 117 | included by default on recent glibc libraries, so it doesn't need to |
| 118 | be installed specifically on linux. It seems it's now <a |
| 119 | href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part of |
| 120 | the official UNIX</a> specification, though I could not find a home |
| 121 | page for the project.</li> |
| 122 | </ul> |
| 123 | </li> |
| 124 | <li><em>The Makefile for the example gjobread is not generated</em> |
| 125 | <p>This is due to a circular dependancy in automake. No solution found so |
| 126 | far (if you know how to fix this the patch will be very welcome), that |
| 127 | failure won't affect the actually building of the xml library. You can |
| 128 | later go in and create the example Makefile by hand or reuse the |
| 129 | following:</p> |
| 130 | <pre>CC=gcc |
| 131 | CFLAGS=`xml-config --cflags` |
| 132 | LDFLAGS=`xml-config --libs` |
| 133 | |
| 134 | all: gjobread |
| 135 | |
| 136 | clean: |
| 137 | <TAB>@(rm -f gjobread gjobread.o) |
| 138 | |
| 139 | gjobread.o : gjobread.c |
| 140 | <TAB>$(CC) $(CFLAGS) -c gjobread.c |
| 141 | |
| 142 | gjobread: gjobread.o |
| 143 | <TAB>$(CC) -o gjobread gjobread.o $(LDFLAGS)</pre> |
| 144 | </li> |
| 145 | <li><em>libxml does not compile with HP-UX's optional ANSI-C compiler</em> |
| 146 | <p>this is due to macro limitations. Try to add " -Wp,-H16800 -Ae" to the |
| 147 | CFLAGS</p> |
| 148 | <p>you can also install and use gcc instead or use a precompiled version |
| 149 | of libxml, both available from the <a |
| 150 | href="http://hpux.cae.wisc.edu/hppd/auto/summary_all.html">HP-UX Porting |
| 151 | and Archive Centre</a></p> |
| 152 | </li> |
| 153 | <li><em>make check fails on some platforms</em> |
| 154 | <p>Sometime the regression tests results don't completely match the value |
| 155 | produced by the parser, and the makefile uses diff to print the delta. On |
| 156 | some platforms the diff return breaks the compilation process, if the diff |
| 157 | is small this is probably not a serious problem</p> |
| 158 | </li> |
| 159 | </ol> |
| 160 | |
| 161 | <h2><a name="Developper">Developper</a> corner</h2> |
| 162 | <ol> |
| 163 | <li><em>I get compilation errors of existing code like when accessing |
| 164 | <strong>root</strong> or <strong>childs fields</strong> of nodes</em> |
| 165 | <p>You are compiling code developped for libxml version 1 and using a |
| 166 | libxml2 developement environment. Either switch back to libxml v1 devel or |
| 167 | even better fix the code to compile with libxml2 (or both) by <a |
| 168 | href="upgrade.html">following the instructions</a>.</p> |
| 169 | </li> |
| 170 | <li><em>I get compilation errors about non existing |
| 171 | <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong> |
| 172 | fields</em> |
| 173 | <p>The source code you are using has been <a |
| 174 | href="upgrade.html">upgraded</a> to be able to compile with both libxml |
| 175 | and libxml2, but you need to install a more recent version: libxml(-devel) |
| 176 | >= 1.8.8 or libxml2(-devel) >= 2.1.0</p> |
| 177 | </li> |
| 178 | <li><em>XPath implementation looks seriously broken</em> |
| 179 | <p>True, it's incomplete and the version released in 2.0.0 was nearly |
| 180 | unusable. A set of patches from <a href="http://www.picdar.co.uk/">Picdar |
| 181 | Technology</a> have been integrated in 2.1.0 fixing the most nasty bugs. |
| 182 | But there is still bugs and its incomplete. Patches and bug reports are |
| 183 | welcome. This will be worked out, XPath implementation is not abandonned, |
| 184 | just a momentary lack of time.</p> |
| 185 | </li> |
| 186 | <li><em>The example provided in the web page does not compile</em> |
| 187 | <p>It's hard to maintain the documentation in sync with the code |
| 188 | <grin/> ...</p> |
| 189 | <p>Check the previous points 1/ and 2/ raised before, and send |
| 190 | patches.</p> |
| 191 | </li> |
| 192 | <li><em>Where can I get more examples and informations than in the web |
| 193 | page</em> |
| 194 | <p>Ideally a libxml book would be nice. I have no such plan ... But you |
| 195 | can:</p> |
| 196 | <ul> |
Daniel Veillard | 32c3ad9 | 2000-07-03 13:04:50 +0000 | [diff] [blame] | 197 | <li>check more deeply the <a href="html/libxml-lib.html">existing generated |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 198 | doc</a></li> |
| 199 | <li>looks for examples of use for libxml function using the Gnome code |
| 200 | for example the following will query the full Gnome CVs base for the |
| 201 | use of the <strong>xmlAddChild()</strong> function: |
| 202 | <p><a |
| 203 | href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p> |
| 204 | <p>This may be slow, a large hardware donation to the gnome project |
| 205 | could cure this :-)</p> |
| 206 | </li> |
| 207 | <li><a |
| 208 | href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Browse |
| 209 | the libxml source</a>, I try to write code as clean and documented as |
| 210 | possible, so looking at it may be helpful</li> |
| 211 | </ul> |
| 212 | </li> |
| 213 | <li>What about C++ ? |
| 214 | <p>libxml is written in pure C in order to allow easy reuse on a number of |
| 215 | platforms, including embedded systems. I don't intend to convert to |
| 216 | C++.</p> |
| 217 | <p>There is however a C++ wrapper provided by Ari Johnson |
| 218 | <ari@btigate.com> which may fullfill your needs:</p> |
| 219 | <p>Website: <a |
| 220 | href="http://lusis.org/~ari/xml++/">http://lusis.org/~ari/xml++/</a></p> |
| 221 | <p>Download: <a |
| 222 | href="http://lusis.org/~ari/xml++/libxml++.tar.gz">http://lusis.org/~ari/xml++/libxml++.tar.gz</a></p> |
| 223 | </li> |
| 224 | <li>How to validate a document a posteriori ? |
| 225 | <p>It is possible to validate documents which had not been validated at |
| 226 | initial parsing time or documents who have been built from scratch using |
| 227 | the API. Use the <a |
Daniel Veillard | 32c3ad9 | 2000-07-03 13:04:50 +0000 | [diff] [blame] | 228 | href="http://xmlsoft.org/html/gnome-xml-valid.html#XMLVALIDATEDTD">xmlValidateDtd()</a> |
Daniel Veillard | af74379 | 2000-07-01 11:49:28 +0000 | [diff] [blame] | 229 | function. It is also possible to simply add a Dtd to an existing |
| 230 | document:</p> |
| 231 | <pre>xmlDocPtr doc; /* your existing document */ |
| 232 | xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */ |
| 233 | dtd->name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */ |
| 234 | |
| 235 | doc->intSubset = dtd; |
| 236 | if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd); |
| 237 | else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd); |
| 238 | </pre> |
| 239 | </li> |
| 240 | <li>etc ...</li> |
| 241 | </ol> |
| 242 | |
| 243 | <p><a href="mailto:Daniel.Veillard@w3.org">Daniel Veillard</a></p> |
| 244 | |
| 245 | <p>$Id$</p> |
| 246 | </body> |
| 247 | </html> |