libxml2

libxml2 is an XML toolkit implemented in C, originally developed for the GNOME Project.

Official releases can be downloaded from https://download.gnome.org/sources/libxml2/

The git repository is hosted on GNOME's GitLab server: https://gitlab.gnome.org/GNOME/libxml2

Bugs should be reported at https://gitlab.gnome.org/GNOME/libxml2/-/issues.

Documentation is available at https://gitlab.gnome.org/GNOME/libxml2/-/wikis

License

This code is released under the MIT License, see the Copyright file.

Security

This is open-source software written by hobbyists and maintained by volunteers.

It's NOT recommended to use this software to process untrusted data. There is a lot of ways that a malicious crafted xml could exploit a hidden vulnerability in the software.

The software is provided "as is", without warranty of any kind, express or implied. Use this software at your own risk.

To report security bugs, you can create a confidential issue with the "security" label. We will review and work on it as a best effort. But remember that this is a community project, maintained by volunteer developers, so if you are concern about any important security bug that's critical for you, feel free to collaborate and provide a patch.

The main rule is to be kind. Do not pressure developers to fix a CVE or to work on a functionality that you need, because that won't work. This is a community project, developers will work in the issues that they consider interesting and when they want. All contributions are welcome, so if something is important for you, you can always get involved, implement it yourself and be part of the open source community.

Build instructions

libxml2 can be built with GNU Autotools, CMake or meson.

Autotools (for POSIX systems like Linux, BSD, macOS)

If you build from a Git tree, you have to install Autotools and start by generating the configuration files with:

./autogen.sh [configuration options]

If you build from a source tarball, extract the archive with:

tar xf libxml2-xxx.tar.gz
cd libxml2-xxx

Then you can configure and build the library:

./configure [configuration options]
make

The following options disable or enable code modules and relevant symbols:

--with-c14n             Canonical XML 1.0 support (on)
--with-catalog          XML Catalogs support (on)
--with-debug            debugging module (on)
--with-docs             Build documentation (off)
--with-history          history support for xmllint shell (off)
--with-readline[=DIR]   use readline in DIR for shell (off)
--with-html             HTML parser (on)
--with-http             ABI compatibility for removed HTTP support (off)
--with-iconv[=DIR]      iconv support (on)
--with-icu              ICU support (off)
--with-iso8859x         ISO-8859-X support if no iconv (on)
--with-modules          dynamic modules support (on)
--with-output           serialization support (on)
--with-pattern          xmlPattern selection interface (on)
--with-push             push parser interfaces (on)
--with-python           Python bindings (off)
--with-reader           xmlReader parsing interface (on)
--with-regexps          regular expressions support (on)
--with-relaxng          RELAX NG support (on)
--with-sax1             older SAX1 interface (on)
--with-schemas          XML Schemas 1.0 support (on)
--with-schematron       Schematron support (off)
--with-threads          multithreading support (on)
--with-thread-alloc     per-thread malloc hooks (off)
--with-valid            DTD validation support (on)
--with-winpath          Windows path support (on for Windows)
--with-writer           xmlWriter serialization interface (on)
--with-xinclude         XInclude 1.0 support (on)
--with-xpath            XPath 1.0 support (on)
--with-xptr             XPointer support (on)
--with-zlib[=DIR]       use libz in DIR (off)

Other options:

--prefix=DIR            set installation prefix
--with-minimum          build a minimally sized library (off)
--with-legacy           maximum ABI compatibility (off)

Note that by default, no optimization options are used. You have to enable them manually, for example with:

CFLAGS='-O2 -fno-semantic-interposition' ./configure

Now you can run the test suite with:

make check

Please report test failures to the bug tracker.

Then you can install the library:

make install

At that point you may have to rerun ldconfig or a similar utility to update your list of installed shared libs.

CMake (mainly for Windows)

Example commands:

cmake -E tar xf libxml2-xxx.tar.xz
cmake -S libxml2-xxx -B builddir [options]
cmake --build builddir
ctest --test-dir builddir
cmake --install builddir

Common CMake options include:

-D BUILD_SHARED_LIBS=OFF            # build static libraries
-D CMAKE_BUILD_TYPE=Release         # specify build type (single-config)
--config Release                    # specify build type (multi-config)
-D CMAKE_INSTALL_PREFIX=/usr/local  # specify the install path
-D LIBXML2_WITH_ICONV=OFF           # disable iconv
-D LIBXML2_WITH_ZLIB=ON             # enable zlib

You can also open the libxml source directory with its CMakeLists.txt directly in various IDEs such as CLion, QtCreator, or Visual Studio.

Meson

Example commands:

meson setup [options] builddir
ninja -C builddir
meson test -C builddir
ninja -C builddir install

See the meson_options.txt file for options. For example:

-Dprefix=$prefix
-Dhistory=enabled
-Dschemas=disabled
-Dzlib=enabled

Dependencies

libxml2 supports POSIX and Windows operating systems.

The iconv function is required for conversion of character encodings. This function is part of POSIX.1-2001. If your platform doesn't provide iconv, you need an external libiconv library, for example GNU libiconv. Using ICU is also supported but discouraged.

The xmllint executable uses libreadline and libhistory if enabled.

Build requirements

Besides build system tools, only a C compiler should be required. Reconfiguration of the Autotools build requires the pkg.m4 macro from pkg-config. Building the documentation requires Doxygen, xsltproc and the DocBook 4 XSLT stylesheets. Building the Python bindings requires Doxygen.

Contributing

The current version of the code can be found in GNOME's GitLab at https://gitlab.gnome.org/GNOME/libxml2. The best way to get involved is by creating issues and merge requests on GitLab.

All code must conform to C89 and pass the GitLab CI tests. Add regression tests if possible.

Strict No LLM / No AI Policy

No LLMs for issues.

No LLMs for patches / pull requests.

No LLMs for comments on the bug tracker, including translation.

English is encouraged, but not required. You are welcome to post in your native language and rely on others to have their own translation tools of choice to interpret your words.

Authors

• Daniel Veillard
• Bjorn Reese
• William Brack
• Igor Zlatkovic for the Windows port
• Aleksey Sanin
• Nick Wellnhofer