libxml2/README.md

# 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>.
Please report *security issues* to our bug tracker as well. Make sure to
mark the issue as *confidential*.

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

## License

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

## Build instructions

libxml2 can be built with GNU Autotools, CMake, meson or several other
build systems in platform-specific subdirectories.

### 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-history          history support for xmllint shell (off)
    --with-readline[=DIR]   use readline in DIR for shell (off)
    --with-html             HTML parser (on)
    --with-http             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-lzma[=DIR]       use liblzma in DIR (off)
    --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 (on)
    --with-reader           xmlReader parsing interface (on)
    --with-regexps          regular expressions support (on)
    --with-sax1             older SAX1 interface (on)
    --with-schemas          XML Schemas 1.0 and RELAX NG support (on)
    --with-schematron       Schematron support (on)
    --with-threads          multithreading support (on)
    --with-thread-alloc     per-thread malloc hooks (off)
    --with-valid            DTD validation support (on)
    --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:

    --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)

Another option for compiling libxml is using CMake:

    cmake -E tar xf libxml2-xxx.tar.gz
    cmake -S libxml2-xxx -B libxml2-xxx-build [possible options]
    cmake --build libxml2-xxx-build
    cmake --install libxml2-xxx-build

Common CMake options include:

    -D BUILD_SHARED_LIBS=OFF            # build static libraries
    -D CMAKE_BUILD_TYPE=Release         # specify build type
    -D CMAKE_INSTALL_PREFIX=/usr/local  # specify the install path
    -D LIBXML2_WITH_ICONV=OFF           # disable iconv
    -D LIBXML2_WITH_LZMA=OFF            # disable liblzma
    -D LIBXML2_WITH_PYTHON=OFF          # disable Python
    -D LIBXML2_WITH_ZLIB=OFF            # disable libz

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

### Meson

Still somewhat experimental, see
[issue 743](https://gitlab.gnome.org/GNOME/libxml2/-/issues/743).

Libxml can also be built with meson. Without option, simply call

    meson setup builddir
    ninja -C builddir

To add options, see the meson_options.txt file. For example:

    meson setup \
        -Dprefix=$prefix \
        -Dhistory=enabled \
        -Dhttp=enabled \
        -Dschematron=disabled \
        -Dzlib=enabled \
        builddir

To install libxml:

    ninja -C builddir install

To launch tests:

    meson test -C builddir

## 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](https://www.gnu.org/software/libiconv/). Using
[ICU](https://icu.unicode.org/) is also supported but discouraged.

If enabled, libxml uses [libz](https://zlib.net/) or
[liblzma](https://tukaani.org/xz/) to support reading compressed files.
Use of this feature is discouraged.

The xmllint executable uses libreadline and libhistory if enabled.

## 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.

## Authors

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