libyang is YANG data modelling language parser and toolkit written (and providing API) in C.

• parsing (and validating) data models in YIN format
• reading instance data in XML format and validating
• reading instance data in JSON format and validating
• providing instance data in XML format
• providing instance data in JSON format

• parsing (and validating) data models in YANG format

• cmake >= 2.6
• libpcre
• cmocka >= 1.0.0 (for tests only, see Tests)

$ mkdir build; cd build
$ cmake ..
$ make 
# make install

The library documentation can be generated directly from the source codes using Doxygen tool:

$ make doc

Set CC variable:

$ CC=/usr/bin/clang cmake ..

To change the prefix where the library, headers and any other files are installed, set CMAKE_INSTALL_PREFIX variable:

$ cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr ..

Default prefix is /usr/local.

There are two build modes:

• Release. This generates library for the production use without any debug information.
• Debug. This generates library with the debug information and disables optimization of the code.

The Debug mode is currently used as the default one. to switch to the Release mode, enter at the command line:

$ cmake -D CMAKE_BUILD_TYPE:String="Release" ..

Note that, with CMake, if you want to change the compiler or its options after you already ran CMake, you need to clear its cache first - the most simple way to do it is to remove all content from the 'build' directory.

libyang includes several tests built with cmocka. The tests can be found in tests subdirectory and they are designed for checking library functionality after code changes.

The tests are by default built in the Debug build mode by running

$ make

In case of the Release mode, the tests are not built by default (it requires additional dependency), but it can be enabled via cmake option:

$ cmake -DENABLE_BUILD_TESTS=ON ..

Note that if the necessary cmocka headers are not present in the system include paths, tests are not available despite the build mode or cmake's options.

Tests can be run by the make's test target:

$ make test

libyang source codes include a simple example tool to demanstrate how an application can work with the libyang library. The tool is called yanglint. It is not being installed together with the library itself, but it is built together with the library binary and you can find it in tools/lint directory.

There is also README describing some examples of using yanglint.