libyang is YANG data modelling language parser and toolkit written (and providing API) in C. The library is used e.g. in libnetconf2, Netopeer2 or sysrepo projects.
- Parsing (and validating) schemas in YANG format.
- Parsing (and validating) schemas in YIN format.
- Parsing, validating and printing instance data in XML format.
- Parsing, validating and printing instance data in JSON format (RFC 7951).
- Manipulation with the instance data.
- Support for default values in the instance data (RFC 6243).
Current implementation covers YANG 1.0 (RFC 6020) as well as YANG 1.1 (RFC 7950).
- cmake >= 2.8.9
- 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
$ google-chrome ../doc/html/index.html
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.
All libyang functions are available via the main header:
#include <libyang/libyang.h>
To compile your program with libyang, it is necessary to link it with libyang using the following linker parameters:
-lyang
Note, that it may be necessary to call ldconfig(8) after library installation and if the
library was installed into a non-standard path, the path to libyang must be specified to the
linker. To help with setting all the compiler's options, there is libyang.pc file for
pkg-config(1) available in the source tree. The file is installed with the library.
If you are using cmake in you project, it is also possible to use the provided
FindLibYANG.cmake file to detect presence of the libyang library in the system.
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 they 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
We provide bindings for high-level languages using SWIG generator. The bindings are optional and to enable building of the specific binding, the appropriate cmake option must be enabled, for example:
$ cmake -DJAVASCRIPT_BINDING=ON ..
More information about the specific binding can be found in their README files.
Currently supported bindings are:
- JavaScript
- cmake option:
JAVASCRIPT_BINDING - README
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.