json-c-0.16.tar.gz

\mainpage `json-c` ======== 1. [Overview and Build Status](#overview) 2. [Building on Unix](#buildunix) * [Prerequisites](#installprereq) * [Build commands](#buildcmds) 3. [CMake options](#CMake) 4. [Testing](#testing) 5. [Building with `vcpkg`](#buildvcpkg) 6. [Linking to libjson-c](#linking) 7. [Using json-c](#using) JSON-C - A JSON implementation in C <a name="overview"></a> ----------------------------------- JSON-C implements a reference counting object model that allows you to easily construct JSON objects in C, output them as JSON formatted strings and parse JSON formatted strings back into the C representation of JSON objects. It aims to conform to [RFC 7159](https://tools.ietf.org/html/rfc7159). Skip down to [Using json-c](#using) or check out the [API docs](https://json-c.github.io/json-c/), if you already have json-c installed and ready to use. Home page for json-c: https://github.com/json-c/json-c/wiki Build Status * [AppVeyor Build](https://ci.appveyor.com/project/hawicz/json-c)  * [Travis Build](https://travis-ci.org/json-c/json-c)  Test Status * [Coveralls](https://coveralls.io/github/json-c/json-c?branch=master) [](https://coveralls.io/github/json-c/json-c?branch=master) Building on Unix with `git`, `gcc` and `cmake` <a name="buildunix"></a> -------------------------------------------------- If you already have json-c installed, see [Linking to `libjson-c`](#linking) for how to build and link your program against it. ### Prerequisites: <a name="installprereq"></a> - `gcc`, `clang`, or another C compiler - `cmake>=2.8`, `>=3.16` recommended, `cmake=>3.1` for tests To generate docs you'll also need: - `doxygen>=1.8.13` If you are on a relatively modern system, you'll likely be able to install the prerequisites using your OS's packaging system. ### Install using apt (e.g. Ubuntu 16.04.2 LTS) ```sh sudo apt install git sudo apt install cmake sudo apt install doxygen # optional sudo apt install valgrind # optional ``` ### Build instructions: <a name="buildcmds"></a> `json-c` GitHub repo: https://github.com/json-c/json-c ```sh $ git clone https://github.com/json-c/json-c.git $ mkdir json-c-build $ cd json-c-build $ cmake ../json-c # See CMake section below for custom arguments ``` Note: it's also possible to put your build directory inside the json-c source directory, or even not use a separate build directory at all, but certain things might not work quite right (notably, `make distcheck`) Then: ```sh $ make $ make test $ make USE_VALGRIND=0 test # optionally skip using valgrind $ make install ``` ### Generating documentation with Doxygen: The library documentation can be generated directly from the source code using Doxygen tool: ```sh # in build directory make doc google-chrome doc/html/index.html ``` CMake Options <a name="CMake"></a> -------------------- The json-c library is built with [CMake](https://cmake.org/cmake-tutorial/), which can take a few options. Variable | Type | Description -----------------------------|--------|-------------- CMAKE_INSTALL_PREFIX | String | The install location. CMAKE_BUILD_TYPE | String | Defaults to "debug". BUILD_SHARED_LIBS | Bool | The default build generates a dynamic (dll/so) library. Set this to OFF to create a static library only. BUILD_STATIC_LIBS | Bool | The default build generates a static (lib/a) library. Set this to OFF to create a shared library only. DISABLE_STATIC_FPIC | Bool | The default builds position independent code. Set this to OFF to create a shared library only. DISABLE_BSYMBOLIC | Bool | Disable use of -Bsymbolic-functions. DISABLE_THREAD_LOCAL_STORAGE | Bool | Disable use of Thread-Local Storage (HAVE___THREAD). DISABLE_WERROR | Bool | Disable use of -Werror. ENABLE_RDRAND | Bool | Enable RDRAND Hardware RNG Hash Seed. ENABLE_THREADING | Bool | Enable partial threading support. OVERRIDE_GET_RANDOM_SEED | String | A block of code to use instead of the default implementation of json_c_get_random_seed(), e.g. on embedded platforms where not even the fallback to time() works. Must be a single line. Pass these options as `-D` on CMake's command-line. ```sh # build a static library only cmake -DBUILD_SHARED_LIBS=OFF .. ``` ### Building with partial threading support Although json-c does not support fully multi-threaded access to object trees, it has some code to help make its use in threaded programs a bit safer. Currently, this is limited to using atomic operations for json_object_get() and json_object_put(). Since this may have a performance impact, of at least 3x slower according to https://stackoverflow.com/a/11609063, it is disabled by default. You may turn it on by adjusting your cmake command with: -DENABLE_THREADING=ON Separately, the default hash function used for object field keys, lh_char_hash, uses a compare-and-swap operation to ensure the random seed is only generated once. Because this is a one-time operation, it is always compiled in when the compare-and-swap operation is available. ### cmake-configure wrapper script For those familiar with the old autoconf/autogen.sh/configure method, there is a `cmake-configure` wrapper script to ease the transition to cmake. ```sh mkdir build cd build ../cmake-configure --prefix=/some/install/path make ``` cmake-configure can take a few options. | options | Description| | ---- | ---- | | prefix=PREFIX | install architecture-independent files in PREFIX | | enable-threading | Enable code to support partly multi-threaded use | | enable-rdrand | Enable RDRAND Hardware RNG Hash Seed generation on supported x86/x64 platforms. | | enable-shared | build shared libraries [default=yes] | | enable-static | build static libraries [default=yes] | | disable-Bsymbolic | Avoid linking with -Bsymbolic-function | | disable-werror | Avoid treating compiler warnings as fatal errors | Testing: <a name="testing"></a> ---------- By default, if valgrind is available running tests uses it. That can slow the tests down considerably, so to disable it use: ```sh export USE_VALGRIND=0 ``` To run tests a separate build directory is recommended: ```sh mkdir build-test cd build-test # VALGRIND=1 causes -DVALGRIND=1 to be passed when compiling code # which uses slightly slower, but valgrind-safe code. VALGRIND=1 cmake .. make make test # By default, if valgrind is available running tests uses it. make USE_VALGRIND=0 test # optionally skip using valgrind ``` If a test fails, check `Testing/Temporary/LastTest.log`, `tests/testSubDir/${testname}/${testname}.vg.out`, and other similar files. If there is insufficient output try: ```sh VERBOSE=1 CTEST_OUTPUT_ON_FAILURE=1 make test ``` or ```sh JSONC_TEST_TRACE=1 make test ``` and check the log files again. Building on Unix and Windows with `vcpkg` <a name="buildvcpkg"></a> -------------------------------------------------- You can download and install JSON-C using the [vcpkg](https://github.com/Microsoft/vcpkg/) dependency manager: git clone https://github.com/Microsoft/vcpkg.git cd vcpkg ./bootstrap-vcpkg.sh ./vcpkg integrate install vcpkg install json-c The JSON-C port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository. Linking to `libjson-c` <a name="linking"> ---------------------- If your system has `pkgconfig`, then you can just add this to your `makefile`: ```make CFLAGS += $(shell pkg-config --cflags json-c) LDFLAGS +