ECHMETUpdateCheck is a tiny library that fetches a JSON-formatted manifest formatted accordingly to specification described in format-description.txt and evaluates if there is an update available. The library features a minimalist C interface, uses CMake build system depends on libcurl and uses the awesome nlohmann's json parser to process JSON files. In addition to standard C bindings, bindings for Python using CTypes are available as well.
Assuming that you have libcurl and its development files installed, the building process is very straightforward.
cd /path/to/ECHMETUpdateCheck
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make
make install
libcurl for Windows must be obtained separately before the library can be built. The LIBCURL_DIR CMake variable must be set to a path that contains the libcurl installation with lib and include directories inside. CMake can then generate appropriate project files for your compiler of choice. MinGW64 and MSVC 2015 compilers have been tested to build ECHMETUpdateCheck correctly.
Please refer to the documentation in include\echmetupdatecheck.h, python\echmetupdatecheck.py and format-description.txt for technical details how to interface with the library.
The library is released under the Lesser GNU GPLv3 software license.