GNU getopt for Visual Studio
Please do not use this port any more, use vcpkg instead. There are also better solutions like Boost, Clara, or CXXOpts.
This project contains code from getopt.h and getopt.c from the MinGW repositories. The license terms from MinGW apply when using these files.
Copy the file to the include folder in Visual Studio. That should be in Program Files\Microsoft Visual Studio xxx\VC\include