Method getWindowsEnvironmentVariable

src/thundersvm/util/log.cpp:959–966

@brief Gets environment variables for Windows based OS. We are not using getenv(const char*) because of CRT deprecation @param varname Variable name to get environment variable value for @return If variable exist the value of it otherwise nullptr

/// @param varname Variable name to get environment variable value for
/// @return If variable exist the value of it otherwise nullptr
const char* OS::getWindowsEnvironmentVariable(const char* varname) {
  const DWORD bufferLen = 50;
  static char buffer[bufferLen];
  if (GetEnvironmentVariableA(varname, buffer, bufferLen)) {
    return buffer;
  }
  return nullptr;
}
#endif  // ELPP_OS_WINDOWS
#if ELPP_OS_ANDROID
            std::string OS::getProperty(const char* prop) {