WMI library for modern C++

A simple WMI library for C++ 17.

Simple example

This example shows how to get processes on the local system.

// ...

int main()
{
  wmi::ComManager::Initialize();
  
  {
    wmi::ManagementResource resource("ROOT\\CIMV2");
    resource.Connect();

    wmi::ManagementQueryProcessor processor(resource, "SELECT * FROM Win32_Process");

    auto stream = processor.GetStream();
    auto object = stream.Current();

    std::wcout << object["Name"].bstrVal << "\n";
  }
  
  wmi::ComManager::Uninitialize();
}

Using STL algorithms

The ManagementQueryStream contains methods that returns iterators. With these iterators we are able to use STL algorithms.

Example of copying elements into a std::vector.

// ...

int main()
{
  // ...

  auto stream = processor->GetStream();

  // Copying the objects into a vector
  std::vector<wmi::ManagementObject> objects;
  std::copy(std::begin(objects), std::end(objects), std::back_inserter(objects));

  // Do something with `objects`

  return 0;
}

Example of finding a process with a specific name.

// ...

int main()
{
  // ...

  auto stream = processor->GetStream();

  auto found = std::find_if(std::begin(stream),
                            std::end(stream),
                            [](const wmi::ManagementObject& object) {
                                auto name = object["Name"].bstrVal;
                                return wcscmp(name, TEXT("ProcessNameToSearchFor"));
                            });

  if (found != std::end(stream)) {
    // Found
  }

  return 0;
}

Mapping

The library allows to map returned objects from ManagementQueryStream to data structures. In this example we will create custom structure called Win32Process. After we have queried the data from stream we will map the object to the structure Win32Process.

The stream class has a template parameter that allows to map the returned object a specific class.

To map the structure you need to implement the function MapManagementObject.

// ...

struct Win32Process
{
  bstr_t name;
};

void MapManagementObject(const wmi::ManagementObject& from, Win32Process& to)
{
  to.name = from["Name"].bstrVal;
}

int main()
{
  // ...
  wmi::ManagementResource resource("ROOT\\CIMV2");
  resource.Connect();

  wmi::ManagementQueryProcessor processor(resource, "SELECT * FROM Win32_Process");

  auto stream = processor.GetStream<Win32Process>();
  auto object = stream.Current();

  std::wcout << object.name << "\n";
}

Calling class methods

The following example shows how to call the method Create from Win32_Process and process the results.

// ...

int main()
{
  // ...
  auto resource = std::make_shared<wmi::ManagementResource>();
  resource->Connect("ROOT\\CIMV2");

  // Prepare the parameters
  std::unordered_map<std::string_view, variant_t> parameters;
  parameters["CommandLine"] = bstr_t("notepad.exe").Detach();
  
  auto result = resource->ExecuteMethod("Win32_Process", "Create", parameters);

  // Using the ResultObject to get the `ReturnValue` and the `ProcessId` of our newly created process.
  if (result["ReturnValue"].lVal == 0) {
    std::cout << "Successfully created process with the process id: " << result.Get<LONG>("ProcessId") << "\n";
  }

  return 0;
}

Current state

The library works only on Windows. It is possible to just clone, compile and test it yourself. You need to link to the libaries wbemuuid.lib and crypt32.lib if you are including it in your project.

License

The WMI library is licensed under the MIT License.

bozali / wmi