WMI++ 🤕

WMI++ is a tiny-but-mighty header-only C++ library that takes away the pain of dealing with the Windows Management Instrumentation (WMI).

How To

Manual Install

WMI++ is a header-only library, which means you only need to include the necessary header file in your C++ code (#include <wmipp/wmipp.hxx>) to start using it. There is no need for any additional setup or installation.

Simply copy the wmipp directory to your project's include directory and you're ready to go.

Install With Vcpkg

If you are using Vcpkg, you can quickly install WMI++ by running the following command:

./vcpkg install wmipp

Once the installation is complete, you can include the necessary header file in your C++ code (#include <wmipp/wmipp.hxx>) and start using WMI++.

Usage

Minimal Example

Retrieve a specific property from a WMI query using WMI++.

The code executes a query that selects the Name property from the Win32_Processor class.

The result is accessed and stored as a std::optional<std::string> in the cpu_name variable.

#include <wmipp/wmipp.hxx>

const auto cpu_name = wmipp::Interface::Create()
  ->ExecuteQuery(L"SELECT Name FROM Win32_Processor")
  .GetProperty<std::string>(L"Name");

Custom Path

Connect to a specific WMI namespace by providing a custom path to the wmipp::Interface::Create method.

Replace "CUSTOM_PATH_HERE" with the desired custom path, such as the namespace or machine path.

#include <wmipp/wmipp.hxx>

const auto iface = wmipp::Interface::Create("CUSTOM_PATH_HERE");

MSDN

Object Iteration

Iterate over multiple WMI objects returned by a query.

The code executes a query that selects the Model property from the Win32_DiskDrive.

Because this query may return more than one result (with disks > 1), you can choose to iterate all the returned objects in the result with range-based loops.

Within the loop, retrieve the Model property value of each object using the GetProperty function and store it in the disk_model variable.

#include <wmipp/wmipp.hxx>

for (const auto& obj : wmipp::Interface::Create()->ExecuteQuery(L"SELECT Model FROM Win32_DiskDrive")) {
  const auto disk_model = obj.GetProperty<std::string>(L"Model");
}

Object Indexing

Similarly to iterating over multiple objects, you can use the GetAt() function or [] operator to access a specific Object in the QueryResult.

Here's an example of how you can get the Model of the second DiskDrive, if at least two drives are available.

#include <wmipp/wmipp.hxx>

const auto result : wmipp::Interface::Create()->ExecuteQuery(L"SELECT Model FROM Win32_DiskDrive");
if (result.Count() >= 2) {
  // Alternatively you can index the second element by doing [1]. These two operations are
  // functionally identical and you can safely pick the one you like the most.
  const auto disk_model = result.GetAt(1).GetProperty<std::string>(L"Model");
}

Reutilizing Interfaces

If you need to perform more than one query on the same path, you can utilize the same Interface to avoid creating a new connection for each query.

The Interface instance will automatically get uninitialized when all other Objects and QueryResults using it go out of scope.

#include <wmipp/wmipp.hxx>

const auto iface = wmipp::Interface::Create();
const auto cpu_name = iface->ExecuteQuery(L"SELECT Name FROM Win32_Processor")
  .GetProperty<std::string>(L"Name");
const auto user_name = iface->ExecuteQuery(L"SELECT UserName FROM Win32_ComputerSystem")
  .GetProperty<std::string>(L"UserName");

About Type Conversions

Currently there is support for the majority of the types you would usually need to query. This is done by building a variant_t and delegating it to handle the conversions. Furthermore, strings are converted from bstr_ts, and arrays are built from CComSafeArrays.

However, support is currently not guaranteed for all types that can be present in VARIANTs.

If you need to use a type that is not automatically convertible, you can read the variant_t by calling the GetProperty method without specifying a template argument, and then you can manipulate the returned object as you like.