WMI

Created by Thomas Sparber 2016

GOAL

This is a very simple library written in C++ to execute WMI queries. The aim is to make it as simple as possible and stick as much as possible to the C++ standard (avoid Microsoft specific things) so that it even compiles smoothly on MinGW.

Usage

I think it is so simple that a small program explains the usage without any further comments:

    int main(int /*argc*/, char */*args*/[])
    {
        try {
            Win32_ComputerSystem computer = retrieveWmi<Win32_ComputerSystem>();
            Win32_ComputerSystemProduct product  = retrieveWmi<Win32_ComputerSystemProduct>();
            SoftwareLicensingService liscense  = retrieveWmi<SoftwareLicensingService>();
            Win32_OperatingSystem os_info  = retrieveWmi<Win32_OperatingSystem>();

            cout<<"Computername: "<<computer.Name<<" Domaind:"<<computer.Domain<<endl;
            cout<<"Product: "<<product.Name<<" UUID:"<<product.UUID<<endl;
            cout<<"Architecture: "<<os_info.OSArchitecture<<std::endl;
            cout<<"Roles: "<<endl;
            for(const string role : computer.Roles)
            {
                cout<<" - "<<role<<std::endl;
            }
            cout<<endl;
            cout<<"Installed services:"<<endl;
            for(const Win32_Service &service : retrieveAllWmi<Win32_Service>())
            {
                cout<<service.Caption<<endl;
            }
        } catch (const WmiException &ex) {
            cerr<<"Wmi error: "<<ex.errorMessage<<", Code: "<<ex.hexErrorCode()<<endl;
            return 1;
        }
    
        return 0;
    }

The include file <wmi.hpp> contains all interfaces to execute WMI queries. The include file <wmiclasses.hpp> contains some predefined WMI classes (e.g. Win32_ComputerSystem or Win32_Service...)

Create WMI classes

As already mentioned, the include file <wmiclasses.hpp> provides some standard WMI classes, but it is also very easy to add more of them. All you need to do is:

    struct Win32_MyCustomClass
    {
    
        /**
          * This function is called by requestWmi and requestAllWmi
          * with the actual WmiResult
         **/
        void setProperties(const WmiResult &result, std::size_t index)
        {
            //EXAMPLE EXTRACTING PROPERTY TO CLASS
		    result.extract(index, "name", (*this).name);
        }
    
        /**
          * This function is used to determine the actual WMI class name
         **/
        static std::string getWmiClassName()
        {
            return "Win32_MyCustomClass";
        }
    
        /**
          * This function can be optionally implemented if the wmi class
		  * is not member of cimv2. In such a case, this function needs
		  * to return the root for this WMI class
         **/
        /*static std::string getWmiPath()
        {
            return "not cimv2";
        }*/

        string name;
        //All the other properties you wish to read from WMI
    
    }; //end struct Win32_ComputerSystem

These two functions are the only requirements your class needs to have.