Windows: Calling a WMI function -- Working example?

Forum > Windows

(1/1)

oh_ha:
Hallo all,

I am looking for sample code on how to call a WMI function. Does anyone has a working example in FreePascal, ideally including code on how to pass parameters to the function? Unfortunately, the "Delphi WMI code Creator" does not help me as the FreePascal code for creating a function does not work.

Just to be clear: This is not about querying WMI properties, but calling a function like Win32_OperatingSystem.LocalDateTime.

Thanks and regards, Olaf

marcov:
If you click through, then it is just calling a method on the olevariant.

IOW use the query method to get the right object in an olevariant, and then call the method on it.

But I would find some other method to test, setdatetime has permission aspects to it (The calling process must have the SE_SYSTEMTIME_NAME privilege.) , so is not a suitable first test subject.

PascalDragon:
The second example given here on the WMI Delphi Code Generator to start a process using WMI works correctly with FPC 3.2.0. So what exactly is the problem you have? Maybe it's indeed the priviledge as marcov mentioned?

Jurassic Pork:
hello,
you can try something like that :

--- Code: Pascal [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} ---program SetLocalDateTime;{$mode objfpc} {$H+}uses SysUtils, ActiveX, ComObj; procedure Invoke_Win32_OperatingSystem_SetDateTime;const WbemUser =''; WbemPassword =''; WbemComputer ='localhost'; wbemFlagForwardOnly = $00000020;var FSWbemLocator : OLEVariant; FWMIService : OLEVariant; FWbemObjectSet : OLEVariant; FWbemObject : OLEVariant; FInParams : OLEVariant; FOutParams : OLEVariant; sValue : string; MyDateTime : OLEVariant; oEnum : IEnumvariant; dummy : LongWord;begin MyDateTime := CreateOleObject('WbemScripting.SWbemDateTime'); FSWbemLocator := CreateOleObject('WbemScripting.SWbemLocator'); FWMIService := FSWbemLocator.ConnectServer(WbemPassword, 'root\CIMV2', WbemUser, WbemPassword); FWbemObjectSet:= FWMIService.ExecQuery('SELECT * FROM Win32_OperatingSystem','WQL',wbemFlagForwardOnly); oEnum := IUnknown(FWbemObjectSet._NewEnum) as IEnumVariant; dummy := 0; while oEnum.Next(1, FWbemObject, dummy) = 0 do begin sValue:= FWbemObject.Properties_.Item('LocalDateTime').Value; Writeln(Format('ReturnValue %s',[sValue])); MyDateTime := FWbemObject.Properties_.Item('LocalDateTime'); end; FWbemObjectSet:= FWMIService.Get('Win32_OperatingSystem'); FInParams := FWbemObjectSet.Methods_.Item('SetDateTime').InParameters.SpawnInstance_(); FInParams.LocalDatetime:= ???????????? FOutParams := FWMIService.ExecMethod('Win32_OperatingSystem', 'SetDateTime', FinParams); sValue:=FOutParams.ReturnValue; Writeln(Format('ReturnValue %s',[sValue])); end; begin try Invoke_Win32_OperatingSystem_SetDateTime; except on E:EOleException do Writeln(Format('EOleException %s %x', [E.Message,E.ErrorCode])); on E:Exception do Writeln(E.Classname, ':', E.Message); end; Writeln('Press Enter to exit'); Readln;end.

--- Quote ---ReturnValue 20201022134901.176000+120

--- End quote ---
but :
1 - I can't find how to set FInParams.LocalDatetime. I have tried some values but when i execute the ExecMethod i have always an exception : OleException - ArgumentException : The exception that is thrown when one of the arguments provided to a method is not valid
2 - The calling process must have the SE_SYSTEMTIME_NAME privilege.

Friendly,J.P

marcov:
OP put it on SO, and somebody posted a C++ example. I found some similar code in Delphi to setup the WMI with security identifiers, and changed the actual executing by translating the rest of the C++.

Total work searching and translating: about 2 hours.

This code works for me in 32-bit win32 (it uses Jedi units though)

--- Code: Pascal [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} --- program wmiedidint2;// based on https://theroadtodelphi.com/2011/04/21/accesing-the-wmi-from-delphi-and-fpc-via-com-without-late-binding-or-wbemscripting_tlb/// modified to function as https://docs.microsoft.com/en-us/answers/questions/95631/wmi-c-application-problem-wmimonitordescriptormeth.html?childToView=96407#answer-96407{$IFDEF FPC} {$MODE DELPHI} {$H+}{$ENDIF} {$APPTYPE CONSOLE} uses Windows, Variants, SysUtils, ActiveX, JwaWbemCli; const RPC_C_AUTHN_LEVEL_DEFAULT = 0; RPC_C_IMP_LEVEL_IMPERSONATE = 3; RPC_C_AUTHN_WINNT = 10; RPC_C_AUTHZ_NONE = 0; RPC_C_AUTHN_LEVEL_CALL = 3; EOAC_NONE = 0; function GetBytesFromVariant(const V: Variant): TBytes;// this function is a mess and only works for bytes. From SOvar Len: Integer; SafeArray: PVarArray;begin Len := 1+VarArrayHighBound(v, 1)-VarArrayLowBound(v, 1); SetLength(Result, Len); SafeArray := VarArrayAsPSafeArray(V); Move(SafeArray.Data^, Pointer(Result)^, Length(result)*SizeOf(result[0]));end; procedure Test_IWbemServices_ExecQuery;const strLocale = ''; strUser = ''; strPassword = ''; strNetworkResource = 'root\WMI'; strAuthority = ''; WQL = 'SELECT * FROM WmiMonitorDescriptorMethods'; EDIDMethodname = 'WmiGetMonitorRawEEdidV1Block'; EDIDClassName = 'WmiMonitorDescriptorMethods'; var FWbemLocator : IWbemLocator; FWbemServices : IWbemServices; FUnsecuredApartment : IUnsecuredApartment; ppEnum : IEnumWbemClassObject; apObjects : IWbemClassObject; puReturned : ULONG; pVal : OleVariant; pType : Integer; plFlavor : Integer; Succeed : HRESULT; varreturnvalue : olevariant; varotherval : longint; varcmd2 : tagVariant; varcommand : olevariant; // tagVARIANT; pOutParamsDefinition, pInParamsDefinition, pClass, pClassInstance : IWbemClassObject; callres : IWbemCallResult; err : IErrorInfo; aname,w2 : Widestring; bytes : TBytes; i : integer; procedure teststatus(const msg:string);begin if Succeeded(succeed) then writeln('Successs:',msg) else writeln('Fail:',msg)end; begin // Set general COM security levels -------------------------- // Note: If you are using Windows 2000, you need to specify - // the default authentication credentials for a user by using // a SOLE_AUTHENTICATION_LIST structure in the pAuthList ---- // parameter of CoInitializeSecurity ------------------------ if Failed(CoInitializeSecurity(nil, -1, nil, nil, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, nil, EOAC_NONE, nil)) then Exit; // Obtain the initial locator to WMI ------------------------- if Succeeded(CoCreateInstance(CLSID_WbemLocator, nil, CLSCTX_INPROC_SERVER, IID_IWbemLocator, FWbemLocator)) then try // Connect to WMI through the IWbemLocator::ConnectServer method if Succeeded(FWbemLocator.ConnectServer(strNetworkResource, strUser, strPassword, strLocale, WBEM_FLAG_CONNECT_USE_MAX_WAIT, strAuthority, nil, FWbemServices)) then try // Set security levels on the proxy ------------------------- if Failed(CoSetProxyBlanket(FWbemServices, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE, nil, RPC_C_AUTHN_LEVEL_CALL, RPC_C_IMP_LEVEL_IMPERSONATE, nil, EOAC_NONE)) then Exit; if Succeeded(CoCreateInstance(CLSID_UnsecuredApartment, nil, CLSCTX_LOCAL_SERVER, IID_IUnsecuredApartment, FUnsecuredApartment)) then try // Use the IWbemServices pointer to make requests of WMI //Succeed := FWbemServices.ExecQuery('WQL', WQL, WBEM_FLAG_FORWARD_ONLY OR WBEM_FLAG_RETURN_IMMEDIATELY, nil, ppEnum); Succeed := FWbemServices.ExecQuery('WQL', WQL, WBEM_FLAG_FORWARD_ONLY, nil, ppEnum); if Succeeded(Succeed) then begin Writeln('Running Wmi Query..Press Enter to exit'); // Get the data from the query while (ppEnum.Next(WBEM_INFINITE, 1, apObjects, puReturned)=0) do begin succeed:= apObjects.Get('__PATH', 0, pVal, pType, plFlavor); teststatus('get __PATH'); aname:=pval; writeln('__PATH: ',aname); succeed:=fwbemservices.GetObject(edidclassname,0,nil,pClass,callres); teststatus('getobject'); succeed:=pClass.GetMethod(EDIDMethodname,0,pInParamsDefinition,pOutParamsDefinition); teststatus('getmethod'); succeed:=pInParamsDefinition.SpawnInstance(0, pClassInstance); teststatus('Spawn'); fillchar(varcmd2,sizeof(varcommand),#0); varcmd2.vt:=VT_UI1; varcmd2.bval:=0; move(varcmd2,varcommand,sizeof(varcmd2)); succeed:= pClassInstance.Put('BlockId',0,@VarCommand,0); teststatus('put blockid'); writeln('The BlockId is: ,',varCommand); pOutParamsDefinition:=Nil; callres:=nil; w2:=EDIDMethodname; succeed:= fwbemservices.ExecMethod(aname,w2,0,nil,pClassInstance,pOutParamsDefinition,callres); if succeeded(succeed) then begin writeln('execute success!'); end; succeed:= pOutParamsDefinition.Get('BlockType', 0, varreturnvalue,ptype,plFlavor); if succeeded(succeed) then begin writeln('blocktype:',varreturnvalue); varotherval:=varreturnvalue; if varotherval=1 then begin succeed:= pOutParamsDefinition.Get('BlockContent', 0, varreturnvalue,ptype,plFlavor); if succeeded(succeed) then begin bytes:=GetBytesFromVariant(varreturnvalue); write('bytes:'); for i:=0 to length(bytes)-1 do begin write('$',inttohex(bytes[i],2),' '); end; writeln; end; end; end; end; end else Writeln(Format('Error executing WQL sentence %x',[Succeed])); finally FUnsecuredApartment := nil; end; finally FWbemServices := nil; end; finally FWbemLocator := nil; end;end; begin // Initialize COM. ------------------------------------------ if Succeeded(CoInitializeEx(nil, COINIT_MULTITHREADED)) then try Test_IWbemServices_ExecQuery; finally CoUninitialize(); end; Readln;end.

Navigation

[0] Message Index