freepascal - How to call a list of the physically attached hard disks using Free Pascal, or, failing that, Delphi?

Question

Further to this question and this one that I asked more recently but without the correct specifics...and lastly this one that I asked at the Free Pascal forum specifically....

Can anyone provide me with guidance, examples or a link to something somewhere that explains how to call a list of the physically attached hard disks using Free Pascal, or, failing that, Delphi, regardless of whether the disks have been mounted by the operating system or not? An example is shown in the screenshot of what I am trying to achive (what is shown in this screenshot is by another software product). So pulling a list of logical volumes (C:, E: etc) is not what I am trying to do. And if the disk has a filesystem that the operating system cannot mount, I still want to see the physical disk listed.

I stress that CC++C Sharp examples are plentifull but not what I am after. I need primarily Free Pascal example, or, failing that, Delphi.

Answer 1

Try the Win32_DiskDrive WMI class, check this sample code

{$mode objfpc}{$H+}
uses
  SysUtils,ActiveX,ComObj,Variants;
{$R *.res}

// The Win32_DiskDrive class represents a physical disk drive as seen by a computer running the Win32 operating system. Any interface to a Win32 physical disk drive is a descendent (or member) of this class. The features of the disk drive seen through this object correspond to the logical and management characteristics of the drive. In some cases, this may not reflect the actual physical characteristics of the device. Any object based on another logical device would not be a member of this class.
// Example: IDE Fixed Disk.

procedure  GetWin32_DiskDriveInfo;
const
  WbemUser            ='';
  WbemPassword        ='';
  WbemComputer        ='localhost';
  wbemFlagForwardOnly = $00000020;
var
  FSWbemLocator : OLEVariant;
  FWMIService   : OLEVariant;
  FWbemObjectSet: OLEVariant;
  FWbemObject   : Variant;
  oEnum         : IEnumvariant;
  sValue        : string;
begin;
  FSWbemLocator := CreateOleObject('WbemScripting.SWbemLocator');
  FWMIService   := FSWbemLocator.ConnectServer(WbemComputer, 'rootCIMV2', WbemUser, WbemPassword);
  FWbemObjectSet:= FWMIService.ExecQuery('SELECT * FROM Win32_DiskDrive','WQL',wbemFlagForwardOnly);
  oEnum         := IUnknown(FWbemObjectSet._NewEnum) as IEnumVariant;
  while oEnum.Next(1, FWbemObject, nil) = 0 do
  begin
    sValue:= FWbemObject.Properties_.Item('Caption').Value;
    Writeln(Format('Caption        %s',[sValue]));// String
    sValue:= FWbemObject.Properties_.Item('DeviceID').Value;
    Writeln(Format('DeviceID       %s',[sValue]));// String
    sValue:= FWbemObject.Properties_.Item('Model').Value;
    Writeln(Format('Model          %s',[sValue]));// String
    sValue:= FWbemObject.Properties_.Item('Partitions').Value;
    Writeln(Format('Partitions     %s',[sValue]));// Uint32
    sValue:= FWbemObject.Properties_.Item('PNPDeviceID').Value;
    Writeln(Format('PNPDeviceID    %s',[sValue]));// String
    sValue:= FormatFloat('#,', FWbemObject.Properties_.Item('Size').Value / (1024*1024));
    Writeln(Format('Size           %s mb',[sValue]));// Uint64

    Writeln;
    FWbemObject:= Unassigned;
  end;
end;

begin
  try
    GetWin32_DiskDriveInfo;
  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.    

After of running this code you will get a output like this