如何以编程方式区分由subst命令创建的虚拟驱动器和实际可移动驱动器

Question

When we attach removable drive, OS assigns drive letter to it. Other way is to use subst command to map local folder to any drive. I am writing the hook to Explorer where I need to differentiate between these two drives. I tried to use GetVolumePathName but it is not working correctly for virtual drives.

Answer 1

I found the answer to the question by just adding one additional verification step.

Suppose I mapped c:\\Folder1 to z:.

I have a path z:\\file1.txt. If I try to get the mount point using API GetVolumePathName() then it fails so I can guess that z:\\ is nothing but the virtual drive which is pointing to some folder in other drive.

But If I have a path z:\\Folder2\\file1.txt then GetVolumePathName() gives me Mount Point as z:\\Folder2. I do not understand why. But to verify that whether it is actually pointing to any device volume I used API GetVolumeNameForVolumeMountPoint() to get volume name of Mount Point return above. If Mount Point is for any device then it returns the actual volume name GUID of that device else it fails (for virtual drive).

Now to know if Mount Point return above is FIXED or REMOVABLE use GetDriveType() if it returns DRIVE_FIXED then it is fixed drive else DRIVE_REMOVABLE then it is removable.

It solved my purpose.