Question

I have a difference between files size and used disk space (total file size is even more than disk size). I suppose because there are many hard links exist (to WinSxS components) in Windows 7/Vista. But how can I programmatically distinguish hard links from real files in Windows 7?

Answer 1

You can’t, because all files are hard links. No. Really. A file is just a hard link to a data chunk — a listing in a directory. (Perhaps you mean symlinks? You can distinguish those…)

Use the builtin methods Windows provides for calculating used space instead.

EDIT: Reference (emphasis mine)

The link itself is only a directory entry, and does not have a security descriptor. Therefore, when you change the security descriptor of a hard link, you a change the security descriptor of the underlying file, and all hard links that point to the file allow the newly specified access.