Windows cmd : fsutil

 
Create an empty file of an arbitrary size

This command is useful if you quickly need a file of a certain size  that contains only zeros.

fsutil file createnew filename length


Create a hardlink

A hardlink is useful when you want to make the same file appear in different folders. Even if you can see it in many places on your drive, the hard drive space is allocated for only one instance.

The file is physically deleted when the last hardlink is removed.

fsutil hardlink create new_filename existing_filename