While on the subject, what is the difference between file:/path/to/file and file:///path/to/file ? Usually I only see the latter being used.
I have never seen file:/ used before, so I can't really comment, but it seems invalid to me (and browsers auto-redirect it to ///).
The file: signifies the protocol. The /// is actually //<machinename>/ with an empty machinename as a shorthand for 'localhost'.
Why is this interpreted as a relative path?
cd /etc
curl file://resolv.conf