NTFS supports Reparse Points -- MS's name for hard links -- so it's possible to have two paths refer to the same file. There is a function you can call to get the GUID of the Reparse Point. Judging by the name, this should be unique across all devices and machines.

On a given FAT device, the path is the unique identifier (once "." and ".." are properly removed). However, it is tricky to determine whether two devices are the same (in part or in whole). Given

net use z: \\127.0.0.1\c$
net use y: \\127.0.0.1\share_c
net use x: \\10.0.0.5\c$
net use w: \\tribble05\c$
subst v: c:\

net use u: \\127.0.0.1\c$\dir
net use t: \\127.0.0.1\share_dir
subst s: c:\dir
[download]

c:\dir\file

z:\dir\file
y:\dir\file
w:\dir\file
v:\dir\file
x:\dir\file

u:\file
t:\file
s:\file
[download]

It's even trickier once virtual drivers and shares on non-Windows machine come into play.

That will identify unique file contents, but it won't identify unique files. In other words, making a copy of a file will appear to be the same file.

Do not rebuke them with harsh words ... but rather lead them gently - with URLs - so that they may learn wisdom.

Yes, but there is no such thing like an "ununique" file under windows (except you can have hard links, but I have never seen a real life usage of that).


holli, /regexed monk/