Psutil: proc.open_files() limiting results on Windows

open_files on Windows is basically unreliable and a pain in the ass historically, see the red warning here:
https://pythonhosted.org/psutil/#psutil.Process.open_files
...and:
https://github.com/giampaolo/psutil/pull/597
I'm not surprised this is yet another problem I wasn't aware of.
Realistically I think I'll just add another warning to the doc, but I won't invest time into fixing it because I consider it a lost cause.

CC @mrjefftang

It's too bad it's such a pain. It's a great feature to use when Windows is doing dumb things and keeping open file handles on things it shouldn't need too.

If I have some spare time at some point maybe I can take a look at this specific bug.

Thank you for your hard work on this project!

What version of Windows are you running on?

Windows 10

The simple test I used is to open a folder in a drive other than C: using explorer. The path to that folder should show up in the open file handles for explorer.exe.

Strange, that shouldn't be missing file handles unless they are network drives.

The reality is that open_files was hacked together to make it work. There's a proper solution using Windows APIs that are available in 7+ and drop support for prior versions.

Jeff, what about it? If you're sure about it I'm all for dropping the hack currently in place and support Win 7 only.

I don't remember the exact API calls at the time but I remember it only working on Windows 7+ when I tested it. And at that point in time, I needed to support WinXP for a project that relied on psutil. I might have documented it in one of the previous PRs/issues.

I don't have time to work on it but I believe it would be straight forward for someone to implement this using the right APIs.

Hello, I am starting to look into this matter as I would like to accurately observe opening/closing events on windows, but I am not familiar with Windows API. Is it possible that the API @mrjefftang was mentioning is TDH? An answer on StackOverflow refers to it as something introduced in Vista/7.

Looking back at this because I am rewriting open_files() code on Windows: it seems that psutil is able to list files living on drives other than C:\ after all. I've just created a file on another drive (E:) and it shows up. The doc mentions this limitation but it appears it's either wrong or outdated. Closing this out.