proc.open_files() limiting results on Windows

[osstony]

proc.open_files() seems to only be returning files located on my C: drive but no files located on any other drives. I found this out by iterating over every running proc, calling open_files and comparing the results to what is spit out of executing the handle program located at https://technet.microsoft.com/en-us/sysinternals/handle.aspx.

I don't have any further details other than the open_files returned always only exist on my C: drive and no other available drives.

If you need further details please let me know.

[giampaolo]

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:
#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

[osstony]

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!

[mrjefftang]

What version of Windows are you running on?

[osstony]

Windows 10

[osstony]

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.

[mrjefftang]

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.

[giampaolo]

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.

[mrjefftang]

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.

[akiross]

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.

[giampaolo]

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.