How to find all open files ?

Hi,
I'm looking for a tip using C to retrieve

-all the opened/locked files in the system (in a Dos system structure ?)
Or
-the file that a process has currently locked/opened (in an anchor in the process structure ?)

I must have made bad research but I found nothing in the autodocs and include.

Is somebody know a "simple" way to achieve this ?

Thank by advance for your help.

There is no system API for that AFAIK. Colin Wenzel (dos.library maintainer) has some special tools to do the trick but I don't think you can do that from a generic app yet.

Thank for reply,
hoping in a next version...

Hmmm... at least, the locks made by the dos.library should be accessible in any way, as system monitors like e.g. Scout are able to show all locks that are currently active.

So there must be some linked list to traverse and investigate...

The locks are made by the filesystem, not by DOS, although the memory structures used are allocated by DOS.

Some filesystems use a linked list of Locks, but the links are unidirectional and the start of the list is not accessible, so you can only see the "downstream" part of the list, which is not exhaustive.

You will also see everyone's locks, not just your own. There is no identification of which Processes own which Locks.

Why do you want to know? What can you do with such a list? Perhaps you want a list of FileHandles, not Locks, but these are not chained together by any filesystem that I know of.

Quote:
This is important for resource tracking and is something I'd love to know when debugging problems.

What we lack today is an API to obtain such information. Tools like Scout have to resort to nasty hacks to try and obtain this information and that should not be necessary.

@tonyw:

Thx for the clarification.

@ssolie:

Yeah, some API extensions regarding this (and other things needed for debugging) would be very nice.

Thank you Tony for the explanations,
I wanted to use it to monitor all the files opened in the system at a precise instant.

@zzd10h
Quote:

Since most programs open a file, load data and close the file, you wouldn't find out much at most specific instances.