How to check if file is in use (Windows)

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Thu, 10/10/2013 - 04:16 am

Hi!

I have a question regarding how to check if a file is in use by another program, before trying to open it for reading in data with IGOR? I have checked the WaitForFileProcs.ipf procedure file and the WaitForWriteAccesToFile function defined there which will (I think) not work in my case, because I am trying to read from a remote machine where I do not have write access and therefore the trick in the function with trying to append to file will always fail.

Are there any other options, tricks?

Thanks a lot!

Gregor
Quote:
Are there any other options, tricks?


Not that I know of. There may be some low-level way, using the Win32 API, to check if a file is open but I am not aware of it.

Other than that you would need the cooperation of the software on the other machine that is opening the file.

October 10, 2013 at 06:13 am - Permalink

The GetFileFolderInfo operation provides a lot of info on a disk file, unfortunately, none of it directly answers your question. Maybe you can use something such as the returned value V_modificationDate to get an indirect answer?

October 10, 2013 at 06:53 am - Permalink

Hi!

Quote:
Not that I know of. There may be some low-level way, using the Win32 API, to check if a file is open but I am not aware of it.


I briefly checked the Win32 API and the MSDN pages and it really seems that there is no direct way to check if a file is in use.

Quote:
The GetFileFolderInfo operation provides a lot of info on a disk file, unfortunately, none of it directly answers your question. Maybe you can use something such as the returned value V_modificationDate to get an indirect answer?


I will try this, probably using the file size information.

Thank you both for your quick response and help!

Cheers,
Gregor

October 11, 2013 at 05:20 am - Permalink

gregorK wrote:
Hi!

I briefly checked the Win32 API and the MSDN pages and it really seems that there is no direct way to check if a file is in use.



Shouldn't LockFileEx[1] with LOCKFILE_EXCLUSIVE_LOCK set accomplish that?
As far as I understand it, you will only get an exclusive lock if no other process has already locked the file.

[1]: http://msdn.microsoft.com/en-us/library/windows/desktop/aa365203%28v=vs…

October 11, 2013 at 05:42 am - Permalink