Can I bypass ERROR_SHARING_VIOLATION?

Question

I have the following C# code:

static void Main(string[] args)
    {
        FileStream fileStream = null;
        try
        {
            // read from file or write to file
            fileStream = new FileStream(@"D:\FileLock.txt", FileMode.Open, FileAccess.Read, FileShare.None);
        }
        catch
        {
        }
        finally
        {
            fileStream.Close();
        }
    }

and I'm trying to copy the file "D:\FileLock.txt" to another location using the following C (WinAPI) code:

CopyFile(_T("D:\\FileLock.txt"), _T("D:\\temp\\FileLock.txt"),FALSE);

But I get ERROR_SHARING_VIOLATION (as expected).

Is there anyway I can bypass this? (i.e. copy the file under these conditions) --without modifying the C# code

That doesn't make sense. If there's a way to bypass file sharing, then someone's just going to ask fo a way to disallow bypassing file sharing, and someone else's just going to ask for a way to bypass even that, etc. You end up in a never-ending loop. — , Feb 13 '15 at 10:36
Are you sure you can't change the C# code to FileShare.Read? — Polyfun, Feb 13 '15 at 10:37
Let me rephrase. It there a way to copy a file that's in use? — conectionist, Feb 13 '15 at 10:39
Maybe the process "forgot" to unlock it. Maybe I want to unlock it without killing that process. — conectionist, Feb 13 '15 at 12:29
The last time I remember someone trying to override mechanisms that protect system integrity a nuclear power plant blew up, and Europe got its share of nuclear fallout. You are free to learn from mistakes others have made. — IInspectable, Feb 13 '15 at 13:25

score -1 · Answer 1 · answered Feb 13 '15 at 10:40

If you can change the C# code, then this should work (changed the OP code to use FileShare.Read):

static void Main(string[] args)
{
    using (FileStream fileStream = new FileStream(@"D:\FileLock.txt", FileMode.Open, FileAccess.Read, FileShare.Read);
    {
    }
}

score -2 · Answer 2 · answered Feb 13 '15 at 12:44

-2

Upon further research, it would seem that this is possible by writing a driver and using some low level functions.

answered Feb 13 '15 at 12:44

conectionist

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Please don't. The sharing mechanism is designed to protect the integrity of both the system and apps running on it. Please go back and tell us why you need to "bypass a sharing violation", what program isn't playing nice, and why modifying the source is out of the question. – andlabs Feb 13 '15 at 16:44

Can I bypass ERROR_SHARING_VIOLATION?

2 Answers2