🚀 go-pugleaf

>So my question is, how can I determnine whether some other application has a
>particular file open so I don't try to open it and get slapped across the
>wrist?  What combination of flags in OpenFile gives me some code that
>tells me the file is in use (or hangs me up until it it not), WITHOUT
>giving me these unpleasant `sharing violations'?

I encountered problems with Openfile that may be similar to yours.
In my case I have multiple computers on a network simultaneously accessing 
a single file. To create the file I used a call similar to the following:

   hFile = OpenFile( szFileName, OFile, 
                     OF_CREATE | OF_READWRITE | OF_SHARE_DENY_NONE );

However, when a second application attempted to open the file access was
denied!  The call used by the second application was the following:

   hFile = OpenFile( szFileName, OFile, 
                     OF_READWRITE | OF_SHARE_DENY_NONE );

I was able to resolve this problem by first creating the file, closing
it, then reopening it:

   hFile = OpenFile( szFileName, OFile, OF_CREATE );
   if ( hFile != -1 )
      {
      _lclose( hFile );
      hFile = OpenFile( szFileName, OFile, 
                        OF_READWRITE | OF_SHARE_DENY_NONE );
      }

With this code I enabled simultaneous access to the file by multiple 
applications.

Hope this helps. Good luck.

Kevin