>>- get sending program to do something to indicate that the transfer is done. Something like transfer a 2nd file with the same name but with a .DNE extension so that you know the original is done.
>
>I've been using that method for some time now, and it works just fine. I send the filename.ext, followed by a filename.ok if the first file was successfully transferred. My pickup program looks for the .ok file, then processes the main file when it's found.

There is something to be said for simplicity. :-)