I need to know if a user selected download then clicked the cancel button, which is not the same as readfile having an error. I have inspected the count returned by the rea
I fear the correct answer is "Impossible" - let me explain: You might be able to correctly figure out, when the file has crossed the wire, but you can't figure out reliably, whether the client threw it away or not.
Example (chronological sequence):
Result: