My automation script that downloads foreign exchange rates data and email myself the information is crapping out this past week. For whatever reason, my code to use perl to do inline edit is throwing an error about "Can't do inplace edit...."
After googling a bit, I find the following Sysinternals utilities that shows what processes might potentially be locking on the file:
https://docs.microsoft.com/en-us/sysinternals/downloads/handle. I can see this being quite useful for other things as well, and therefore is making a note of it here.