pv is invaluable but my issue with it is it’s only useful if you think to include it before you run the command. Usually the thought doesn’t occur to me until I have some runaway cp or dd and I want to be reassured that it’s going to be done soon. For that case that this looks super interesting.

You can attach pv to an existing process. IIRC it's the -p option.

-p is same as "--progess":

https://linux.die.net/man/1/pv

Ah, it was -d I was thinking of. Anyway, the point is that you can run pv retrospectively just fine while your slow command is running.

wow I usually just use rsync with the progress flag but this looks way cooler. thanks!