Module progress 

Saying that a long walk is still walking.

--all fetches pages until there are none left, and twenty pages of silence is indistinguishable from a hang. Three rules keep the cure from being worse than the disease:

1. Always stderr. stdout is a data channel; a progress line in the middle of a result set would corrupt whatever is parsing it.
2. Only when stderr is a terminal, not when stdout is. find --all > out run by a person has a piped stdout and a watching human — that is exactly the case progress is for. A command whose stderr is captured has no watcher, so it gets nothing.
3. Nothing is left behind. The bar clears itself; the tally on stdout is the record of what happened.

Structs

Walk

A progress indicator, or nothing at all.