Following and stopping a scan

A scan runs in two steps, and the progress bar means something different in each. Knowing which step is running explains why a large scan seems to stall and then race.

Step one: walking the folders

The app looks through the folder tree and collects the files worth opening. It does not yet know how many there will be — that is what it is finding out — so the bar has no total to fill up to and only shows that something is happening.

On a large home folder this step alone can take a while, and it is the step people mistake for a hang. The line under the window title says which step is running.

Step two: reading the files

The number of files is known now, so the bar fills up for real. Each file that can carry a date of its own is opened and the date is read out of it. The work is spread across as many processor cores as your Mac has.

Results arrive in batches while this is going on, so the window fills up as it works. You can select, look at and delete files before the scan has finished.

Stopping

The square button beside the bar ends the scan. What has been found so far stays in the window and behaves exactly like a finished result: you can filter it, search it, inspect it and act on it.

Stopping is worth reaching for. If you pointed the app at a whole disk and the month you wanted has already appeared, there is no reason to wait for the rest.

Reading the count

The line under the window title counts two things: how many items the window is listing and how many the scan has found. When they differ — 1 765 of 8 198 items — the difference is what the filter and the search field are hiding, not something that went wrong. See Filtering by type.