Identical folders
When every file inside one folder matches every file inside another, DupliWalker reports one identical-folder result instead of thousands of file results.
Why
Copy a photo library and scan both. Reported file by file, that is one result per photograph — tens of thousands of rows, every one of them saying the same thing: this folder was copied.
You cannot read that. You certainly cannot act on it carefully. And acting on it carelessly is exactly the risk — selecting ten thousand individual files is ten thousand chances to include one you meant to keep.
So the finding is reported at the level it actually occurred: the folder was duplicated, and here it is, as one row you can reason about.
What “identical” means for a folder
A folder is identical to another when everything inside it matches — the same files, with the same content, in the same structure. Not merely a folder with the same name, and not a folder that mostly matches.
If one file inside differs, the folders are not identical, and DupliWalker falls back to reporting what it did find inside them.
Nested identical folders
Identical folders nest. If Photos/2019/ matches, and Photos/ as a whole
matches too, the useful result is the outermost one — Photos/. Reporting the
children as well would recreate the flood the collapse exists to prevent.
The practical consequence: act at the level you were shown. If DupliWalker tells you a parent folder is duplicated, that is the row to work with.
Seeing the files inside
The collapse is presentation, not concealment. Nothing is hidden from the model — the file groups still exist, and the result row shows how many are inside.
To see them, use Show All File Groups — in the View menu. It restores the flat, file-by-file presentation for the whole result set, and toggling it back re-applies the collapse. It is a view setting; it does not change what was found, what is selected, or what any cleanup would do.
Use it when you want to confirm the contents of a folder result, or when you want to keep a handful of files from an otherwise redundant folder.
Next
- Duplicate groups — the file-level unit.
- Safety model — what is read-only, and what is not.