How to detect a file exists in destination?

[tangyue1]

Summary

I am downloading from multiple icloud accounts to the same destination folder. Will the downloader download and rename if a file with the same name exists in destination but is a different photo?

Context

[AndreyNikiforov]

de-duplication uses file name and size, not account. as long as files with the same name from multiple accounts come with different sizes, you'll have both downloaded

[hartzde]

Andrey, Any thoughts of using file hash comparison for dedup check?

[AndreyNikiforov]

Andrey, Any thoughts of using file hash comparison for dedup check?

Good idea and for general file comparison is proven to be helpful, e.g. git uses hash. I don't know what value can hashing bring for image/video deduping, e.g. what is the chance that two different videos are exactly the same size, same name, and shot on the same date (assuming that person is downloading using folder structure with date)?

Of course deduping fails miserably when EXIF data is modified during downloading, either using hash or name-size pair.