Implement file verification

[Mark Hayes]

Consider providing an option to make the backup copy not from the original files on the memory cards, but from the first copy on the hard drive. That way, a verification of the backup copy on the secondary location against the originals still on the card will most likely verify that both versions are good copies.
e.g. Copy from card to hard drive > Make backup copy by copying from hard drive to backup drive (and not from card to backup drive) > verify backup copy against original data on card - if all OK, then both copies are likely good, bit by bit copies.

[Mark Hayes (mark-hayes-1973)]

Whilst thinking about this - I came across another unanswered question that might be covered by the same solution.

Verification of the second copy (or first) can be done in several ways that I know of - please excuse any errors, I am not a coder. As far as I understand, rather than do a bit-by-bit verification during the download, which may turn Rapid Photo Downloader into SLOW photo downloader, maybe you can just verify a hash of each file instead.

So then, create and save a hash of each file on the card, download all photos to their download location and then run a hash on each file again. Compare A to B or even A to B and C - any differences would highlight incorrect file transfer.

It does NOT confirm that the file is not corrupted, only that the file has been transferred correctly from the card to the download locations.

That way, you solve two problems with the same solution...?

[Damon Lynch (dlynch3)]

Thank you for your bug report. If you take a look at the code, Rapid Photo Downloader has always copied from the hard drive to the backup mediums.

Verification of downloaded files is indeed a wishlist item. Are you motivated to code it?