Disable checksum filtering

[szabgab]

I have a slow external disks connected to the computer with thousands of large files (videos). comparing the checksums take a lot of time. Would it be possible to disable it?

[fire-eggs]

You might try the -maxsize option to ignore files larger than a given size.

[szabgab]

Thanks for the suggestion, but I think the -maxsize option would mean I don't get the report about the large file and I would like to see if I might have 2-3 copies of the same 1GB files so I can get rid of them.

[einsteinx2]

I have this text in my PR, but figured it would be good to comment with it here as well for discussion.

To the maintainer(s), I think there is a real use case for this:

In my example, I have a NAS with dozens of TB of storage. I have a lot of files that are significantly large (dozens to hundreds of GB). I've been doing some file reorganization and my goal is just to get a short list of files that might be duplicates that I can then process later.

In my case, if these large files have the same name and size and first/last bytes, I can be basically 100% sure they're the same file. It would take exponentially longer to checksum every file at discovery time only to find out what I already know...they're the same.

Later if needed I can manually checksum files in the results list, or even do something like test/checksum random byte ranges in the files rather than checksumming the whole thing to save a ton of time, but in my case (and I assume others' as well) I already know they're the same so even that isn't needed.

To be clear, I think the default should stay the same (or even go up to sha256/512), but at least having the option to disable checksumming can be very useful and the change is only a few lines.