This very simple and naïve program computes entity tag (Etag) checksums, à la those reported by various AWS components.
See also https://nonempty.org/software/etagsum.
This software is in no way affiliated with AWS.
The code is licensed under the GNU General Public License, verson 3.0.
For now, etagsum is just a single executable Python script
bin/etagsum, and can be installed any way you like. All Python 3
versions should be supported.
Invocations are similar to those of sha256sum and friends from GNU
Coreutils, but one needs to explicitly specify the chunk size. This is
done with the --size switch. In
etagsum --size 8M a b --size 16M c
the files a and b are checksummed with a chunk size of 8 MB, and
c with a size of 16 MB. AWS tools tend to pick 8 or 16 MB as defaults.
More options can be seen by running etagsum --help.