* Package name    : rshasum
  Version         : 0.6.1
  Upstream Author : Shlomi Fish <shlomif@cpan.org>
* URL             : https://metacpan.org/release/App-rshasum
* License         : Expat/MIT
  Programming Lang: Perl
  Description     : Recursive digest calculator

A recursive digest calculator that prints digests for all files in a
directory tree, as well as a total, summary, digest of the output.

Similar packages:

https://github.com/rhash/RHash - "recursive hash". Seems to emit the tree
in an unpredictable, not-always-sorted, order.

https://www.shlomifish.org/open-source/projects/File-Dir-Dumper/ - also on
CPAN, dumps metadata and supports caching the digests.

https://github.com/gokyle/rshasum - written in golang, but slurps entire
files into memory (see https://github.com/gokyle/rshasum/issues/1 ).