Checksums look like they could use some practice. I see how to
manually run a sha1 checksum:

cksum -a sha1 [file]

I can visually inspect that, but I should be able to use the -c or
-C checklist methods.

It appears I can generate a hash file (the same as a checklist?)
by doing:

cksum -a sha1 -h [hashfile] [file]

This creates the hashfile even if it's a new one and it has the
same output format as stdout did. Now, how do I read that back in?

cksum -a sha1 -c [hashfile] [file] spits out a ton of errors, so
that's not it.

OH!

cksum -a sha1 -C [hashfile] [file]

-or-

cksum -a sha1 -c [hashfile]

Sa-weet!
.