I don't believe that what you are asking for can be done with rsync. At
first thought you can't mix --ignore-existing with --ignore-non-existing
as that would ignore everything. Something would have to at least exist
and not be ignored for rsync to link to it.
Anyway, for a laugh, I asked
Recently I was thinking about --link-dest= and if it was possible to use
rsync to de-duplicate two nearly-identical directory structures.
Normally I would use a tool like hardlink, jdupes, or rdfind, but in
this case the files are huge and numerous, so hashing them would take
forever. I did a
