It is a rather theoretical question but is there some (not too obscure) incremental archive format allowing to append to an existing archive using
>> or to join several archives using a simple
archive file1 file2 > backup archive file3 file4 >> backup
cat first.archive second.archive > full.archive
I initially thought about
cpio. But it uses a special
TRAILER!!! marker at the end of the initial archive, so if you catenate two CPIO archives, the second one is never read. Unless I missed some option?