I have a process that creates a tar file with copies of files that need to be updated.
I want to backup existing files before overwriting with the new files.
I've tried
tar cf backup.tar -T `tar tf updated.tar`
Which didn't work. If I pipe the output from tar tf to a file, then use that as the -T param it works:
tar tf updated.tar > list; tar cf backup.tar -T list
But it seems to me that I should be able to accomplish this in one command. Is it possible?