On 03/12/2013 10:17 PM, Joerg Schilling wrote: > Paul Eggert <egg...@cs.ucla.edu> wrote: > >> On 03/12/13 02:03, Glauber Costa wrote: >>> With that, it is extremely useful when unpacking tar archives, to be >>> able to add that offset to the end result. Specifying a user won't help, >>> since the tar archive can have many >> >> Sorry, I'm not following this part. Why can't you extract the >> tar image in a context where the mapping is already in place? >> If user "foo" is host user ID 4000, for example, and you're running >> in an environment where uid 0 maps to 10000, then presumably >> user "foo" is namespace user 14000, which is what you want, no? > > Also, TAR should map by name rather then by uid in the first attempt. >
I am not sure what exactly you mean here. In my proposed implementation, I documented this option to imply numeric offset. This is precisely because only numeric UIDs matter. If you are extracting an archive that contains a distribution image with a particular user, there is no guarantee that such user exists in the host system. Much less that it has an equal user id.