hi,

say I have

dirA/file1
dirB/file2

and I tar them up, and then do

Sometimes I will see:

dirA/
dirA/file1
dirB/
dirB/file2

yet other times I will see

dirA/file1
dirB/file2

i.e. no directory stuff

Why is this?

thanks

tar has evolved over the years. The very first versions of tar did not copy directory information into the archive. The feeling was that if a directory was needed, just create it on the fly. But this lost directory ownership and permission info so it was fixed. A few current versions of tar has options to create an archive in this manner for compatibility with very old tar versions.

The way you phrase the question suggests that you thing omitting directories from a tar archive is normal or good. This is not the case.

yes, but say I want to tar up

a/b/c/d/file1
x/y/z/file2

then if directory information is stored I will have

a/
a/b/
a/b/c/
a/b/c/d/
a/b/c/d/file1
x/
x/y/
x/y/z/
z/y/z/file2

Also, if I want to untar this and I already have these directories created on my system, then these new directory information will overwrite my directory information?

thanks

It should if you run it as root. Generally only root can give files away. Also if tar sets a directory to read-only, root can still put files in it. This is what tar usable to backup and restore files.

thanks