Re: tar and permissions

[Bruno Raoult <braoult@example.com>]

Hector Akamine wrote:

>Hi,
>
>I am confused about the meaning of the "preserve permissions" (-p)
>switch in tar. According to what I have read, using -p keeps the file
>permissions as the original files. Then, what happens when I use tar without
>-p?
>
>I want to copy the contents of some user's directory using tar. I think
>I should make the operation as root. If I use -p, will it keep the
>file-directory permissions and owners as the original ones? What happens
>if I don't use -p? 
>
>
>Thanks in advance 
>
Here is an example of the difference using or not -p. This is linked to 
umask.
Not using -p could give files more restrictive permissions to file, 
depending on umask value.

pern br> mkdir tar
pern br> cd tar
pern br> touch foo
pern br> ls -l
total 0
-rw-r--r--    1 br       users           0 Oct 24 21:52 foo
pern br> tar cvf foo.tar foo
foo
pern br> mv foo foo.orig
pern br> umask 777
pern br> tar xpvf foo.tar
foo
pern br> mv foo foo-p
pern br> tar xpvf foo.tar
foo
123 pern br> ls -l
total 12
----------    1 br       users           0 Oct 24 21:52 foo
-rw-r--r--    1 br       users           0 Oct 24 21:52 foo-p
-rw-r--r--    1 br       users           0 Oct 24 21:52 foo.orig
-rw-rw-rw-    1 br       users       10240 Oct 24 21:53 foo.tar