during unpacking with tar hide the error message: 'tar: Removing leading `/' from member names' for archive created with --absolute-names

Question

It is not duplicate, other questions on stackexchange are about getting rid of this message as archive is created.

Is it possible, given archive that was created with -P option (with leading `/')?

I have an archive created with "--absolute-names" (-P option) - with leading /.

I want to unpack it, with / stripped (tar is doing it by default).

It is almost ideal, but I want to silence:

tar: Removing leading `/' from member names.

without removing other messages (so brute force in the form of 2>/dev/null is not a solution).

I found multiple solution how to silence this message during creating archive but none for unpacking. I know about grep -v but it will (a) hide error code from tar (b) add its own error code if message about / is not stripped.

This situation may be replicated with

cd /home/user/tmp
touch a.txt
mateusz@Grisznak:~/Desktop/tmp$ tar --create -P /home/user/tmp > a.tar
mateusz@Grisznak:~/Desktop/tmp$ tar --extract --file=a.tar 

To avoid XY problem: I am unpacking archives created by backup gem (http://backup.github.io/backup/v4/).

Answer 1

This seems to do what you want:

tar --extract --xform 's/^\///' --file=a.tar

Per the man page:

--transform, --xform EXPRESSION
      use sed replace EXPRESSION to transform file names

So it still strips the leading slash, but doesn't talk about it.