After tar extract, Changing Permissions

If you want to keep the permissions on files then you have to add the -p (or --preserve-permissions or --same-permissions) switch when extracting the tarball. From the tar man pages :

--preserve-permissions--same-permissions-p    When `tar' is extracting an archive, it normally subtracts the    users' umask from the permissions specified in the archive and    uses that number as the permissions to create the destination    file.  Specifying this option instructs `tar' that it should use    the permissions directly from the archive.

So PHP code should be :

exec("tar -xzfp foo.tar.gz");

Edit: --delay-directory-restore solved the problem below about being unable to untar a file. The permissions of pwd are still altered, so the problem of the original poster might not be solved.

Not really an answer, but a way to reproduce the error.

First create some files and directories. Remove write access to the directories:

mkdir hellomkdir hello/worldecho "bar" > hello/world/foo.txtchmod -w hello/worldchmod -w hello

Next, create the tar file from within the directory, preserving permissions.

cd hellotar -cpf ../hw.tar --no-recursion ./ world world/foo.txtcd ..

Listing the archive:

tar -tvf hw.tar# dr-xr-xr-x ./# dr-xr-xr-x world/# -rw-r--r-- world/foo.txt

So far, I've been unable to untar the archive as a normal user due to the "Permission denied"-error. The archive can't be untarred naively. The permissions of the local directory change as well.

mkdir untarcd untarls -ld .# drwxr-xr-x ./tar -xvf ../hw.tar# ./# world/# tar: world: Cannot mkdir: Permission denied# world/foo.txt# tar: world/foo.txt: Cannot open: No such file or directory# tar: Exiting with failure status due to previous errorsls -ld .# dr-xr-xr-x ./

Experimenting with umask and/or -p did not help. However, adding --delay-directory-restore does help untarring:

tar -xv --delay-directory-restore -f ../hw.tar# ./# world/# world/foo.txtls -ld .# dr-xr-xr-x ./chmod +w .

It is also possible to untar the file as root. What suprised me most is that tar apparently can change the permissions of pwd, which is still unsolved.

By the way, I originally got into this problem by creating a tarball for / with

tar -cvpzf backup.tar.gz --exclude=/backup.tar.gz --one-file-system /

as root (pwd=/) and untarring it as a normal user to create a linux container.