How can I modify a directory so that it is owned by a group and users in that group can add and delete files and create sub directories but are unable to change the permissions on the parent directory? For example I would like any use in the 'users' group to be able to add files to the directory foobar but not change the permissions of foobar? I think an ACL is probably the way to go but I've never had to do this.
[peter@cobbler foobar]# ls -la total 16 drwxrwx---. 2 peter users 4096 May 14 18:37 . drwxr-xr-x. 3 root root 4096 May 14 18:37 .. -rw-rw----. 1 peter users 37 May 14 18:39 bar -rw-rw----. 1 sam users 24 May 14 18:39 foo