Editing files using sudo and emacs

I often edit config files with:
sudo emacs /etc/whatever

The problem with that is I would end up with ~ backup files littering my filesystem and also emacs is run as root so it gets root’s config file. I’d rather use emacs with my config.
The solution, thanks to emacs-fu is twofold:
First set emacs’s backup directory, which tells it to save backup files in a
specific directory rather in the same dir as the file you edited. Put something like this in your emacs init file:

 (setq
   backup-by-copying t      ; don't clobber symlinks
   backup-directory-alist
    '(("." . "~/.saves"))    ; don't litter my fs tree
   delete-old-versions t
   kept-new-versions 6
   kept-old-versions 2
   version-control t)       ; use versioned backups

Then you add this to your .bashrc:

# see http://emacs-fu.blogspot.com.au/2011/12/system-administration-with-emacs.html
# edit file with root privs
function E() {
    filename=$1
    without_beg_slash="${1##/}"
    if [[ $without_beg_slash == $1 ]];then
        filename="${PWD%//}/$1"
    fi
    emacsclient -c -a emacs "/sudo:root@localhost:$filename"
}

Now just edit files with: E someconfigfile and it loads it in your emacs, asks your pw to edit and off you go.