Adicionando PPA no Debian

Crie um arquivo com o nome add-apt-repository e copie o texto abaixo para dentro dele. 

#!/bin/bash
if [ $# -eq 1 ]
then
            ppa_name=`echo "$1" | cut -d":" -f2 -s`
            if [ -z "$ppa_name" ]
            then
                        echo "PPA name not found"
                        echo "Utility to add PPA repositories in your debian machine"
                        echo "$0 ppa:user/ppa-name"
            else
                        echo "$ppa_name"
                        echo "deb http://ppa.launchpad.net/$ppa_name/ubuntu lucid main"
>> /etc/apt/sources.list
                        apt-get update >> /dev/null 2> /tmp/apt_add_key.txt
                        key=`cat /tmp/apt_add_key.txt | cut -d":" -f6 | cut -d" " -f3`
                        apt-key adv --keyserver keyserver.ubuntu.com --recv-keys $key
                        rm -rf /tmp/apt_add_key.txt
            fi
else
            echo "Utility to add PPA repositories in your debian machine"
            echo "$0 ppa:user/ppa-name"
fi

Depois use os comandos para mover ele no terminal

sudo mv add-apt-repository /usr/sbin && sudo chmod o+x /usr/sbin/add-apt-repository && sudo chown root:root /usr/sbin/add-apt-repository