_have debconf-show &&
_debconf_show()
{
        local cur

        COMPREPLY=()
        cur=${COMP_WORDS[COMP_CWORD]}
        COMPREPLY=($( compgen -W '--listowners --listdbs --db=' -- $cur ) \
                        $( apt-cache pkgnames -- $cur ) )
}
complete -F _debconf_show debconf-show
