#!/bin/bash 
dirs=()
do=
for arg ; do 
    case "$arg" in
    -n) do=echo ;;
    -*) echo "Usage:"
        echo "   $(basename $0) [-n] directory ..."
        echo "Remove all backup files that don't have a head."
        exit 1
        ;;
    *)  dirs[${#dirs}]="$arg" ;;
    esac
done
for dir in "${dirs[@]}" ; do 
    find "$dir" -maxdepth 1 \( -name \*~ -o -name .\?\*~ \) -print  \
    |while read file ; do 
        base="$(echo "$file" | sed -e 's/\(\.~[.0-9]\+\)\?~$//')"
        if [ ! -e "$base" ] ; then
            $do rm "$file" 
        fi
     done
done