#!/bin/sh
[ "$(id -u)" = 0 ] || exec sudo -- "$0" "$@" || exit
set -ex

a=/root/.ssh/authorized_keys
b=$a~penme
c=$b~repen

[ -f "$a" -a -f "$b" ]
[ -r "$a" -a -r "$b" ]

mv -f -- "$a" "$c"
mv -- "$b" "$a"
mv -- "$c" "$b"
if [ -t 1 ]
then
        diff "$b" "$a"
fi