#!/bin/sh

if [ $# -ne 2 ]
then
	echo "usage: $0 old-address new-address" >&2
	exit 2
fi

old=$1
new=$2

[ -d bak ] || mkdir bak

for i in test[1-9] test[1-8][0-9]
do
	sed "s/$1/$2/gp" $i > $i.new
	diff $i $i.new
	mv $i bak/$i
	mv $i.new $i
done

echo
echo "NB: originals have been put in directory 'bak'."
