mfiles=""
for f in $files
do
	rm -f m$f
	[ -f $f ] && cp $f m$f
	mfiles="$mfiles m$f"
done
unifdef -M~ $opts $mfiles
e=$?
for f in $mfiles
do
	diff -u $f~ $f | sed '/^[+-]\{3\} /s/	.*//'
	rm -f $f~ $f
done
exit $e