set -e
{
	echo 1
	echo two
	echo three
} | {
	read x
	[ "$x" = 1 ]
	(read x
	[ "$x" = two ])
	read x
	[ "$x" = three ]
}

T=`mktemp sh-test.XXXXXX`
trap 'rm -f "$T"' 0
{
	echo 1
	echo two
	echo three
} >$T
{
	read x
	[ "$x" = 1 ]
	(read x
	[ "$x" = two ])
	read x
	[ "$x" = three ]
} <$T