1 2failures= 3failure() { 4 echo "Error at line $1" >&2 5 failures=x$failures 6} 7 8exit 4 & p4=$! 9exit 8 & p8=$! 10wait $p4 11[ $? = 4 ] || failure $LINENO 12wait $p8 13[ $? = 8 ] || failure $LINENO 14 15exit 3 & p3=$! 16exit 7 & p7=$! 17wait $p7 18[ $? = 7 ] || failure $LINENO 19wait $p3 20[ $? = 3 ] || failure $LINENO 21 22test -z "$failures" 23