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