In this aphorism, “prove” has an archaic meaning: “tests the rule”.
The point is that handling the host unreachable is almost always semantically higher level than the code opening the connection. This the code opening doesn’t implement the policy of what to do when the situation occurs. In the case, say, of a hard-coded address then it’s possible the author of that piece of code does know how to handle a host unreachable case.
The point is that handling the host unreachable is almost always semantically higher level than the code opening the connection. This the code opening doesn’t implement the policy of what to do when the situation occurs. In the case, say, of a hard-coded address then it’s possible the author of that piece of code does know how to handle a host unreachable case.