EAI_AGAIN          The name could not be resolved at this time.
                       Future attempts may succeed.
    EAI_BADFLAGS       The flags argument had an invalid value.
    EAI_FAIL           A nonrecoverable error occurred when
                       attempting to resolve the name.
    EAI_FAMILY         The address family was not recognized.
    EAI_MEMORY         There was a memory allocation failure when
                       trying to allocate storage for the return
                       value.
    EAI_NONAME         The name does not resolve for the supplied
                       parameters. Neither the node name nor the
                       service name were supplied. At least one of
                       these must be supplied.
    EAI_SYSTEM         A system error occurred; the error code can be
                       found in errno.