Look up the {|ns_class|, |ns_type|} Resource Record (RR) associated
with Domain Name |dname| on the given |network|.
The typical value for |ns_class| is ns_c_in, while |type| can be any
record type (for instance, ns_t_aaaa or ns_t_txt).
|flags| is a additional config to control actual querying behavior, see
ResNsendFlags for detail.
Returns a file descriptor to watch for read events, or a negative
POSIX error code (see errno.h) if an immediate error occurs.
Look up the {|ns_class|, |ns_type|} Resource Record (RR) associated with Domain Name |dname| on the given |network|. The typical value for |ns_class| is ns_c_in, while |type| can be any record type (for instance, ns_t_aaaa or ns_t_txt). |flags| is a additional config to control actual querying behavior, see ResNsendFlags for detail.
Returns a file descriptor to watch for read events, or a negative POSIX error code (see errno.h) if an immediate error occurs.