Gets reachability information from a host.
- iOS 2.0+
- macOS 10.3+
- Mac Catalyst 13.0+
- tvOS 9.0+
The host whose reachability is to be obtained. The host must have been previously resolved. (To resolve a host, call
CFHost.) This value must not be
Start Info Resolution(_: _: _:)
On return, contains
TRUEif the reachability was available, otherwise
FALSE. This value may be
A CFData object that wraps the reachability flags (
SCNetwork) defined in
NULL if reachability information was not available.
This function gets reachability information in a thread-safe way, but the resulting data is not thread-safe. The data is returned as a “get” as opposed to a copy, so the data is not safe if the CFHost is altered from another thread.