Sometimes, we would like to check if a remote host is reachable before we establish a connection. This is much like the function of the ping command in terminal. Well in Cocoa programing, you can use the function SCNetworkReachabilityCreateWithName().
Here is the code:
objc Test If A Host Is Active
bool success = false;
const char *host_name = [ip cStringUsingEncoding:NSASCIIStringEncoding];
SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, host_name);
SCNetworkConnectionFlags flags;
success = SCNetworkReachabilityGetFlags(reachability, &flags);
bool isAvailable = success && (flags & kSCNetworkFlagsReachable) &&
!(flags & kSCNetworkFlagsConnectionRequired);if (isAvailable) {
NSLog(@"Host is reachable: %d", flags);
}
else {
NSLog(@"Host is unreachable");
}