Question

I am new to iOS development. I am attempting to create a read and write stream. I am using the CFNetworking programming guide’s examples to try and get something working.

I am trying to schedule the read stream on the run loop to work around the issue of the streams blocking. Right away I have run into issues. How can I create a CFHost object using CFHhostCreateWithAddress? Here is what I have so far:

NSString *address = @"irc.ubuntu.net";
CFDataRef addressDataRef = (CFDataRef)[address dataUsingEncoding:NSASCIIStringEncoding];

CFHostRef host = CFHostCreateWithAddress(kCFAllocatorDefault, addressDataRef);

//Create Read and Write Stream
CFStreamCreatePairWithSocketToCFHost(kCFAllocatorDefault, host, 8008, &readStream, &writeStream);

The second line bombs. Can someone please tell me how to create a CFHostRef?

Thanks a lot!

Answer 1

The documentation states that the second argument to CFHostCreateWithAddress() must be “A CFDataRef object containing a sockaddr structure for the address of the host. This value must not be NULL.”

You’re passing a CFDataRef representing “irc.ubuntu.net”, which is by no means a sockaddr struct.

Use CFHostCreateWithName:

CFHostRef CFHostCreateWithName (
   CFAllocatorRef allocator,
   CFStringRef hostname
);

As you probably know, you can cast an NSString * to CFStringRef, or create a constant CFStringRef with the macro CFSTR().