Most applications that use the Internet to communicate will eventually need to convert a hostname to an IP address or an IP address to a hostname. This recipe will encapsulate the network address resolution functionality into a standalone Objective-C class. You will notice in this recipe that most of the CFNetworking API calls are made up of C functions, and use a structure similar to the addrinfo structure that the BSD API uses.

#import <Foundation/Foundation.h>

typedef NS_ENUM(NSUInteger, CFNetworkingSelf.errorCode) {
  NOERROR,
  HOSTRESOLUTIONERROR,
  ADDRESSRESOLUTIONERROR
};
@interface CFNetworkUtilities : NSObject

@property int (nonatomic) self.errorCode;

-(NSArray *)addressesForHostname...