Get IP

GetIP.m

//
//  AppDelegate.m
//  demo
//
//  Created by 61 on 13-4-25.
//  Copyright (c) 2013年 61. All rights reserved.
//

#import "AppDelegate.h"
#import <netinet/in.h>
#import <sys/types.h>
#import <ifaddrs.h>
#include <arpa/inet.h>

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    [self getIPAddress];
}

-(NSString *)getIPAddress
{
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    
    if (success == 0)
    {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        while(temp_addr != NULL)
        {
            if(temp_addr->ifa_addr->sa_family == AF_INET)
            {
                NSString *networkInfo = [NSString stringWithUTF8String:temp_addr->ifa_name];
                if ([networkInfo hasPrefix:@"en"]) {
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    break;
                }            }
            
            temp_addr = temp_addr->ifa_next;
        }
    }
    
    // Free memory
    freeifaddrs(interfaces);
    return address;
}
@end