iOS 获取客户端的IP地址

#import <ifaddrs.h>

#import <arpa/inet.h>

- (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) {

                // Check if interface is en0 which is the wifi connection on the iPhone

                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {

                    // Get NSString from C String

                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];

                }

            }

            temp_addr = temp_addr->ifa_next;

        }

    }

    // Free memory

    freeifaddrs(interfaces);

    return address;

}