IOS的mac地址获取

由于目前苹果对UUID之类的封杀比较厉害，所以为了获取用户手机的一个唯一标识，我们可以使用MAC地址，因为全球没有一台设备的MAC地址是一样的。当然PC上面是可以用软件改的。这个我们不考虑，下面贴出代码

#include  // Per msqr
#include 
#include 
#include 

#pragma mark MAC
// Return the local MAC addy
// Courtesy of FreeBSD hackers email list
// Accidentally munged during previous update. Fixed thanks to mlamb.
- (NSString *) macaddress
{
	int                    mib[6];
	size_t                len;
	char                *buf;
	unsigned char        *ptr;
	struct if_msghdr    *ifm;
	struct sockaddr_dl    *sdl;
	
	mib[0] = CTL_NET;
	mib[1] = AF_ROUTE;
	mib[2] = 0;
	mib[3] = AF_LINK;
	mib[4] = NET_RT_IFLIST;
	
	if ((mib[5] = if_nametoindex("en0")) == 0) {
		printf("Error: if_nametoindex error/n");
		return NULL;
	}
	
	if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
		printf("Error: sysctl, take 1/n");
		return NULL;
	}
	
	if ((buf = malloc(len)) == NULL) {
		printf("Could not allocate memory. error!/n");
		return NULL;
	}
	
	if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
		printf("Error: sysctl, take 2");
		return NULL;
	}
	
	ifm = (struct if_msghdr *)buf;
	sdl = (struct sockaddr_dl *)(ifm + 1);
	ptr = (unsigned char *)LLADDR(sdl);
	// NSString *outstring = [NSString stringWithFormat:@"%02x:%02x:%02x:%02x:%02x:%02x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
	NSString *outstring = [NSString stringWithFormat:@"%02x%02x%02x%02x%02x%02x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
	free(buf);
	return [outstring uppercaseString];
	
}