问在OS X上获取型号标识符字符串

EN

#import <Foundation/Foundation.h>
#import <sys/sysctl.h>

NSString *ModelIdentifier()
{
    NSString *result=@"Unknown Mac";
    size_t len=0;
    sysctlbyname("hw.model", NULL, &len, NULL, 0);
    if (len) {
        NSMutableData *data=[NSMutableData dataWithLength:len];
        sysctlbyname("hw.model", [data mutableBytes], &len, NULL, 0);
        result=[NSString stringWithUTF8String:[data bytes]];
    }
    return result;
}

static private func modelIdentifier() -> String? {
    let service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("IOPlatformExpertDevice"))
    defer { IOObjectRelease(service) }

    if let modelData = IORegistryEntryCreateCFProperty(service, "model" as CFString, kCFAllocatorDefault, 0).takeRetainedValue() as? Data {
        return modelData.withUnsafeBytes { (cString: UnsafePointer<UInt8>) -> String in
            return String(cString: cString)
        }
    }

    return nil
}

CFStringRef model = IORegistryEntryCreateCFProperty(service, 
                                                        CFSTR("model"), 
                                                        kCFAllocatorDefault, 
                                                        0);  ? type is ok ?

CFSDataRef model = IORegistryEntryCreateCFProperty(service, 
                                                        CFSTR("model"), 
                                                        kCFAllocatorDefault, 
                                                        0);