iphone model returns nil?

Question

I have the following code in my iPhone app which returns the model type

size_t size;
sysctlbyname("hw.machine", NULL, &size, NULL, 0);
char *modelType = malloc(size);
sysctlbyname("hw.machine", modelType, &size, NULL, 0);
NSString *deviceModel = [NSString stringWithCString:modelType encoding:NSUTF8StringEncoding];
free(modelType);

but on some user's devices I get nil. The devices that return nil have Location Services.

1) What could cause nil to be returned?

2) Is nil returned on jail broken devices?

3) Is there a better way to check for model type on iDevices?

Answer 1

Try this instead:

#import <sys/utsname.h>

- (NSString *)machine {
    struct utsname si;
    uname(&si);

    NSString *res = [NSString stringWithCString:si.machine encoding:NSUTF8StringEncoding];

    return res;
}

I actually added this as a category method on UIDevice .

This gives the various "iPhone4,1", "iPad2,4" type values.