people.m

ABAddressBookRef addressBook = ABAddressBookCreate();
CFArrayRef people = ABAddressBookCopyArrayOfAllPeople(addressBook);
CFMutableArrayRef peopleMutable = CFArrayCreateMutableCopy(
                                          kCFAllocatorDefault,
                                          CFArrayGetCount(people),
                                          people
                                  );

CFRelease(people);
 
CFArraySortValues(
        peopleMutable,
        CFRangeMake(0, CFArrayGetCount(peopleMutable)),
        (CFComparatorFunction) ABPersonComparePeopleByName,
        (void*) ABPersonGetSortOrdering()
);

for (int i = 0; i < CFArrayGetCount(peopleMutable); i++) {
    ABRecordRef abrecord = CFArrayGetValueAtIndex(peopleMutable, i);
    // code that expects the ABRecordRef to actually be valid
}
CFRelease(addressBook);
CFRelease(peopleMutable);