gistfile1.txt

       struct task_basic_info info;
       mach_msg_type_number_t size = sizeof(info);
       kern_return_t kerr = task_info(mach_task_self(),
                                      TASK_BASIC_INFO,
                                      (task_info_t)&info,
                                      &size);
       if (kerr == KERN_SUCCESS)
       {
           static vm_size_t last_resident_size = 0;
           if(last_resident_size != info.resident_size)
           {
               last_resident_size = info.resident_size;
               NSLog(@"Memory usage: %u", last_resident_size);
           }

           static natural_t last_virtual_size = 0;
           if(last_virtual_size != info.virtual_size)
           {
               last_virtual_size = info.virtual_size;
               NSLog(@"Virtual memory usage: %u", last_virtual_size);
           }
       }