title: How to observe the content of static lib in mac OS?
body: <p>I create a static library project in my xCode and build a <em>.a named mylib.a.  There some code (</em>.m files) and another static lib file named common.a to inform the static library nylib.a.
  But I doubt that if the contend of common.a are pack in the mylib.a really.
  So how can I observe the content of the mylib.a in mac OS? I knew there are some command such as ar, nm to complete this task in Linux. but It does't run in mac OS.</p>