title: How su binary works?
body: <p>I was browsing su binary code by Chainsdd when I was browsing it i saw it using <code>setuid(0)</code>
  <code>setgid(0)</code>
  to give root permissions  </p>
  
  <p>so my question is : <strong>Can this method used in my own c library ?</strong> </p>
  
  <p>if not then how does the su does it? is it because it is placed in <code>/system</code> partition with some <code>chmod</code> or other operations like that have been perfomed on it? </p>