title: How to close socket
body: <p>Run c++ on Ubuntu.
  I open socket in this way:</p>
  
  <pre><code>socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW))
  </code></pre>
  
  <p>What do i need to do in the end of the use?
  Some socket will be used as long as the program run , do i need to check them from a while? to see if socket still exist?</p>