title: How can I know the current state of signals
body: <p>Is there a way in C to know the following information about signals:</p>
  
  <ol>
  <li>Is certain signal is blocked now?</li>
  <li>Are we inside a signal handling function chanin (i.e, was the current code called from function which was called as signal handler for certain signal)? If so, can I know what is the current signal?</li>
  </ol>
  
  <p>Thanks</p>