title: How to check if a forked process is still running from the c program
body: <p>I have the pid of a forked process. Now, from my c code (running on Linux), I have to check periodically whether this process is still running or terminated. I do not want to use blocking calls like <code>wait()</code> or <code>waitpid()</code>. Need (preferably) a non-blocking system call which would just check whether this pid is still running and return the status of the child.</p>
  
  <p>What is best and easiest way to do it?</p>