title: Test cases in C for WIFSIGNALED, WIFSTOPPED, WIFCONTINUED
body: <p>I'm playing with waitpid() and signal() and I'm looking for reliable test cases for returning WIFSIGNALED(status) = WIFSTOPPED(status) = WIFCONTINUED (status) = true but can't find any...</p>
  
  <p>Care to tell me how can I make sure those return true so I can debug my code?</p>
  
  <p>Also, a few hints about what signals should I catch with signal() to test those macros would be helpful...</p>