title: how to know the process who has sent the signal to the process traced?
body: <p>I was using strace to debug an issue. and the process I traced will exit like:
  kill(-27335, SIGTERM)                   = 0
  --- SIGTERM (Terminated) @ 0 (0) ---</p>
  
  <p>27335 is the PID of the process I traced.</p>
  
  <p>is there anyway to know who has sent the SIGTERM to the process?</p>