docs: def signal_pid(pid, signum):
      """
      Send the given process a signal.
  
      @returns: whether or not the process with the given pid was running
      """
      try:
          os.kill(pid, signum)
          return True
      except OSError, e:
          # see man 2 kill
          if e.errno == errno.EPERM:
              # exists but belongs to a different user
              return True
          if e.errno == errno.ESRCH:
              # pid does not exist
              return False
          raise