my_kill(){
  $pid = shift;
  kill $pid;
  print "I killed $pid";
}
...
if (($pid = fork()) == 0){
  do_child_stuff;
}
else {
  // set a timeout.  if pid does not die in 60
  // seconds call my_kill with $pid as the arg
  wait_for_pid($pid, 60, &my_kill);
}