# Note that I've hardcoded things like EPERM,EFAULT,EINVAL from sys/errno.h,
  # SYS_setrlimit from sys/syscall.h, and RLIMIT_CPU from sys/resource.h
  # it might be preferable to h2ph the respective .h files...

  sub set_max_cpu_time
  {
    my $n_seconds = shift;
    my $s = pack( 'LL', $n_seconds, $n_seconds+1 );
    $! = 0;
    if ( syscall( 128, 0, $s ) == -1 )  # SYS_setrlimit, RLIMIT_CPU
    {
      if ( $! == 1 )  # EPERM
      {
        die "$!; Sorry, you need to be superuser to do that.\n";
      }
      elsif ( $! == 14 )  # EFAULT
      {
        die "$!; Error: argument to setrlimit pointed to an illegal address.\n";
      }
      elsif ( $! == 22 )  # EINVAL
      {
        die "$!; Error: the new rlim_cur exceeds the new rlim_max,
          or the limit specified cannot be lowered because current usage
          is already higher than the limit.\n";
      }
    }
  }

  # test it:
  set_max_cpu_time( 8 );
  my $n = 0;
  while ( 1 ) { $n++ }
  # Hmm, mysteriously dumps core after about 8 seconds!  :-)