Mock This Code

• BAD:

      ($pid = fork) ? waitpid($pid, 0) : exec @ARGS;
  

• GOOD:

      if ($pid = fork) {
          waitpid($pid, 0);
      } else {
          die "can't fork: $!"    unless defined $pid;
          exec @ARGS;
          die "can't exec @ARGS: $!";
      }