if ($nread == 0) {
   ...
   ...
   blah
   blah
   $exp->hard_close();
}

##</code><code>##

    close(STDIN);
    open(STDIN,"<&". $slv->fileno())
      or die "Couldn't reopen STDIN for reading, $!\n";
    close(STDOUT);
    open(STDOUT,">&". $slv->fileno())
      or die "Couldn't reopen STDOUT for writing, $!\n";
    close(STDERR);
    open(STDERR,">&". $slv->fileno())
      or die "Couldn't reopen STDERR for writing, $!\n";