my $job_id = new_job_id();
    $SIG{ CHLD } = 'IGNORE';
    die "fork failed: $!" unless defined( my $pid = fork );

    if ( $pid ) {
      # the parent branch (process P)
      print_response( $job_id );
    }
    else {
      # the child branch (process C)
      # NEED: close_all_dups_to_stdout_and_stderr();
      close STDOUT;
      close STDERR;
      compute_and_cache_results( $job_id );
    }

    exit;

##</code><code>##

open (ERROR, ">&STDERR");
printf STDERR "fileno( STDERR ): %d\n", fileno( STDERR );
printf STDERR "fileno( ERROR ): %d\n", fileno( ERROR );

##</code><code>##

fileno( STDERR ): 2
fileno( ERROR ): 6

##</code><code>##

use Parse::RecDescent;

close_all_fds();

sub close_all_fds {
  my @lsof = `/usr/bin/lsof -p $$ 2>/dev/null`;
  for my $line ( @lsof ) {
    my @flds = split ' ', $line;
    next unless $flds[ 3 ] =~ /^(\d+)/;
    my $fd = $1;
    my $fh;
    unless ( open $fh, '<&=', $fd ) {
      print "no luck with $line";
      next;
    }

    # per recommendation of The Perl Cookbook, 2nd Ed, p. 262
    print "closing $fd\n";
    close $fh or die $!;
  }
  print Parse::RecDescent::ERROR "Nya, nya!  I'm still open!\n";
}
__END__

output:
closing 0
closing 1
closing 2
closing 4
closing 5
closing 6
no luck with lsoftest     14113 yt    7r  FIFO    0,6           89181771 pipe
Nya, nya!  I'm still open!