text: /**************************************************************************/
  /*                                                                        */
  /*                                 OCaml                                  */
  /*                                                                        */
  /*             Xavier Leroy, projet Cristal, INRIA Rocquencourt           */
  /*                                                                        */
  /*   Copyright 1996 Institut National de Recherche en Informatique et     */
  /*     en Automatique.                                                    */
  /*                                                                        */
  /*   All rights reserved.  This file is distributed under the terms of    */
  /*   the GNU Lesser General Public License version 2.1, with the          */
  /*   special exception on linking described in the file LICENSE.          */
  /*                                                                        */
  /**************************************************************************/
  
  #include <caml/mlvalues.h>
  #include "unixsupport.h"
  
  CAMLprim value unix_dup2(value cloexec, value fd1, value fd2)
  {
    HANDLE oldh, newh;
  
    oldh = Handle_val(fd2);
    if (! DuplicateHandle(GetCurrentProcess(), Handle_val(fd1),
                          GetCurrentProcess(), &newh,
                          0L,
                          unix_cloexec_p(cloexec) ? FALSE : TRUE,
                          DUPLICATE_SAME_ACCESS)) {
      win32_maperr(GetLastError());
      return -1;
    }
    Handle_val(fd2) = newh;
    if (Descr_kind_val(fd2) == KIND_SOCKET)
      closesocket((SOCKET) oldh);
    else
      CloseHandle(oldh);
    Descr_kind_val(fd2) = Descr_kind_val(fd1);
    /* Reflect the dup2 on the CRT fds, if any */
    if (CRT_fd_val(fd1) != NO_CRT_FD || CRT_fd_val(fd2) != NO_CRT_FD)
      _dup2(win_CRT_fd_of_filedescr(fd1), win_CRT_fd_of_filedescr(fd2));
    return Val_unit;
  }
  