1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2  
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <unistd.h>
      20  
      21  /* Duplicate FD to FD2, closing the old FD2 and making FD2 be
      22     open on the same file as FD is.  Return FD2 or -1.  */
      23  int
      24  __dup2 (int fd, int fd2)
      25  {
      26    int flags = 0;
      27  
      28    if (fd2 == fd)
      29      /* See the comment in dup3.  */
      30      flags = -1;
      31  
      32    return __dup3 (fd, fd2, flags);
      33  }
      34  libc_hidden_def (__dup2)
      35  weak_alias (__dup2, dup2)