io/dup3.c

   1 /* Copyright (C) 2008, 2011 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <unistd.h>
  22
  23
  24 /* Duplicate FD to FD2, closing the old FD2 and making FD2 be
  25    open the same file as FD is which setting flags according to
  26    FLAGS.  Return FD2 or -1.  */
  27 int
  28 dup3 (fd, fd2, flags)
  29      int fd;
  30      int fd2;
  31      int flags;
  32 {
  33   if (fd < 0 || fd2 < 0)
  34     {
  35       __set_errno (EBADF);
  36       return -1;
  37     }
  38
  39   if (fd == fd2)
  40     /* No way to check that they are valid.  */
  41     return fd2;
  42
  43   __set_errno (ENOSYS);
  44   return -1;
  45 }
  46 libc_hidden_def (dup3)
  47 stub_warning (dup3)
  48
  49 #include <stub-tag.h>