io/linkat.c

   1 /* Copyright (C) 2005-2023 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, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <fcntl.h>
  20 #include <stddef.h>
  21 #include <unistd.h>
  22
  23
  24 /* Make a link to FROM relative to FROMFD called TO relative to TOFD.  */
  25 int
  26 linkat (int fromfd, const char *from, int tofd, const char *to, int flags)
  27 {
  28   if (from == NULL || to == NULL)
  29     {
  30       __set_errno (EINVAL);
  31       return -1;
  32     }
  33
  34   if ((tofd != AT_FDCWD && tofd < 0 && *to != '/')
  35       || (fromfd != AT_FDCWD && fromfd < 0 && *from != '/'))
  36     {
  37       __set_errno (EBADF);
  38       return -1;
  39     }
  40
  41   __set_errno (ENOSYS);
  42   return -1;
  43 }
  44 stub_warning (linkat)