io/readlinkat.c

   1 /* Copyright (C) 2005, 2006 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 /* Read the contents of the symbolic link PATH relative to FD into no
  24    more than LEN bytes of BUF.  The contents are not null-terminated.
  25    Returns the number of characters read, or -1 for errors.  */
  26 ssize_t
  27 readlinkat (fd, path, buf, len)
  28      int fd;
  29      const char *path;
  30      char *buf;
  31      size_t len;
  32 {
  33   if (path == NULL)
  34     {
  35       __set_errno (EINVAL);
  36       return -1;
  37     }
  38
  39   if (fd != AT_FDCWD && fd < 0 && *path != '/')
  40     {
  41       __set_errno (EBADF);
  42       return -1;
  43     }
  44
  45   __set_errno (ENOSYS);
  46   return -1;
  47 }
  48 stub_warning (readlinkat)
  49 libc_hidden_def (readlinkat)
  50
  51 #include <stub-tag.h>