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 <unistd.h>
      21  
      22  /* Read the contents of the symbolic link PATH relative to FD into no
      23     more than LEN bytes of BUF.  The contents are not null-terminated.
      24     Returns the number of characters read, or -1 for errors.  */
      25  ssize_t
      26  readlinkat (int fd, const char *path, char *buf, size_t len)
      27  {
      28    if (path == NULL)
      29      {
      30        __set_errno (EINVAL);
      31        return -1;
      32      }
      33  
      34    if (fd != AT_FDCWD && fd < 0 && *path != '/')
      35      {
      36        __set_errno (EBADF);
      37        return -1;
      38      }
      39  
      40    __set_errno (ENOSYS);
      41    return -1;
      42  }
      43  stub_warning (readlinkat)
      44  libc_hidden_def (readlinkat)