/* areadlink.c -- readlink wrapper to return the link name in malloc'd storage

   Unlike xreadlink and xreadlink_with_size, don't ever call exit.

   Copyright (C) 2001, 2003-2007, 2009-2017 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Jim Meyering <jim@meyering.net>

   and Bruno Haible <bruno@clisp.org>.  */

#include <config.h>

/* Specification.  */

#include "areadlink.h"

#include "careadlinkat.h"

#include <stdlib.h>

#include <unistd.h>

/* Get the symbolic link value of FILENAME and put it into BUFFER, with

   size BUFFER_SIZE.  This function acts like readlink but has

   readlinkat's signature.  */

static ssize_t

careadlinkatcwd (int fd, char const *filename, char *buffer,

                 size_t buffer_size)

{

  /* FD must be AT_FDCWD here, otherwise the caller is using this

     function in contexts it was not meant for.  */

  if (fd != AT_FDCWD)

    abort ();

  return readlink (filename, buffer, buffer_size);

}

/* Call readlink to get the symbolic link value of FILENAME.

   Return a pointer to that NUL-terminated string in malloc'd storage.

   If readlink fails, return NULL and set errno.

   If allocation fails, or if the link value is longer than SIZE_MAX :-),

   return NULL and set errno to ENOMEM.  */

char *

areadlink (char const *filename)

{

  return careadlinkat (AT_FDCWD, filename, NULL, 0, NULL, careadlinkatcwd);

}