/* Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

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

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdio.h>

#include <unistd.h>

#include <errno.h>

/* Rename the file OLD to NEW.  */

int

rename (const char *old, const char *new)

{

  int save = errno;

  if (__link (old, new) < 0)

    {

      if (errno == EEXIST)

	{

	  __set_errno (save);

	  /* Race condition, required for 1003.1 conformance.  */

	  if (__unlink (new) < 0 ||

	      __link (old, new) < 0)

	    return -1;

	}

      else

	return -1;

    }

  if (__unlink (old) < 0)

    {

      save = errno;

      if (__unlink (new) == 0)

	__set_errno (save);

      return -1;

    }

  return 0;

}