/* Copyright (C) 1991, 1992 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>

/* Rename the file OLD to NEW.  */
int
DEFUN(rename, (old, new), CONST char *old AND CONST char *new)
{
  int save = errno;
  if (__link(old, new) < 0)
    {
      if (errno == EEXIST)
	{
	  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)
	errno = save;
      return -1;
    }
  return 0;
}