1  /* Copyright (C) 1991-2023 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 <stdio.h>
      19  #include <unistd.h>
      20  #include <errno.h>
      21  
      22  /* Rename the file OLD to NEW.  */
      23  int
      24  rename (const char *old, const char *new)
      25  {
      26    int save = errno;
      27    if (__link (old, new) < 0)
      28      {
      29        if (errno == EEXIST)
      30  	{
      31  	  __set_errno (save);
      32  	  /* Race condition, required for 1003.1 conformance.  */
      33  	  if (__unlink (new) < 0
      34  	      || __link (old, new) < 0)
      35  	    return -1;
      36  	}
      37        else
      38  	return -1;
      39      }
      40    if (__unlink (old) < 0)
      41      {
      42        save = errno;
      43        if (__unlink (new) == 0)
      44  	__set_errno (save);
      45        return -1;
      46      }
      47    return 0;
      48  }