1 /* Copyright (C) 1991-2022 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
rename(const char * old,const char * new)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 }
49