sysdeps/posix/rename.c

   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 }