sysdeps/posix/rename.c

   1 /* Copyright (C) 1991-2014 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    <http://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 (old, new)
  25      const char *old;
  26      const char *new;
  27 {
  28   int save = errno;
  29   if (__link (old, new) < 0)
  30     {
  31       if (errno == EEXIST)
  32         {
  33           __set_errno (save);
  34           /* Race condition, required for 1003.1 conformance.  */
  35           if (__unlink (new) < 0 ||
  36               __link (old, new) < 0)
  37             return -1;
  38         }
  39       else
  40         return -1;
  41     }
  42   if (__unlink (old) < 0)
  43     {
  44       save = errno;
  45       if (__unlink (new) == 0)
  46         __set_errno (save);
  47       return -1;
  48     }
  49   return 0;
  50 }