sysdeps/posix/rename.c

   1 /* Copyright (C) 1991, 1992, 1996 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <stdio.h>
  20 #include <unistd.h>
  21 #include <errno.h>
  22
  23 /* Rename the file OLD to NEW.  */
  24 int
  25 rename (old, new)
  26      const char *old;
  27      const char *new;
  28 {
  29   int save = errno;
  30   if (__link (old, new) < 0)
  31     {
  32       if (errno == EEXIST)
  33         {
  34           errno = save;
  35           /* Race condition, required for 1003.1 conformance.  */
  36           if (__unlink (new) < 0 ||
  37               __link (old, new) < 0)
  38             return -1;
  39         }
  40       else
  41         return -1;
  42     }
  43   if (__unlink (old) < 0)
  44     {
  45       save = errno;
  46       if (__unlink (new) == 0)
  47         __set_errno (save);
  48       return -1;
  49     }
  50   return 0;
  51 }