lib/sh/rename.c

   1 /*
   2  * rename - rename a file
   3  */
   4
   5 /* Copyright (C) 1999 Free Software Foundation, Inc.
   6
   7    This file is part of GNU Bash, the Bourne Again SHell.
   8
   9    Bash is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation, either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    Bash is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include <config.h>
  24
  25 #if !defined (HAVE_RENAME)
  26
  27 #include <bashtypes.h>
  28 #include <posixstat.h>
  29
  30 #if defined (HAVE_UNISTD_H)
  31 #  include <unistd.h>
  32 #endif
  33 #include <errno.h>
  34
  35 #include <stdc.h>
  36
  37 #ifndef errno
  38 extern int errno;
  39 #endif
  40
  41 int
  42 rename (from, to)
  43      const char *from, *to;
  44 {
  45   struct stat fb, tb;
  46
  47   if (stat (from, &fb) < 0)
  48     return -1;
  49
  50   if (stat (to, &tb) < 0)
  51     {
  52       if (errno != ENOENT)
  53         return -1;
  54     }
  55   else
  56     {
  57       if (fb.st_dev == tb.st_dev && fb.st_ino == tb.st_ino)
  58         return 0;               /* same file */
  59       if (unlink (to) < 0 && errno != ENOENT)
  60         return -1;
  61     }
  62
  63   if (link (from, to) < 0)
  64     return (-1);
  65
  66   if (unlink (from) < 0 && errno != ENOENT)
  67     {
  68       int e = errno;
  69       unlink (to);
  70       errno = e;
  71       return (-1);
  72     }
  73
  74   return (0);
  75 }
  76 #endif /* !HAVE_RENAME */