usr/src/lib/libast/common/comp/rename.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23
  24 #include <ast.h>
  25
  26 #if _lib_rename
  27
  28 NoN(rename)
  29
  30 #else
  31
  32 #include <error.h>
  33 #include <proc.h>
  34
  35 #ifdef EPERM
  36
  37 static int
  38 mvdir(const char* from, const char* to)
  39 {
  40         char*                   argv[4];
  41         int                     oerrno;
  42
  43         static const char       mvdir[] = "/usr/lib/mv_dir";
  44
  45         oerrno = errno;
  46         if (!eaccess(mvdir, X_OK))
  47         {
  48                 argv[0] = mvdir;
  49                 argv[1] = from;
  50                 argv[2] = to;
  51                 argv[3] = 0;
  52                 if (!procrun(argv[0], argv, 0))
  53                 {
  54                         errno = oerrno;
  55                         return 0;
  56                 }
  57         }
  58         errno = EPERM;
  59         return -1;
  60 }
  61
  62 #endif
  63
  64 int
  65 rename(const char* from, const char* to)
  66 {
  67         int     oerrno;
  68         int     ooerrno;
  69
  70         ooerrno = errno;
  71         while (link(from, to))
  72         {
  73 #ifdef EPERM
  74                 if (errno == EPERM)
  75                 {
  76                         errno = ooerrno;
  77                         return mvdir(from, to);
  78                 }
  79 #endif
  80                 oerrno = errno;
  81                 if (unlink(to))
  82                 {
  83 #ifdef EPERM
  84                         if (errno == EPERM)
  85                         {
  86                                 errno = ooerrno;
  87                                 return mvdir(from, to);
  88                         }
  89 #endif
  90                         errno = oerrno;
  91                         return -1;
  92                 }
  93         }
  94         errno = ooerrno;
  95         return unlink(from);
  96 }
  97
  98 #endif