compiler/clib/symlink.c

   1 /*
   2     Copyright © 2004-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     POSIX function symlink().
   6 */
   7
   8 #include <aros/debug.h>
   9
  10 #include <stdlib.h>
  11 #include <proto/dos.h>
  12 #include <errno.h>
  13 #include "__upath.h"
  14
  15 /*****************************************************************************
  16
  17     NAME */
  18 #include <unistd.h>
  19
  20         int symlink(
  21
  22 /*  SYNOPSIS */
  23         const char *oldpath,
  24         const char *newpath)
  25
  26 /*  FUNCTION
  27
  28     INPUTS
  29
  30     RESULT
  31
  32     NOTES
  33
  34     EXAMPLE
  35
  36     BUGS
  37
  38     SEE ALSO
  39
  40     INTERNALS
  41
  42 ******************************************************************************/
  43 {
  44     int retval = -1;
  45     BPTR lock;
  46     LONG ioerr = 0;
  47     UBYTE *buffer;
  48     int buffersize = 256;
  49
  50     if (!oldpath || !newpath) /*safety check */
  51     {
  52         errno = EFAULT;
  53         return -1;
  54     }
  55
  56     oldpath = __path_u2a(oldpath);
  57     if(!oldpath)
  58         return -1;
  59
  60     oldpath = strdup(oldpath);
  61     if(!oldpath)
  62     {
  63         errno = ENOMEM;
  64         return -1;
  65     }
  66
  67     newpath = __path_u2a(newpath);
  68     if (!newpath)
  69     {
  70         free((void*) oldpath);
  71         return -1;
  72     }
  73
  74     if((lock = Lock((STRPTR)oldpath, SHARED_LOCK)))
  75     {
  76         do
  77         {
  78             if(!(buffer = AllocVec(buffersize, MEMF_ANY)))
  79             {
  80                 ioerr = ERROR_NO_FREE_STORE;
  81                 break;
  82             }
  83
  84             /* Get the full path of oldpath */
  85             if(NameFromLock(lock, buffer, buffersize))
  86             {
  87                 if(MakeLink((STRPTR)newpath, (STRPTR)buffer, TRUE))
  88                     retval = 0;
  89                 else
  90                 {
  91                     ioerr = IoErr();
  92                     FreeVec(buffer);
  93                     break;
  94                 }
  95             }
  96             else if(IoErr() != ERROR_LINE_TOO_LONG)
  97             {
  98                 ioerr = IoErr();
  99                 FreeVec(buffer);
 100                 break;
 101             }
 102             FreeVec(buffer);
 103             buffersize *= 2;
 104         }
 105         while(retval != RETURN_OK);
 106         UnLock(lock);
 107     }
 108     else
 109     {
 110         /* MakeLink can create symlinks to non-existing files or
 111            directories. */
 112         if(IoErr() == ERROR_OBJECT_NOT_FOUND)
 113         {
 114             /* In this case it may be difficult to get the full absolute
 115                path, so we simply trust the caller here for now */
 116             if(MakeLink((STRPTR)newpath, (STRPTR)oldpath, TRUE))
 117                 retval = 0;
 118             else
 119                 ioerr = IoErr();
 120         }
 121         else
 122             ioerr = IoErr();
 123     }
 124     free((void*) oldpath);
 125
 126     if(ioerr)
 127         errno = __arosc_ioerr2errno(ioerr);
 128
 129     return retval;
 130 } /* symlink */
 131