workbench/libs/rexxsupport/next.c

   1 /*
   2     Copyright © 1995-2006, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Get the pointer value a pointer is pointing to, often used to get
   6           the next element of a list
   7     Lang: English
   8 */
   9
  10 #include <proto/exec.h>
  11 #include <proto/rexxsyslib.h>
  12 #include <exec/types.h>
  13 #include <exec/memory.h>
  14 #include <rexx/storage.h>
  15 #include <rexx/errors.h>
  16
  17 #include <ctype.h>
  18 #include <stdlib.h>
  19
  20 #include "rexxsupport_intern.h"
  21 #include "rxfunctions.h"
  22
  23 LONG rxsupp_next(struct Library *RexxSupportBase, struct RexxMsg *msg, UBYTE **argstring)
  24 {
  25     char *ptr, *end;
  26     LONG offset = 0;
  27
  28     if ((msg->rm_Action & RXARGMASK) > 1)
  29     {
  30         offset = strtol(ARG2(msg), &end, 10);
  31         while (isspace(*end)) end++;
  32         if (*end != 0)
  33         {
  34             *argstring = NULL;
  35             return ERR10_018;
  36         }
  37     }
  38
  39     if (LengthArgstring(ARG1(msg)) != sizeof(void *))
  40     {
  41         *argstring = NULL;
  42         return ERR10_018;
  43     }
  44
  45     ptr = (char *)ARG1(msg) + offset;
  46
  47     *argstring = CreateArgstring((UBYTE *)ptr, sizeof(void *));
  48     return RC_OK;
  49 }