workbench/libs/iffparse/goodid.c

   1 /*
   2     Copyright © 1995-2004, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #define DEBUG 0
   7 #include <aros/debug.h>
   8 #include "iffparse_intern.h"
   9
  10 #define DEBUG_GOODID(x)         ;
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/iffparse.h>
  16
  17         AROS_LH1(LONG, GoodID,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(LONG, id, D0),
  21
  22 /*  LOCATION */
  23         struct Library *, IFFParseBase, 43, IFFParse)
  24
  25 /*  FUNCTION
  26         Determines whether an ID is valid according to the IFF specification.
  27
  28     INPUTS
  29         id - An IFF chunk ID to be tested.
  30
  31     RESULT
  32         TRUE if valid.
  33         FALSE otherwise.
  34
  35     NOTES
  36         Assumes input to be in local byte order.
  37
  38     EXAMPLE
  39
  40     BUGS
  41
  42     SEE ALSO
  43
  44     INTERNALS
  45
  46 *****************************************************************************/
  47 {
  48     AROS_LIBFUNC_INIT
  49     AROS_LIBBASE_EXT_DECL(struct Library *,IFFParseBase)
  50
  51     UBYTE theId[4];
  52
  53     (void) IFFParseBase;
  54
  55     theId[0] = id >> 24;
  56     theId[1] = id >> 16;
  57     theId[2] = id >> 8;
  58     theId[3] = id;
  59
  60     DEBUG_GOODID(bug("theid: 0x%08lx [%c%c%c%c]\n",
  61                          id, theId[0], theId[1], theId[2], theId[3]));
  62
  63     /* If the ID starts with a space, but is not all spaces, then invalid */
  64     if((theId[0] == 0x20) && (id != 0x20202020))
  65     {
  66         DEBUG_GOODID(bug("badid 1\n"));
  67         return (FALSE);
  68     }
  69
  70     /*
  71         Check whether the ID is within the allowed character ranges.
  72         This loop is unrolled
  73     */
  74
  75     if( (theId[0] < 0x20) || (theId[0] > 0x7e))
  76     {
  77         DEBUG_GOODID(bug("badid 2\n"));
  78         return (FALSE);
  79     }
  80     if( (theId[1] < 0x20) || (theId[1] > 0x7e))
  81     {
  82         DEBUG_GOODID(bug("badid 3\n"));
  83         return (FALSE);
  84     }
  85     if( (theId[2] < 0x20) || (theId[2] > 0x7e))
  86     {
  87         DEBUG_GOODID(bug("badid 4\n"));
  88         return (FALSE);
  89     }
  90     if( (theId[3] < 0x20) || (theId[3] > 0x7e))
  91     {
  92         DEBUG_GOODID(bug("badid 5\n"));
  93         return (FALSE);
  94     }
  95
  96     DEBUG_GOODID(bug("goodid\n"));
  97     return (TRUE);
  98
  99     AROS_LIBFUNC_EXIT
 100 } /* GoodID */