rom/dos/fault.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: dos.library function Fault()
   6     Lang: english
   7 */
   8 #include <aros/system.h>
   9 #include "dos_intern.h"
  10 #if PassThroughErrnos
  11 #   include <errno.h>
  12 #endif
  13 #include <string.h>
  14
  15 /*****************************************************************************
  16
  17     NAME */
  18 #include <proto/dos.h>
  19
  20         AROS_LH4(BOOL, Fault,
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(LONG,         code,   D1),
  24         AROS_LHA(CONST_STRPTR, header, D2),
  25         AROS_LHA(STRPTR,       buffer, D3),
  26         AROS_LHA(LONG,         len,    D4),
  27
  28 /*  LOCATION */
  29         struct DosLibrary *, DOSBase, 78, Dos)
  30
  31 /*  FUNCTION
  32         Fault will obtain the error message string for the given error
  33         code. First the header string is copied to the buffer, followed
  34         by a ":" (colon), then the NULL terminated string for the error
  35         message into the buffer.
  36
  37         By convention, error messages are ALWAYS less than 80 (plus 1 for
  38         NULL termination), and ideally less than 60 characters.
  39
  40         If the error code is not known, then the string "Unknown error"
  41         followed by the error number will be added to the string.
  42
  43     INPUTS
  44         code   - The error code.
  45         header - The string to prepend to the buffer before the error
  46                  text. This may be NULL in which case nothing is prepended.
  47         buffer - The destination buffer.
  48         len    - Length of the buffer.
  49
  50     RESULT
  51         Number of characters placed in the buffer. May be 0.
  52
  53     NOTES
  54
  55     EXAMPLE
  56
  57     BUGS
  58
  59     SEE ALSO
  60
  61     INTERNALS
  62
  63 *****************************************************************************/
  64 {
  65     AROS_LIBFUNC_INIT
  66
  67     LONG index = 0;
  68     STRPTR theString;
  69
  70     if (code == 0)
  71     {
  72         *buffer = '\0';
  73         return 0;
  74     }
  75
  76     /* Do this to make sure there is room for a NULL terminator */
  77     len--;
  78
  79     if (header)
  80     {
  81         while((index < len) && *header)
  82         {
  83             buffer[index++] = *header++;
  84         }
  85
  86         buffer[index++] = ':';
  87         buffer[index++] = ' ';
  88     }
  89
  90     theString = DosGetString(code);
  91     if(theString)
  92     {
  93         while((index < len) && *theString)
  94         {
  95             buffer[index++] = *theString++;
  96         }
  97     }
  98     else
  99     {
 100         /* String buffer/index for long 2 string */
 101         UBYTE l2str[12], l2idx = 11;
 102
 103         theString = "Error";
 104         while((index < len) && *theString)
 105         {
 106             buffer[index++] = *theString++;
 107         }
 108
 109         /* If the number is negative, whack in a - sign. */
 110         if(code < 0)
 111         {
 112             code = -code;
 113             buffer[index++] = '-';
 114         }
 115
 116         /* Convert the number to a string, I work backwards, its easier */
 117         l2str[l2idx--] = '\0';
 118         while(code != 0)
 119         {
 120             l2str[l2idx--] = (code % 10) + '0';
 121             code /= 10;
 122         }
 123
 124         l2str[l2idx] = ' ';
 125
 126         /* Copy the number onto the fault string */
 127         while((index < len) && l2str[l2idx])
 128         {
 129             buffer[index++] = l2str[l2idx++];
 130         }
 131     }
 132     buffer[index] = '\0';
 133     return (len - index + 1);
 134
 135     AROS_LIBFUNC_EXIT
 136 } /* Fault */