rom/dos/fault.c

   1 /*
   2     Copyright © 1995-2008, 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 know, 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 PassThroughErrnos
  92     if ((!theString) && (code & PassThroughErrnos))
  93     {
  94         theString = strerror (code ^ PassThroughErrnos);
  95     }
  96 #endif
  97     if(theString)
  98     {
  99         while((index < len) && *theString)
 100         {
 101             buffer[index++] = *theString++;
 102         }
 103     }
 104     else
 105     {
 106         /* String buffer/index for long 2 string */
 107         UBYTE l2str[12], l2idx = 11;
 108
 109         theString = "Unknown error ";
 110         while((index < len) && *theString)
 111         {
 112             buffer[index++] = *theString++;
 113         }
 114
 115         /* If the number is negative, whack in a - sign. */
 116         if(code < 0)
 117         {
 118             code = -code;
 119             buffer[index++] = '-';
 120         }
 121
 122         /* Convert the number to a string, I work backwards, its easier */
 123         l2str[l2idx--] = '\0';
 124         while(code != 0)
 125         {
 126             l2str[l2idx--] = (code % 10) + '0';
 127             code /= 10;
 128         }
 129
 130         l2str[l2idx] = ' ';
 131
 132         /* Copy the number onto the fault string */
 133         while((index < len) && l2str[l2idx])
 134         {
 135             buffer[index++] = l2str[l2idx++];
 136         }
 137     }
 138     buffer[index] = '\0';
 139     return (len - index + 1);
 140
 141     AROS_LIBFUNC_EXIT
 142 } /* Fault */