Err is local

[Lance Edmonds]

I don't think that ERR and ERRAPI could ever be made GLOBAL because it opens up too meny problems for threaded and reenterant sub/function calls...

The usual technique is to use the same technique as the Windows API offers - instead of using SUB's, use a function that returns an error code. You could also call a function that could be used to store the ERR and ERRAPI values in static variables, and then these could be retrieved from other subs/functions.

' Psuedocode
FUNCTION GlobalError(BYVAL PBerr&) AS LONG
  STATIC LastErr&
  IF PBErr& = 0 THEN 
    FUNCTION = LastErr&
  ELSE
    LastErr& = PBerr&
  END IF
END FUNCTION
  
...
call GlobalError(7) ' set "lasterr" to 7
...
if GlobalError(0) = 7 THEN...  ' Retrieve the last error
...

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Terry Webb]

Here's what I do:

SUB                                         _
Show_Error                                  _
(                                           _
    BYVAL   proc            AS  STRING      _   '   procedure
,   BYVAL   m               AS  STRING      _   '   message
,   BYVAL   e               AS  LONG        _   '   ERR
,   BYVAL   ea              AS  LONG        _   '   ERRAPI
)

#REGISTER   NONE

LOCAL   s                       AS  STRING

'   procedure
s   =   "Procedure: "                       _
    +   proc                                _
    +   $CRLF                               _
    +   $CRLF

'   messsage
IF  LEN(m)                                  THEN
s   =   s                                   _
    +   m                                   _
    +   $CRLF                               _
    +   $CRLF
END IF

'   ERR
s   =   s                                   _
    +   "Error # "
SELECT  CASE    e
    CASE    0
        s   =   s                           _
            +   " 0 No error"
    CASE    5
        s   =   s                           _
            +   " 5 Illegal function call"
    CASE    7
        s   =   s                           _
            +   " 7 Out of memory"
    CASE    9
        s   =   s                           _
            +   " 9 Subscript / Pointer out of range"
    CASE    24
        s   =   s                           _
            +   " 24 Device Time-Out"
    CASE    51
        s   =   s                           _
            +   " 51 Internal error"
    CASE    52
        s   =   s                           _
            +   " 52 Bad file name or number"
    CASE    53
        s   =   s                           _
            +   " 53 File not found"
    CASE    54
        s   =   s                           _
            +   " 54 Bad file mode"
    CASE    55
        s   =   s                           _
            +   " 55 File is already open"
    CASE    57
        s   =   s                           _
            +   " 57 Device I/O error"
    CASE    58
        s   =   s                           _
            +   " 58 File already exists"
    CASE    61
        s   =   s                           _
            +   " 61 Disk full"
    CASE    62
        s   =   s                           _
            +   " 62 Input past end"
    CASE    63
        s   =   s                           _
            +   " 63 Bad record number"
    CASE    64
        s   =   s                           _
            +   " 64 Bad file name"
    CASE    67
        s   =   s                           _
            +   " 67 Too many files"
    CASE    68
        s   =   s                           _
            +   " 68 Device unavailable"
    CASE    70
        s   =   s                           _
            +   " 70 Permission denied"
    CASE    71
        s   =   s                           _
            +   " 71 Disk not ready"
    CASE    72
        s   =   s                           _
            +   " 72 Disk media error"
    CASE    74
        s   =   s                           _
            +   " 74 Rename across disks"
    CASE    75
        s   =   s                           _
            +   " 75 Path/file access error"
    CASE    76
        s   =   s                           _
            +   " 76 Path not found"
    CASE    ELSE
        s   =   s                           _
            +   FORMAT$(e)
END SELECT
s   =   s                                   _
    +   $CRLF                               _
    +   $CRLF

'   ERRAPI
IF  ea                                      THEN
s   =   s                                   _
    +   "API # "                            _
    +   FORMAT$(ea)                         _
    +   $CRLF                               _
    +   $CRLF
END IF

MSGBOX                                      _
    s                                       _
,       %MB_OK                              _
    OR  %MB_ICONERROR                       _
,   "Error"

END SUB

Example code to check for error and call Show-Error.

'   error?
IF  (ERR    +   ERRAPI)                     THEN
CALL                                        _
Show_Error                                  _
(                                           _
    "Load_Array"                            _   '   procedure
,   "Error occurred during Win32API ReadFile operation."    _   '   message
,   ERR                                     _
,   ERRAPI                                  _
)
END IF

HTH,
Terry


[This message has been edited by Terry Webb (edited June 21, 2000).]

Just found out that the Err and ErrApi are kept local.
When i have an err in a special proc. to open a file for example, i tried to read the err result in the calling proc.
Unf. this read 0.

Is there a mode in PB to make this one global?

(The example above WAS just an example, normally the proc. returns the filehandle or sort of, this would conflict with a err value, tricks enough of course.)