Hi Senthil / Raymond,

two pointers that might help:
http://firebird.sourceforge.net/index.php?op=useful&id=geldenhuis
http://firebird.sourceforge.net/index.php?op=useful&id=deatz_udf#left

both from the "really useful" section -- the name says it all! <g>

you can also download http://www.cvalde.com/utilities/FreeUDFLib.zip,
it includes Delphi sources so you can see how it's done.

regards & hth,
fingerman

Senthil Palanisamy wrote:

> Hi Raymond,
>
> This problem occurs due to access violation in the Usage of pointer
> variable.
> im not aware of delphi.
> in C and C++ if we try like "copying a string to a pointer variable without
> allocating the memory", then an access violation will take place and it will
> kill the IB/firebird service.
>
> regards,
> senthil.
>
> ----- Original Message -----
> From: "Raymond Kennington" <progsol@...>
> Newsgroups: egroups.ib-support
> To: <ib-support@yahoogroups.com>
> Sent: Thursday, November 07, 2002 10:05 PM
> Subject: [ib-support] Using UDF: "Connection Lost to Database"
>
>
>
>>Using a UDF causes the error message: "Connection Lost to Database" to
>
> appear.
>
>>All the relevant code is below. What is causing this?
>>
>>Is all memory correctly allocated and destroyed by the following?
>>
>>How to make the following thread-safe?
>>
>>Any other suggestions to improve the following?
>>
>>TIA.
>>
>>Raymond.
>>--------
>>
>>library Algorithms;
>>
>>uses
>> SysUtils,
>> Classes,
>> ConfNum in 'ConfNum.pas';
>>
>>{$R *.res}
>>
>>exports
>> CalcCheckDigit;
>>
>>begin
>>end.
>>
>>unit ConfNum;
>>
>>interface
>>
>>function CalcCheckDigit(var TheConfNum : PChar; ResultBuffer : PChar) :
>
> PChar; cdecl;
>
>>export;
>>
>>implementation
>>
>>uses
>> SysUtils;
>>
>>function CalcCheckDigit(var TheConfNum : PChar; ResultBuffer : PChar) :
>
> PChar; cdecl;
>
>>export;
>>var
>> c : array[0..1] of Char;
>>
>> i : Integer;
>>begin
>> Result := ResultBuffer;
>>
>> c[0] := 'A';
>> c[1] := #0;
>>
>> StrCopy(Result, c);
>>end;
>>
>>initialization
>> IsMultiThread := True;
>>
>>end.
>>
>>DECLARE EXTERNAL FUNCTION CalcCheckDigit
>>CSTRING(11) CHARACTER SET NONE,
>>CSTRING(2) CHARACTER SET NONE
>>RETURNS PARAMETER 2
>>ENTRY_POINT 'CalcCheckDigit' MODULE_NAME 'Algorithms';
>>
>>SELECT CalcCheckDigit('0000111111') FROM RDB$DATABASE;
>>
>>--
>>Raymond Kennington
>>Programming Solutions
>>W2W Team B
>>

--
-------------------------------------------------------------------------
when parsers parse, and compilers compile, then why don't objects object?

fingerbirdy - fingerman's door to Firebird
http://www.fingerbird.de