Translate a DLL call from PowerBasic to Delphi - delphi

Question

I would like to call SPSS 'backend' from Delphi. There is a DLL that I can use (it seems): SPSSio64.DLL. But I can not find the interface definition.
What I have found is an example in PowerBasic:
Read and write SPSS sav files
DECLARE FUNCTION spssOpenRead LIB "spssio32.dll" ALIAS "spssOpenRead#8" (BYVAL fileName AS STRING, BYREF hHandle AS LONG) AS LONG
DECLARE FUNCTION spssCloseRead LIB "spssio32.dll" ALIAS "spssCloseRead#4" (BYVAL hHandle AS LONG) AS LONG
Since I only need functions to read and write a file (all the processing will be done via a syntax in that file), I thought that this example might be enough to deduce how to call equivalent functions from Delphi.
So the question is: how would these declarations be in Delphi (64-bit)?

Answer 1

Based on the SPSS 14.0 for Windows Developer's Guide, and PowerBasic documentation, try something like this:
32-bit:
// spssio32.dll exports both 'spssOpenRead' and 'spssOpenRead#8', which are the same function...
function spssOpenRead(filename: PAnsiChar; var hHandle: Integer): Integer; stdcall; external 'spssio32.dll' {name 'spssOpenRead#8'};
// spssio32.dll exports both 'spssCloseRead' and 'spssCloseRead#4', which are the same function...
function spssCloseRead(hHandle: Integer): Integer; stdcall; external 'spssio32.dll' {name 'spssCloseRead#4'};
64-bit:
// I can't find a copy of spssio64.dll to download, so I can't verify the exported names. Adjust if needed..
function spssOpenRead(filename: PAnsiChar; var hHandle: Integer): Integer; stdcall; external 'spssio64.dll' {name 'spssOpenRead#16'};
function spssCloseRead(hHandle: Integer): Integer; stdcall; external 'spssio64.dll' {name 'spssCloseRead#8'};

Answer 2

For the record, this works:
function LoadDLL(DLLname : string) : Uint64;
var
em : TArithmeticExceptionMask;
begin
em:=GetExceptionmask;
SetExceptionmask(em+[exInvalidOp,exZeroDivide,exOverflow,exUnderflow]);
result:=LoadLibrary(PwideChar(DLLname));
SetExceptionmask(em);
end;
function RunSPSSio(filename : string; instructions : Tinstructions) : boolean;
// This will only read SAV files, not SPS files !
type
TspssOpenRead = function (filename: PAnsiChar; var hHandle: Uint64): Integer;
TspssCloseRead = function(hHandle: Uint64): Integer;
TspssGetInterfaceEncoding = function(hHandle : Uint64): Integer;
TspssSetInterfaceEncoding = function(encoding : integer; hHandle : Uint64): Integer;
const
SPSS_ENCODING_UTF8 = 1;
var
p : integer;
spssOpenRead : TspssOpenRead;
spssCloseRead : TspssCloseRead;
spssGetIFencoding : TspssGetInterfaceEncoding;
spssSetIFencoding : TspssSetInterfaceEncoding;
DLLhandle : Uint64;
fileref : PANSIchar;
begin
result:=false;
DLLhandle:=LoadDLL('C:\SPSS\spssio64.dll'); // hardcoded
if DLLhandle=0
then begin p:=GetLastError();
report('DLL load error '+IntToStr(p));
exit;
end;
try
#SPSSopenRead:=getProcAddress(DLLhandle,'spssOpenRead');
#SPSScloseRead:=getProcAddress(DLLhandle,'spssCloseRead');
#SPSSsetIFencoding:=getProcAddress(DLLhandle,'spssSetInterfaceEncoding');
SPSSsetIFencoding(SPSS_ENCODING_UTF8,DLLhandle);
fileref:=PANSIchar(ANSIstring(filename));
p:=SPSSopenRead(fileref,DLLhandle);
if p<>0
then report('*** SPSSio error '+IntToStr(p))
else begin // SPSS database interactions here
result:=SPSScloseRead(DLLhandle)=0;
end;
finally
freeLibrary(DLLhandle);
end;
end;