IntToStr bring me to lost hairs

[paule32]

I have this Function:

Code: Pascal  [Select][+][-]

1. function IntToStr32(AValue: Integer): PChar; stdcall; export;
2. var
3.   temp   : PChar;
4. begin
5.   temp := StrAlloc(64);
6.   _itoa(AValue, temp, 10);
7.   if AValue = 123 then
8.   writeln('temp: ' + temp);
9.   Exit(temp);
10. end;

when I call it with IntToStr32(123) I get no writeln

the Function _itioa is:

Code: Pascal  [Select][+][-]

1. function _itoa  (Value: Integer; Buffer: PChar; Radix: Integer): PChar; cdecl; external 'msvcrt.dll' name '_itoa';

But the following Code works:

Code: Pascal  [Select][+][-]

1. function IntToStr32(AValue: Integer): PChar; stdcall; export;
2. var
3.   temp   : PChar;
4. begin
5.   AValue := 123;
6.   temp := StrAlloc(64);
7.   _itoa(AValue, temp, 10);
8.   if AValue = 123 then
9.   writeln('temp: ' + temp);
10.   Exit(temp);
11. end;

[marcov]

_itoa has a return value. This is so you know how many characters you have written so that you can provide proper zero terminating. 

[paule32]

when I do:

temp := _itoa(AValue, temp, 10);

or:

StrCopy(temp, _itoa(AValue, temp, 10));

I get same results:
temp: 20971088

But not 123.

[Thaddy]

If you see a pointer value why do you stop thinking about what the pointer points to?

Also,

Why do you use C libraries for that?
The Pascal compiler handles that just as efficient.

If I wasn't already certified mad, you will make me even more mad with such questions where you do not do your own research.

Funny you focus on 32 Intel Windows, which is not obtainable from MS anymore.

[paule32]

good news:
I have found a Solution:

Code: Pascal  [Select][+][-]

1. function IntToStr32(Value: Integer): string; stdcall; export;
2. var
3.   Buffer: array[0..31] of Char;
4.   Temp: PChar;
5.   Negative: Boolean;
6.   Digit: Integer;
7.   Len: Integer;
8. begin
9.   Len := 0;
10.   Temp := @Buffer[0];
11.   Buffer[0] := #0;
12.  
13.   Negative := Value < 0;
14.   if Negative then
15.     Value := -Value;
16.  
17.   repeat
18.     Digit := Value mod 10;
19.     Move(Buffer[0], Buffer[1], Len + 1);
20.     Buffer[0] := Chr(Ord('0') + Digit);
21.     Inc(Len);
22.     Value := Value div 10;
23.   until Value = 0;
24.  
25.   if Negative then
26.   begin
27.     Move(Buffer[0], Buffer[1], Len + 1);
28.     Buffer[0] := '-';
29.     Inc(Len);
30.   end;
31.  
32.   SetString(Result, Buffer, Len);
33. end;

[Thaddy]

 
Yup, the setstring trick. (it is not a trick!)

One day you will learn.

 

Your code is still highly inefficient, though: you should use val(), which is also used by inttostr.
Then again: we discussed that.... and you did not understand that.

This part is exceptionally bad, what are you trying there?

Code: Pascal  [Select][+][-]

1.   repeat
2.     Digit := Value mod 10;
3.     Move(Buffer[0], Buffer[1], Len + 1);
4.     Buffer[0] := Chr(Ord('0') + Digit);
5.     Inc(Len);
6.     Value := Value div 10;
7.   until Value = 0;

Makes no sense.

[paule32]

it is not the efficency that I looking for.
I looking for workable...