[fpc-pascal]files handler in FPC

[Adam Naumowicz]

Hello,

On 6 Mar 2002, [iso-8859-2] £ukasz Le¶niak wrote:

> Hello!
> My name is Lukasz Lesniak and I am from Poland (Central Europe).

Although I'm in Japan now, I remember where Poland is quite well :-))

> I use Pascal very often.
>
> I've declared structure:
> (* ------------------------------------------------------------ *)
> type Person = record
> 		name: string[20];
> 		.
> 		{something else}
> 		{about 40 position}
> 		.
> 		age : Word;
>               end;
>      SetOfPerson = ^ElemOfSetOfPerson;
>      ElemOfSetOfPerson = record
>                            desc: Person;
> 			   prev: SetOfPerson;
> 			   next: SetOfPerson;
> 			 end;
>
>    filePerson = file of Person;
> (* ------------------------------------------------------------ *)
>
> First I wrote my program in Turbo Pascal. Now I want
> to convert source to FPC and the problem is:
>
> (* ------------------------------------------------------------ *)
> procedure ReadDataFromFile(var s: SetOfperson)
> var F: filePerson;
>     p: SetOfPerson;
>  .
> .
> Assign(F, path_to_F);
> {$i-}
> Reset(F);
> {$i+}
> if IOResult <> 0 then Halt(1);
> while not Eof(F) do
>  begin
>   new(p);
>   Read(F, p^.desc);
>   p^.next:=s;
>   s:=p;
> end;
>  .
> .
> (* ------------------------------------------------------------ *)
>
> and trying the same in FPC
>
> (* ------------------------------------------------------------ *)
> procedure ReadDataFromFile(var s: SetOfperson)
> var i, F: LongInt;
>     p: SetOfPerson;
>  .
> .
>  i:=0;
>  F:=FileOpen(path_to_F, fmOpenRead);
>  if F = -1 then Halt(1);
>  new(p);
>  FileSeek(F, i, fsFromBeginning);
>  FileRead(F, p^.desc, SizeOf(p^.desc));
>  (* XXX *)
>  p^.next:=s;
>  s:=p;
>  i:= i + 1;
>  end;
> (* ------------------------------------------------------------ *)
>
> XXX - question is: how to read file with FileRead function
>       from beginning to end, beacause this code reads only one person!
>       I am using FileSeek. It is good?

I can't see no loop here ! How do you think this is supposed to read all
the list ?
BTW - the BP snippet you included is a little old style but I can't see
there anything the FPC compiler should complain at.
Regards,
Adam Naumowicz

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WWW: http://math.uwb.edu.pl/~adamn/
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