Steam id finder

[Fido^]

I wrote a function to do this in Delphi:

Code:

function GetSteamID(): String;
var
  Reg: TRegistry;
  Input: Integer;
  Beginning: Boolean;
  TextLine, SteamPath: String;
begin
  try
    // Init our classes.
    Reg := TRegistry.Create;

    // Obtain steam path.
    Reg.RootKey := HKEY_CURRENT_USER;
    Reg.OpenKey('Software\Valve\Steam\', false);
    SteamPath := Reg.ReadString('SteamPath');

    // Copy the file to prevent IO error.
    CopyFile(PChar(SteamPath + '/Steam.log'), PChar(SteamPath + '/Steam2.log'), False);

    // Read the last entry containing a steamid.
    Input := FileOpen (SteamPath + '/Steam2.log', 0);
    FileSeek(Input, 0, 2);
    repeat
      ReadBack(Input, TextLine, Beginning);
      if Pos('for ', TextLine) <> 0 then
      begin
        // Delete all the crap and keep the steamid.
        Delete(TextLine, 1, Pos('for ', TextLine) + 3);
        Result := 'STEAM_' + TextLine;
        // Free.
        Reg.Free;
        FileClose(Input);
        DeleteFile(SteamPath + '/Steam2.log');
        Exit;
      end;
    until Beginning;

    // Free.
    Result := '0';
    Reg.Free;
    FileClose(Input);
    DeleteFile(SteamPath + '/Steam2.log');
  except
    Result := '0';
  end;
end;

This is the ReadBack function I use:

Code:

procedure ReadBack(const F: Integer; var Line: String; var Beginning: Boolean);
const
  MAXLINELENGTH = 256;
var
  Current, Before: LongInt;
  Buffer: array [0..MAXLINELENGTH] of Char;
  P: PChar;
begin
  Current := FileSeek(F, 0, 1);
  Before := Current - MAXLINELENGTH;
  if Before < 0 then
    Before := 0;
  FileSeek (F, Before, 0);
  FileRead (F, Buffer, Current - Before);
  Buffer[Current - Before] := #0;
  P := StrRScan(Buffer, #10);
  if P = nil then
  begin
    Line := StrPas(Buffer);
    FileSeek(F, 0, 0);
    Beginning := True
  end
  else
  begin
    Line := StrPas (p + 1);
    FileSeek (F, Before + LongInt(P) - LongInt(@Buffer), 0);
    Beginning := False
  end;
  if Length(Line) > 0 then
    if Line[Length (Line)] = #13 then
    begin
      SetLength (Line, Length(Line) - 1)
    end
end;