In my previous post, I described differences in saving text with TStringStream and TStringList.  TStringList helpfully adds a preamble.  TStringStream doesn’t.  Now when loading text from a stream, you’ll typically want to strip off the preamble.  But if you want the text to be otherwise unmodified, then TStringList is not safe, and TStringStream doesn’t strip off the preamble.

Here’s a helper function that does strip the preamble.  If you don’t pass an encoding, it will guess on the basis of the preamble (but won’t otherwise sniff the stream content to guess the encoding heuristically). If the content does not have a preamble, it assumes the current code page (TEncoding.Default).  If you do pass an encoding, the preamble will be stripped if it is there but no encoding detection will take place.

function LoadStringFromFile(const filename: string; encoding: TEncoding = nil): string;
var
  FPreambleLength: Integer;
begin
  with TBytesStream.Create do
  try
    LoadFromFile(filename);
    FPreambleLength := TEncoding.GetBufferEncoding(Bytes, encoding);
    Result := encoding.GetString(Bytes, FPreambleLength, Size - FPreambleLength);
  finally
    Free;
  end;
end;

Obviously not fantastic for very large files (you can solve that one yourself) but for your plain old bite sized files, quick and easy solution.