Can one do this?

I know that you can append test to the end of Text files, but can you tack on data to an existing file?

Yes...

"Seek" the end of the file, and then write to the file...

I think it's FileSeek these days.

(that's if you binary file is a "file of TMyRecord")

procedure Append();
var
  sBuffer:string;
  iLength:integer;
begin
  sBuffer:='My Appended String'#13#10;
  iLength:=Length(sBuffer);
  FS:=TFileStream.Create(sFileName, fmshareDenyWrite);
  Try
    FS.Seek(0,soFromEnd);
    FS.WriteBuffer(sBuffer[1],iLength);
  Finally
    FreeAndNil(FS):
  end;
end;

The file is type 'File'

var MF: File;
  bffer: array [0..127] of Byte;
begin
  AssignFile(MF,fname);
  FileMode:=fmOpenWrite;
  Reset(MF,1);
  Blockwrite(MF,bffer,128);
  CloseFile(MF);
end;

Do you reckon that would do it?

2008/12/19 Reenen Laurie :

Ok, so if you want to use TFileStream you would just

FS.Seek(0,sofromEnd);
FS.Write(MyRec,SizeOf(MyRec));

Thanks Andrew.

In future I will look at using filestreams rather than go down the AssignFile route.

2008/12/19 Andrew Brunner :

Andrew (or anyone else), in the example you provided below, you instantiate the Filestream:

FS:=TFileStream.Create(sFileName, fmshareDenyWrite);

after which you use a try...finally block to write data to the file

 Try
    FS.Seek(0,soFromEnd);
    FS.WriteBuffer(sBuffer[1],iLength);
  Finally
    FreeAndNil(FS):
  end;

My question is: Does the FreeAndNil line free the stream? If I want to write again to the file, don't I need to instantiate the FS TFileStream object again using TFileStream.Create?

2008/12/19 Andrew Brunner :

Yes, if you've got a bunch of operations into this method write a wrapper class this way you can keep the stream alive until such time as it's not needed. Using FS.Seek(0 sofromEnd) or whatever you need to position the Stream.