System.Append Function

Prepares an existing file for adding text to the end.

Pascal

procedure Append(var F: Text);

C++

Append(Text F);

File

System

Description

Call Append to ensure that a file is opened with write-only access with the file pointer positioned at the end of the file. F is a text file variable and must be associated with an external file using AssignFile. If no external file of the given name exists, an error occurs. If F is already open, it is closed, then reopened. The current file position is set to the end of the file.

Note: If a Ctrl+Z (ASCII 26) is present in the last 128-byte block of the file, the current file position is set so that the next character added to the file overwrites the first Ctrl+Z in the block. In this way, text can be appended to a file that terminates with a Ctrl+Z.

If F was not assigned a name, then, after the call to Append, F refers to the standard output file.

Delphi Examples:

Copy Code

{
Click the button and select a file to append a string to the bottom of the file.
}

procedure TForm1.Button1Click(Sender: TObject);
var
  f: TextFile;
begin
  if OpenDialog1.Execute then
  begin                    { open a text file }
    AssignFile(f, OpenDialog1.FileName);
    Append(f);
    Writeln(f, 'I am appending some stuff to the end of the file.'); 
    { insert code here that would require a Flush before closing the file }
    Flush(f);  { ensures that the text was actually written to file }
    CloseFile(f);
    MessageDlg(OpenDialog1.FileName + ' has been altered, please validate.', mtInformation, [mbOK], 0)
  end;
end;