program FileTest (infile);
var
   Line: string[30];
   infile: text;
begin
   Assign(infile, 'hello.txt');
   Append(infile);
   WriteLn(infile, 'Hello, world!');
   Close(infile);
   Reset(infile);
   while not EOF(infile) do
   begin
      ReadLn(infile, Line);
      WriteLn(Line);
   end;
   Close(infile)
end.