Recommendations to read and parse an Fixed Width Text File using Delphi

Question

Wich is the best way to read and parse an Fixed Width Text File using Delphi?

exist any component for that?

thanks in advance.

Answer 1

You could do with a simple TMemo or TRichEdit. But the #1 (?) text editor component for Delphi, I believe, is TSynEdit.

Answer 2

If by read you mean parse, try using a TStringList. Call TStringList.LoadFromFile and you'll get a list of individual lines. Then you can go over each individual line and parse it out into a record or class based on the various fixed-length columns in the line. Check out the Copy function for a way to make this easier.

It's hard to be more specific without any details about what you're trying to do, but that's the general idea.

Answer 3

If its fixed width and ansi, you can use streams to read into a record containing fields made up of array of ansichar.

type
  rTest = record
    Field1 : array[1..12] of ansichar;
    Field2 : array[1..02] of ansichar;
    CRLF   : array[1..02] of ansichar;
  end;

var
  // Sample record for testing.
  Test1 : rTest = (Field1 : '123456789012'; Field2: 'AB'; CRLF: ^M+^J);

procedure TForm1.Button1Click(Sender: TObject);
var
  St : tStream;
  rdest : rTest;
  SVar : string;
begin
  St := TMemoryStream.Create;
  // write the record from the constant 
  st.Write(Test1,SizeOf(rTest));
  st.Seek(0,soFromBeginning);
  // read the record from the stream
  St.Read(rDest,SizeOf(rTest));
  // pull out field 1 and display
  SVar := Copy(rDest.Field1,1,12);
  ShowMessage(SVar);
  // pull out field 2 and display
  SVar := Copy(rDest.Field2,1,2);
  ShowMessage(SVar);
  st.free;
end;