Revision 1 of 1, by WikiArchive on 11-4-2026. The page as it is now.

TFileStream

A TFileStream is a descendant of TStream that gets/stores its data from/to a file on disk.

Constant	Decimal	Description
fmCreate	65280	Creates a new file
fmOpenRead	0	opens a file for reading
fmOpenWrite	1	opens a file for writing
fmOpenReadWrite	2	opens a file for reading and writing
fmShareDenyWrite	32	prohibit writing if file is already opened

read entire file fnam into a string.

pascal

function readstream(fnam: string): string;
var
  strm: TFileStream;
  n: longint;
  txt: string;
begin
  txt := '';
  strm := TFileStream.Create(fnam, fmOpenRead or fmShareDenyWrite);
  try
    n := strm.Size;
    SetLength(txt, n);
    strm.Read(txt[1], n);
  finally
    strm.Free;
  end;
  result := txt;
end;

read 8 bytes of fnam into a byte array:

pascal

..
type
    TByte8Array = array [0..7] of byte;
..
function readstream(fnam: string; position= integer): TByte8Array;
var
  strm : TFileStream;
begin
  strm := TFileStream.Create(fnam, fmOpenRead or fmShareDenyWrite);
  try
    strm.Position:=position;
    strm.Read (Result[0],8);
  finally
    strm.Free;
  end;
end;

Write a string txt to the file fnam.

pascal

procedure writestream(fnam: string; txt: string);
var
  strm: TFileStream;
  n: longint;
begin
  strm := TFileStream.Create(fnam, fmCreate);
  n := Length(txt);
  try
    strm.Position := 0;
    strm.Write(txt[1], n);
  finally
    strm.Free;
  end;
end;

TFileStream

See also