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TBufStream.Flush procedure

Member of TBufStreamIn unit Objects

FLush data from buffer, and write it to stream.

Declaration

pascal
procedure Flush; virtual

Description

When the stream is in write mode, the contents of the buffer are written to disk, and the buffer position is set to zero. When the stream is in read mode, the buffer position is set to zero.

Errors

Write errors may occur if the file was in write mode. see Write for more info on the errors.

See also

Example: ex15

pascal
Program ex15;

{ Program to demonstrate the TStream.Flush method }

Uses Objects;

Var L : String;
    P : PString;
    S : PBufStream; { Only one with Flush implemented. }

begin
  L:='Some constant string';
  { Buffer size of 100 }
  S:=New(PBufStream,Init('test.dat',stcreate,100));
  Writeln ('Writing "',L,'" to stream with handle ',S^.Handle);
  S^.WriteStr(@L);
  { At this moment, there is no data on disk yet. }
  S^.Flush;
  { Now there is. }
  S^.WriteStr(@L);
  { Close calls flush first }
  S^.Close;
  Writeln ('Closed stream. File handle is ',S^.Handle);
  S^.Open (stOpenRead);
  P:=S^.ReadStr;
  L:=P^;
  DisposeStr(P);
  Writeln ('Read "',L,'" from stream with handle ',S^.Handle);
  S^.Close;
  Dispose (S,Done);
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.