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Truncate procedure

In unit System

Truncate the file at position.

Declaration

pascal
procedure Truncate(var F: File)

Description

Truncate truncates the (opened) file F at the current file position.

Errors

Depending on the state of the {$I} switch, a runtime error can be generated if there is an error. In the {$I-} state, use IOResult to check for errors.

See also

Example: ex71

pascal
Program Example71;

{ Program to demonstrate the Truncate function. }

Var F : File of longint;
    I,L : Longint;

begin
  Assign (F,'test.tmp');
  Rewrite (F);
  For I:=1 to 10 Do
    Write (F,I);
  Writeln ('Filesize before Truncate : ',FileSize(F));
  Close (f);
  Reset (F);
  Repeat
    Read (F,I);
  Until i=5;
  Truncate (F);
  Writeln ('Filesize after Truncate  : ',Filesize(F));
  Close (f);
end.

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