Andres Valloud <avalloud at exobox.com> wrote:
	I just read a comment in class FileStream saying that in DOS
	files can't be shortened.

Microsoft MS-DOS Programmer's Reference
for MS-DOS 6.0

    Interrupt 21 Function 40h Write File or Device (pp 280-281)
	Writing 0 bytes to the file truncates the file
	at the current position of the file pointer.

A typically bizarre way to do it, but it has been there are a long time.

In Windows there is SetEndOfFile().