NAME
        SetFileSize -- Sets the size of a file (V36)

   SYNOPSIS
        newsize = SetFileSize(fh, offset, mode)
        D0                    D1    D2     D3

        long setfilesize(bptr, long, long)

   FUNCTION
        Changes the file size, truncating or extending as needed.  Not all
        handlers may support this; be careful and check the return code.  If
        the file is extended, no values should be assumed for the new bytes.
        If the new position would be before the filehandle's current position
        in the file, the filehandle will end with a position at the
        end-of-file.  If there are other filehandles open onto the file, the
        new size will not leave any filehandle pointing past the end-of-file.
        You can check for this by looking at the new size (which would be
        different than what you requested).

        The seek position should not be changed unless the file is made
        smaller than the current seek position.  However, see BUGS.

        Do NOT count on any specific values to be in any extended area.

   INPUTS
        fh     - File to be truncated/extended.
        offset - Offset from position determined by mode.
        mode   - One of OFFSET_BEGINNING, OFFSET_CURRENT, or OFFSET_END.

   RESULT
        newsize - position of new end-of-file or -1 for error.

   BUGS
        The RAM: filesystem and the normal Amiga filesystem act differently
        in where the file position is left after SetFileSize().  RAM: leaves
        you at the new end of the file (incorrectly), while the Amiga ROM
        filesystem leaves the seek position alone, unless the new position
        is less than the current position, in which case you're left at the
        new EOF.

        The best workaround is to not make any assumptions about the seek
        position after SetFileSize().

   SEE ALSO
        seek()