human
Complete this python program:
def _get_size_linux():
assistant
#Here is the Python program you requested.

    """Attempt to discover the dimensions of a terminal window, on Linux.
    """
    def ioctl_GWINSZ(fd):
        '\n                                Attempt    to    discover    the    dimensions    of    a    terminal    window,    using    IOCTL.\n                                '
        try:
            import fcntl, termios
            cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
        except:
            return None
        return cr
    cr = (ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2))
    if (not cr):
        try:
            fd = os.open(os.ctermid(), os.O_RDONLY)
            cr = ioctl_GWINSZ(fd)
            os.close(fd)
        except:
            pass
    if (not cr):
        try:
            cr = (env['LINES'], env['COLUMNS'])
        except:
            return None
    return (int(cr[1]), int(cr[0]))