Various screen-oriented programs, such as
<citerefentry><refentrytitle>vi
</refentrytitle><manvolnum>1
</manvolnum></citerefentry>, must be able to determine the current screen dimensions. As this is achieved this through
<command>ioctl
</command> calls to the console driver (such as
<citerefentry><refentrytitle>syscons
</refentrytitle><manvolnum>4
</manvolnum></citerefentry>) they will correctly determine the new screen dimensions.