input available, the command returns an empty string and
does not consume any input.
If <I>varName</I> is specified and an empty string is returned in
<I>varName</I> because of end-of-file or because of insufficient
data in non-blocking mode, then the return count is -1.
Note that if <I>varName</I> is not specified then the end-of-file
and no-full-line-available cases can
produce the same results as if there were an input line consisting
only of the end-of-line character(s).
The <B><A HREF="eof.html">eof</A