 run the program with command-line `<font color="#82140F"><code>gri -debug file.gri</code></font>'
the code in the `<font color="#82140F"><code>if</code></font>' block will print out the columnar data, but
when you run it with `<font color="#82140F"><code>gri file.gri</code></font>' these lines are not printed.
<p>
<li> `<font color="#82140F"><code>..eof..</code></font>'
<!-- latex: \index{@code{..eof..}, flag indicating end-of-file} -->
Flag indicating whether an end-of-file was encountered on the last
`<f