 code for Success is 0.</p>
<pre>
yes? LIST test_opendap ("http://test.opendap.org/opendap/data/nc/test.nc")
       VARIABLE : TEST_OPENDAP ("http://test.opendap.org/opendap/data/nc/test.nc")
       X        : 1
       0.0000</pre><p>Here is a test of an invalid URL</p>
<pre>
yes? LIST test_opendap ("http://not_a_valid_server/test.nc")
      VARIABLE : TEST_OPENDAP ("http://not_a_valid_server/test.nc")
             X        : 1
          1001.
</pre><p>The function may also be run on local files, returning 