e>error</code></td><td><span><a href='https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error'>Error</a></span></td><td><span> not null if an error is occurred</span></td></tr><tr><td><span class="method-depth1"></span><code>fd</code></td><td><span><a href='https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Number'>Number</a></span></td><td><span> a file descriptor</span></td></tr></table><h4>Returns</h4><table class="table table-bordered table-condensed table-hover"><tr