title: See where a symbol is defined in irb
body: <p>I work on a pretty large rails project at work. Sometimes I need to hunt down class / constant definitions. Is there some built-in method in Ruby to do this for me? Example:</p>
  
  <pre><code>irb&gt; SOME_CONSTANT.__file__
  =&gt; /some/path/to/a/file
  </code></pre>