title: JSONPath/JSONQuery filter on key
body: <p>I know how to use JSONPath in JavaScript <a href="https://stackoverflow.com/questions/2003252/jsonpath-contains-filter">to filter on the values</a>:</p>
  
  <pre><code>var o = {
    current_user_url: "https://api.github.com/user",
    other_user_url: "https://api.github.com/user",
    otherstuff: "stuff"
  };
  jsonPath(o, "$.[?(/https.*/.test(@))]") //returns ["https://api.github.com/user"]
  </code></pre>
  
  <p>But how to filter on the keys? I want to have all values returned where the key ends in <code>*_url</code>. The following doesn't work since <code>@</code> apparently only contains the value of the JSON objects.</p>
  
  <pre><code>jsonPath(o, "$.[?(/.*_url/.test(@))]")
  </code></pre>
  
  <p>If it's not possible with JSONPath or JSONQuery, is there another library that's easy to use and setup? I want the user to enter the query-expression, that's why I'd prefer to use a query language instead of just evaling plain JavaScript (like <a href="https://stackoverflow.com/questions/8628949">these guys</a>).</p>