title: what is the extension of an executable file in an xcode project
body: <p>I downloaded apple researchkit last month and run its sample. It worked and every thing was fine. This week i tried to run it , i had build failed and the error is that i need to have appledoc: </p>
  
  <p>error: appledoc is required for building ResearchKit's documentation. See <a href="http://appledoc.gentlebytes.com" rel="nofollow">http://appledoc.gentlebytes.com</a></p>
  
  <p>I did some research and i found this page </p>
  
  <pre><code> [1]: https://github.com/tomaz/appledoc#quick-install
  </code></pre>
  
  <p>I downloaded the project and built it and i found my </p>
  
  <blockquote>
    <p>build directory.</p>
  </blockquote>
  
  <p><strong>But</strong>, i didn't know what is the executable file in this directory and how can i add it to the path. Can someone help me ? thanks a lot.</p>