title: Determine path of the executing script
body: <p>I have a script called <code>foo.R</code> that includes another script <code>other.R</code>, which is in the same directory:</p>
  
  <pre><code>#!/usr/bin/env Rscript
  message("Hello")
  source("other.R")
  </code></pre>
  
  <p>But I want <code>R</code> to find that <code>other.R</code> no matter what the current working directory. </p>
  
  <p>In other words, <code>foo.R</code> needs to know its own path. How can I do that?</p>