title: Get current username in Julia (Linux)
body: <p>I must be doing something stupid, but I can't seem to retrieve the current username using Julia. The closest function in <code>Base</code> appears to be <code>gethostname()</code>, but that returns the computer name, not the username. I tried system calls but am having trouble due to the interpolation character <code>$</code>. Specifically, although <code>echo $USER</code> returns the appropriate username in a terminal, when I try the following in Julia I get various errors or incorrect answers:</p>
  
  <pre><code>run(`echo $USER`)
  run(`echo "$USER"`)
  run(`echo '$USER'`)
  run(`echo '$'USER`)
  run(`echo \$USER`)
  </code></pre>
  
  <p>I guess the issue is that <code>Julia</code> is misinterpreting the <code>$</code> as an interpolation, but I've got no idea how to get around this.</p>
  
  <p>Any ideas?</p>