title: while IFS= read -r -d $'\0' file ... explanation
body: <p>I do not understand this line of shell script. Doesn't the while statement need a 'test' or [ ] or [[ ]] expression that will set $? to 1 or 0? How does</p>
  
  <pre><code>while IFS= read -r -d $'\0'; do ...; done
  </code></pre>
  
  <p>do that? Any help understanding the syntax here is greatly appreciated.</p>