title: How can I append NULL onto the end of a string pointer array?
body: <p>I am trying to use execvp to execute unix commands with given flags.</p>
  
  <p>My array, argv, might contain these elements:</p>
  
  <pre><code>{"ls", "-a"}
  </code></pre>
  
  <p>I am then passing this array to</p>
  
  <pre><code>execvp(argv[0], argv);
  </code></pre>
  
  <p>How can I safely append <em>NULL</em> onto the end of the argv array so execvp will know where to terminate?</p>