title: How do I delete an exported environment variable?
body: <p>Before installing <a href="https://en.wikipedia.org/wiki/Gnuplot" rel="noreferrer">gnuplot</a>, I set the environment variable <code>GNUPLOT_DRIVER_DIR = /home/gnuplot/build/src</code>. During the installation, something went wrong.</p>
  <p>I want to remove the <code>GNUPLOT_DRIVER_DIR</code> environment variable. How can I achieve it?</p>