title: Sed error "command a expects \ followed by text"
body: <p>Here is my script:</p>
  
  <pre><code>openscad $1 -D generate=1 -o $1.csg 2&gt;&amp;1 &gt;/dev/null |
  sed 's/ECHO: \"\[LC\] //' |
  sed 's/"$//' |
  sed '$a;' &gt;./2d_$1
  </code></pre>
  
  <p>That output:</p>
  
  <pre><code>sed: 1: "$a;": command a expects \ followed by text
  </code></pre>