title: How to use variable in sed search pattern
body: <p>I will show an example to explain my problem.</p>
  
  <pre><code>VARIABLE='some string'
  </code></pre>
  
  <p>I want to search the string in file like:</p>
  
  <pre><code>sed -n "/$VARIABLE,test/p" aFile
  </code></pre>
  
  <p>I know it's wrong, because the variable identifier "$" is conflict with perl pattern $ which means the end of the line.</p>
  
  <p>So my question is: is there any way to use variable in sed patter search?</p>