title: Sed replacement not working when using variables
body: <p>something strange is happening when trying to replace string with sed. This works :</p>
  
  <pre><code>find /home/loni/config -type f -exec sed -i 's/some_pattern/replacement/g' {} \;
  </code></pre>
  
  <p>So it works when I manually type the strings. But in the case below replacement doesn't occur :</p>
  
  <pre><code>find /home/loni/config -type f -exec sed -i 's/${PATTERN}/${REPLACEMENT}/g' {} \;
  </code></pre>
  
  <p>When I echo these two variables PATTERN and REPLACEMENT they have the correct values. </p>
  
  <p>I'm trying to replace all occurences of pattern string with replacement string in all files in my config directory.</p>