title: How to add a string from variables to each line in a file in BASH
body: <p>I have this one : </p>
  
  <pre><code>sed -e 's/$/string after each line/' -i filename
  </code></pre>
  
  <p>but i want instead of "string after each line"
  <br>
  have a string from the following result:
  <br></p>
  
  <pre><code>cat filename2 | tr '\n' ' '
  </code></pre>
  
  <p>what should I do?</p>