title: How to replace the last char of a string in bash with another char
body: <p>I have strings which represent versions (always in the following format):</p>
  
  <pre><code>1.0.0
  1.1.0
  1.5.0
  20.189.0
  456874.0.0
  </code></pre>
  
  <p>The last part of the string will always be <code>.0</code>.
  Now I'm searching for a way in bash how I can replace this with <code>.X</code></p>
  
  <pre><code>1.0.X
  1.1.X
  9.5.X
  20.189.X
  ...
  </code></pre>