title: view the file from bottom to top
body: <p>HI,</p>
  
  <p>I know that <code>cat</code> prints the contents of the file on screen.</p>
  
  <p>i never worked on linux.But i am aware that <code>tac</code> is the command to show the file from bottom to top.I am not even sure whether tac is on unix.Atleast on my unix box its not present.
  i want to know is there a simple command unix which gives the output from bottom to top?</p>
  
  <p>i am expecting like below :</p>
  
  <pre><code>&lt;command&gt; file_name;
  </code></pre>
  
  <p>I know this can be done using some tools like <code>awk</code>,<code>sed</code>.
  but could anyone please tell me a most simple command to perform that task?</p>