title: How to check if a file is empty in Bash?
body: <p>I have a file called <em><strong>diff.txt</strong></em>. I Want to check whether it is empty.</p>
  <p>I wrote a bash script something like below, but I couldn't get it work.</p>
  <pre><code>if [ -s diff.txt ]
  then
          touch empty.txt
          rm full.txt
  else
          touch full.txt
          rm emtpy.txt
  fi
  </code></pre>