title: While loop in shell script get error : too many arguments
body: <p>I'm trying to run a very simple script that reads input from a user and continuously loop.But they show error [:too many arguments</p>
  
  <pre><code>i=0
  while [ $i -le 5 ]
  do
  echo $i
  i='expr $i + 1'
  done
  </code></pre>