title: Error: ps command not found in bash
body: <p>I'm getting an error while executing this bash script which prints 'hello' till a background process continues its execution.</p>
  
  <pre><code>ps command not found 
  </code></pre>
  
  <p>I've done this couple of times before but not sure why I'm getting error this time.</p>
  
  <pre><code>./a.sh &amp;
  while ps -p $! &gt; /dev/null; do
         echo hello
  done
  </code></pre>