title: Bash shell question: Error occurs when running a simple shell script
body: <p>test.sh:</p>
  
  <pre><code>#!/bin/bash
  echo "helloworld"
  </code></pre>
  
  <p>I set the file mode to 755. when I try to run the script by typing "./test.sh", I get this:</p>
  
  <pre><code>helloworld
  ./test.sh: line 2: /root: is a directory
  </code></pre>
  
  <p>what's going on???</p>