title: Unix shell to prompt user for filename
body: <p>please pardon since I am a UNIX beginner.</p>
  
  <p>I wanna write a shell script that can ask user type in the filename and output the number of lines in that file, here is my code:</p>
  
  <pre><code>echo "Pls enter your filename:"
  read filename
  result=wc -l $filename
  
  echo "Your file has $result lines"
  </code></pre>
  
  <p>However, I couldn't get it working since it complains about the identifier "filename". Could experts help?Thanks !!</p>