title: newline character in comm perl script
body: <p>There is a newline character getting inserted between the 2 filenames. 
  How do I avoid this?</p>
  
  <pre><code>$diff = `comm -3 "/tmp/${PATH1U}_${SITE1}_s_${USER} /tmp/${PATH2U}_${SITE2}_s_${USER}"|wc -l`;
  </code></pre>
  
  <p>This is the error message while executing:</p>
  
  <blockquote>
    <p>comm: missing operand after `/tmp/file1\n /tmp/file2\n'</p>
  </blockquote>