title: How does "wc -w < file.txt" work?
body: <p>I was trying to get only the number of words in a file using wc. <code>wc -w file.txt</code> gives me that plus the file name. I don't want the file name. So, I saw that <code>wc -w &lt; file.txt</code> works.</p>
  
  <p>I don't understand how this command works. I cannot even add a comment below <a href="https://stackoverflow.com/a/10239606/1743811">the answer where I saw this command</a>.</p>
  
  <p>Why does it not print filename in the case of <code>wc -w &lt; file.txt</code>?</p>