title: wget gets not expecting exit code
body: <p>I'm using wget into a bash script and I check the exit code to print some message. That's what I do:</p>
  
  <pre><code>wget -U mozilla -O my_page.html https://example.com/page
  echo $?
  </code></pre>
  
  <p>Sometimes I get the page succesfully, because it exists, and somethimes I get a void file, because a 404 error (the page does not exist).</p>
  
  <p>Well, I always get the exit code number <code>4</code>, in every case.</p>
  
  <p>The man page for wget says this for wget exit codes:</p>
  
  <pre><code>0   No problems occurred.
  1   Generic error code.
  2   Parse error---for instance, when parsing command-line options, the .wgetrc or .netrc...
  3   File I/O error.
  4   Network failure.
  5   SSL verification failure.
  6   Username/password authentication failure.
  7   Protocol errors.
  8   Server issued an error response.
  </code></pre>
  
  <p>I expect to get code <code>0</code> when I get a successful download and the code <code>8</code> when I get a 404 error.</p>
  
  <p>What's happening?</p>