title: What is hints parameter for getaddrinfo?
body: <p>I can't understand usage for <code>hints</code> parameter in <code>getaddrinfo()</code></p>
  
  <pre><code>getaddrinfo(node, service, &amp;hints, &amp;res);
  </code></pre>
  
  <p>Same sample code for <code>getadderinfo()</code> like below doesn't read <code>hints</code> as if <code>hints</code>’ll never be set value.</p>
  
  <p><a href="http://manpages.ubuntu.com/manpages/hardy/man3/getaddrinfo.3.html" rel="nofollow">http://manpages.ubuntu.com/manpages/hardy/man3/getaddrinfo.3.html</a></p>
  
  <p><a href="http://www.freebsd.org/cgi/man.cgi?query=getaddrinfo&amp;sektion=3" rel="nofollow">http://www.freebsd.org/cgi/man.cgi?query=getaddrinfo&amp;sektion=3</a></p>
  
  <p>Then what is <code>hints</code> for ? </p>
  
  <p>Do I have to check the value of the <code>hints</code> when <code>getaddrinfo</code> returns?</p>