title: Scraping a web link with Rvest
body: <p>I am trying to figure out a way to extract a link from a wiki page. 
  The web page is the following:</p>
  
  <pre><code>wiki &lt;- html("https://en.wikipedia.org/wiki/Category:1879_births")
  </code></pre>
  
  <p>I am interested by the following link:</p>
  
  <pre><code>v =  html_node(wiki, "a[href*='pages']")
  &lt;a href="/w/index.php?title=Category:1879_births&amp;amp;pagefrom=Barrymore%2C+Ethel%0AEthel+Barrymore#mw-pages" title="Category:1879 births"&gt;next page&lt;/a&gt; 
  </code></pre>
  
  <p>I want to extract the link after <code>href</code> but when I try to convert <code>v</code> as a character and split it, I get the following error message: <em>" cannot coerce type 'externalptr' to vector of type 'character' "</em></p>
  
  <p>Does anyone know how to deal with this <em>"externalptr"</em> type and extracting the link ? </p>
  
  <p>Thanks in advance ! </p>