Incorporate user note re: following redirects.

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@137859 c90b9560-bf6c-de11-be94-00142212c4b1

appendices/wrappers.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.23 $ -->
+<!-- $Revision: 1.24 $ -->
 <appendix id="wrappers">
  <title>List of Supported Protocols/Wrappers</title>
  <para>
@@ -32,8 +32,35 @@
   <simpara>
    Redirects have been supported since PHP 4.0.5; if you are using
    an earlier version you will need to include trailing slashes in
-   your URLs.
+   your URLs.  If it's important to know the url of the resource where
+   your document came from (after all redirects have been processed),
+   you'll need to process the series of response headers returned by the
+   stream.
   </simpara>
+  <informalexample>
+   <programlisting role="php">
+<![CDATA[
+<?php
+$url = 'http://www.example.com/redirecting_page.php';
+
+$fp = fopen($url, 'r');
+
+/* Prior to PHP 4.3.0 use $http_response_header 
+   instead of stream_get_meta_data() */
+foreach(stream_get_meta_data($fp) as $response) {
+
+  /* Were we redirected? */
+  if (substr(strtolower($response), 0, 10) == 'location: ') {
+    /* update $url with where we were redirected to */
+    $url = substr($response, 10);
+  }
+
+}
+
+?>
+]]>
+   </programlisting>
+  </informalexample>
   <simpara>
    The stream allows access to the <emphasis>body</emphasis> of
    the resource; the headers are stored in the