forked from GNUsocial/gnu-social
		
	From their tree on a4090d0b30f850044413630333341cd327cbb55a Source: https://github.com/openid/php-openid
		
			
				
	
	
		
			236 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			236 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
| <?php
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| 
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| /**
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|  * This is the HTML pseudo-parser for the Yadis library.
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|  *
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|  * PHP versions 4 and 5
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|  *
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|  * LICENSE: See the COPYING file included in this distribution.
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|  *
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|  * @package OpenID
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|  * @author JanRain, Inc. <openid@janrain.com>
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|  * @copyright 2005-2008 Janrain, Inc.
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|  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
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|  */
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| 
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| /**
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|  * This class is responsible for scanning an HTML string to find META
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|  * tags and their attributes.  This is used by the Yadis discovery
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|  * process.  This class must be instantiated to be used.
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|  *
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|  * @package OpenID
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|  */
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| class Auth_Yadis_ParseHTML {
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| 
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|     /**
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|      * @access private
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|      */
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|     var $_re_flags = "si";
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| 
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|     /**
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|      * @access private
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|      */
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|     var $_removed_re =
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|            "<!--.*?-->|<!\[CDATA\[.*?\]\]>|<script\b(?!:)[^>]*>.*?<\/script>";
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| 
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|     /**
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|      * @access private
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|      */
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|     var $_tag_expr = "<%s%s(?:\s.*?)?%s>";
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| 
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|     /**
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|      * @access private
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|      */
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|     var $_attr_find = '\b([-\w]+)=(".*?"|\'.*?\'|.+?)[\/\s>]';
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| 
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|     function Auth_Yadis_ParseHTML()
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|     {
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|         $this->_attr_find = sprintf("/%s/%s",
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|                                     $this->_attr_find,
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|                                     $this->_re_flags);
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| 
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|         $this->_removed_re = sprintf("/%s/%s",
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|                                      $this->_removed_re,
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|                                      $this->_re_flags);
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| 
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|         $this->_entity_replacements = array(
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|                                             'amp' => '&',
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|                                             'lt' => '<',
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|                                             'gt' => '>',
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|                                             'quot' => '"'
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|                                             );
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| 
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|         $this->_ent_replace =
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|             sprintf("&(%s);", implode("|",
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|                                       $this->_entity_replacements));
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|     }
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| 
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|     /**
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|      * Strip single and double quotes off of a string, if they are
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|      * present.
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|      *
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|      * @access private
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|      * @param string $str The original string
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|      * @return string $new_str The new string with leading and
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|      * trailing quotes removed
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|      */
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|     function removeQuotes($str)
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|     {
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|         $matches = array();
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|         $double = '/^"(.*)"$/';
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|         $single = "/^\'(.*)\'$/";
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| 
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|         if (preg_match($double, $str, $matches)) {
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|             return $matches[1];
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|         } else if (preg_match($single, $str, $matches)) {
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|             return $matches[1];
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|         } else {
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|             return $str;
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|         }
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|     }
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| 
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|     /**
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|      * Create a regular expression that will match an opening 
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|      * or closing tag from a set of names.
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|      *
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|      * @access private
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|      * @param mixed $tag_names Tag names to match
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|      * @param mixed $close false/0 = no, true/1 = yes, other = maybe
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|      * @param mixed $self_close false/0 = no, true/1 = yes, other = maybe
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|      * @return string $regex A regular expression string to be used
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|      * in, say, preg_match.
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|      */
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|     function tagPattern($tag_names, $close, $self_close)
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|     {
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|         if (is_array($tag_names)) {
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|             $tag_names = '(?:'.implode('|',$tag_names).')';
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|         }
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|         if ($close) {
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|             $close = '\/' . (($close == 1)? '' : '?');
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|         } else {
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|             $close = '';
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|         }
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|         if ($self_close) {
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|             $self_close = '(?:\/\s*)' . (($self_close == 1)? '' : '?');
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|         } else {
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|             $self_close = '';
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|         }
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|         $expr = sprintf($this->_tag_expr, $close, $tag_names, $self_close);
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| 
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|         return sprintf("/%s/%s", $expr, $this->_re_flags);
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|     }
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| 
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|     /**
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|      * Given an HTML document string, this finds all the META tags in
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|      * the document, provided they are found in the
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|      * <HTML><HEAD>...</HEAD> section of the document.  The <HTML> tag
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|      * may be missing.
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|      *
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|      * @access private
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|      * @param string $html_string An HTMl document string
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|      * @return array $tag_list Array of tags; each tag is an array of
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|      * attribute -> value.
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|      */
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|     function getMetaTags($html_string)
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|     {
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|         $html_string = preg_replace($this->_removed_re,
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|                                     "",
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|                                     $html_string);
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| 
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|         $key_tags = array($this->tagPattern('html', false, false),
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|                           $this->tagPattern('head', false, false),
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|                           $this->tagPattern('head', true, false),
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|                           $this->tagPattern('html', true, false),
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|                           $this->tagPattern(array(
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|                           'body', 'frameset', 'frame', 'p', 'div',
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|                           'table','span','a'), 'maybe', 'maybe'));
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|         $key_tags_pos = array();
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|         foreach ($key_tags as $pat) {
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|             $matches = array();
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|             preg_match($pat, $html_string, $matches, PREG_OFFSET_CAPTURE);
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|             if($matches) {
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|                 $key_tags_pos[] = $matches[0][1];
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|             } else {
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|                 $key_tags_pos[] = null;
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|             }
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|         }
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|         // no opening head tag
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|         if (is_null($key_tags_pos[1])) {
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|             return array();
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|         }
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|         // the effective </head> is the min of the following
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|         if (is_null($key_tags_pos[2])) {
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|             $key_tags_pos[2] = strlen($html_string);
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|         }
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|         foreach (array($key_tags_pos[3], $key_tags_pos[4]) as $pos) {
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|             if (!is_null($pos) && $pos < $key_tags_pos[2]) {
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|                 $key_tags_pos[2] = $pos;
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|             }
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|         }
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|         // closing head tag comes before opening head tag
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|         if ($key_tags_pos[1] > $key_tags_pos[2]) {
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|             return array();
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|         }
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|         // if there is an opening html tag, make sure the opening head tag
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|         // comes after it
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|         if (!is_null($key_tags_pos[0]) && $key_tags_pos[1] < $key_tags_pos[0]) {
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|             return array();
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|         }
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|         $html_string = substr($html_string, $key_tags_pos[1],
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|                               ($key_tags_pos[2]-$key_tags_pos[1]));
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| 
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|         $link_data = array();
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|         $link_matches = array();
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|         
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|         if (!preg_match_all($this->tagPattern('meta', false, 'maybe'),
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|                             $html_string, $link_matches)) {
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|             return array();
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|         }
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| 
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|         foreach ($link_matches[0] as $link) {
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|             $attr_matches = array();
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|             preg_match_all($this->_attr_find, $link, $attr_matches);
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|             $link_attrs = array();
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|             foreach ($attr_matches[0] as $index => $full_match) {
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|                 $name = $attr_matches[1][$index];
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|                 $value = html_entity_decode(
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|                               $this->removeQuotes($attr_matches[2][$index]));
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| 
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|                 $link_attrs[strtolower($name)] = $value;
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|             }
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|             $link_data[] = $link_attrs;
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|         }
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| 
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|         return $link_data;
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|     }
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| 
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|     /**
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|      * Looks for a META tag with an "http-equiv" attribute whose value
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|      * is one of ("x-xrds-location", "x-yadis-location"), ignoring
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|      * case.  If such a META tag is found, its "content" attribute
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|      * value is returned.
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|      *
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|      * @param string $html_string An HTML document in string format
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|      * @return mixed $content The "content" attribute value of the
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|      * META tag, if found, or null if no such tag was found.
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|      */
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|     function getHTTPEquiv($html_string)
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|     {
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|         $meta_tags = $this->getMetaTags($html_string);
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| 
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|         if ($meta_tags) {
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|             foreach ($meta_tags as $tag) {
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|                 if (array_key_exists('http-equiv', $tag) &&
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|                     (in_array(strtolower($tag['http-equiv']),
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|                               array('x-xrds-location', 'x-yadis-location'))) &&
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|                     array_key_exists('content', $tag)) {
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|                     return $tag['content'];
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|                 }
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|             }
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|         }
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| 
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|         return null;
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|     }
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| }
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| 
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