php regular crawl Pictures (403 crawl image processing)

? < PHP
 // crawl page picture when the picture to prevent 403 (to prevent hotlinking) 
echo "<Meta name = 'referrer' Content = 'NO-referrer'>" ;
 $ List = file_get_contents ( $ url ); 


$ k = preg_match_all ( '/ <IMG [^>] * \ /> /', $ List , $ Data );
 $ m = preg_grep ( '/ Alt /', $ Data [0 ]);
 the foreach ( $ m  AS  $ V ) {
         echo  $ V '<br>'. ; 
}