php code to generate thunderbolt express whirlwind links from addresses [passed test]

Online demo address: http: / / tools jb51. net/tools/cs php

<?php 
function zhuanhuan() { 
$urlodd=explode('//',$_GET["url"],2);// Divide links into 2 Section, // The first paragraph is in front and the second paragraph is behind  
$head=strtolower($urlodd[0]);//PHP Case sensitive, convert to lowercase first, otherwise   appear HtTp: or ThUNDER: This weird way of writing is hard to deal with  
$behind=$urlodd[1]; 
if($head=="thunder:"){ 
$url=substr(base64_decode($behind), 2, -2);//base64 Decrypt, remove the front AA And the back ZZ 
}elseif($head=="flashget:"){ 
$url1=explode('&',$behind,2); 
$url=substr(base64_decode($url1[0]), 10, -10);//base64 Decrypt, remove the front and back [FLASHGET] 
}elseif($head=="qqdl:"){ 
$url=base64_decode($behind);//base64 decryption  
}elseif($head=="http:"||$head=="ftp:"||$head=="mms:"||$head=="rtsp:"||$head=="https:"){ 
$url=$_GET["url"];// General address is supported only http,https,ftp,mms,rtsp Transport protocols, other places seem to be few, like XX Network disk is actually based on base64 , but some decryption also can not download  
}else{ 
echo " This page does not currently support this protocol "; 
} 
return $url; 
} 
if($_GET["url"]!=NULL){ 
$url=zhuanhuan($_GET["url"]); 
$url_thunder="thunder://".base64_encode("AA".$url."ZZ");//base64 Encryption, down here 2 Is the same  
$url_flashget="Flashget://".base64_encode("[FLASHGET]".$url."[FLASHGET]")."&aiyh"; 
$url_qqdl="qqdl://".base64_encode($url); 
} 
?> 
<form action=cs.php method=GET> 
jb51.net  Please enter normal links or thunderbolt , Express train, whirlwind chain address : 
<input type=text name="url" size="80"> 
<input type=submit value=" conversion "> 
</form> 
<p> Actual address: <a href="<?php echo $url;?>" target="_blank"><?php echo $url;?></a> 
<p> Thunderbolt chain: <a href="<?php echo $url_thunder;?>" target="_blank"><?php echo $url_thunder;?></a> 
<p> Express chain: <a href="<?php echo $url_flashget;?>" target="_blank"><?php echo $url_flashget;?></a> 
<p> A whirlwind chain: <a href="<?php echo $url_qqdl;?>" target="_blank"><?php echo $url_qqdl;?></a>