PHP获取301重定向页面跳转后真实URL地址

function getrealurl($url){
$header = get_headers($url,1);
if (strpos($header[0],'301') || strpos($header[0],'302')) {
if(is_array($header['Location'])) {
return $header['Location'][count($header

['Location'])-1];
}else{
return $header['Location'];
}
}else {
return $url;
}
}

$url = 'http://111com.net';

print_r(get_headers($url));

Array
(
[0] => HTTP/1.1 301 Moved Permanently
[1] => Date: Tue, 01 Jul 2014 07:49:26 GMT
[2] => Server: Apache/2.2.22 (Win32) PHP/5.2.17
[3] => Location: https://www.111cn.net/
[4] => Content-Length: 314
[5] => Content-Type: text/html; charset=iso-8859-1
[6] => X-Via: 1.1 jszjsx60:8080 (Cdn Cache Server V2.0), 1.1 zb51:6 (Cdn Cache Server V2.0)
[7] => Connection: close
[8] => HTTP/1.1 200 OK
[9] => Date: Tue, 01 Jul 2014 07:49:27 GMT
[10] => Server: Apache/2.2.22 (Win32) PHP/5.2.17
[11] => Last-Modified: Tue, 01 Jul 2014 07:41:43 GMT
[12] => ETag: "7a0000002fe1a1-68a9-4fd1ce83bc0f7"
[13] => Accept-Ranges: bytes
[14] => Content-Length: 26793
[15] => Content-Type: text/html
[16] => X-Via: 1.1 jszjsx60:8080 (Cdn Cache Server V2.0), 1.1 zb62:5 (Cdn Cache Server V2.0)
[17] => Connection: close
)