方法一：使用get_headers()函数

这个方法很多人使用，也很简单便捷，只需要两行代码即可搞定。如下：

$thisurl = "https://www.jb51.net/";
print_r(get_headers($thisurl, 1));

得到的结果为：

Array
(
    [0] => HTTP/1.1 200 OK
    [Content-Type] => text/html
    [Last-Modified] => Wed, 15 Aug 2018 01:23:03 GMT
    [ETag] => "99a921833634d41:0"
    [Server] => Microsoft-IIS/7.5
    [X-Powered-By] => jb51.net
    [Date] => Wed, 15 Aug 2018 01:31:48 GMT
    [Connection] => close
    [Content-Length] => 89251
)

方法二：使用http_response_header

代码也很简单，仅需三行：

$thisurl = "https://www.jb51.net/";
$html = file_get_contents($thisurl ); 
print_r($http_response_header);

得到的结果为：

Array
(
    [0] => HTTP/1.1 200 OK
    [1] => Content-Type: text/html
    [2] => Last-Modified: Wed, 15 Aug 2018 01:33:04 GMT
    [3] => ETag: "7b9757e93734d41:0"
    [4] => Server: Microsoft-IIS/7.5
    [5] => X-Powered-By: jb51.net
    [6] => Date: Wed, 15 Aug 2018 01:34:15 GMT
    [7] => Connection: close
    [8] => Content-Length: 89282
)

方法三：使用stream_get_meta_data()函数

代码也只有三行：

$thisurl = "https://www.jb51.net/";
$fp = fopen($thisurl, 'r'); 
print_r(stream_get_meta_data($fp));

得到的结果为：

Array
(
    [wrapper_data] => Array
        (
            [0] => HTTP/1.1 200 OK
            [1] => Content-Type: text/html
            [2] => Last-Modified: Wed, 15 Aug 2018 01:38:45 GMT
            [3] => ETag: "ecc8f8b43834d41:0"
            [4] => Server: Microsoft-IIS/7.5
            [5] => X-Powered-By: jb51.net
            [6] => Date: Wed, 15 Aug 2018 01:39:35 GMT
            [7] => Connection: close
            [8] => Content-Length: 89421
        )
    [wrapper_type] => http
    [stream_type] => tcp_socket/ssl
    [mode] => r
    [unread_bytes] => 7945
    [seekable] =>
    [uri] => https://www.jb51.net/
    [timed_out] =>
    [blocked] => 1
    [eof] =>
)

上述三种方法都可以轻松获得网页header信息，且包含的信息都已经相当丰富，满足一般要求，不过比较遗憾的是，上述三种方法都不能用来检测网页是否启用了GZip压缩。要检测GZip压缩，还需其他的方法才行。这里介绍的是用curl()函数来检测。

使用curl获得header可以检测GZip压缩

先贴出代码：

', $pHeader); //使用
换行符格式化输出到网页上
  echo $pHeader;
}
?>

输出结果如下：

HTTP/1.1 200 OK
Cache-Control: max-age=86400
Content-Length: 15189
Content-Type: text/html
Content-Encoding: gzip
Content-Location: http://www.webkaka.com/index.html
Last-Modified: Fri, 19 Jul 2013 03:52:28 GMT
Accept-Ranges: bytes
ETag: "0268633384ce1:5cb3"
Vary: Accept-Encoding
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Date: Fri, 19 Jul 2013 09:27:21 GMT