php获取网页header信息的方法多种多样，就php语言来说，我知道的方法有4种, 下面逐一献上。

方法一：使用get_headers()函数

推荐指数: ★★★★★

get_header方法最简单只要两行代码即可搞定。如下：

1. $thisurl = "http://www.lao8.org/";
2. print_r(get_headers($thisurl, 1));

得到的结果为：

1. Array
2. (
3. [0] => HTTP/1.1 200 OK
4. [Cache-Control] => max-age=86400
5. [Content-Length] => 76102
6. [Content-Type] => text/html
7. [Content-Location] => http://www.lao8.org/index.html
8. [Last-Modified] => Fri, 19 Jul 2013 03:52:30 GMT
9. [Accept-Ranges] => bytes
10. [ETag] => "50bc48643384ce1:5cb3"
11. [Server] => Microsoft-IIS/6.0
12. [X-Powered-By] => ASP.NET
13. [Date] => Fri, 19 Jul 2013 09:06:39 GMT
14. [Connection] => close
15. )

方法二：使用http_response_header

推荐指数: ★★★

http_response_headerf方法也很简单，仅三行：

1. $thisurl = "http://www.lao8.org";
2. $html = file_get_contents($thisurl );
3. print_r($http_response_header);

得到的结果为：

1. Array
2. (
3. [0] => HTTP/1.1 200 OK
4. [1] => Cache-Control: max-age=86400
5. [2] => Content-Length: 76102
6. [3] => Content-Type: text/html
7. [4] => Content-Location: http://www.lao8.org/index.html
8. [5] => Last-Modified: Fri, 19 Jul 2013 03:52:30 GMT
9. [6] => Accept-Ranges: bytes
10. [7] => ETag: "50bc48643384ce1:5cb3"
11. [8] => Server: Microsoft-IIS/6.0
12. [9] => X-Powered-By: ASP.NET
13. [10] => Date: Fri, 19 Jul 2013 09:06:41 GMT
14. [11] => Connection: close
15. )

方法三：使用stream_get_meta_data()函数

推荐指数: ★★★

使用stream_get_meta_data()代码也只需三行：

1. $thisurl = "http://www.lao8.org/";
2. $fp = fopen($thisurl, 'r');
3. print_r(stream_get_meta_data($fp));

得到的结果为：

1. Array
2. (
3. [wrapper_data] => Array
4. (
5. [0] => HTTP/1.1 200 OK
6. [1] => Cache-Control: max-age=86400
7. [2] => Content-Length: 76102
8. [3] => Content-Type: text/html
9. [4] => Content-Location: http://www.lao8.org/index.html
10. [5] => Last-Modified: Fri, 19 Jul 2013 03:52:30 GMT
11. [6] => Accept-Ranges: bytes
12. [7] => ETag: "50bc48643384ce1:5cb3"
13. [8] => Server: Microsoft-IIS/6.0
14. [9] => X-Powered-By: ASP.NET
15. [10] => Date: Fri, 19 Jul 2013 09:06:41 GMT
16. [11] => Connection: close
17. )
18. [wrapper_type] => http
19. [stream_type] => tcp_socket
20. [mode] => r+
21. [unread_bytes] => 1086
22. [seekable] =>
23. [uri] => http://www.lao8.org/
24. [timed_out] =>
25. [blocked] => 1
26. [eof] =>
27. )

第四种方法: 使用php的高级函数 CURL()来获取

推荐指数: ★★★★

上面的三种方法能获取一般的网页header信息，如果想要获取更详细的header信息比如网页是否启用了GZip压缩。这时候可以用php的高级函数curl()来获取。

使用curl获得header可以检测GZip压缩
先贴出代码：

1. <?php
2. $szUrl = 'http://www.lao8.org/';
3. $curl = curl_init();
4. curl_setopt($curl, CURLOPT_URL, $szUrl);
5. curl_setopt($curl, CURLOPT_HEADER, 1);  //输出header信息
6. curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);  //不显示网页内容
7. curl_setopt($curl, CURLOPT_ENCODING, ''); //允许执行gzip
8. $data=curl_exec($curl);
9. if(!curl_errno($curl))
10. {
11. $info = curl_getinfo($curl);
12. $httpHeaderSize = $info['header_size'];  //header字符串体积
13. $pHeader = substr($data, 0, $httpHeaderSize); //获得header字符串
14. $split   = array("rn", "n", "r");  //需要格式化header字符串
15. $pHeader = str_replace($split, '<br>', $pHeader); //使用<br>换行符格式化输出到网页上
16. echo $pHeader;
17. }
18. ?>

输出结果如下：

1. HTTP/1.1 200 OK
2. Cache-Control: max-age=86400
3. Content-Length: 15189
4. Content-Type: text/html
5. Content-Encoding: gzip
6. Content-Location: http://www.lao8.org/index.html
7. Last-Modified: Fri, 19 Jul 2013 03:52:28 GMT
8. Accept-Ranges: bytes
9. ETag: "0268633384ce1:5cb3"
10. Vary: Accept-Encoding
11. Server: Microsoft-IIS/6.0
12. X-Powered-By: ASP.NET
13. Date: Fri, 19 Jul 2013 09:27:21 GMT

可以看到使用curl获取到的header信息多了这行：Content-Encoding: gzip，网页启用了GZip压缩。